Merge branch 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - the core has now a lockless variant of i2c_smbus_xfer. Some open
   coded versions of this got removed in drivers. This also enables
   proper SCCB support in regmap.

 - locking got a more precise naming. i2c_{un}lock_adapter() had to go,
   and we know use i2c_lock_bus() consistently with flags like
   I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT to avoid ambiguity.

 - the gpio fault injector got a new delicate testcase

 - the bus recovery procedure got fixed to handle the new testcase
   correctly

 - a new quirk flag for controllers not able to handle zero length
   messages together with driver updates to use it

 - new drivers: FSI bus attached I2C masters, GENI I2C controller, Owl
   family S900

 - and a good set of driver improvements and bugfixes

* 'i2c/for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (77 commits)
  i2c: rcar: implement STOP and REP_START according to docs
  i2c: rcar: refactor private flags
  i2c: core: ACPI: Make acpi_gsb_i2c_read_bytes() check i2c_transfer return value
  i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes
  dt-bindings: i2c: rcar: Add r8a774a1 support
  dt-bindings: i2c: sh_mobile: Add r8a774a1 support
  i2c: imx: Simplify stopped state tracking
  i2c: imx: Fix race condition in dma read
  i2c: pasemi: remove hardcoded bus numbers on smbus
  i2c: designware: Add SPDX license tag
  i2c: designware: Convert to use struct i2c_timings
  i2c: core: Parse SDA hold time from firmware
  i2c: designware-pcidrv: Mark expected switch fall-through
  i2c: amd8111: Mark expected switch fall-through
  i2c: sh_mobile: use core to detect 'no zero length read' quirk
  i2c: xlr: use core to detect 'no zero length' quirk
  i2c: rcar: use core to detect 'no zero length' quirk
  i2c: stu300: use core to detect 'no zero length' quirk
  i2c: pmcmsp: use core to detect 'no zero length' quirk
  i2c: mxs: use core to detect 'no zero length' quirk
  ...

Documentation/devicetree/bindings/eeprom/at24.txt

@@ -72,6 +72,8 @@ Optional properties:
 
   - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
 
+  - address-width: number of address bits (one of 8, 16).
+
 Example:
 
 eeprom@52 {

Documentation/devicetree/bindings/i2c/i2c-fsi.txt

@@ -0,0 +1,40 @@
+Device-tree bindings for FSI-attached I2C master and busses
+-----------------------------------------------------------
+
+Required properties:
+ - compatible = "ibm,i2c-fsi";
+ - reg = < address size >;		: The FSI CFAM address and address
+					  space size.
+ - #address-cells = <1>;		: Number of address cells in child
+					  nodes.
+ - #size-cells = <0>;			: Number of size cells in child nodes.
+ - child nodes				: Nodes to describe busses off the I2C
+					  master.
+
+Child node required properties:
+ - reg = < port number >		: The port number on the I2C master.
+
+Child node optional properties:
+ - child nodes				: Nodes to describe devices on the I2C
+					  bus.
+
+Examples:
+
+    i2c@1800 {
+        compatible = "ibm,i2c-fsi";
+        reg = < 0x1800 0x400 >;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        i2c-bus@0 {
+            reg = <0>;
+        };
+
+        i2c-bus@1 {
+            reg = <1>;
+
+            eeprom@50 {
+                compatible = "vendor,dev-name";
+            };
+        };
+    };

Documentation/devicetree/bindings/i2c/i2c-owl.txt

@@ -0,0 +1,27 @@
+Actions Semiconductor Owl I2C controller
+
+Required properties:
+
+- compatible        : Should be "actions,s900-i2c".
+- reg               : Offset and length of the register set for the device.
+- #address-cells    : Should be 1.
+- #size-cells       : Should be 0.
+- interrupts        : A single interrupt specifier.
+- clocks            : Phandle of the clock feeding the I2C controller.
+
+Optional properties:
+
+- clock-frequency   : Desired I2C bus clock frequency in Hz. As only Normal and
+                      Fast modes are supported, possible values are 100000 and
+                      400000.
+Examples:
+
+        i2c0: i2c@e0170000 {
+                compatible = "actions,s900-i2c";
+                reg = <0 0xe0170000 0 0x1000>;
+                #address-cells = <1>;
+                #size-cells = <0>;
+                interrupts = <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
+                clocks = <&clock CLK_I2C0>;
+                clock-frequency = <100000>;
+        };

Documentation/devicetree/bindings/i2c/i2c-rcar.txt

@@ -4,6 +4,7 @@ Required properties:
 - compatible:
 	"renesas,i2c-r8a7743" if the device is a part of a R8A7743 SoC.
 	"renesas,i2c-r8a7745" if the device is a part of a R8A7745 SoC.
+	"renesas,i2c-r8a774a1" if the device is a part of a R8A774A1 SoC.
 	"renesas,i2c-r8a7778" if the device is a part of a R8A7778 SoC.
 	"renesas,i2c-r8a7779" if the device is a part of a R8A7779 SoC.
 	"renesas,i2c-r8a7790" if the device is a part of a R8A7790 SoC.
@@ -16,11 +17,13 @@ Required properties:
 	"renesas,i2c-r8a77965" if the device is a part of a R8A77965 SoC.
 	"renesas,i2c-r8a77970" if the device is a part of a R8A77970 SoC.
 	"renesas,i2c-r8a77980" if the device is a part of a R8A77980 SoC.
+	"renesas,i2c-r8a77990" if the device is a part of a R8A77990 SoC.
 	"renesas,i2c-r8a77995" if the device is a part of a R8A77995 SoC.
 	"renesas,rcar-gen1-i2c" for a generic R-Car Gen1 compatible device.
 	"renesas,rcar-gen2-i2c" for a generic R-Car Gen2 or RZ/G1 compatible
 				device.
-	"renesas,rcar-gen3-i2c" for a generic R-Car Gen3 compatible device.
+	"renesas,rcar-gen3-i2c" for a generic R-Car Gen3 or RZ/G2 compatible
+				device.
 	"renesas,i2c-rcar" (deprecated)
 
 	When compatible with the generic version, nodes must list the

Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt

@@ -6,6 +6,7 @@ Required properties:
 			- "renesas,iic-r8a7740" (R-Mobile A1)
 			- "renesas,iic-r8a7743" (RZ/G1M)
 			- "renesas,iic-r8a7745" (RZ/G1E)
+			- "renesas,iic-r8a774a1" (RZ/G2M)
 			- "renesas,iic-r8a7790" (R-Car H2)
 			- "renesas,iic-r8a7791" (R-Car M2-W)
 			- "renesas,iic-r8a7792" (R-Car V2H)
@@ -17,7 +18,8 @@ Required properties:
 			- "renesas,iic-sh73a0" (SH-Mobile AG5)
 			- "renesas,rcar-gen2-iic" (generic R-Car Gen2 or RZ/G1
 							compatible device)
-			- "renesas,rcar-gen3-iic" (generic R-Car Gen3 compatible device)
+			- "renesas,rcar-gen3-iic" (generic R-Car Gen3 or RZ/G2
+							compatible device)
 			- "renesas,rmobile-iic" (generic device)
 
 			When compatible with a generic R-Car version, nodes

Documentation/i2c/busses/i2c-i801

@@ -21,24 +21,21 @@ Supported adapters:
   * Intel DH89xxCC (PCH)
   * Intel Panther Point (PCH)
   * Intel Lynx Point (PCH)
-  * Intel Lynx Point-LP (PCH)
   * Intel Avoton (SOC)
   * Intel Wellsburg (PCH)
   * Intel Coleto Creek (PCH)
   * Intel Wildcat Point (PCH)
-  * Intel Wildcat Point-LP (PCH)
   * Intel BayTrail (SOC)
   * Intel Braswell (SOC)
-  * Intel Sunrise Point-H (PCH)
+  * Intel Sunrise Point (PCH)
-  * Intel Sunrise Point-LP (PCH)
+  * Intel Kaby Lake (PCH)
-  * Intel Kaby Lake-H (PCH)
   * Intel DNV (SOC)
   * Intel Broxton (SOC)
   * Intel Lewisburg (PCH)
   * Intel Gemini Lake (SOC)
-  * Intel Cannon Lake-H (PCH)
+  * Intel Cannon Lake (PCH)
-  * Intel Cannon Lake-LP (PCH)
   * Intel Cedar Fork (PCH)
+  * Intel Ice Lake (PCH)
    Datasheets: Publicly available at the Intel website
 
 On Intel Patsburg and later chipsets, both the normal host SMBus controller

Documentation/i2c/gpio-fault-injection

@@ -34,21 +34,48 @@ I2C specification version 4, section 3.1.16) using the helpers of the Linux I2C
 core (see 'struct bus_recovery_info'). However, the bus recovery will not
 succeed because SDA is still pinned low until you manually release it again
 with "echo 1 > sda". A test with an automatic release can be done with the
-'incomplete_transfer' file.
+following class of fault injectors.
 
-"incomplete_transfer"
+Introduction to incomplete transfers
----------------------
+------------------------------------
+
+The following fault injectors create situations where SDA will be held low by a
+device. Bus recovery should be able to fix these situations. But please note:
+there are I2C client devices which detect a stuck SDA on their side and release
+it on their own after a few milliseconds. Also, there might be an external
+device deglitching and monitoring the I2C bus. It could also detect a stuck SDA
+and will init a bus recovery on its own. If you want to implement bus recovery
+in a bus master driver, make sure you checked your hardware setup for such
+devices before. And always verify with a scope or logic analyzer!
+
+"incomplete_address_phase"
+--------------------------
 
 This file is write only and you need to write the address of an existing I2C
-client device to it. Then, a transfer to this device will be started, but it
+client device to it. Then, a read transfer to this device will be started, but
-will stop at the ACK phase after the address of the client has been
+it will stop at the ACK phase after the address of the client has been
 transmitted. Because the device will ACK its presence, this results in SDA
 being pulled low by the device while SCL is high. So, similar to the "sda" file
 above, the bus master under test should detect this condition and try a bus
 recovery. This time, however, it should succeed and the device should release
-SDA after toggling SCL. Please note: there are I2C client devices which detect
+SDA after toggling SCL.
-a stuck SDA on their side and release it on their own after a few milliseconds.
+
-Also, there are external devices deglitching and monitoring the I2C bus. They
+"incomplete_write_byte"
-can also detect a stuck SDA and will init a bus recovery on their own. If you
+-----------------------
-want to implement bus recovery in a bus master driver, make sure you checked
+
-your hardware setup carefully before.
+Similar to above, this file is write only and you need to write the address of
+an existing I2C client device to it.
+
+The injector will again stop at one ACK phase, so the device will keep SDA low
+because it acknowledges data. However, there are two differences compared to
+'incomplete_address_phase':
+
+a) the message sent out will be a write message
+b) after the address byte, a 0x00 byte will be transferred. Then, stop at ACK.
+
+This is a highly delicate state, the device is set up to write any data to
+register 0x00 (if it has registers) when further clock pulses happen on SCL.
+This is why bus recovery (up to 9 clock pulses) must either check SDA or send
+additional STOP conditions to ensure the bus has been released. Otherwise
+random data will be written to a device!
+

MAINTAINERS

@@ -5961,6 +5961,14 @@ F:	fs/crypto/
 F:	include/linux/fscrypt*.h
 F:	Documentation/filesystems/fscrypt.rst
 
+FSI-ATTACHED I2C DRIVER
+M:	Eddie James <eajames@linux.vnet.ibm.com>
+L:	linux-i2c@vger.kernel.org
+L:	openbmc@lists.ozlabs.org (moderated for non-subscribers)
+S:	Maintained
+F:	drivers/i2c/busses/i2c-fsi.c
+F:	Documentation/devicetree/bindings/i2c/i2c-fsi.txt
+
 FSNOTIFY: FILESYSTEM NOTIFICATION INFRASTRUCTURE
 M:	Jan Kara <jack@suse.cz>
 R:	Amir Goldstein <amir73il@gmail.com>
@@ -12014,6 +12022,14 @@ L:	netdev@vger.kernel.org
 S:	Maintained
 F:	drivers/net/ethernet/qualcomm/emac/
 
+QUALCOMM GENERIC INTERFACE I2C DRIVER
+M:	Alok Chauhan <alokc@codeaurora.org>
+M:	Karthikeyan Ramasubramanian <kramasub@codeaurora.org>
+L:	linux-i2c@vger.kernel.org
+L:	linux-arm-msm@vger.kernel.org
+S:	Supported
+F:	drivers/i2c/busses/i2c-qcom-geni.c
+
 QUALCOMM HEXAGON ARCHITECTURE
 M:	Richard Kuo <rkuo@codeaurora.org>
 L:	linux-hexagon@vger.kernel.org

drivers/i2c/busses/Kconfig

@@ -116,24 +116,21 @@ config I2C_I801
 	    DH89xxCC (PCH)
 	    Panther Point (PCH)
 	    Lynx Point (PCH)
-	    Lynx Point-LP (PCH)
 	    Avoton (SOC)
 	    Wellsburg (PCH)
 	    Coleto Creek (PCH)
 	    Wildcat Point (PCH)
-	    Wildcat Point-LP (PCH)
 	    BayTrail (SOC)
 	    Braswell (SOC)
-	    Sunrise Point-H (PCH)
+	    Sunrise Point (PCH)
-	    Sunrise Point-LP (PCH)
+	    Kaby Lake (PCH)
-	    Kaby Lake-H (PCH)
 	    DNV (SOC)
 	    Broxton (SOC)
 	    Lewisburg (PCH)
 	    Gemini Lake (SOC)
-	    Cannon Lake-H (PCH)
+	    Cannon Lake (PCH)
-	    Cannon Lake-LP (PCH)
 	    Cedar Fork (PCH)
+	    Ice Lake (PCH)
 
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-i801.
@@ -762,6 +759,13 @@ config I2C_OMAP
 	  Like OMAP1510/1610/1710/5912 and OMAP242x.
 	  For details see http://www.ti.com/omap.
 
+config I2C_OWL
+	tristate "Actions Semiconductor Owl I2C Controller"
+	depends on ARCH_ACTIONS || COMPILE_TEST
+	help
+	  Say Y here if you want to use the I2C bus controller on
+	  the Actions Semiconductor Owl SoC's.
+
 config I2C_PASEMI
 	tristate "PA Semi SMBus interface"
 	depends on PPC_PASEMI && PCI
@@ -828,6 +832,19 @@ config I2C_PXA_SLAVE
 	  is necessary for systems where the PXA may be a target on the
 	  I2C bus.
 
+config I2C_QCOM_GENI
+	tristate "Qualcomm Technologies Inc.'s GENI based I2C controller"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on QCOM_GENI_SE
+	help
+	  This driver supports GENI serial engine based I2C controller in
+	  master mode on the Qualcomm Technologies Inc.'s SoCs. If you say
+	  yes to this option, support will be included for the built-in I2C
+	  interface on the Qualcomm Technologies Inc.'s SoCs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-qcom-geni.
+
 config I2C_QUP
 	tristate "Qualcomm QUP based I2C controller"
 	depends on ARCH_QCOM
@@ -1330,4 +1347,15 @@ config I2C_ZX2967
 	  This driver can also be built as a module. If so, the module will be
 	  called i2c-zx2967.
 
+config I2C_FSI
+	tristate "FSI I2C driver"
+	depends on FSI
+	help
+	  Driver for FSI bus attached I2C masters. These are I2C masters that
+	  are connected to the system over an FSI bus, instead of the more
+	  common PCI or MMIO interface.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called as i2c-fsi.
+
 endmenu

drivers/i2c/busses/Makefile

@@ -76,6 +76,7 @@ obj-$(CONFIG_I2C_MXS)		+= i2c-mxs.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
 obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
 obj-$(CONFIG_I2C_OMAP)		+= i2c-omap.o
+obj-$(CONFIG_I2C_OWL)		+= i2c-owl.o
 obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
 obj-$(CONFIG_I2C_PCA_PLATFORM)	+= i2c-pca-platform.o
 obj-$(CONFIG_I2C_PMCMSP)	+= i2c-pmcmsp.o
@@ -83,6 +84,7 @@ obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o
 obj-$(CONFIG_I2C_PUV3)		+= i2c-puv3.o
 obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o
 obj-$(CONFIG_I2C_PXA_PCI)	+= i2c-pxa-pci.o
+obj-$(CONFIG_I2C_QCOM_GENI)	+= i2c-qcom-geni.o
 obj-$(CONFIG_I2C_QUP)		+= i2c-qup.o
 obj-$(CONFIG_I2C_RIIC)		+= i2c-riic.o
 obj-$(CONFIG_I2C_RK3X)		+= i2c-rk3x.o
@@ -137,5 +139,6 @@ obj-$(CONFIG_I2C_PCA_ISA)	+= i2c-pca-isa.o
 obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o
 obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o
 obj-$(CONFIG_SCx200_ACB)	+= scx200_acb.o
+obj-$(CONFIG_I2C_FSI)		+= i2c-fsi.o
 
 ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG

drivers/i2c/busses/i2c-amd8111.c

@@ -384,6 +384,7 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
 			if (status)
 				return status;
 			len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
+			/* fall through */
 		case I2C_SMBUS_I2C_BLOCK_DATA:
 			for (i = 0; i < len; i++) {
 				status = amd_ec_read(smbus, AMD_SMB_DATA + i,

drivers/i2c/busses/i2c-aspeed.c

@@ -111,22 +111,22 @@
 #define ASPEED_I2CD_DEV_ADDR_MASK			GENMASK(6, 0)
 
 enum aspeed_i2c_master_state {
+	ASPEED_I2C_MASTER_INACTIVE,
 	ASPEED_I2C_MASTER_START,
 	ASPEED_I2C_MASTER_TX_FIRST,
 	ASPEED_I2C_MASTER_TX,
 	ASPEED_I2C_MASTER_RX_FIRST,
 	ASPEED_I2C_MASTER_RX,
 	ASPEED_I2C_MASTER_STOP,
-	ASPEED_I2C_MASTER_INACTIVE,
 };
 
 enum aspeed_i2c_slave_state {
+	ASPEED_I2C_SLAVE_STOP,
 	ASPEED_I2C_SLAVE_START,
 	ASPEED_I2C_SLAVE_READ_REQUESTED,
 	ASPEED_I2C_SLAVE_READ_PROCESSED,
 	ASPEED_I2C_SLAVE_WRITE_REQUESTED,
 	ASPEED_I2C_SLAVE_WRITE_RECEIVED,
-	ASPEED_I2C_SLAVE_STOP,
 };
 
 struct aspeed_i2c_bus {
@@ -234,7 +234,6 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus)
 	bool irq_handled = true;
 	u8 value;
 
-	spin_lock(&bus->lock);
 	if (!slave) {
 		irq_handled = false;
 		goto out;
@@ -325,7 +324,6 @@ static bool aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus)
 	writel(status_ack, bus->base + ASPEED_I2C_INTR_STS_REG);
 
 out:
-	spin_unlock(&bus->lock);
 	return irq_handled;
 }
 #endif /* CONFIG_I2C_SLAVE */
@@ -389,7 +387,6 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 	u8 recv_byte;
 	int ret;
 
-	spin_lock(&bus->lock);
 	irq_status = readl(bus->base + ASPEED_I2C_INTR_STS_REG);
 	/* Ack all interrupt bits. */
 	writel(irq_status, bus->base + ASPEED_I2C_INTR_STS_REG);
@@ -407,7 +404,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 	 */
 	ret = aspeed_i2c_is_irq_error(irq_status);
 	if (ret < 0) {
-		dev_dbg(bus->dev, "received error interrupt: 0x%08x",
+		dev_dbg(bus->dev, "received error interrupt: 0x%08x\n",
 			irq_status);
 		bus->cmd_err = ret;
 		bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
@@ -416,7 +413,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 
 	/* We are in an invalid state; reset bus to a known state. */
 	if (!bus->msgs) {
-		dev_err(bus->dev, "bus in unknown state");
+		dev_err(bus->dev, "bus in unknown state\n");
 		bus->cmd_err = -EIO;
 		if (bus->master_state != ASPEED_I2C_MASTER_STOP)
 			aspeed_i2c_do_stop(bus);
@@ -431,7 +428,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 	 */
 	if (bus->master_state == ASPEED_I2C_MASTER_START) {
 		if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) {
-			pr_devel("no slave present at %02x", msg->addr);
+			pr_devel("no slave present at %02x\n", msg->addr);
 			status_ack |= ASPEED_I2CD_INTR_TX_NAK;
 			bus->cmd_err = -ENXIO;
 			aspeed_i2c_do_stop(bus);
@@ -451,11 +448,11 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 	switch (bus->master_state) {
 	case ASPEED_I2C_MASTER_TX:
 		if (unlikely(irq_status & ASPEED_I2CD_INTR_TX_NAK)) {
-			dev_dbg(bus->dev, "slave NACKed TX");
+			dev_dbg(bus->dev, "slave NACKed TX\n");
 			status_ack |= ASPEED_I2CD_INTR_TX_NAK;
 			goto error_and_stop;
 		} else if (unlikely(!(irq_status & ASPEED_I2CD_INTR_TX_ACK))) {
-			dev_err(bus->dev, "slave failed to ACK TX");
+			dev_err(bus->dev, "slave failed to ACK TX\n");
 			goto error_and_stop;
 		}
 		status_ack |= ASPEED_I2CD_INTR_TX_ACK;
@@ -478,7 +475,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 		/* fallthrough intended */
 	case ASPEED_I2C_MASTER_RX:
 		if (unlikely(!(irq_status & ASPEED_I2CD_INTR_RX_DONE))) {
-			dev_err(bus->dev, "master failed to RX");
+			dev_err(bus->dev, "master failed to RX\n");
 			goto error_and_stop;
 		}
 		status_ack |= ASPEED_I2CD_INTR_RX_DONE;
@@ -509,7 +506,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 		goto out_no_complete;
 	case ASPEED_I2C_MASTER_STOP:
 		if (unlikely(!(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP))) {
-			dev_err(bus->dev, "master failed to STOP");
+			dev_err(bus->dev, "master failed to STOP\n");
 			bus->cmd_err = -EIO;
 			/* Do not STOP as we have already tried. */
 		} else {
@@ -520,7 +517,7 @@ static bool aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus)
 		goto out_complete;
 	case ASPEED_I2C_MASTER_INACTIVE:
 		dev_err(bus->dev,
-			"master received interrupt 0x%08x, but is inactive",
+			"master received interrupt 0x%08x, but is inactive\n",
 			irq_status);
 		bus->cmd_err = -EIO;
 		/* Do not STOP as we should be inactive. */
@@ -547,22 +544,29 @@ out_no_complete:
 		dev_err(bus->dev,
 			"irq handled != irq. expected 0x%08x, but was 0x%08x\n",
 			irq_status, status_ack);
-	spin_unlock(&bus->lock);
 	return !!irq_status;
 }
 
 static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id)
 {
 	struct aspeed_i2c_bus *bus = dev_id;
+	bool ret;
+
+	spin_lock(&bus->lock);
 
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 	if (aspeed_i2c_slave_irq(bus)) {
 		dev_dbg(bus->dev, "irq handled by slave.\n");
-		return IRQ_HANDLED;
+		ret = true;
+		goto out;
 	}
 #endif /* CONFIG_I2C_SLAVE */
 
-	return aspeed_i2c_master_irq(bus) ? IRQ_HANDLED : IRQ_NONE;
+	ret = aspeed_i2c_master_irq(bus);
+
+out:
+	spin_unlock(&bus->lock);
+	return ret ? IRQ_HANDLED : IRQ_NONE;
 }
 
 static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
@@ -851,7 +855,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
 	bus->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
 	if (IS_ERR(bus->rst)) {
 		dev_err(&pdev->dev,
-			"missing or invalid reset controller device tree entry");
+			"missing or invalid reset controller device tree entry\n");
 		return PTR_ERR(bus->rst);
 	}
 	reset_control_deassert(bus->rst);
@@ -868,7 +872,7 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
 	if (!match)
 		bus->get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val;
 	else
-		bus->get_clk_reg_val = match->data;
+		bus->get_clk_reg_val = (u32 (*)(u32))match->data;
 
 	/* Initialize the I2C adapter */
 	spin_lock_init(&bus->lock);

drivers/i2c/busses/i2c-brcmstb.c

@@ -689,9 +689,9 @@ static int brcmstb_i2c_suspend(struct device *dev)
 {
 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 
-	i2c_lock_adapter(&i2c_dev->adapter);
+	i2c_lock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 	i2c_dev->is_suspended = true;
-	i2c_unlock_adapter(&i2c_dev->adapter);
+	i2c_unlock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	return 0;
 }
@@ -700,10 +700,10 @@ static int brcmstb_i2c_resume(struct device *dev)
 {
 	struct brcmstb_i2c_dev *i2c_dev = dev_get_drvdata(dev);
 
-	i2c_lock_adapter(&i2c_dev->adapter);
+	i2c_lock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 	brcmstb_i2c_set_bsc_reg_defaults(i2c_dev);
 	i2c_dev->is_suspended = false;
-	i2c_unlock_adapter(&i2c_dev->adapter);
+	i2c_unlock_bus(&i2c_dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	return 0;
 }

drivers/i2c/busses/i2c-davinci.c

@@ -718,14 +718,14 @@ static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
 
 	dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
 
-	i2c_lock_adapter(&dev->adapter);
+	i2c_lock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 	if (val == CPUFREQ_PRECHANGE) {
 		davinci_i2c_reset_ctrl(dev, 0);
 	} else if (val == CPUFREQ_POSTCHANGE) {
 		i2c_davinci_calc_clk_dividers(dev);
 		davinci_i2c_reset_ctrl(dev, 1);
 	}
-	i2c_unlock_adapter(&dev->adapter);
+	i2c_unlock_bus(&dev->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	return 0;
 }

drivers/i2c/busses/i2c-designware-baytrail.c

@@ -1,15 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel BayTrail PMIC I2C bus semaphore implementaion
  * Copyright (c) 2014, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
  */
 #include <linux/delay.h>
 #include <linux/device.h>

drivers/i2c/busses/i2c-designware-common.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Synopsys DesignWare I2C adapter driver.
  *
@@ -6,20 +7,6 @@
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
 #include <linux/clk.h>
 #include <linux/delay.h>
@@ -31,6 +18,7 @@
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/swab.h>
 
 #include "i2c-designware-core.h"
 
@@ -94,6 +82,40 @@ void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
 	}
 }
 
+/**
+ * i2c_dw_set_reg_access() - Set register access flags
+ * @dev: device private data
+ *
+ * Autodetects needed register access mode and sets access flags accordingly.
+ * This must be called before doing any other register access.
+ */
+int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
+{
+	u32 reg;
+	int ret;
+
+	ret = i2c_dw_acquire_lock(dev);
+	if (ret)
+		return ret;
+
+	reg = dw_readl(dev, DW_IC_COMP_TYPE);
+	i2c_dw_release_lock(dev);
+
+	if (reg == swab32(DW_IC_COMP_TYPE_VALUE)) {
+		/* Configure register endianess access */
+		dev->flags |= ACCESS_SWAP;
+	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
+		/* Configure register access mode 16bit */
+		dev->flags |= ACCESS_16BIT;
+	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
+		dev_err(dev->dev,
+			"Unknown Synopsys component type: 0x%08x\n", reg);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset)
 {
 	/*
@@ -149,6 +171,47 @@ u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset)
 	return ((ic_clk * (tLOW + tf) + 500000) / 1000000) - 1 + offset;
 }
 
+int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
+{
+	u32 reg;
+	int ret;
+
+	ret = i2c_dw_acquire_lock(dev);
+	if (ret)
+		return ret;
+
+	/* Configure SDA Hold Time if required */
+	reg = dw_readl(dev, DW_IC_COMP_VERSION);
+	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
+		if (!dev->sda_hold_time) {
+			/* Keep previous hold time setting if no one set it */
+			dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+		}
+
+		/*
+		 * Workaround for avoiding TX arbitration lost in case I2C
+		 * slave pulls SDA down "too quickly" after falling egde of
+		 * SCL by enabling non-zero SDA RX hold. Specification says it
+		 * extends incoming SDA low to high transition while SCL is
+		 * high but it apprears to help also above issue.
+		 */
+		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
+			dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
+
+		dev_dbg(dev->dev, "SDA Hold Time TX:RX = %d:%d\n",
+			dev->sda_hold_time & ~(u32)DW_IC_SDA_HOLD_RX_MASK,
+			dev->sda_hold_time >> DW_IC_SDA_HOLD_RX_SHIFT);
+	} else if (dev->sda_hold_time) {
+		dev_warn(dev->dev,
+			"Hardware too old to adjust SDA hold time.\n");
+		dev->sda_hold_time = 0;
+	}
+
+	i2c_dw_release_lock(dev);
+
+	return 0;
+}
+
 void __i2c_dw_disable(struct dw_i2c_dev *dev)
 {
 	int timeout = 100;

drivers/i2c/busses/i2c-designware-core.h

@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * Synopsys DesignWare I2C adapter driver.
  *
@@ -6,20 +7,6 @@
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
 
 #include <linux/i2c.h>
@@ -212,7 +199,8 @@
  * @tx_fifo_depth: depth of the hardware tx fifo
  * @rx_fifo_depth: depth of the hardware rx fifo
  * @rx_outstanding: current master-rx elements in tx fifo
- * @clk_freq: bus clock frequency
+ * @timings: bus clock frequency, SDA hold and other timings
+ * @sda_hold_time: SDA hold value
  * @ss_hcnt: standard speed HCNT value
  * @ss_lcnt: standard speed LCNT value
  * @fs_hcnt: fast speed HCNT value
@@ -264,10 +252,8 @@ struct dw_i2c_dev {
 	unsigned int		tx_fifo_depth;
 	unsigned int		rx_fifo_depth;
 	int			rx_outstanding;
-	u32			clk_freq;
+	struct i2c_timings	timings;
 	u32			sda_hold_time;
-	u32			sda_falling_time;
-	u32			scl_falling_time;
 	u16			ss_hcnt;
 	u16			ss_lcnt;
 	u16			fs_hcnt;
@@ -295,8 +281,10 @@ struct dw_i2c_dev {
 
 u32 dw_readl(struct dw_i2c_dev *dev, int offset);
 void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
+int i2c_dw_set_reg_access(struct dw_i2c_dev *dev);
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
+int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev);
 unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev);
 int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare);
 int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);

drivers/i2c/busses/i2c-designware-master.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Synopsys DesignWare I2C adapter driver (master only).
  *
@@ -6,20 +7,6 @@
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -45,6 +32,114 @@ static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
 	dw_writel(dev, dev->master_cfg, DW_IC_CON);
 }
 
+static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
+{
+	u32 ic_clk = i2c_dw_clk_rate(dev);
+	const char *mode_str, *fp_str = "";
+	u32 comp_param1;
+	u32 sda_falling_time, scl_falling_time;
+	struct i2c_timings *t = &dev->timings;
+	int ret;
+
+	ret = i2c_dw_acquire_lock(dev);
+	if (ret)
+		return ret;
+	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
+	i2c_dw_release_lock(dev);
+
+	/* Set standard and fast speed dividers for high/low periods */
+	sda_falling_time = t->sda_fall_ns ?: 300; /* ns */
+	scl_falling_time = t->scl_fall_ns ?: 300; /* ns */
+
+	/* Calculate SCL timing parameters for standard mode if not set */
+	if (!dev->ss_hcnt || !dev->ss_lcnt) {
+		dev->ss_hcnt =
+			i2c_dw_scl_hcnt(ic_clk,
+					4000,	/* tHD;STA = tHIGH = 4.0 us */
+					sda_falling_time,
+					0,	/* 0: DW default, 1: Ideal */
+					0);	/* No offset */
+		dev->ss_lcnt =
+			i2c_dw_scl_lcnt(ic_clk,
+					4700,	/* tLOW = 4.7 us */
+					scl_falling_time,
+					0);	/* No offset */
+	}
+	dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n",
+		dev->ss_hcnt, dev->ss_lcnt);
+
+	/*
+	 * Set SCL timing parameters for fast mode or fast mode plus. Only
+	 * difference is the timing parameter values since the registers are
+	 * the same.
+	 */
+	if (t->bus_freq_hz == 1000000) {
+		/*
+		 * Check are fast mode plus parameters available and use
+		 * fast mode if not.
+		 */
+		if (dev->fp_hcnt && dev->fp_lcnt) {
+			dev->fs_hcnt = dev->fp_hcnt;
+			dev->fs_lcnt = dev->fp_lcnt;
+			fp_str = " Plus";
+		}
+	}
+	/*
+	 * Calculate SCL timing parameters for fast mode if not set. They are
+	 * needed also in high speed mode.
+	 */
+	if (!dev->fs_hcnt || !dev->fs_lcnt) {
+		dev->fs_hcnt =
+			i2c_dw_scl_hcnt(ic_clk,
+					600,	/* tHD;STA = tHIGH = 0.6 us */
+					sda_falling_time,
+					0,	/* 0: DW default, 1: Ideal */
+					0);	/* No offset */
+		dev->fs_lcnt =
+			i2c_dw_scl_lcnt(ic_clk,
+					1300,	/* tLOW = 1.3 us */
+					scl_falling_time,
+					0);	/* No offset */
+	}
+	dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n",
+		fp_str, dev->fs_hcnt, dev->fs_lcnt);
+
+	/* Check is high speed possible and fall back to fast mode if not */
+	if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
+		DW_IC_CON_SPEED_HIGH) {
+		if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
+			!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
+			dev_err(dev->dev, "High Speed not supported!\n");
+			dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
+			dev->master_cfg |= DW_IC_CON_SPEED_FAST;
+			dev->hs_hcnt = 0;
+			dev->hs_lcnt = 0;
+		} else if (dev->hs_hcnt && dev->hs_lcnt) {
+			dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n",
+				dev->hs_hcnt, dev->hs_lcnt);
+		}
+	}
+
+	ret = i2c_dw_set_sda_hold(dev);
+	if (ret)
+		goto out;
+
+	switch (dev->master_cfg & DW_IC_CON_SPEED_MASK) {
+	case DW_IC_CON_SPEED_STD:
+		mode_str = "Standard Mode";
+		break;
+	case DW_IC_CON_SPEED_HIGH:
+		mode_str = "High Speed Mode";
+		break;
+	default:
+		mode_str = "Fast Mode";
+	}
+	dev_dbg(dev->dev, "Bus speed: %s%s\n", mode_str, fp_str);
+
+out:
+	return ret;
+}
+
 /**
  * i2c_dw_init() - Initialize the designware I2C master hardware
  * @dev: device private data
@@ -55,118 +150,32 @@ static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
  */
 static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 {
-	u32 hcnt, lcnt;
-	u32 reg, comp_param1;
-	u32 sda_falling_time, scl_falling_time;
 	int ret;
 
 	ret = i2c_dw_acquire_lock(dev);
 	if (ret)
 		return ret;
 
-	reg = dw_readl(dev, DW_IC_COMP_TYPE);
-	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
-		/* Configure register endianess access */
-		dev->flags |= ACCESS_SWAP;
-	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
-		/* Configure register access mode 16bit */
-		dev->flags |= ACCESS_16BIT;
-	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
-		dev_err(dev->dev,
-			"Unknown Synopsys component type: 0x%08x\n", reg);
-		i2c_dw_release_lock(dev);
-		return -ENODEV;
-	}
-
-	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
-
 	/* Disable the adapter */
 	__i2c_dw_disable(dev);
 
-	/* Set standard and fast speed deviders for high/low periods */
+	/* Write standard speed timing parameters */
+	dw_writel(dev, dev->ss_hcnt, DW_IC_SS_SCL_HCNT);
+	dw_writel(dev, dev->ss_lcnt, DW_IC_SS_SCL_LCNT);
 
-	sda_falling_time = dev->sda_falling_time ?: 300; /* ns */
+	/* Write fast mode/fast mode plus timing parameters */
-	scl_falling_time = dev->scl_falling_time ?: 300; /* ns */
+	dw_writel(dev, dev->fs_hcnt, DW_IC_FS_SCL_HCNT);
+	dw_writel(dev, dev->fs_lcnt, DW_IC_FS_SCL_LCNT);
 
-	/* Set SCL timing parameters for standard-mode */
+	/* Write high speed timing parameters if supported */
-	if (dev->ss_hcnt && dev->ss_lcnt) {
+	if (dev->hs_hcnt && dev->hs_lcnt) {
-		hcnt = dev->ss_hcnt;
+		dw_writel(dev, dev->hs_hcnt, DW_IC_HS_SCL_HCNT);
-		lcnt = dev->ss_lcnt;
+		dw_writel(dev, dev->hs_lcnt, DW_IC_HS_SCL_LCNT);
-	} else {
-		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
-					4000,	/* tHD;STA = tHIGH = 4.0 us */
-					sda_falling_time,
-					0,	/* 0: DW default, 1: Ideal */
-					0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
-					4700,	/* tLOW = 4.7 us */
-					scl_falling_time,
-					0);	/* No offset */
-	}
-	dw_writel(dev, hcnt, DW_IC_SS_SCL_HCNT);
-	dw_writel(dev, lcnt, DW_IC_SS_SCL_LCNT);
-	dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
-
-	/* Set SCL timing parameters for fast-mode or fast-mode plus */
-	if ((dev->clk_freq == 1000000) && dev->fp_hcnt && dev->fp_lcnt) {
-		hcnt = dev->fp_hcnt;
-		lcnt = dev->fp_lcnt;
-	} else if (dev->fs_hcnt && dev->fs_lcnt) {
-		hcnt = dev->fs_hcnt;
-		lcnt = dev->fs_lcnt;
-	} else {
-		hcnt = i2c_dw_scl_hcnt(i2c_dw_clk_rate(dev),
-					600,	/* tHD;STA = tHIGH = 0.6 us */
-					sda_falling_time,
-					0,	/* 0: DW default, 1: Ideal */
-					0);	/* No offset */
-		lcnt = i2c_dw_scl_lcnt(i2c_dw_clk_rate(dev),
-					1300,	/* tLOW = 1.3 us */
-					scl_falling_time,
-					0);	/* No offset */
-	}
-	dw_writel(dev, hcnt, DW_IC_FS_SCL_HCNT);
-	dw_writel(dev, lcnt, DW_IC_FS_SCL_LCNT);
-	dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt);
-
-	if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) ==
-		DW_IC_CON_SPEED_HIGH) {
-		if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK)
-			!= DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) {
-			dev_err(dev->dev, "High Speed not supported!\n");
-			dev->master_cfg &= ~DW_IC_CON_SPEED_MASK;
-			dev->master_cfg |= DW_IC_CON_SPEED_FAST;
-		} else if (dev->hs_hcnt && dev->hs_lcnt) {
-			hcnt = dev->hs_hcnt;
-			lcnt = dev->hs_lcnt;
-			dw_writel(dev, hcnt, DW_IC_HS_SCL_HCNT);
-			dw_writel(dev, lcnt, DW_IC_HS_SCL_LCNT);
-			dev_dbg(dev->dev, "HighSpeed-mode HCNT:LCNT = %d:%d\n",
-				hcnt, lcnt);
-		}
 	}
 
-	/* Configure SDA Hold Time if required */
+	/* Write SDA hold time if supported */
-	reg = dw_readl(dev, DW_IC_COMP_VERSION);
+	if (dev->sda_hold_time)
-	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
-		if (!dev->sda_hold_time) {
-			/* Keep previous hold time setting if no one set it */
-			dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
-		}
-		/*
-		 * Workaround for avoiding TX arbitration lost in case I2C
-		 * slave pulls SDA down "too quickly" after falling egde of
-		 * SCL by enabling non-zero SDA RX hold. Specification says it
-		 * extends incoming SDA low to high transition while SCL is
-		 * high but it apprears to help also above issue.
-		 */
-		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
-			dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
 		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
-	} else if (dev->sda_hold_time) {
-		dev_warn(dev->dev,
-			"Hardware too old to adjust SDA hold time.\n");
-	}
 
 	i2c_dw_configure_fifo_master(dev);
 	i2c_dw_release_lock(dev);
@@ -253,13 +262,6 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 			break;
 		}
 
-		if (msgs[dev->msg_write_idx].len == 0) {
-			dev_err(dev->dev,
-				"%s: invalid message length\n", __func__);
-			dev->msg_err = -EINVAL;
-			break;
-		}
-
 		if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
 			/* new i2c_msg */
 			buf = msgs[dev->msg_write_idx].buf;
@@ -502,6 +504,10 @@ static const struct i2c_algorithm i2c_dw_algo = {
 	.functionality = i2c_dw_func,
 };
 
+static const struct i2c_adapter_quirks i2c_dw_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
 {
 	u32 stat;
@@ -681,6 +687,14 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
+	ret = i2c_dw_set_reg_access(dev);
+	if (ret)
+		return ret;
+
+	ret = i2c_dw_set_timings_master(dev);
+	if (ret)
+		return ret;
+
 	ret = dev->init(dev);
 	if (ret)
 		return ret;
@@ -689,6 +703,7 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 		 "Synopsys DesignWare I2C adapter");
 	adap->retries = 3;
 	adap->algo = &i2c_dw_algo;
+	adap->quirks = &i2c_dw_quirks;
 	adap->dev.parent = dev->dev;
 	i2c_set_adapdata(adap, dev);
 

drivers/i2c/busses/i2c-designware-pcidrv.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Synopsys DesignWare I2C adapter driver (master only).
  *
@@ -7,22 +8,7 @@
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
  * Copyright (C) 2011, 2015, 2016 Intel Corporation.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
-
 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -105,6 +91,7 @@ static int mfld_setup(struct pci_dev *pdev, struct dw_pci_controller *c)
 	case 0x0817:
 		c->bus_cfg &= ~DW_IC_CON_SPEED_MASK;
 		c->bus_cfg |= DW_IC_CON_SPEED_STD;
+		/* fall through */
 	case 0x0818:
 	case 0x0819:
 		c->bus_num = pdev->device - 0x817 + 3;

drivers/i2c/busses/i2c-designware-platdrv.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Synopsys DesignWare I2C adapter driver.
  *
@@ -6,20 +7,6 @@
  * Copyright (C) 2006 Texas Instruments.
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
 #include <linux/acpi.h>
 #include <linux/clk-provider.h>
@@ -96,6 +83,7 @@ static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 static int dw_i2c_acpi_configure(struct platform_device *pdev)
 {
 	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct i2c_timings *t = &dev->timings;
 	u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
 	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
 	const struct acpi_device_id *id;
@@ -115,7 +103,7 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev)
 	dw_i2c_acpi_params(pdev, "HSCN", &dev->hs_hcnt, &dev->hs_lcnt, &hs_ht);
 	dw_i2c_acpi_params(pdev, "FMCN", &dev->fs_hcnt, &dev->fs_lcnt, &fs_ht);
 
-	switch (dev->clk_freq) {
+	switch (t->bus_freq_hz) {
 	case 100000:
 		dev->sda_hold_time = ss_ht;
 		break;
@@ -175,6 +163,8 @@ static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
 
 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
 {
+	struct i2c_timings *t = &dev->timings;
+
 	dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY;
 
 	dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
@@ -182,7 +172,7 @@ static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
 
 	dev->mode = DW_IC_MASTER;
 
-	switch (dev->clk_freq) {
+	switch (t->bus_freq_hz) {
 	case 100000:
 		dev->master_cfg |= DW_IC_CON_SPEED_STD;
 		break;
@@ -240,7 +230,8 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct i2c_adapter *adap;
 	struct dw_i2c_dev *dev;
-	u32 acpi_speed, ht = 0;
+	struct i2c_timings *t;
+	u32 acpi_speed;
 	struct resource *mem;
 	int i, irq, ret;
 	static const int supported_speeds[] = {
@@ -272,18 +263,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 		reset_control_deassert(dev->rst);
 	}
 
-	if (pdata) {
+	t = &dev->timings;
-		dev->clk_freq = pdata->i2c_scl_freq;
+	if (pdata)
-	} else {
+		t->bus_freq_hz = pdata->i2c_scl_freq;
-		device_property_read_u32(&pdev->dev, "i2c-sda-hold-time-ns",
+	else
-					 &ht);
+		i2c_parse_fw_timings(&pdev->dev, t, false);
-		device_property_read_u32(&pdev->dev, "i2c-sda-falling-time-ns",
-					 &dev->sda_falling_time);
-		device_property_read_u32(&pdev->dev, "i2c-scl-falling-time-ns",
-					 &dev->scl_falling_time);
-		device_property_read_u32(&pdev->dev, "clock-frequency",
-					 &dev->clk_freq);
-	}
 
 	acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
 	/*
@@ -300,12 +284,12 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	 * Find bus speed from the "clock-frequency" device property, ACPI
 	 * or by using fast mode if neither is set.
 	 */
-	if (acpi_speed && dev->clk_freq)
+	if (acpi_speed && t->bus_freq_hz)
-		dev->clk_freq = min(dev->clk_freq, acpi_speed);
+		t->bus_freq_hz = min(t->bus_freq_hz, acpi_speed);
-	else if (acpi_speed || dev->clk_freq)
+	else if (acpi_speed || t->bus_freq_hz)
-		dev->clk_freq = max(dev->clk_freq, acpi_speed);
+		t->bus_freq_hz = max(t->bus_freq_hz, acpi_speed);
 	else
-		dev->clk_freq = 400000;
+		t->bus_freq_hz = 400000;
 
 	if (has_acpi_companion(&pdev->dev))
 		dw_i2c_acpi_configure(pdev);
@@ -314,11 +298,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	 * Only standard mode at 100kHz, fast mode at 400kHz,
 	 * fast mode plus at 1MHz and high speed mode at 3.4MHz are supported.
 	 */
-	if (dev->clk_freq != 100000 && dev->clk_freq != 400000
+	if (t->bus_freq_hz != 100000 && t->bus_freq_hz != 400000 &&
-	    && dev->clk_freq != 1000000 && dev->clk_freq != 3400000) {
+	    t->bus_freq_hz != 1000000 && t->bus_freq_hz != 3400000) {
 		dev_err(&pdev->dev,
 			"%d Hz is unsupported, only 100kHz, 400kHz, 1MHz and 3.4MHz are supported\n",
-			dev->clk_freq);
+			t->bus_freq_hz);
 		ret = -EINVAL;
 		goto exit_reset;
 	}
@@ -334,12 +318,14 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (!i2c_dw_prepare_clk(dev, true)) {
-		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
+		u64 clk_khz;
 
-		if (!dev->sda_hold_time && ht)
+		dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
-			dev->sda_hold_time = div_u64(
+		clk_khz = dev->get_clk_rate_khz(dev);
-				(u64)dev->get_clk_rate_khz(dev) * ht + 500000,
+
-				1000000);
+		if (!dev->sda_hold_time && t->sda_hold_ns)
+			dev->sda_hold_time =
+				div_u64(clk_khz * t->sda_hold_ns + 500000, 1000000);
 	}
 
 	dw_i2c_set_fifo_size(dev, pdev->id);

drivers/i2c/busses/i2c-designware-slave.c

@@ -1,23 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Synopsys DesignWare I2C adapter driver (slave only).
  *
  * Based on the Synopsys DesignWare I2C adapter driver (master).
  *
  * Copyright (C) 2016 Synopsys Inc.
- *
- * ----------------------------------------------------------------------------
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * ----------------------------------------------------------------------------
- *
  */
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -51,53 +38,18 @@ static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
  */
 static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 {
-	u32 reg, comp_param1;
 	int ret;
 
 	ret = i2c_dw_acquire_lock(dev);
 	if (ret)
 		return ret;
 
-	reg = dw_readl(dev, DW_IC_COMP_TYPE);
-	if (reg == ___constant_swab32(DW_IC_COMP_TYPE_VALUE)) {
-		/* Configure register endianness access. */
-		dev->flags |= ACCESS_SWAP;
-	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
-		/* Configure register access mode 16bit. */
-		dev->flags |= ACCESS_16BIT;
-	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
-		dev_err(dev->dev,
-			"Unknown Synopsys component type: 0x%08x\n", reg);
-		i2c_dw_release_lock(dev);
-		return -ENODEV;
-	}
-
-	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
-
 	/* Disable the adapter. */
 	__i2c_dw_disable(dev);
 
-	/* Configure SDA Hold Time if required. */
+	/* Write SDA hold time if supported */
-	reg = dw_readl(dev, DW_IC_COMP_VERSION);
+	if (dev->sda_hold_time)
-	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
-		if (!dev->sda_hold_time) {
-			/* Keep previous hold time setting if no one set it. */
-			dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
-		}
-		/*
-		 * Workaround for avoiding TX arbitration lost in case I2C
-		 * slave pulls SDA down "too quickly" after falling egde of
-		 * SCL by enabling non-zero SDA RX hold. Specification says it
-		 * extends incoming SDA low to high transition while SCL is
-		 * high but it apprears to help also above issue.
-		 */
-		if (!(dev->sda_hold_time & DW_IC_SDA_HOLD_RX_MASK))
-			dev->sda_hold_time |= 1 << DW_IC_SDA_HOLD_RX_SHIFT;
 		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
-	} else {
-		dev_warn(dev->dev,
-			 "Hardware too old to adjust SDA hold time.\n");
-	}
 
 	i2c_dw_configure_fifo_slave(dev);
 	i2c_dw_release_lock(dev);
@@ -299,6 +251,14 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
+	ret = i2c_dw_set_reg_access(dev);
+	if (ret)
+		return ret;
+
+	ret = i2c_dw_set_sda_hold(dev);
+	if (ret)
+		return ret;
+
 	ret = dev->init(dev);
 	if (ret)
 		return ret;

drivers/i2c/busses/i2c-exynos5.c

@@ -176,7 +176,10 @@
 
 #define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(100))
 
-#define HSI2C_EXYNOS7	BIT(0)
+enum i2c_type_exynos {
+	I2C_TYPE_EXYNOS5,
+	I2C_TYPE_EXYNOS7,
+};
 
 struct exynos5_i2c {
 	struct i2c_adapter	adap;
@@ -212,27 +215,30 @@ struct exynos5_i2c {
 /**
  * struct exynos_hsi2c_variant - platform specific HSI2C driver data
  * @fifo_depth: the fifo depth supported by the HSI2C module
+ * @hw: the hardware variant of Exynos I2C controller
  *
  * Specifies platform specific configuration of HSI2C module.
  * Note: A structure for driver specific platform data is used for future
  * expansion of its usage.
  */
 struct exynos_hsi2c_variant {
-	unsigned int	fifo_depth;
+	unsigned int		fifo_depth;
-	unsigned int	hw;
+	enum i2c_type_exynos	hw;
 };
 
 static const struct exynos_hsi2c_variant exynos5250_hsi2c_data = {
 	.fifo_depth	= 64,
+	.hw		= I2C_TYPE_EXYNOS5,
 };
 
 static const struct exynos_hsi2c_variant exynos5260_hsi2c_data = {
 	.fifo_depth	= 16,
+	.hw		= I2C_TYPE_EXYNOS5,
 };
 
 static const struct exynos_hsi2c_variant exynos7_hsi2c_data = {
 	.fifo_depth	= 16,
-	.hw		= HSI2C_EXYNOS7,
+	.hw		= I2C_TYPE_EXYNOS7,
 };
 
 static const struct of_device_id exynos5_i2c_match[] = {
@@ -300,7 +306,7 @@ static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, bool hs_timings)
 	 */
 	t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7;
 	temp = clkin / op_clk - 8 - t_ftl_cycle;
-	if (i2c->variant->hw != HSI2C_EXYNOS7)
+	if (i2c->variant->hw != I2C_TYPE_EXYNOS7)
 		temp -= t_ftl_cycle;
 	div = temp / 512;
 	clk_cycle = temp / (div + 1) - 2;
@@ -424,7 +430,7 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
 	writel(int_status, i2c->regs + HSI2C_INT_STATUS);
 
 	/* handle interrupt related to the transfer status */
-	if (i2c->variant->hw == HSI2C_EXYNOS7) {
+	if (i2c->variant->hw == I2C_TYPE_EXYNOS7) {
 		if (int_status & HSI2C_INT_TRANS_DONE) {
 			i2c->trans_done = 1;
 			i2c->state = 0;
@@ -571,7 +577,7 @@ static void exynos5_i2c_bus_check(struct exynos5_i2c *i2c)
 {
 	unsigned long timeout;
 
-	if (i2c->variant->hw != HSI2C_EXYNOS7)
+	if (i2c->variant->hw != I2C_TYPE_EXYNOS7)
 		return;
 
 	/*
@@ -612,7 +618,7 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 	unsigned long flags;
 	unsigned short trig_lvl;
 
-	if (i2c->variant->hw == HSI2C_EXYNOS7)
+	if (i2c->variant->hw == I2C_TYPE_EXYNOS7)
 		int_en |= HSI2C_INT_I2C_TRANS;
 	else
 		int_en |= HSI2C_INT_I2C;

drivers/i2c/busses/i2c-fsi.c

@@ -0,0 +1,752 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FSI-attached I2C master algorithm
+ *
+ * Copyright 2018 IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fsi.h>
+#include <linux/i2c.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#define FSI_ENGID_I2C		0x7
+
+#define I2C_DEFAULT_CLK_DIV	6
+
+/* i2c registers */
+#define I2C_FSI_FIFO		0x00
+#define I2C_FSI_CMD		0x04
+#define I2C_FSI_MODE		0x08
+#define I2C_FSI_WATER_MARK	0x0C
+#define I2C_FSI_INT_MASK	0x10
+#define I2C_FSI_INT_COND	0x14
+#define I2C_FSI_OR_INT_MASK	0x14
+#define I2C_FSI_INTS		0x18
+#define I2C_FSI_AND_INT_MASK	0x18
+#define I2C_FSI_STAT		0x1C
+#define I2C_FSI_RESET_I2C	0x1C
+#define I2C_FSI_ESTAT		0x20
+#define I2C_FSI_RESET_ERR	0x20
+#define I2C_FSI_RESID_LEN	0x24
+#define I2C_FSI_SET_SCL		0x24
+#define I2C_FSI_PORT_BUSY	0x28
+#define I2C_FSI_RESET_SCL	0x2C
+#define I2C_FSI_SET_SDA		0x30
+#define I2C_FSI_RESET_SDA	0x34
+
+/* cmd register */
+#define I2C_CMD_WITH_START	BIT(31)
+#define I2C_CMD_WITH_ADDR	BIT(30)
+#define I2C_CMD_RD_CONT		BIT(29)
+#define I2C_CMD_WITH_STOP	BIT(28)
+#define I2C_CMD_FORCELAUNCH	BIT(27)
+#define I2C_CMD_ADDR		GENMASK(23, 17)
+#define I2C_CMD_READ		BIT(16)
+#define I2C_CMD_LEN		GENMASK(15, 0)
+
+/* mode register */
+#define I2C_MODE_CLKDIV		GENMASK(31, 16)
+#define I2C_MODE_PORT		GENMASK(15, 10)
+#define I2C_MODE_ENHANCED	BIT(3)
+#define I2C_MODE_DIAG		BIT(2)
+#define I2C_MODE_PACE_ALLOW	BIT(1)
+#define I2C_MODE_WRAP		BIT(0)
+
+/* watermark register */
+#define I2C_WATERMARK_HI	GENMASK(15, 12)
+#define I2C_WATERMARK_LO	GENMASK(7, 4)
+
+#define I2C_FIFO_HI_LVL		4
+#define I2C_FIFO_LO_LVL		4
+
+/* interrupt register */
+#define I2C_INT_INV_CMD		BIT(15)
+#define I2C_INT_PARITY		BIT(14)
+#define I2C_INT_BE_OVERRUN	BIT(13)
+#define I2C_INT_BE_ACCESS	BIT(12)
+#define I2C_INT_LOST_ARB	BIT(11)
+#define I2C_INT_NACK		BIT(10)
+#define I2C_INT_DAT_REQ		BIT(9)
+#define I2C_INT_CMD_COMP	BIT(8)
+#define I2C_INT_STOP_ERR	BIT(7)
+#define I2C_INT_BUSY		BIT(6)
+#define I2C_INT_IDLE		BIT(5)
+
+/* status register */
+#define I2C_STAT_INV_CMD	BIT(31)
+#define I2C_STAT_PARITY		BIT(30)
+#define I2C_STAT_BE_OVERRUN	BIT(29)
+#define I2C_STAT_BE_ACCESS	BIT(28)
+#define I2C_STAT_LOST_ARB	BIT(27)
+#define I2C_STAT_NACK		BIT(26)
+#define I2C_STAT_DAT_REQ	BIT(25)
+#define I2C_STAT_CMD_COMP	BIT(24)
+#define I2C_STAT_STOP_ERR	BIT(23)
+#define I2C_STAT_MAX_PORT	GENMASK(19, 16)
+#define I2C_STAT_ANY_INT	BIT(15)
+#define I2C_STAT_SCL_IN		BIT(11)
+#define I2C_STAT_SDA_IN		BIT(10)
+#define I2C_STAT_PORT_BUSY	BIT(9)
+#define I2C_STAT_SELF_BUSY	BIT(8)
+#define I2C_STAT_FIFO_COUNT	GENMASK(7, 0)
+
+#define I2C_STAT_ERR		(I2C_STAT_INV_CMD |			\
+				 I2C_STAT_PARITY |			\
+				 I2C_STAT_BE_OVERRUN |			\
+				 I2C_STAT_BE_ACCESS |			\
+				 I2C_STAT_LOST_ARB |			\
+				 I2C_STAT_NACK |			\
+				 I2C_STAT_STOP_ERR)
+#define I2C_STAT_ANY_RESP	(I2C_STAT_ERR |				\
+				 I2C_STAT_DAT_REQ |			\
+				 I2C_STAT_CMD_COMP)
+
+/* extended status register */
+#define I2C_ESTAT_FIFO_SZ	GENMASK(31, 24)
+#define I2C_ESTAT_SCL_IN_SY	BIT(15)
+#define I2C_ESTAT_SDA_IN_SY	BIT(14)
+#define I2C_ESTAT_S_SCL		BIT(13)
+#define I2C_ESTAT_S_SDA		BIT(12)
+#define I2C_ESTAT_M_SCL		BIT(11)
+#define I2C_ESTAT_M_SDA		BIT(10)
+#define I2C_ESTAT_HI_WATER	BIT(9)
+#define I2C_ESTAT_LO_WATER	BIT(8)
+#define I2C_ESTAT_PORT_BUSY	BIT(7)
+#define I2C_ESTAT_SELF_BUSY	BIT(6)
+#define I2C_ESTAT_VERSION	GENMASK(4, 0)
+
+/* port busy register */
+#define I2C_PORT_BUSY_RESET	BIT(31)
+
+/* wait for command complete or data request */
+#define I2C_CMD_SLEEP_MAX_US	500
+#define I2C_CMD_SLEEP_MIN_US	50
+
+/* wait after reset; choose time from legacy driver */
+#define I2C_RESET_SLEEP_MAX_US	2000
+#define I2C_RESET_SLEEP_MIN_US	1000
+
+/* choose timeout length from legacy driver; it's well tested */
+#define I2C_ABORT_TIMEOUT	msecs_to_jiffies(100)
+
+struct fsi_i2c_master {
+	struct fsi_device	*fsi;
+	u8			fifo_size;
+	struct list_head	ports;
+	struct mutex		lock;
+};
+
+struct fsi_i2c_port {
+	struct list_head	list;
+	struct i2c_adapter	adapter;
+	struct fsi_i2c_master	*master;
+	u16			port;
+	u16			xfrd;
+};
+
+static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg,
+			    u32 *data)
+{
+	int rc;
+	__be32 data_be;
+
+	rc = fsi_device_read(fsi, reg, &data_be, sizeof(data_be));
+	if (rc)
+		return rc;
+
+	*data = be32_to_cpu(data_be);
+
+	return 0;
+}
+
+static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg,
+			     u32 *data)
+{
+	__be32 data_be = cpu_to_be32p(data);
+
+	return fsi_device_write(fsi, reg, &data_be, sizeof(data_be));
+}
+
+static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c)
+{
+	int rc;
+	u32 mode = I2C_MODE_ENHANCED, extended_status, watermark;
+	u32 interrupt = 0;
+
+	/* since we use polling, disable interrupts */
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, &interrupt);
+	if (rc)
+		return rc;
+
+	mode |= FIELD_PREP(I2C_MODE_CLKDIV, I2C_DEFAULT_CLK_DIV);
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return rc;
+
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_ESTAT, &extended_status);
+	if (rc)
+		return rc;
+
+	i2c->fifo_size = FIELD_GET(I2C_ESTAT_FIFO_SZ, extended_status);
+	watermark = FIELD_PREP(I2C_WATERMARK_HI,
+			       i2c->fifo_size - I2C_FIFO_HI_LVL);
+	watermark |= FIELD_PREP(I2C_WATERMARK_LO, I2C_FIFO_LO_LVL);
+
+	return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_WATER_MARK, &watermark);
+}
+
+static int fsi_i2c_set_port(struct fsi_i2c_port *port)
+{
+	int rc;
+	struct fsi_device *fsi = port->master->fsi;
+	u32 mode, dummy = 0;
+
+	rc = fsi_i2c_read_reg(fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return rc;
+
+	if (FIELD_GET(I2C_MODE_PORT, mode) == port->port)
+		return 0;
+
+	mode = (mode & ~I2C_MODE_PORT) | FIELD_PREP(I2C_MODE_PORT, port->port);
+	rc = fsi_i2c_write_reg(fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return rc;
+
+	/* reset engine when port is changed */
+	return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy);
+}
+
+static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg,
+			 bool stop)
+{
+	struct fsi_i2c_master *i2c = port->master;
+	u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR;
+
+	port->xfrd = 0;
+
+	if (msg->flags & I2C_M_RD)
+		cmd |= I2C_CMD_READ;
+
+	if (stop || msg->flags & I2C_M_STOP)
+		cmd |= I2C_CMD_WITH_STOP;
+
+	cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr);
+	cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len);
+
+	return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd);
+}
+
+static int fsi_i2c_get_op_bytes(int op_bytes)
+{
+	/* fsi is limited to max 4 byte aligned ops */
+	if (op_bytes > 4)
+		return 4;
+	else if (op_bytes == 3)
+		return 2;
+	return op_bytes;
+}
+
+static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
+			      u8 fifo_count)
+{
+	int write;
+	int rc;
+	struct fsi_i2c_master *i2c = port->master;
+	int bytes_to_write = i2c->fifo_size - fifo_count;
+	int bytes_remaining = msg->len - port->xfrd;
+
+	bytes_to_write = min(bytes_to_write, bytes_remaining);
+
+	while (bytes_to_write) {
+		write = fsi_i2c_get_op_bytes(bytes_to_write);
+
+		rc = fsi_device_write(i2c->fsi, I2C_FSI_FIFO,
+				      &msg->buf[port->xfrd], write);
+		if (rc)
+			return rc;
+
+		port->xfrd += write;
+		bytes_to_write -= write;
+	}
+
+	return 0;
+}
+
+static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
+			     u8 fifo_count)
+{
+	int read;
+	int rc;
+	struct fsi_i2c_master *i2c = port->master;
+	int bytes_to_read;
+	int xfr_remaining = msg->len - port->xfrd;
+	u32 dummy;
+
+	bytes_to_read = min_t(int, fifo_count, xfr_remaining);
+
+	while (bytes_to_read) {
+		read = fsi_i2c_get_op_bytes(bytes_to_read);
+
+		if (xfr_remaining) {
+			rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO,
+					     &msg->buf[port->xfrd], read);
+			if (rc)
+				return rc;
+
+			port->xfrd += read;
+			xfr_remaining -= read;
+		} else {
+			/* no more buffer but data in fifo, need to clear it */
+			rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, &dummy,
+					     read);
+			if (rc)
+				return rc;
+		}
+
+		bytes_to_read -= read;
+	}
+
+	return 0;
+}
+
+static int fsi_i2c_get_scl(struct i2c_adapter *adap)
+{
+	u32 stat = 0;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+	return !!(stat & I2C_STAT_SCL_IN);
+}
+
+static void fsi_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	u32 dummy = 0;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	if (val)
+		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
+	else
+		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
+}
+
+static int fsi_i2c_get_sda(struct i2c_adapter *adap)
+{
+	u32 stat = 0;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+	return !!(stat & I2C_STAT_SDA_IN);
+}
+
+static void fsi_i2c_set_sda(struct i2c_adapter *adap, int val)
+{
+	u32 dummy = 0;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	if (val)
+		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);
+	else
+		fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);
+}
+
+static void fsi_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+	int rc;
+	u32 mode;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return;
+
+	mode |= I2C_MODE_DIAG;
+	fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static void fsi_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	int rc;
+	u32 mode;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *i2c = port->master;
+
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return;
+
+	mode &= ~I2C_MODE_DIAG;
+	fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c,
+			     struct fsi_i2c_port *port)
+{
+	int rc;
+	u32 stat, dummy = 0;
+
+	/* force bus reset, ignore errors */
+	i2c_recover_bus(&port->adapter);
+
+	/* reset errors */
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+	if (rc)
+		return rc;
+
+	/* wait for command complete */
+	usleep_range(I2C_RESET_SLEEP_MIN_US, I2C_RESET_SLEEP_MAX_US);
+
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+	if (rc)
+		return rc;
+
+	if (stat & I2C_STAT_CMD_COMP)
+		return 0;
+
+	/* failed to get command complete; reset engine again */
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+	if (rc)
+		return rc;
+
+	/* re-init engine again */
+	return fsi_i2c_dev_init(i2c);
+}
+
+static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port)
+{
+	int rc;
+	u32 mode, dummy = 0;
+
+	/* reset engine */
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+	if (rc)
+		return rc;
+
+	/* re-init engine */
+	rc = fsi_i2c_dev_init(i2c);
+	if (rc)
+		return rc;
+
+	rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+	if (rc)
+		return rc;
+
+	/* set port; default after reset is 0 */
+	if (port) {
+		mode &= ~I2C_MODE_PORT;
+		mode |= FIELD_PREP(I2C_MODE_PORT, port);
+		rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+		if (rc)
+			return rc;
+	}
+
+	/* reset busy register; hw workaround */
+	dummy = I2C_PORT_BUSY_RESET;
+	rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_PORT_BUSY, &dummy);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
+{
+	int rc;
+	unsigned long start;
+	u32 cmd = I2C_CMD_WITH_STOP;
+	u32 stat;
+	struct fsi_i2c_master *i2c = port->master;
+	struct fsi_device *fsi = i2c->fsi;
+
+	rc = fsi_i2c_reset_engine(i2c, port->port);
+	if (rc)
+		return rc;
+
+	rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &stat);
+	if (rc)
+		return rc;
+
+	/* if sda is low, peform full bus reset */
+	if (!(stat & I2C_STAT_SDA_IN)) {
+		rc = fsi_i2c_reset_bus(i2c, port);
+		if (rc)
+			return rc;
+	}
+
+	/* skip final stop command for these errors */
+	if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR))
+		return 0;
+
+	/* write stop command */
+	rc = fsi_i2c_write_reg(fsi, I2C_FSI_CMD, &cmd);
+	if (rc)
+		return rc;
+
+	/* wait until we see command complete in the master */
+	start = jiffies;
+
+	do {
+		rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &status);
+		if (rc)
+			return rc;
+
+		if (status & I2C_STAT_CMD_COMP)
+			return 0;
+
+		usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US);
+	} while (time_after(start + I2C_ABORT_TIMEOUT, jiffies));
+
+	return -ETIMEDOUT;
+}
+
+static int fsi_i2c_handle_status(struct fsi_i2c_port *port,
+				 struct i2c_msg *msg, u32 status)
+{
+	int rc;
+	u8 fifo_count;
+
+	if (status & I2C_STAT_ERR) {
+		rc = fsi_i2c_abort(port, status);
+		if (rc)
+			return rc;
+
+		if (status & I2C_STAT_INV_CMD)
+			return -EINVAL;
+
+		if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN |
+		    I2C_STAT_BE_ACCESS))
+			return -EPROTO;
+
+		if (status & I2C_STAT_NACK)
+			return -ENXIO;
+
+		if (status & I2C_STAT_LOST_ARB)
+			return -EAGAIN;
+
+		if (status & I2C_STAT_STOP_ERR)
+			return -EBADMSG;
+
+		return -EIO;
+	}
+
+	if (status & I2C_STAT_DAT_REQ) {
+		fifo_count = FIELD_GET(I2C_STAT_FIFO_COUNT, status);
+
+		if (msg->flags & I2C_M_RD)
+			return fsi_i2c_read_fifo(port, msg, fifo_count);
+
+		return fsi_i2c_write_fifo(port, msg, fifo_count);
+	}
+
+	if (status & I2C_STAT_CMD_COMP) {
+		if (port->xfrd < msg->len)
+			return -ENODATA;
+
+		return msg->len;
+	}
+
+	return 0;
+}
+
+static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg,
+			unsigned long timeout)
+{
+	u32 status = 0;
+	int rc;
+	unsigned long start = jiffies;
+
+	do {
+		rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT,
+				      &status);
+		if (rc)
+			return rc;
+
+		if (status & I2C_STAT_ANY_RESP) {
+			rc = fsi_i2c_handle_status(port, msg, status);
+			if (rc < 0)
+				return rc;
+
+			/* cmd complete and all data xfrd */
+			if (rc == msg->len)
+				return 0;
+
+			/* need to xfr more data, but maybe don't need wait */
+			continue;
+		}
+
+		usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US);
+	} while (time_after(start + timeout, jiffies));
+
+	return -ETIMEDOUT;
+}
+
+static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+			int num)
+{
+	int i, rc;
+	unsigned long start_time;
+	struct fsi_i2c_port *port = adap->algo_data;
+	struct fsi_i2c_master *master = port->master;
+	struct i2c_msg *msg;
+
+	mutex_lock(&master->lock);
+
+	rc = fsi_i2c_set_port(port);
+	if (rc)
+		goto unlock;
+
+	for (i = 0; i < num; i++) {
+		msg = msgs + i;
+		start_time = jiffies;
+
+		rc = fsi_i2c_start(port, msg, i == num - 1);
+		if (rc)
+			goto unlock;
+
+		rc = fsi_i2c_wait(port, msg,
+				  adap->timeout - (jiffies - start_time));
+		if (rc)
+			goto unlock;
+	}
+
+unlock:
+	mutex_unlock(&master->lock);
+	return rc ? : num;
+}
+
+static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING |
+		I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = fsi_i2c_get_scl,
+	.set_scl = fsi_i2c_set_scl,
+	.get_sda = fsi_i2c_get_sda,
+	.set_sda = fsi_i2c_set_sda,
+	.prepare_recovery = fsi_i2c_prepare_recovery,
+	.unprepare_recovery = fsi_i2c_unprepare_recovery,
+};
+
+static const struct i2c_algorithm fsi_i2c_algorithm = {
+	.master_xfer = fsi_i2c_xfer,
+	.functionality = fsi_i2c_functionality,
+};
+
+static int fsi_i2c_probe(struct device *dev)
+{
+	struct fsi_i2c_master *i2c;
+	struct fsi_i2c_port *port;
+	struct device_node *np;
+	int rc;
+	u32 port_no;
+
+	i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	mutex_init(&i2c->lock);
+	i2c->fsi = to_fsi_dev(dev);
+	INIT_LIST_HEAD(&i2c->ports);
+
+	rc = fsi_i2c_dev_init(i2c);
+	if (rc)
+		return rc;
+
+	/* Add adapter for each i2c port of the master. */
+	for_each_available_child_of_node(dev->of_node, np) {
+		rc = of_property_read_u32(np, "reg", &port_no);
+		if (rc || port_no > USHRT_MAX)
+			continue;
+
+		port = kzalloc(sizeof(*port), GFP_KERNEL);
+		if (!port)
+			break;
+
+		port->master = i2c;
+		port->port = port_no;
+
+		port->adapter.owner = THIS_MODULE;
+		port->adapter.dev.of_node = np;
+		port->adapter.dev.parent = dev;
+		port->adapter.algo = &fsi_i2c_algorithm;
+		port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info;
+		port->adapter.algo_data = port;
+
+		snprintf(port->adapter.name, sizeof(port->adapter.name),
+			 "i2c_bus-%u", port_no);
+
+		rc = i2c_add_adapter(&port->adapter);
+		if (rc < 0) {
+			dev_err(dev, "Failed to register adapter: %d\n", rc);
+			kfree(port);
+			continue;
+		}
+
+		list_add(&port->list, &i2c->ports);
+	}
+
+	dev_set_drvdata(dev, i2c);
+
+	return 0;
+}
+
+static int fsi_i2c_remove(struct device *dev)
+{
+	struct fsi_i2c_master *i2c = dev_get_drvdata(dev);
+	struct fsi_i2c_port *port, *tmp;
+
+	list_for_each_entry_safe(port, tmp, &i2c->ports, list) {
+		list_del(&port->list);
+		i2c_del_adapter(&port->adapter);
+		kfree(port);
+	}
+
+	return 0;
+}
+
+static const struct fsi_device_id fsi_i2c_ids[] = {
+	{ FSI_ENGID_I2C, FSI_VERSION_ANY },
+	{ }
+};
+
+static struct fsi_driver fsi_i2c_driver = {
+	.id_table = fsi_i2c_ids,
+	.drv = {
+		.name = "i2c-fsi",
+		.bus = &fsi_bus_type,
+		.probe = fsi_i2c_probe,
+		.remove = fsi_i2c_remove,
+	},
+};
+
+module_fsi_driver(fsi_i2c_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@us.ibm.com>");
+MODULE_DESCRIPTION("FSI attached I2C master");
+MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-gpio.c

@@ -78,49 +78,43 @@ static struct dentry *i2c_gpio_debug_dir;
 #define getscl(bd)	((bd)->getscl((bd)->data))
 
 #define WIRE_ATTRIBUTE(wire) \
-static int fops_##wire##_get(void *data, u64 *val)	\
+static int fops_##wire##_get(void *data, u64 *val)		\
-{							\
+{								\
-	struct i2c_gpio_private_data *priv = data;	\
+	struct i2c_gpio_private_data *priv = data;		\
-							\
+								\
-	i2c_lock_adapter(&priv->adap);			\
+	i2c_lock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);	\
-	*val = get##wire(&priv->bit_data);		\
+	*val = get##wire(&priv->bit_data);			\
-	i2c_unlock_adapter(&priv->adap);		\
+	i2c_unlock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);	\
-	return 0;					\
+	return 0;						\
-}							\
+}								\
-static int fops_##wire##_set(void *data, u64 val)	\
+static int fops_##wire##_set(void *data, u64 val)		\
-{							\
+{								\
-	struct i2c_gpio_private_data *priv = data;	\
+	struct i2c_gpio_private_data *priv = data;		\
-							\
+								\
-	i2c_lock_adapter(&priv->adap);			\
+	i2c_lock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);	\
-	set##wire(&priv->bit_data, val);		\
+	set##wire(&priv->bit_data, val);			\
-	i2c_unlock_adapter(&priv->adap);		\
+	i2c_unlock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);	\
-	return 0;					\
+	return 0;						\
-}							\
+}								\
 DEFINE_DEBUGFS_ATTRIBUTE(fops_##wire, fops_##wire##_get, fops_##wire##_set, "%llu\n")
 
 WIRE_ATTRIBUTE(scl);
 WIRE_ATTRIBUTE(sda);
 
-static int fops_incomplete_transfer_set(void *data, u64 addr)
+static void i2c_gpio_incomplete_transfer(struct i2c_gpio_private_data *priv,
+					u32 pattern, u8 pattern_size)
 {
-	struct i2c_gpio_private_data *priv = data;
 	struct i2c_algo_bit_data *bit_data = &priv->bit_data;
-	int i, pattern;
+	int i;
 
-	if (addr > 0x7f)
+	i2c_lock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);
-		return -EINVAL;
-
-	/* ADDR (7 bit) + RD (1 bit) + SDA hi (1 bit) */
-	pattern = (addr << 2) | 3;
-
-	i2c_lock_adapter(&priv->adap);
 
 	/* START condition */
 	setsda(bit_data, 0);
 	udelay(bit_data->udelay);
 
-	/* Send ADDR+RD, request ACK, don't send STOP */
+	/* Send pattern, request ACK, don't send STOP */
-	for (i = 8; i >= 0; i--) {
+	for (i = pattern_size - 1; i >= 0; i--) {
 		setscl(bit_data, 0);
 		udelay(bit_data->udelay / 2);
 		setsda(bit_data, (pattern >> i) & 1);
@@ -129,11 +123,44 @@ static int fops_incomplete_transfer_set(void *data, u64 addr)
 		udelay(bit_data->udelay);
 	}
 
-	i2c_unlock_adapter(&priv->adap);
+	i2c_unlock_bus(&priv->adap, I2C_LOCK_ROOT_ADAPTER);
+}
+
+static int fops_incomplete_addr_phase_set(void *data, u64 addr)
+{
+	struct i2c_gpio_private_data *priv = data;
+	u32 pattern;
+
+	if (addr > 0x7f)
+		return -EINVAL;
+
+	/* ADDR (7 bit) + RD (1 bit) + Client ACK, keep SDA hi (1 bit) */
+	pattern = (addr << 2) | 3;
+
+	i2c_gpio_incomplete_transfer(priv, pattern, 9);
 
 	return 0;
 }
-DEFINE_DEBUGFS_ATTRIBUTE(fops_incomplete_transfer, NULL, fops_incomplete_transfer_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_incomplete_addr_phase, NULL, fops_incomplete_addr_phase_set, "%llu\n");
+
+static int fops_incomplete_write_byte_set(void *data, u64 addr)
+{
+	struct i2c_gpio_private_data *priv = data;
+	u32 pattern;
+
+	if (addr > 0x7f)
+		return -EINVAL;
+
+	/* ADDR (7 bit) + WR (1 bit) + Client ACK (1 bit) */
+	pattern = (addr << 2) | 1;
+	/* 0x00 (8 bit) + Client ACK, keep SDA hi (1 bit) */
+	pattern = (pattern << 9) | 1;
+
+	i2c_gpio_incomplete_transfer(priv, pattern, 18);
+
+	return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(fops_incomplete_write_byte, NULL, fops_incomplete_write_byte_set, "%llu\n");
 
 static void i2c_gpio_fault_injector_init(struct platform_device *pdev)
 {
@@ -156,8 +183,10 @@ static void i2c_gpio_fault_injector_init(struct platform_device *pdev)
 
 	debugfs_create_file_unsafe("scl", 0600, priv->debug_dir, priv, &fops_scl);
 	debugfs_create_file_unsafe("sda", 0600, priv->debug_dir, priv, &fops_sda);
-	debugfs_create_file_unsafe("incomplete_transfer", 0200, priv->debug_dir,
+	debugfs_create_file_unsafe("incomplete_address_phase", 0200, priv->debug_dir,
-				   priv, &fops_incomplete_transfer);
+				   priv, &fops_incomplete_addr_phase);
+	debugfs_create_file_unsafe("incomplete_write_byte", 0200, priv->debug_dir,
+				   priv, &fops_incomplete_write_byte);
 }
 
 static void i2c_gpio_fault_injector_exit(struct platform_device *pdev)

drivers/i2c/busses/i2c-i801.c

@@ -70,6 +70,7 @@
  * Cannon Lake-H (PCH)		0xa323	32	hard	yes	yes	yes
  * Cannon Lake-LP (PCH)		0x9da3	32	hard	yes	yes	yes
  * Cedar Fork (PCH)		0x18df	32	hard	yes	yes	yes
+ * Ice Lake-LP (PCH)		0x34a3	32	hard	yes	yes	yes
  *
  * Features supported by this driver:
  * Software PEC				no
@@ -220,6 +221,7 @@
 #define PCI_DEVICE_ID_INTEL_DH89XXCC_SMBUS		0x2330
 #define PCI_DEVICE_ID_INTEL_COLETOCREEK_SMBUS		0x23b0
 #define PCI_DEVICE_ID_INTEL_GEMINILAKE_SMBUS		0x31d4
+#define PCI_DEVICE_ID_INTEL_ICELAKE_LP_SMBUS		0x34a3
 #define PCI_DEVICE_ID_INTEL_5_3400_SERIES_SMBUS		0x3b30
 #define PCI_DEVICE_ID_INTEL_BROXTON_SMBUS		0x5ad4
 #define PCI_DEVICE_ID_INTEL_LYNXPOINT_SMBUS		0x8c22
@@ -1034,6 +1036,7 @@ static const struct pci_device_id i801_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_KABYLAKE_PCH_H_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CANNONLAKE_H_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CANNONLAKE_LP_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICELAKE_LP_SMBUS) },
 	{ 0, }
 };
 
@@ -1518,6 +1521,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	case PCI_DEVICE_ID_INTEL_CDF_SMBUS:
 	case PCI_DEVICE_ID_INTEL_DNV_SMBUS:
 	case PCI_DEVICE_ID_INTEL_KABYLAKE_PCH_H_SMBUS:
+	case PCI_DEVICE_ID_INTEL_ICELAKE_LP_SMBUS:
 		priv->features |= FEATURE_I2C_BLOCK_READ;
 		priv->features |= FEATURE_IRQ;
 		priv->features |= FEATURE_SMBUS_PEC;

drivers/i2c/busses/i2c-imx.c

@@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
 			return -EAGAIN;
 		}
 
-		if (for_busy && (temp & I2SR_IBB))
+		if (for_busy && (temp & I2SR_IBB)) {
+			i2c_imx->stopped = 0;
 			break;
-		if (!for_busy && !(temp & I2SR_IBB))
+		}
+		if (!for_busy && !(temp & I2SR_IBB)) {
+			i2c_imx->stopped = 1;
 			break;
+		}
 		if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
 			dev_dbg(&i2c_imx->adapter.dev,
 				"<%s> I2C bus is busy\n", __func__);
@@ -538,7 +542,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
 	result = i2c_imx_bus_busy(i2c_imx, 1);
 	if (result)
 		return result;
-	i2c_imx->stopped = 0;
 
 	temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
 	temp &= ~I2CR_DMAEN;
@@ -567,10 +570,8 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
 		udelay(i2c_imx->disable_delay);
 	}
 
-	if (!i2c_imx->stopped) {
+	if (!i2c_imx->stopped)
 		i2c_imx_bus_busy(i2c_imx, 0);
-		i2c_imx->stopped = 1;
-	}
 
 	/* Disable I2C controller */
 	temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
@@ -668,9 +669,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
 	struct imx_i2c_dma *dma = i2c_imx->dma;
 	struct device *dev = &i2c_imx->adapter.dev;
 
-	temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
-	temp |= I2CR_DMAEN;
-	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 
 	dma->chan_using = dma->chan_rx;
 	dma->dma_transfer_dir = DMA_DEV_TO_MEM;
@@ -727,7 +725,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
 		temp &= ~(I2CR_MSTA | I2CR_MTX);
 		imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 		i2c_imx_bus_busy(i2c_imx, 0);
-		i2c_imx->stopped = 1;
 	} else {
 		/*
 		 * For i2c master receiver repeat restart operation like:
@@ -783,6 +780,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
 	int i, result;
 	unsigned int temp;
 	int block_data = msgs->flags & I2C_M_RECV_LEN;
+	int use_dma = i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data;
 
 	dev_dbg(&i2c_imx->adapter.dev,
 		"<%s> write slave address: addr=0x%x\n",
@@ -809,12 +807,14 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
 	 */
 	if ((msgs->len - 1) || block_data)
 		temp &= ~I2CR_TXAK;
+	if (use_dma)
+		temp |= I2CR_DMAEN;
 	imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 	imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); /* dummy read */
 
 	dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
 
-	if (i2c_imx->dma && msgs->len >= DMA_THRESHOLD && !block_data)
+	if (use_dma)
 		return i2c_imx_dma_read(i2c_imx, msgs, is_lastmsg);
 
 	/* read data */
@@ -850,7 +850,6 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
 				temp &= ~(I2CR_MSTA | I2CR_MTX);
 				imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
 				i2c_imx_bus_busy(i2c_imx, 0);
-				i2c_imx->stopped = 1;
 			} else {
 				/*
 				 * For i2c master receiver repeat restart operation like:

drivers/i2c/busses/i2c-mxs.c

@@ -567,9 +567,6 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
 	dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
 		msg->addr, msg->len, msg->flags, stop);
 
-	if (msg->len == 0)
-		return -EINVAL;
-
 	/*
 	 * The MX28 I2C IP block can only do PIO READ for transfer of to up
 	 * 4 bytes of length. The write transfer is not limited as it can use
@@ -683,6 +680,10 @@ static const struct i2c_algorithm mxs_i2c_algo = {
 	.functionality = mxs_i2c_func,
 };
 
+static const struct i2c_adapter_quirks mxs_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static void mxs_i2c_derive_timing(struct mxs_i2c_dev *i2c, uint32_t speed)
 {
 	/* The I2C block clock runs at 24MHz */
@@ -854,6 +855,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
 	strlcpy(adap->name, "MXS I2C adapter", sizeof(adap->name));
 	adap->owner = THIS_MODULE;
 	adap->algo = &mxs_i2c_algo;
+	adap->quirks = &mxs_i2c_quirks;
 	adap->dev.parent = dev;
 	adap->nr = pdev->id;
 	adap->dev.of_node = pdev->dev.of_node;

drivers/i2c/busses/i2c-owl.c

@@ -0,0 +1,495 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Actions Semiconductor Owl SoC's I2C driver
+ *
+ * Copyright (c) 2014 Actions Semi Inc.
+ * Author: David Liu <liuwei@actions-semi.com>
+ *
+ * Copyright (c) 2018 Linaro Ltd.
+ * Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+/* I2C registers */
+#define OWL_I2C_REG_CTL		0x0000
+#define OWL_I2C_REG_CLKDIV	0x0004
+#define OWL_I2C_REG_STAT	0x0008
+#define OWL_I2C_REG_ADDR	0x000C
+#define OWL_I2C_REG_TXDAT	0x0010
+#define OWL_I2C_REG_RXDAT	0x0014
+#define OWL_I2C_REG_CMD		0x0018
+#define OWL_I2C_REG_FIFOCTL	0x001C
+#define OWL_I2C_REG_FIFOSTAT	0x0020
+#define OWL_I2C_REG_DATCNT	0x0024
+#define OWL_I2C_REG_RCNT	0x0028
+
+/* I2Cx_CTL Bit Mask */
+#define OWL_I2C_CTL_RB		BIT(1)
+#define OWL_I2C_CTL_GBCC(x)	(((x) & 0x3) << 2)
+#define	OWL_I2C_CTL_GBCC_NONE	OWL_I2C_CTL_GBCC(0)
+#define	OWL_I2C_CTL_GBCC_START	OWL_I2C_CTL_GBCC(1)
+#define	OWL_I2C_CTL_GBCC_STOP	OWL_I2C_CTL_GBCC(2)
+#define	OWL_I2C_CTL_GBCC_RSTART	OWL_I2C_CTL_GBCC(3)
+#define OWL_I2C_CTL_IRQE	BIT(5)
+#define OWL_I2C_CTL_EN		BIT(7)
+#define OWL_I2C_CTL_AE		BIT(8)
+#define OWL_I2C_CTL_SHSM	BIT(10)
+
+#define OWL_I2C_DIV_FACTOR(x)	((x) & 0xff)
+
+/* I2Cx_STAT Bit Mask */
+#define OWL_I2C_STAT_RACK	BIT(0)
+#define OWL_I2C_STAT_BEB	BIT(1)
+#define OWL_I2C_STAT_IRQP	BIT(2)
+#define OWL_I2C_STAT_LAB	BIT(3)
+#define OWL_I2C_STAT_STPD	BIT(4)
+#define OWL_I2C_STAT_STAD	BIT(5)
+#define OWL_I2C_STAT_BBB	BIT(6)
+#define OWL_I2C_STAT_TCB	BIT(7)
+#define OWL_I2C_STAT_LBST	BIT(8)
+#define OWL_I2C_STAT_SAMB	BIT(9)
+#define OWL_I2C_STAT_SRGC	BIT(10)
+
+/* I2Cx_CMD Bit Mask */
+#define OWL_I2C_CMD_SBE		BIT(0)
+#define OWL_I2C_CMD_RBE		BIT(4)
+#define OWL_I2C_CMD_DE		BIT(8)
+#define OWL_I2C_CMD_NS		BIT(9)
+#define OWL_I2C_CMD_SE		BIT(10)
+#define OWL_I2C_CMD_MSS		BIT(11)
+#define OWL_I2C_CMD_WRS		BIT(12)
+#define OWL_I2C_CMD_SECL	BIT(15)
+
+#define OWL_I2C_CMD_AS(x)	(((x) & 0x7) << 1)
+#define OWL_I2C_CMD_SAS(x)	(((x) & 0x7) << 5)
+
+/* I2Cx_FIFOCTL Bit Mask */
+#define OWL_I2C_FIFOCTL_NIB	BIT(0)
+#define OWL_I2C_FIFOCTL_RFR	BIT(1)
+#define OWL_I2C_FIFOCTL_TFR	BIT(2)
+
+/* I2Cc_FIFOSTAT Bit Mask */
+#define OWL_I2C_FIFOSTAT_RNB	BIT(1)
+#define OWL_I2C_FIFOSTAT_RFE	BIT(2)
+#define OWL_I2C_FIFOSTAT_TFF	BIT(5)
+#define OWL_I2C_FIFOSTAT_TFD	GENMASK(23, 16)
+#define OWL_I2C_FIFOSTAT_RFD	GENMASK(15, 8)
+
+/* I2C bus timeout */
+#define OWL_I2C_TIMEOUT		msecs_to_jiffies(4 * 1000)
+
+#define OWL_I2C_MAX_RETRIES	50
+
+#define OWL_I2C_DEF_SPEED_HZ	100000
+#define OWL_I2C_MAX_SPEED_HZ	400000
+
+struct owl_i2c_dev {
+	struct i2c_adapter	adap;
+	struct i2c_msg		*msg;
+	struct completion	msg_complete;
+	struct clk		*clk;
+	spinlock_t		lock;
+	void __iomem		*base;
+	unsigned long		clk_rate;
+	u32			bus_freq;
+	u32			msg_ptr;
+	int			err;
+};
+
+static void owl_i2c_update_reg(void __iomem *reg, unsigned int val, bool state)
+{
+	unsigned int regval;
+
+	regval = readl(reg);
+
+	if (state)
+		regval |= val;
+	else
+		regval &= ~val;
+
+	writel(regval, reg);
+}
+
+static void owl_i2c_reset(struct owl_i2c_dev *i2c_dev)
+{
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+			   OWL_I2C_CTL_EN, false);
+	mdelay(1);
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+			   OWL_I2C_CTL_EN, true);
+
+	/* Clear status registers */
+	writel(0, i2c_dev->base + OWL_I2C_REG_STAT);
+}
+
+static int owl_i2c_reset_fifo(struct owl_i2c_dev *i2c_dev)
+{
+	unsigned int val, timeout = 0;
+
+	/* Reset FIFO */
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+			   OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR,
+			   true);
+
+	/* Wait 50ms for FIFO reset complete */
+	do {
+		val = readl(i2c_dev->base + OWL_I2C_REG_FIFOCTL);
+		if (!(val & (OWL_I2C_FIFOCTL_RFR | OWL_I2C_FIFOCTL_TFR)))
+			break;
+		usleep_range(500, 1000);
+	} while (timeout++ < OWL_I2C_MAX_RETRIES);
+
+	if (timeout > OWL_I2C_MAX_RETRIES) {
+		dev_err(&i2c_dev->adap.dev, "FIFO reset timeout\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void owl_i2c_set_freq(struct owl_i2c_dev *i2c_dev)
+{
+	unsigned int val;
+
+	val = DIV_ROUND_UP(i2c_dev->clk_rate, i2c_dev->bus_freq * 16);
+
+	/* Set clock divider factor */
+	writel(OWL_I2C_DIV_FACTOR(val), i2c_dev->base + OWL_I2C_REG_CLKDIV);
+}
+
+static irqreturn_t owl_i2c_interrupt(int irq, void *_dev)
+{
+	struct owl_i2c_dev *i2c_dev = _dev;
+	struct i2c_msg *msg = i2c_dev->msg;
+	unsigned long flags;
+	unsigned int stat, fifostat;
+
+	spin_lock_irqsave(&i2c_dev->lock, flags);
+
+	i2c_dev->err = 0;
+
+	/* Handle NACK from slave */
+	fifostat = readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT);
+	if (fifostat & OWL_I2C_FIFOSTAT_RNB) {
+		i2c_dev->err = -ENXIO;
+		goto stop;
+	}
+
+	/* Handle bus error */
+	stat = readl(i2c_dev->base + OWL_I2C_REG_STAT);
+	if (stat & OWL_I2C_STAT_BEB) {
+		i2c_dev->err = -EIO;
+		goto stop;
+	}
+
+	/* Handle FIFO read */
+	if (msg->flags & I2C_M_RD) {
+		while ((readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+			OWL_I2C_FIFOSTAT_RFE) && i2c_dev->msg_ptr < msg->len) {
+			msg->buf[i2c_dev->msg_ptr++] = readl(i2c_dev->base +
+							     OWL_I2C_REG_RXDAT);
+		}
+	} else {
+		/* Handle the remaining bytes which were not sent */
+		while (!(readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+			 OWL_I2C_FIFOSTAT_TFF) && i2c_dev->msg_ptr < msg->len) {
+			writel(msg->buf[i2c_dev->msg_ptr++],
+			       i2c_dev->base + OWL_I2C_REG_TXDAT);
+		}
+	}
+
+stop:
+	/* Clear pending interrupts */
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_STAT,
+			   OWL_I2C_STAT_IRQP, true);
+
+	complete_all(&i2c_dev->msg_complete);
+	spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+static u32 owl_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static int owl_i2c_check_bus_busy(struct i2c_adapter *adap)
+{
+	struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+	unsigned long timeout;
+
+	/* Check for Bus busy */
+	timeout = jiffies + OWL_I2C_TIMEOUT;
+	while (readl(i2c_dev->base + OWL_I2C_REG_STAT) & OWL_I2C_STAT_BBB) {
+		if (time_after(jiffies, timeout)) {
+			dev_err(&adap->dev, "Bus busy timeout\n");
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
+static int owl_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+			       int num)
+{
+	struct owl_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+	struct i2c_msg *msg;
+	unsigned long time_left, flags;
+	unsigned int i2c_cmd, val;
+	unsigned int addr;
+	int ret, idx;
+
+	spin_lock_irqsave(&i2c_dev->lock, flags);
+
+	/* Reset I2C controller */
+	owl_i2c_reset(i2c_dev);
+
+	/* Set bus frequency */
+	owl_i2c_set_freq(i2c_dev);
+
+	/*
+	 * Spinlock should be released before calling reset FIFO and
+	 * bus busy check since those functions may sleep
+	 */
+	spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+	/* Reset FIFO */
+	ret = owl_i2c_reset_fifo(i2c_dev);
+	if (ret)
+		goto unlocked_err_exit;
+
+	/* Check for bus busy */
+	ret = owl_i2c_check_bus_busy(adap);
+	if (ret)
+		goto unlocked_err_exit;
+
+	spin_lock_irqsave(&i2c_dev->lock, flags);
+
+	/* Check for Arbitration lost */
+	val = readl(i2c_dev->base + OWL_I2C_REG_STAT);
+	if (val & OWL_I2C_STAT_LAB) {
+		val &= ~OWL_I2C_STAT_LAB;
+		writel(val, i2c_dev->base + OWL_I2C_REG_STAT);
+		ret = -EAGAIN;
+		goto err_exit;
+	}
+
+	reinit_completion(&i2c_dev->msg_complete);
+
+	/* Enable I2C controller interrupt */
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+			   OWL_I2C_CTL_IRQE, true);
+
+	/*
+	 * Select: FIFO enable, Master mode, Stop enable, Data count enable,
+	 * Send start bit
+	 */
+	i2c_cmd = OWL_I2C_CMD_SECL | OWL_I2C_CMD_MSS | OWL_I2C_CMD_SE |
+		  OWL_I2C_CMD_NS | OWL_I2C_CMD_DE | OWL_I2C_CMD_SBE;
+
+	/* Handle repeated start condition */
+	if (num > 1) {
+		/* Set internal address length and enable repeated start */
+		i2c_cmd |= OWL_I2C_CMD_AS(msgs[0].len + 1) |
+			   OWL_I2C_CMD_SAS(1) | OWL_I2C_CMD_RBE;
+
+		/* Write slave address */
+		addr = i2c_8bit_addr_from_msg(&msgs[0]);
+		writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+		/* Write internal register address */
+		for (idx = 0; idx < msgs[0].len; idx++)
+			writel(msgs[0].buf[idx],
+			       i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+		msg = &msgs[1];
+	} else {
+		/* Set address length */
+		i2c_cmd |= OWL_I2C_CMD_AS(1);
+		msg = &msgs[0];
+	}
+
+	i2c_dev->msg = msg;
+	i2c_dev->msg_ptr = 0;
+
+	/* Set data count for the message */
+	writel(msg->len, i2c_dev->base + OWL_I2C_REG_DATCNT);
+
+	addr = i2c_8bit_addr_from_msg(msg);
+	writel(addr, i2c_dev->base + OWL_I2C_REG_TXDAT);
+
+	if (!(msg->flags & I2C_M_RD)) {
+		/* Write data to FIFO */
+		for (idx = 0; idx < msg->len; idx++) {
+			/* Check for FIFO full */
+			if (readl(i2c_dev->base + OWL_I2C_REG_FIFOSTAT) &
+			    OWL_I2C_FIFOSTAT_TFF)
+				break;
+
+			writel(msg->buf[idx],
+			       i2c_dev->base + OWL_I2C_REG_TXDAT);
+		}
+
+		i2c_dev->msg_ptr = idx;
+	}
+
+	/* Ignore the NACK if needed */
+	if (msg->flags & I2C_M_IGNORE_NAK)
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+				   OWL_I2C_FIFOCTL_NIB, true);
+	else
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_FIFOCTL,
+				   OWL_I2C_FIFOCTL_NIB, false);
+
+	/* Start the transfer */
+	writel(i2c_cmd, i2c_dev->base + OWL_I2C_REG_CMD);
+
+	spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+	time_left = wait_for_completion_timeout(&i2c_dev->msg_complete,
+						adap->timeout);
+
+	spin_lock_irqsave(&i2c_dev->lock, flags);
+	if (time_left == 0) {
+		dev_err(&adap->dev, "Transaction timed out\n");
+		/* Send stop condition and release the bus */
+		owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+				   OWL_I2C_CTL_GBCC_STOP | OWL_I2C_CTL_RB,
+				   true);
+		ret = -ETIMEDOUT;
+		goto err_exit;
+	}
+
+	ret = i2c_dev->err < 0 ? i2c_dev->err : num;
+
+err_exit:
+	spin_unlock_irqrestore(&i2c_dev->lock, flags);
+
+unlocked_err_exit:
+	/* Disable I2C controller */
+	owl_i2c_update_reg(i2c_dev->base + OWL_I2C_REG_CTL,
+			   OWL_I2C_CTL_EN, false);
+
+	return ret;
+}
+
+static const struct i2c_algorithm owl_i2c_algorithm = {
+	.master_xfer    = owl_i2c_master_xfer,
+	.functionality  = owl_i2c_func,
+};
+
+static const struct i2c_adapter_quirks owl_i2c_quirks = {
+	.flags		= I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST,
+	.max_read_len   = 240,
+	.max_write_len  = 240,
+	.max_comb_1st_msg_len = 6,
+	.max_comb_2nd_msg_len = 240,
+};
+
+static int owl_i2c_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct owl_i2c_dev *i2c_dev;
+	struct resource *res;
+	int ret, irq;
+
+	i2c_dev = devm_kzalloc(dev, sizeof(*i2c_dev), GFP_KERNEL);
+	if (!i2c_dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2c_dev->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(i2c_dev->base))
+		return PTR_ERR(i2c_dev->base);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get IRQ number\n");
+		return irq;
+	}
+
+	if (of_property_read_u32(dev->of_node, "clock-frequency",
+				 &i2c_dev->bus_freq))
+		i2c_dev->bus_freq = OWL_I2C_DEF_SPEED_HZ;
+
+	/* We support only frequencies of 100k and 400k for now */
+	if (i2c_dev->bus_freq != OWL_I2C_DEF_SPEED_HZ &&
+	    i2c_dev->bus_freq != OWL_I2C_MAX_SPEED_HZ) {
+		dev_err(dev, "invalid clock-frequency %d\n", i2c_dev->bus_freq);
+		return -EINVAL;
+	}
+
+	i2c_dev->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(i2c_dev->clk)) {
+		dev_err(dev, "failed to get clock\n");
+		return PTR_ERR(i2c_dev->clk);
+	}
+
+	ret = clk_prepare_enable(i2c_dev->clk);
+	if (ret)
+		return ret;
+
+	i2c_dev->clk_rate = clk_get_rate(i2c_dev->clk);
+	if (!i2c_dev->clk_rate) {
+		dev_err(dev, "input clock rate should not be zero\n");
+		ret = -EINVAL;
+		goto disable_clk;
+	}
+
+	init_completion(&i2c_dev->msg_complete);
+	spin_lock_init(&i2c_dev->lock);
+	i2c_dev->adap.owner = THIS_MODULE;
+	i2c_dev->adap.algo = &owl_i2c_algorithm;
+	i2c_dev->adap.timeout = OWL_I2C_TIMEOUT;
+	i2c_dev->adap.quirks = &owl_i2c_quirks;
+	i2c_dev->adap.dev.parent = dev;
+	i2c_dev->adap.dev.of_node = dev->of_node;
+	snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
+		 "%s", "OWL I2C adapter");
+	i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+
+	platform_set_drvdata(pdev, i2c_dev);
+
+	ret = devm_request_irq(dev, irq, owl_i2c_interrupt, 0, pdev->name,
+			       i2c_dev);
+	if (ret) {
+		dev_err(dev, "failed to request irq %d\n", irq);
+		goto disable_clk;
+	}
+
+	return i2c_add_adapter(&i2c_dev->adap);
+
+disable_clk:
+	clk_disable_unprepare(i2c_dev->clk);
+
+	return ret;
+}
+
+static const struct of_device_id owl_i2c_of_match[] = {
+	{ .compatible = "actions,s900-i2c" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, owl_i2c_of_match);
+
+static struct platform_driver owl_i2c_driver = {
+	.probe		= owl_i2c_probe,
+	.driver		= {
+		.name	= "owl-i2c",
+		.of_match_table = of_match_ptr(owl_i2c_of_match),
+	},
+};
+module_platform_driver(owl_i2c_driver);
+
+MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Actions Semiconductor Owl SoC's I2C driver");
+MODULE_LICENSE("GPL");

drivers/i2c/busses/i2c-pasemi.c

@@ -365,7 +365,6 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 	smbus->adapter.algo = &smbus_algorithm;
 	smbus->adapter.algo_data = smbus;
-	smbus->adapter.nr = PCI_FUNC(dev->devfn);
 
 	/* set up the sysfs linkage to our parent device */
 	smbus->adapter.dev.parent = &dev->dev;
@@ -373,7 +372,7 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
 		  (CLK_100K_DIV & CTL_CLK_M)));
 
-	error = i2c_add_numbered_adapter(&smbus->adapter);
+	error = i2c_add_adapter(&smbus->adapter);
 	if (error)
 		goto out_release_region;
 

drivers/i2c/busses/i2c-pmcmsp.c

@@ -444,16 +444,6 @@ static enum pmcmsptwi_xfer_result pmcmsptwi_xfer_cmd(
 {
 	enum pmcmsptwi_xfer_result retval;
 
-	if ((cmd->type == MSP_TWI_CMD_WRITE && cmd->write_len == 0) ||
-	    (cmd->type == MSP_TWI_CMD_READ && cmd->read_len == 0) ||
-	    (cmd->type == MSP_TWI_CMD_WRITE_READ &&
-	    (cmd->read_len == 0 || cmd->write_len == 0))) {
-		dev_err(&pmcmsptwi_adapter.dev,
-			"%s: Cannot transfer less than 1 byte\n",
-			__func__);
-		return -EINVAL;
-	}
-
 	mutex_lock(&data->lock);
 	dev_dbg(&pmcmsptwi_adapter.dev,
 		"Setting address to 0x%04x\n", cmd->addr);
@@ -532,11 +522,6 @@ static int pmcmsptwi_master_xfer(struct i2c_adapter *adap,
 		cmd.write_data = msg->buf;
 	}
 
-	if (msg->len == 0) {
-		dev_err(&adap->dev, "Zero-byte messages unsupported\n");
-		return -EINVAL;
-	}
-
 	cmd.addr = msg->addr;
 
 	if (msg->flags & I2C_M_TEN) {
@@ -578,7 +563,7 @@ static u32 pmcmsptwi_i2c_func(struct i2c_adapter *adapter)
 }
 
 static const struct i2c_adapter_quirks pmcmsptwi_i2c_quirks = {
-	.flags = I2C_AQ_COMB_WRITE_THEN_READ,
+	.flags = I2C_AQ_COMB_WRITE_THEN_READ | I2C_AQ_NO_ZERO_LEN,
 	.max_write_len = MSP_MAX_BYTES_PER_RW,
 	.max_read_len = MSP_MAX_BYTES_PER_RW,
 	.max_comb_1st_msg_len = MSP_MAX_BYTES_PER_RW,

drivers/i2c/busses/i2c-qcom-geni.c

@@ -0,0 +1,673 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/qcom-geni-se.h>
+#include <linux/spinlock.h>
+
+#define SE_I2C_TX_TRANS_LEN		0x26c
+#define SE_I2C_RX_TRANS_LEN		0x270
+#define SE_I2C_SCL_COUNTERS		0x278
+
+#define SE_I2C_ERR  (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |\
+			M_GP_IRQ_1_EN | M_GP_IRQ_3_EN | M_GP_IRQ_4_EN)
+#define SE_I2C_ABORT		BIT(1)
+
+/* M_CMD OP codes for I2C */
+#define I2C_WRITE		0x1
+#define I2C_READ		0x2
+#define I2C_WRITE_READ		0x3
+#define I2C_ADDR_ONLY		0x4
+#define I2C_BUS_CLEAR		0x6
+#define I2C_STOP_ON_BUS		0x7
+/* M_CMD params for I2C */
+#define PRE_CMD_DELAY		BIT(0)
+#define TIMESTAMP_BEFORE	BIT(1)
+#define STOP_STRETCH		BIT(2)
+#define TIMESTAMP_AFTER		BIT(3)
+#define POST_COMMAND_DELAY	BIT(4)
+#define IGNORE_ADD_NACK		BIT(6)
+#define READ_FINISHED_WITH_ACK	BIT(7)
+#define BYPASS_ADDR_PHASE	BIT(8)
+#define SLV_ADDR_MSK		GENMASK(15, 9)
+#define SLV_ADDR_SHFT		9
+/* I2C SCL COUNTER fields */
+#define HIGH_COUNTER_MSK	GENMASK(29, 20)
+#define HIGH_COUNTER_SHFT	20
+#define LOW_COUNTER_MSK		GENMASK(19, 10)
+#define LOW_COUNTER_SHFT	10
+#define CYCLE_COUNTER_MSK	GENMASK(9, 0)
+
+enum geni_i2c_err_code {
+	GP_IRQ0,
+	NACK,
+	GP_IRQ2,
+	BUS_PROTO,
+	ARB_LOST,
+	GP_IRQ5,
+	GENI_OVERRUN,
+	GENI_ILLEGAL_CMD,
+	GENI_ABORT_DONE,
+	GENI_TIMEOUT,
+};
+
+#define DM_I2C_CB_ERR		((BIT(NACK) | BIT(BUS_PROTO) | BIT(ARB_LOST)) \
+									<< 5)
+
+#define I2C_AUTO_SUSPEND_DELAY	250
+#define KHZ(freq)		(1000 * freq)
+#define PACKING_BYTES_PW	4
+
+#define ABORT_TIMEOUT		HZ
+#define XFER_TIMEOUT		HZ
+#define RST_TIMEOUT		HZ
+
+struct geni_i2c_dev {
+	struct geni_se se;
+	u32 tx_wm;
+	int irq;
+	int err;
+	struct i2c_adapter adap;
+	struct completion done;
+	struct i2c_msg *cur;
+	int cur_wr;
+	int cur_rd;
+	spinlock_t lock;
+	u32 clk_freq_out;
+	const struct geni_i2c_clk_fld *clk_fld;
+	int suspended;
+};
+
+struct geni_i2c_err_log {
+	int err;
+	const char *msg;
+};
+
+static const struct geni_i2c_err_log gi2c_log[] = {
+	[GP_IRQ0] = {-EIO, "Unknown I2C err GP_IRQ0"},
+	[NACK] = {-ENXIO, "NACK: slv unresponsive, check its power/reset-ln"},
+	[GP_IRQ2] = {-EIO, "Unknown I2C err GP IRQ2"},
+	[BUS_PROTO] = {-EPROTO, "Bus proto err, noisy/unepxected start/stop"},
+	[ARB_LOST] = {-EAGAIN, "Bus arbitration lost, clock line undriveable"},
+	[GP_IRQ5] = {-EIO, "Unknown I2C err GP IRQ5"},
+	[GENI_OVERRUN] = {-EIO, "Cmd overrun, check GENI cmd-state machine"},
+	[GENI_ILLEGAL_CMD] = {-EIO, "Illegal cmd, check GENI cmd-state machine"},
+	[GENI_ABORT_DONE] = {-ETIMEDOUT, "Abort after timeout successful"},
+	[GENI_TIMEOUT] = {-ETIMEDOUT, "I2C TXN timed out"},
+};
+
+struct geni_i2c_clk_fld {
+	u32	clk_freq_out;
+	u8	clk_div;
+	u8	t_high_cnt;
+	u8	t_low_cnt;
+	u8	t_cycle_cnt;
+};
+
+/*
+ * Hardware uses the underlying formula to calculate time periods of
+ * SCL clock cycle. Firmware uses some additional cycles excluded from the
+ * below formula and it is confirmed that the time periods are within
+ * specification limits.
+ *
+ * time of high period of SCL: t_high = (t_high_cnt * clk_div) / source_clock
+ * time of low period of SCL: t_low = (t_low_cnt * clk_div) / source_clock
+ * time of full period of SCL: t_cycle = (t_cycle_cnt * clk_div) / source_clock
+ * clk_freq_out = t / t_cycle
+ * source_clock = 19.2 MHz
+ */
+static const struct geni_i2c_clk_fld geni_i2c_clk_map[] = {
+	{KHZ(100), 7, 10, 11, 26},
+	{KHZ(400), 2,  5, 12, 24},
+	{KHZ(1000), 1, 3,  9, 18},
+};
+
+static int geni_i2c_clk_map_idx(struct geni_i2c_dev *gi2c)
+{
+	int i;
+	const struct geni_i2c_clk_fld *itr = geni_i2c_clk_map;
+
+	for (i = 0; i < ARRAY_SIZE(geni_i2c_clk_map); i++, itr++) {
+		if (itr->clk_freq_out == gi2c->clk_freq_out) {
+			gi2c->clk_fld = itr;
+			return 0;
+		}
+	}
+	return -EINVAL;
+}
+
+static void qcom_geni_i2c_conf(struct geni_i2c_dev *gi2c)
+{
+	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
+	u32 val;
+
+	writel_relaxed(0, gi2c->se.base + SE_GENI_CLK_SEL);
+
+	val = (itr->clk_div << CLK_DIV_SHFT) | SER_CLK_EN;
+	writel_relaxed(val, gi2c->se.base + GENI_SER_M_CLK_CFG);
+
+	val = itr->t_high_cnt << HIGH_COUNTER_SHFT;
+	val |= itr->t_low_cnt << LOW_COUNTER_SHFT;
+	val |= itr->t_cycle_cnt;
+	writel_relaxed(val, gi2c->se.base + SE_I2C_SCL_COUNTERS);
+}
+
+static void geni_i2c_err_misc(struct geni_i2c_dev *gi2c)
+{
+	u32 m_cmd = readl_relaxed(gi2c->se.base + SE_GENI_M_CMD0);
+	u32 m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+	u32 geni_s = readl_relaxed(gi2c->se.base + SE_GENI_STATUS);
+	u32 geni_ios = readl_relaxed(gi2c->se.base + SE_GENI_IOS);
+	u32 dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
+	u32 rx_st, tx_st;
+
+	if (dma) {
+		rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
+		tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
+	} else {
+		rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
+		tx_st = readl_relaxed(gi2c->se.base + SE_GENI_TX_FIFO_STATUS);
+	}
+	dev_dbg(gi2c->se.dev, "DMA:%d tx_stat:0x%x, rx_stat:0x%x, irq-stat:0x%x\n",
+		dma, tx_st, rx_st, m_stat);
+	dev_dbg(gi2c->se.dev, "m_cmd:0x%x, geni_status:0x%x, geni_ios:0x%x\n",
+		m_cmd, geni_s, geni_ios);
+}
+
+static void geni_i2c_err(struct geni_i2c_dev *gi2c, int err)
+{
+	if (!gi2c->err)
+		gi2c->err = gi2c_log[err].err;
+	if (gi2c->cur)
+		dev_dbg(gi2c->se.dev, "len:%d, slv-addr:0x%x, RD/WR:%d\n",
+			gi2c->cur->len, gi2c->cur->addr, gi2c->cur->flags);
+
+	if (err != NACK && err != GENI_ABORT_DONE) {
+		dev_err(gi2c->se.dev, "%s\n", gi2c_log[err].msg);
+		geni_i2c_err_misc(gi2c);
+	}
+}
+
+static irqreturn_t geni_i2c_irq(int irq, void *dev)
+{
+	struct geni_i2c_dev *gi2c = dev;
+	int j;
+	u32 m_stat;
+	u32 rx_st;
+	u32 dm_tx_st;
+	u32 dm_rx_st;
+	u32 dma;
+	struct i2c_msg *cur;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gi2c->lock, flags);
+	m_stat = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+	rx_st = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFO_STATUS);
+	dm_tx_st = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
+	dm_rx_st = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
+	dma = readl_relaxed(gi2c->se.base + SE_GENI_DMA_MODE_EN);
+	cur = gi2c->cur;
+
+	if (!cur ||
+	    m_stat & (M_CMD_FAILURE_EN | M_CMD_ABORT_EN) ||
+	    dm_rx_st & (DM_I2C_CB_ERR)) {
+		if (m_stat & M_GP_IRQ_1_EN)
+			geni_i2c_err(gi2c, NACK);
+		if (m_stat & M_GP_IRQ_3_EN)
+			geni_i2c_err(gi2c, BUS_PROTO);
+		if (m_stat & M_GP_IRQ_4_EN)
+			geni_i2c_err(gi2c, ARB_LOST);
+		if (m_stat & M_CMD_OVERRUN_EN)
+			geni_i2c_err(gi2c, GENI_OVERRUN);
+		if (m_stat & M_ILLEGAL_CMD_EN)
+			geni_i2c_err(gi2c, GENI_ILLEGAL_CMD);
+		if (m_stat & M_CMD_ABORT_EN)
+			geni_i2c_err(gi2c, GENI_ABORT_DONE);
+		if (m_stat & M_GP_IRQ_0_EN)
+			geni_i2c_err(gi2c, GP_IRQ0);
+
+		/* Disable the TX Watermark interrupt to stop TX */
+		if (!dma)
+			writel_relaxed(0, gi2c->se.base +
+					   SE_GENI_TX_WATERMARK_REG);
+		goto irqret;
+	}
+
+	if (dma) {
+		dev_dbg(gi2c->se.dev, "i2c dma tx:0x%x, dma rx:0x%x\n",
+			dm_tx_st, dm_rx_st);
+		goto irqret;
+	}
+
+	if (cur->flags & I2C_M_RD &&
+	    m_stat & (M_RX_FIFO_WATERMARK_EN | M_RX_FIFO_LAST_EN)) {
+		u32 rxcnt = rx_st & RX_FIFO_WC_MSK;
+
+		for (j = 0; j < rxcnt; j++) {
+			u32 val;
+			int p = 0;
+
+			val = readl_relaxed(gi2c->se.base + SE_GENI_RX_FIFOn);
+			while (gi2c->cur_rd < cur->len && p < sizeof(val)) {
+				cur->buf[gi2c->cur_rd++] = val & 0xff;
+				val >>= 8;
+				p++;
+			}
+			if (gi2c->cur_rd == cur->len)
+				break;
+		}
+	} else if (!(cur->flags & I2C_M_RD) &&
+		   m_stat & M_TX_FIFO_WATERMARK_EN) {
+		for (j = 0; j < gi2c->tx_wm; j++) {
+			u32 temp;
+			u32 val = 0;
+			int p = 0;
+
+			while (gi2c->cur_wr < cur->len && p < sizeof(val)) {
+				temp = cur->buf[gi2c->cur_wr++];
+				val |= temp << (p * 8);
+				p++;
+			}
+			writel_relaxed(val, gi2c->se.base + SE_GENI_TX_FIFOn);
+			/* TX Complete, Disable the TX Watermark interrupt */
+			if (gi2c->cur_wr == cur->len) {
+				writel_relaxed(0, gi2c->se.base +
+						SE_GENI_TX_WATERMARK_REG);
+				break;
+			}
+		}
+	}
+irqret:
+	if (m_stat)
+		writel_relaxed(m_stat, gi2c->se.base + SE_GENI_M_IRQ_CLEAR);
+
+	if (dma) {
+		if (dm_tx_st)
+			writel_relaxed(dm_tx_st, gi2c->se.base +
+						SE_DMA_TX_IRQ_CLR);
+		if (dm_rx_st)
+			writel_relaxed(dm_rx_st, gi2c->se.base +
+						SE_DMA_RX_IRQ_CLR);
+	}
+	/* if this is err with done-bit not set, handle that through timeout. */
+	if (m_stat & M_CMD_DONE_EN || m_stat & M_CMD_ABORT_EN)
+		complete(&gi2c->done);
+	else if (dm_tx_st & TX_DMA_DONE || dm_tx_st & TX_RESET_DONE)
+		complete(&gi2c->done);
+	else if (dm_rx_st & RX_DMA_DONE || dm_rx_st & RX_RESET_DONE)
+		complete(&gi2c->done);
+
+	spin_unlock_irqrestore(&gi2c->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void geni_i2c_abort_xfer(struct geni_i2c_dev *gi2c)
+{
+	u32 val;
+	unsigned long time_left = ABORT_TIMEOUT;
+	unsigned long flags;
+
+	spin_lock_irqsave(&gi2c->lock, flags);
+	geni_i2c_err(gi2c, GENI_TIMEOUT);
+	gi2c->cur = NULL;
+	geni_se_abort_m_cmd(&gi2c->se);
+	spin_unlock_irqrestore(&gi2c->lock, flags);
+	do {
+		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
+		val = readl_relaxed(gi2c->se.base + SE_GENI_M_IRQ_STATUS);
+	} while (!(val & M_CMD_ABORT_EN) && time_left);
+
+	if (!(val & M_CMD_ABORT_EN))
+		dev_err(gi2c->se.dev, "Timeout abort_m_cmd\n");
+}
+
+static void geni_i2c_rx_fsm_rst(struct geni_i2c_dev *gi2c)
+{
+	u32 val;
+	unsigned long time_left = RST_TIMEOUT;
+
+	writel_relaxed(1, gi2c->se.base + SE_DMA_RX_FSM_RST);
+	do {
+		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
+		val = readl_relaxed(gi2c->se.base + SE_DMA_RX_IRQ_STAT);
+	} while (!(val & RX_RESET_DONE) && time_left);
+
+	if (!(val & RX_RESET_DONE))
+		dev_err(gi2c->se.dev, "Timeout resetting RX_FSM\n");
+}
+
+static void geni_i2c_tx_fsm_rst(struct geni_i2c_dev *gi2c)
+{
+	u32 val;
+	unsigned long time_left = RST_TIMEOUT;
+
+	writel_relaxed(1, gi2c->se.base + SE_DMA_TX_FSM_RST);
+	do {
+		time_left = wait_for_completion_timeout(&gi2c->done, time_left);
+		val = readl_relaxed(gi2c->se.base + SE_DMA_TX_IRQ_STAT);
+	} while (!(val & TX_RESET_DONE) && time_left);
+
+	if (!(val & TX_RESET_DONE))
+		dev_err(gi2c->se.dev, "Timeout resetting TX_FSM\n");
+}
+
+static int geni_i2c_rx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
+				u32 m_param)
+{
+	dma_addr_t rx_dma;
+	enum geni_se_xfer_mode mode;
+	unsigned long time_left = XFER_TIMEOUT;
+
+	gi2c->cur = msg;
+	mode = msg->len > 32 ? GENI_SE_DMA : GENI_SE_FIFO;
+	geni_se_select_mode(&gi2c->se, mode);
+	writel_relaxed(msg->len, gi2c->se.base + SE_I2C_RX_TRANS_LEN);
+	geni_se_setup_m_cmd(&gi2c->se, I2C_READ, m_param);
+	if (mode == GENI_SE_DMA) {
+		int ret;
+
+		ret = geni_se_rx_dma_prep(&gi2c->se, msg->buf, msg->len,
+								&rx_dma);
+		if (ret) {
+			mode = GENI_SE_FIFO;
+			geni_se_select_mode(&gi2c->se, mode);
+		}
+	}
+
+	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
+	if (!time_left)
+		geni_i2c_abort_xfer(gi2c);
+
+	gi2c->cur_rd = 0;
+	if (mode == GENI_SE_DMA) {
+		if (gi2c->err)
+			geni_i2c_rx_fsm_rst(gi2c);
+		geni_se_rx_dma_unprep(&gi2c->se, rx_dma, msg->len);
+	}
+	return gi2c->err;
+}
+
+static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
+				u32 m_param)
+{
+	dma_addr_t tx_dma;
+	enum geni_se_xfer_mode mode;
+	unsigned long time_left;
+
+	gi2c->cur = msg;
+	mode = msg->len > 32 ? GENI_SE_DMA : GENI_SE_FIFO;
+	geni_se_select_mode(&gi2c->se, mode);
+	writel_relaxed(msg->len, gi2c->se.base + SE_I2C_TX_TRANS_LEN);
+	geni_se_setup_m_cmd(&gi2c->se, I2C_WRITE, m_param);
+	if (mode == GENI_SE_DMA) {
+		int ret;
+
+		ret = geni_se_tx_dma_prep(&gi2c->se, msg->buf, msg->len,
+								&tx_dma);
+		if (ret) {
+			mode = GENI_SE_FIFO;
+			geni_se_select_mode(&gi2c->se, mode);
+		}
+	}
+
+	if (mode == GENI_SE_FIFO) /* Get FIFO IRQ */
+		writel_relaxed(1, gi2c->se.base + SE_GENI_TX_WATERMARK_REG);
+
+	time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
+	if (!time_left)
+		geni_i2c_abort_xfer(gi2c);
+
+	gi2c->cur_wr = 0;
+	if (mode == GENI_SE_DMA) {
+		if (gi2c->err)
+			geni_i2c_tx_fsm_rst(gi2c);
+		geni_se_tx_dma_unprep(&gi2c->se, tx_dma, msg->len);
+	}
+	return gi2c->err;
+}
+
+static int geni_i2c_xfer(struct i2c_adapter *adap,
+			 struct i2c_msg msgs[],
+			 int num)
+{
+	struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap);
+	int i, ret;
+
+	gi2c->err = 0;
+	reinit_completion(&gi2c->done);
+	ret = pm_runtime_get_sync(gi2c->se.dev);
+	if (ret < 0) {
+		dev_err(gi2c->se.dev, "error turning SE resources:%d\n", ret);
+		pm_runtime_put_noidle(gi2c->se.dev);
+		/* Set device in suspended since resume failed */
+		pm_runtime_set_suspended(gi2c->se.dev);
+		return ret;
+	}
+
+	qcom_geni_i2c_conf(gi2c);
+	for (i = 0; i < num; i++) {
+		u32 m_param = i < (num - 1) ? STOP_STRETCH : 0;
+
+		m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK);
+
+		if (msgs[i].flags & I2C_M_RD)
+			ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param);
+		else
+			ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param);
+
+		if (ret)
+			break;
+	}
+	if (ret == 0)
+		ret = num;
+
+	pm_runtime_mark_last_busy(gi2c->se.dev);
+	pm_runtime_put_autosuspend(gi2c->se.dev);
+	gi2c->cur = NULL;
+	gi2c->err = 0;
+	return ret;
+}
+
+static u32 geni_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm geni_i2c_algo = {
+	.master_xfer	= geni_i2c_xfer,
+	.functionality	= geni_i2c_func,
+};
+
+static int geni_i2c_probe(struct platform_device *pdev)
+{
+	struct geni_i2c_dev *gi2c;
+	struct resource *res;
+	u32 proto, tx_depth;
+	int ret;
+
+	gi2c = devm_kzalloc(&pdev->dev, sizeof(*gi2c), GFP_KERNEL);
+	if (!gi2c)
+		return -ENOMEM;
+
+	gi2c->se.dev = &pdev->dev;
+	gi2c->se.wrapper = dev_get_drvdata(pdev->dev.parent);
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	gi2c->se.base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(gi2c->se.base))
+		return PTR_ERR(gi2c->se.base);
+
+	gi2c->se.clk = devm_clk_get(&pdev->dev, "se");
+	if (IS_ERR(gi2c->se.clk)) {
+		ret = PTR_ERR(gi2c->se.clk);
+		dev_err(&pdev->dev, "Err getting SE Core clk %d\n", ret);
+		return ret;
+	}
+
+	ret = device_property_read_u32(&pdev->dev, "clock-frequency",
+							&gi2c->clk_freq_out);
+	if (ret) {
+		dev_info(&pdev->dev,
+			"Bus frequency not specified, default to 100kHz.\n");
+		gi2c->clk_freq_out = KHZ(100);
+	}
+
+	gi2c->irq = platform_get_irq(pdev, 0);
+	if (gi2c->irq < 0) {
+		dev_err(&pdev->dev, "IRQ error for i2c-geni\n");
+		return gi2c->irq;
+	}
+
+	ret = geni_i2c_clk_map_idx(gi2c);
+	if (ret) {
+		dev_err(&pdev->dev, "Invalid clk frequency %d Hz: %d\n",
+			gi2c->clk_freq_out, ret);
+		return ret;
+	}
+
+	gi2c->adap.algo = &geni_i2c_algo;
+	init_completion(&gi2c->done);
+	spin_lock_init(&gi2c->lock);
+	platform_set_drvdata(pdev, gi2c);
+	ret = devm_request_irq(&pdev->dev, gi2c->irq, geni_i2c_irq,
+			       IRQF_TRIGGER_HIGH, "i2c_geni", gi2c);
+	if (ret) {
+		dev_err(&pdev->dev, "Request_irq failed:%d: err:%d\n",
+			gi2c->irq, ret);
+		return ret;
+	}
+	/* Disable the interrupt so that the system can enter low-power mode */
+	disable_irq(gi2c->irq);
+	i2c_set_adapdata(&gi2c->adap, gi2c);
+	gi2c->adap.dev.parent = &pdev->dev;
+	gi2c->adap.dev.of_node = pdev->dev.of_node;
+	strlcpy(gi2c->adap.name, "Geni-I2C", sizeof(gi2c->adap.name));
+
+	ret = geni_se_resources_on(&gi2c->se);
+	if (ret) {
+		dev_err(&pdev->dev, "Error turning on resources %d\n", ret);
+		return ret;
+	}
+	proto = geni_se_read_proto(&gi2c->se);
+	tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se);
+	if (proto != GENI_SE_I2C) {
+		dev_err(&pdev->dev, "Invalid proto %d\n", proto);
+		geni_se_resources_off(&gi2c->se);
+		return -ENXIO;
+	}
+	gi2c->tx_wm = tx_depth - 1;
+	geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth);
+	geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW,
+							true, true, true);
+	ret = geni_se_resources_off(&gi2c->se);
+	if (ret) {
+		dev_err(&pdev->dev, "Error turning off resources %d\n", ret);
+		return ret;
+	}
+
+	dev_dbg(&pdev->dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth);
+
+	ret = i2c_add_adapter(&gi2c->adap);
+	if (ret) {
+		dev_err(&pdev->dev, "Error adding i2c adapter %d\n", ret);
+		return ret;
+	}
+
+	gi2c->suspended = 1;
+	pm_runtime_set_suspended(gi2c->se.dev);
+	pm_runtime_set_autosuspend_delay(gi2c->se.dev, I2C_AUTO_SUSPEND_DELAY);
+	pm_runtime_use_autosuspend(gi2c->se.dev);
+	pm_runtime_enable(gi2c->se.dev);
+
+	return 0;
+}
+
+static int geni_i2c_remove(struct platform_device *pdev)
+{
+	struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(gi2c->se.dev);
+	i2c_del_adapter(&gi2c->adap);
+	return 0;
+}
+
+static int __maybe_unused geni_i2c_runtime_suspend(struct device *dev)
+{
+	int ret;
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	disable_irq(gi2c->irq);
+	ret = geni_se_resources_off(&gi2c->se);
+	if (ret) {
+		enable_irq(gi2c->irq);
+		return ret;
+
+	} else {
+		gi2c->suspended = 1;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused geni_i2c_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	ret = geni_se_resources_on(&gi2c->se);
+	if (ret)
+		return ret;
+
+	enable_irq(gi2c->irq);
+	gi2c->suspended = 0;
+	return 0;
+}
+
+static int __maybe_unused geni_i2c_suspend_noirq(struct device *dev)
+{
+	struct geni_i2c_dev *gi2c = dev_get_drvdata(dev);
+
+	if (!gi2c->suspended) {
+		geni_i2c_runtime_suspend(dev);
+		pm_runtime_disable(dev);
+		pm_runtime_set_suspended(dev);
+		pm_runtime_enable(dev);
+	}
+	return 0;
+}
+
+static const struct dev_pm_ops geni_i2c_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(geni_i2c_suspend_noirq, NULL)
+	SET_RUNTIME_PM_OPS(geni_i2c_runtime_suspend, geni_i2c_runtime_resume,
+									NULL)
+};
+
+static const struct of_device_id geni_i2c_dt_match[] = {
+	{ .compatible = "qcom,geni-i2c" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, geni_i2c_dt_match);
+
+static struct platform_driver geni_i2c_driver = {
+	.probe  = geni_i2c_probe,
+	.remove = geni_i2c_remove,
+	.driver = {
+		.name = "geni_i2c",
+		.pm = &geni_i2c_pm_ops,
+		.of_match_table = geni_i2c_dt_match,
+	},
+};
+
+module_platform_driver(geni_i2c_driver);
+
+MODULE_DESCRIPTION("I2C Controller Driver for GENI based QUP cores");
+MODULE_LICENSE("GPL v2");

drivers/i2c/busses/i2c-rcar.c

@@ -19,6 +19,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */
+#include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
@@ -112,9 +113,10 @@
 #define ID_ARBLOST	(1 << 3)
 #define ID_NACK		(1 << 4)
 /* persistent flags */
-#define ID_P_NO_RXDMA	(1 << 30) /* HW forbids RXDMA sometimes */
+#define ID_P_REP_AFTER_RD	BIT(29)
-#define ID_P_PM_BLOCKED	(1 << 31)
+#define ID_P_NO_RXDMA		BIT(30) /* HW forbids RXDMA sometimes */
-#define ID_P_MASK	(ID_P_PM_BLOCKED | ID_P_NO_RXDMA)
+#define ID_P_PM_BLOCKED		BIT(31)
+#define ID_P_MASK		GENMASK(31, 29)
 
 enum rcar_i2c_type {
 	I2C_RCAR_GEN1,
@@ -183,8 +185,6 @@ static void rcar_i2c_set_scl(struct i2c_adapter *adap, int val)
 	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
 };
 
-/* No get_sda, because the HW only reports its bus free logic, not SDA itself */
-
 static void rcar_i2c_set_sda(struct i2c_adapter *adap, int val)
 {
 	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
@@ -197,10 +197,19 @@ static void rcar_i2c_set_sda(struct i2c_adapter *adap, int val)
 	rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
 };
 
+static int rcar_i2c_get_bus_free(struct i2c_adapter *adap)
+{
+	struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !(rcar_i2c_read(priv, ICMCR) & FSDA);
+
+};
+
 static struct i2c_bus_recovery_info rcar_i2c_bri = {
 	.get_scl = rcar_i2c_get_scl,
 	.set_scl = rcar_i2c_set_scl,
 	.set_sda = rcar_i2c_set_sda,
+	.get_bus_free = rcar_i2c_get_bus_free,
 	.recover_bus = i2c_generic_scl_recovery,
 };
 static void rcar_i2c_init(struct rcar_i2c_priv *priv)
@@ -215,7 +224,7 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv)
 
 static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 {
-	int i, ret;
+	int i;
 
 	for (i = 0; i < LOOP_TIMEOUT; i++) {
 		/* make sure that bus is not busy */
@@ -226,13 +235,7 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
 
 	/* Waiting did not help, try to recover */
 	priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
-	ret = i2c_recover_bus(&priv->adap);
+	return i2c_recover_bus(&priv->adap);
-
-	/* No failure when recovering, so check bus busy bit again */
-	if (ret == 0)
-		ret = (rcar_i2c_read(priv, ICMCR) & FSDA) ? -EBUSY : 0;
-
-	return ret;
 }
 
 static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t)
@@ -343,7 +346,10 @@ static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
 		rcar_i2c_write(priv, ICMSR, 0);
 		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
 	} else {
-		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
+		if (priv->flags & ID_P_REP_AFTER_RD)
+			priv->flags &= ~ID_P_REP_AFTER_RD;
+		else
+			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
 		rcar_i2c_write(priv, ICMSR, 0);
 	}
 	rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
@@ -548,15 +554,15 @@ static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
 		priv->pos++;
 	}
 
-	/*
+	/* If next received data is the _LAST_, go to new phase. */
-	 * If next received data is the _LAST_, go to STOP phase. Might be
+	if (priv->pos + 1 == msg->len) {
-	 * overwritten by REP START when setting up a new msg. Not elegant
+		if (priv->flags & ID_LAST_MSG) {
-	 * but the only stable sequence for REP START I have found so far.
+			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
-	 * If you want to change this code, make sure sending one transfer with
+		} else {
-	 * four messages (WR-RD-WR-RD) works!
+			rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
-	 */
+			priv->flags |= ID_P_REP_AFTER_RD;
-	if (priv->pos + 1 >= msg->len)
+		}
-		rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
+	}
 
 	if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))
 		rcar_i2c_next_msg(priv);
@@ -624,9 +630,11 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
 	struct rcar_i2c_priv *priv = ptr;
 	u32 msr, val;
 
-	/* Clear START or STOP as soon as we can */
+	/* Clear START or STOP immediately, except for REPSTART after read */
-	val = rcar_i2c_read(priv, ICMCR);
+	if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) {
-	rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA);
+		val = rcar_i2c_read(priv, ICMCR);
+		rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA);
+	}
 
 	msr = rcar_i2c_read(priv, ICMSR);
 
@@ -795,14 +803,8 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 	if (ret < 0)
 		goto out;
 
-	for (i = 0; i < num; i++) {
+	for (i = 0; i < num; i++)
-		/* This HW can't send STOP after address phase */
-		if (msgs[i].len == 0) {
-			ret = -EOPNOTSUPP;
-			goto out;
-		}
 		rcar_i2c_request_dma(priv, msgs + i);
-	}
 
 	/* init first message */
 	priv->msg = msgs;
@@ -889,6 +891,10 @@ static const struct i2c_algorithm rcar_i2c_algo = {
 	.unreg_slave	= rcar_unreg_slave,
 };
 
+static const struct i2c_adapter_quirks rcar_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static const struct of_device_id rcar_i2c_dt_ids[] = {
 	{ .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
 	{ .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
@@ -942,6 +948,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	adap->dev.parent = dev;
 	adap->dev.of_node = dev->of_node;
 	adap->bus_recovery_info = &rcar_i2c_bri;
+	adap->quirks = &rcar_i2c_quirks;
 	i2c_set_adapdata(adap, priv);
 	strlcpy(adap->name, pdev->name, sizeof(adap->name));
 

drivers/i2c/busses/i2c-s3c2410.c

@@ -919,9 +919,9 @@ static int s3c24xx_i2c_cpufreq_transition(struct notifier_block *nb,
 
 	if ((val == CPUFREQ_POSTCHANGE && delta_f < 0) ||
 	    (val == CPUFREQ_PRECHANGE && delta_f > 0)) {
-		i2c_lock_adapter(&i2c->adap);
+		i2c_lock_bus(&i2c->adap, I2C_LOCK_ROOT_ADAPTER);
 		ret = s3c24xx_i2c_clockrate(i2c, &got);
-		i2c_unlock_adapter(&i2c->adap);
+		i2c_unlock_bus(&i2c->adap, I2C_LOCK_ROOT_ADAPTER);
 
 		if (ret < 0)
 			dev_err(i2c->dev, "cannot find frequency (%d)\n", ret);

drivers/i2c/busses/i2c-sh_mobile.c

@@ -613,11 +613,6 @@ static void sh_mobile_i2c_xfer_dma(struct sh_mobile_i2c_data *pd)
 static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
 		    bool do_init)
 {
-	if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
-		dev_err(pd->dev, "Unsupported zero length i2c read\n");
-		return -EOPNOTSUPP;
-	}
-
 	if (do_init) {
 		/* Initialize channel registers */
 		iic_wr(pd, ICCR, ICCR_SCP);
@@ -758,6 +753,10 @@ static const struct i2c_algorithm sh_mobile_i2c_algorithm = {
 	.master_xfer	= sh_mobile_i2c_xfer,
 };
 
+static const struct i2c_adapter_quirks sh_mobile_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN_READ,
+};
+
 /*
  * r8a7740 chip has lasting errata on I2C I/O pad reset.
  * this is work-around for it.
@@ -925,6 +924,7 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
 
 	adap->owner = THIS_MODULE;
 	adap->algo = &sh_mobile_i2c_algorithm;
+	adap->quirks = &sh_mobile_i2c_quirks;
 	adap->dev.parent = &dev->dev;
 	adap->retries = 5;
 	adap->nr = dev->id;

drivers/i2c/busses/i2c-sprd.c

@@ -590,9 +590,9 @@ static int __maybe_unused sprd_i2c_suspend_noirq(struct device *pdev)
 {
 	struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
 
-	i2c_lock_adapter(&i2c_dev->adap);
+	i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
 	i2c_dev->is_suspended = true;
-	i2c_unlock_adapter(&i2c_dev->adap);
+	i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
 
 	return pm_runtime_force_suspend(pdev);
 }
@@ -601,9 +601,9 @@ static int __maybe_unused sprd_i2c_resume_noirq(struct device *pdev)
 {
 	struct sprd_i2c *i2c_dev = dev_get_drvdata(pdev);
 
-	i2c_lock_adapter(&i2c_dev->adap);
+	i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
 	i2c_dev->is_suspended = false;
-	i2c_unlock_adapter(&i2c_dev->adap);
+	i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
 
 	return pm_runtime_force_resume(pdev);
 }

drivers/i2c/busses/i2c-stu300.c

@@ -673,12 +673,6 @@ static int stu300_xfer_msg(struct i2c_adapter *adap,
 			msg->addr, msg->len, msg->flags, stop);
 	}
 
-	/* Zero-length messages are not supported by this hardware */
-	if (msg->len == 0) {
-		ret = -EINVAL;
-		goto exit_disable;
-	}
-
 	/*
 	 * For some reason, sending the address sometimes fails when running
 	 * on  the 13 MHz clock. No interrupt arrives. This is a work around,
@@ -863,6 +857,10 @@ static const struct i2c_algorithm stu300_algo = {
 	.functionality	= stu300_func,
 };
 
+static const struct i2c_adapter_quirks stu300_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static int stu300_probe(struct platform_device *pdev)
 {
 	struct stu300_dev *dev;
@@ -920,6 +918,8 @@ static int stu300_probe(struct platform_device *pdev)
 	adap->algo = &stu300_algo;
 	adap->dev.parent = &pdev->dev;
 	adap->dev.of_node = pdev->dev.of_node;
+	adap->quirks = &stu300_quirks;
+
 	i2c_set_adapdata(adap, dev);
 
 	/* i2c device drivers may be active on return from add_adapter() */

drivers/i2c/busses/i2c-tegra.c

@@ -115,6 +115,18 @@
 
 #define I2C_CONFIG_LOAD_TIMEOUT			1000000
 
+#define I2C_MST_FIFO_CONTROL			0x0b4
+#define I2C_MST_FIFO_CONTROL_RX_FLUSH		BIT(0)
+#define I2C_MST_FIFO_CONTROL_TX_FLUSH		BIT(1)
+#define I2C_MST_FIFO_CONTROL_RX_TRIG(x)		(((x) - 1) <<  4)
+#define I2C_MST_FIFO_CONTROL_TX_TRIG(x)		(((x) - 1) << 16)
+
+#define I2C_MST_FIFO_STATUS			0x0b8
+#define I2C_MST_FIFO_STATUS_RX_MASK		0xff
+#define I2C_MST_FIFO_STATUS_RX_SHIFT		0
+#define I2C_MST_FIFO_STATUS_TX_MASK		0xff0000
+#define I2C_MST_FIFO_STATUS_TX_SHIFT		16
+
 /*
  * msg_end_type: The bus control which need to be send at end of transfer.
  * @MSG_END_STOP: Send stop pulse at end of transfer.
@@ -154,6 +166,7 @@ struct tegra_i2c_hw_feature {
 	u16 clk_divisor_fast_plus_mode;
 	bool has_multi_master_mode;
 	bool has_slcg_override_reg;
+	bool has_mst_fifo;
 };
 
 /**
@@ -266,13 +279,24 @@ static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
 static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
 {
 	unsigned long timeout = jiffies + HZ;
-	u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
+	unsigned int offset;
+	u32 mask, val;
 
-	val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
+	if (i2c_dev->hw->has_mst_fifo) {
-	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+		mask = I2C_MST_FIFO_CONTROL_TX_FLUSH |
+		       I2C_MST_FIFO_CONTROL_RX_FLUSH;
+		offset = I2C_MST_FIFO_CONTROL;
+	} else {
+		mask = I2C_FIFO_CONTROL_TX_FLUSH |
+		       I2C_FIFO_CONTROL_RX_FLUSH;
+		offset = I2C_FIFO_CONTROL;
+	}
 
-	while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
+	val = i2c_readl(i2c_dev, offset);
-		(I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
+	val |= mask;
+	i2c_writel(i2c_dev, val, offset);
+
+	while (i2c_readl(i2c_dev, offset) & mask) {
 		if (time_after(jiffies, timeout)) {
 			dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
 			return -ETIMEDOUT;
@@ -290,9 +314,15 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
 	int words_to_transfer;
 
-	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+	if (i2c_dev->hw->has_mst_fifo) {
-	rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
+		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
-		I2C_FIFO_STATUS_RX_SHIFT;
+		rx_fifo_avail = (val & I2C_MST_FIFO_STATUS_RX_MASK) >>
+			I2C_MST_FIFO_STATUS_RX_SHIFT;
+	} else {
+		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+		rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
+			I2C_FIFO_STATUS_RX_SHIFT;
+	}
 
 	/* Rounds down to not include partial word at the end of buf */
 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
@@ -321,6 +351,7 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
 	BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
 	i2c_dev->msg_buf_remaining = buf_remaining;
 	i2c_dev->msg_buf = buf;
+
 	return 0;
 }
 
@@ -332,9 +363,15 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
 	size_t buf_remaining = i2c_dev->msg_buf_remaining;
 	int words_to_transfer;
 
-	val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+	if (i2c_dev->hw->has_mst_fifo) {
-	tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
+		val = i2c_readl(i2c_dev, I2C_MST_FIFO_STATUS);
-		I2C_FIFO_STATUS_TX_SHIFT;
+		tx_fifo_avail = (val & I2C_MST_FIFO_STATUS_TX_MASK) >>
+			I2C_MST_FIFO_STATUS_TX_SHIFT;
+	} else {
+		val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
+		tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
+			I2C_FIFO_STATUS_TX_SHIFT;
+	}
 
 	/* Rounds down to not include partial word at the end of buf */
 	words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
@@ -516,9 +553,15 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 		i2c_writel(i2c_dev, 0x00, I2C_SL_ADDR2);
 	}
 
-	val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
+	if (i2c_dev->hw->has_mst_fifo) {
-		0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
+		val = I2C_MST_FIFO_CONTROL_TX_TRIG(8) |
-	i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+		      I2C_MST_FIFO_CONTROL_RX_TRIG(1);
+		i2c_writel(i2c_dev, val, I2C_MST_FIFO_CONTROL);
+	} else {
+		val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
+			0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
+		i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
+	}
 
 	err = tegra_i2c_flush_fifos(i2c_dev);
 	if (err)
@@ -802,6 +845,7 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
 	.has_config_load_reg = false,
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
+	.has_mst_fifo = false,
 };
 
 static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
@@ -814,6 +858,7 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
 	.has_config_load_reg = false,
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
+	.has_mst_fifo = false,
 };
 
 static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
@@ -826,6 +871,7 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
 	.has_config_load_reg = false,
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = false,
+	.has_mst_fifo = false,
 };
 
 static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
@@ -838,6 +884,7 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
 	.has_config_load_reg = true,
 	.has_multi_master_mode = false,
 	.has_slcg_override_reg = true,
+	.has_mst_fifo = false,
 };
 
 static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
@@ -850,10 +897,25 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
 	.has_config_load_reg = true,
 	.has_multi_master_mode = true,
 	.has_slcg_override_reg = true,
+	.has_mst_fifo = false,
+};
+
+static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
+	.has_continue_xfer_support = true,
+	.has_per_pkt_xfer_complete_irq = true,
+	.has_single_clk_source = true,
+	.clk_divisor_hs_mode = 1,
+	.clk_divisor_std_fast_mode = 0x19,
+	.clk_divisor_fast_plus_mode = 0x10,
+	.has_config_load_reg = true,
+	.has_multi_master_mode = true,
+	.has_slcg_override_reg = true,
+	.has_mst_fifo = true,
 };
 
 /* Match table for of_platform binding */
 static const struct of_device_id tegra_i2c_of_match[] = {
+	{ .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
 	{ .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
 	{ .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
 	{ .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },

drivers/i2c/busses/i2c-xlr.c

@@ -173,9 +173,6 @@ static int xlr_i2c_tx(struct xlr_i2c_private *priv,  u16 len,
 	u8 offset;
 	u32 xfer;
 
-	if (!len)
-		return -EOPNOTSUPP;
-
 	offset = buf[0];
 	xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset);
 	xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr);
@@ -241,9 +238,6 @@ static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr)
 	unsigned long timeout, stoptime, checktime;
 	int nbytes, timedout;
 
-	if (!len)
-		return -EOPNOTSUPP;
-
 	xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG,
 			XLR_I2C_CFG_NOADDR | priv->cfg->cfg_extra);
 	xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1);
@@ -340,6 +334,10 @@ static const struct i2c_algorithm xlr_i2c_algo = {
 	.functionality	= xlr_func,
 };
 
+static const struct i2c_adapter_quirks xlr_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
 static const struct xlr_i2c_config xlr_i2c_config_default = {
 	.status_busy	= XLR_I2C_BUS_BUSY,
 	.cfg_extra	= 0,
@@ -427,6 +425,7 @@ static int xlr_i2c_probe(struct platform_device *pdev)
 	priv->adap.owner	= THIS_MODULE;
 	priv->adap.algo_data	= priv;
 	priv->adap.algo		= &xlr_i2c_algo;
+	priv->adap.quirks	= &xlr_i2c_quirks;
 	priv->adap.nr		= pdev->id;
 	priv->adap.class	= I2C_CLASS_HWMON;
 	snprintf(priv->adap.name, sizeof(priv->adap.name), "xlr-i2c");

drivers/i2c/i2c-core-acpi.c

@@ -453,8 +453,12 @@ static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
 		else
 			dev_err(&client->adapter->dev, "i2c read %d bytes from client@%#x starting at reg %#x failed, error: %d\n",
 				data_len, client->addr, cmd, ret);
-	} else {
+	/* 2 transfers must have completed successfully */
+	} else if (ret == 2) {
 		memcpy(data, buffer, data_len);
+		ret = 0;
+	} else {
+		ret = -EIO;
 	}
 
 	kfree(buffer);
@@ -482,11 +486,16 @@ static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
 	msgs[0].buf = buffer;
 
 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
-	if (ret < 0)
-		dev_err(&client->adapter->dev, "i2c write failed\n");
 
 	kfree(buffer);
-	return ret;
+
+	if (ret < 0) {
+		dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret);
+		return ret;
+	}
+
+	/* 1 transfer must have completed successfully */
+	return (ret == 1) ? 0 : -EIO;
 }
 
 static acpi_status
@@ -590,8 +599,6 @@ i2c_acpi_space_handler(u32 function, acpi_physical_address command,
 		if (action == ACPI_READ) {
 			status = acpi_gsb_i2c_read_bytes(client, command,
 					gsb->data, info->access_length);
-			if (status > 0)
-				status = 0;
 		} else {
 			status = acpi_gsb_i2c_write_bytes(client, command,
 					gsb->data, info->access_length);

drivers/i2c/i2c-core-base.c

@@ -158,6 +158,22 @@ static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
 	gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val);
 }
 
+static int i2c_generic_bus_free(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	int ret = -EOPNOTSUPP;
+
+	if (bri->get_bus_free)
+		ret = bri->get_bus_free(adap);
+	else if (bri->get_sda)
+		ret = bri->get_sda(adap);
+
+	if (ret < 0)
+		return ret;
+
+	return ret ? 0 : -EBUSY;
+}
+
 /*
  * We are generating clock pulses. ndelay() determines durating of clk pulses.
  * We will generate clock with rate 100 KHz and so duration of both clock levels
@@ -169,21 +185,28 @@ static void set_sda_gpio_value(struct i2c_adapter *adap, int val)
 int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 {
 	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-	int i = 0, val = 1, ret = 0;
+	int i = 0, scl = 1, ret;
 
 	if (bri->prepare_recovery)
 		bri->prepare_recovery(adap);
 
-	bri->set_scl(adap, val);
+	/*
+	 * If we can set SDA, we will always create a STOP to ensure additional
+	 * pulses will do no harm. This is achieved by letting SDA follow SCL
+	 * half a cycle later. Check the 'incomplete_write_byte' fault injector
+	 * for details.
+	 */
+	bri->set_scl(adap, scl);
+	ndelay(RECOVERY_NDELAY / 2);
 	if (bri->set_sda)
-		bri->set_sda(adap, 1);
+		bri->set_sda(adap, scl);
-	ndelay(RECOVERY_NDELAY);
+	ndelay(RECOVERY_NDELAY / 2);
 
 	/*
 	 * By this time SCL is high, as we need to give 9 falling-rising edges
 	 */
 	while (i++ < RECOVERY_CLK_CNT * 2) {
-		if (val) {
+		if (scl) {
 			/* SCL shouldn't be low here */
 			if (!bri->get_scl(adap)) {
 				dev_err(&adap->dev,
@@ -191,40 +214,26 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
 				ret = -EBUSY;
 				break;
 			}
-			/* Break if SDA is high */
-			if (bri->get_sda && bri->get_sda(adap))
-				break;
 		}
 
-		val = !val;
+		scl = !scl;
-		bri->set_scl(adap, val);
+		bri->set_scl(adap, scl);
-
+		/* Creating STOP again, see above */
-		/*
-		 * If we can set SDA, we will always create STOP here to ensure
-		 * the additional pulses will do no harm. This is achieved by
-		 * letting SDA follow SCL half a cycle later.
-		 */
 		ndelay(RECOVERY_NDELAY / 2);
 		if (bri->set_sda)
-			bri->set_sda(adap, val);
+			bri->set_sda(adap, scl);
 		ndelay(RECOVERY_NDELAY / 2);
+
+		if (scl) {
+			ret = i2c_generic_bus_free(adap);
+			if (ret == 0)
+				break;
+		}
 	}
 
-	/* check if recovery actually succeeded */
+	/* If we can't check bus status, assume recovery worked */
-	if (bri->get_sda && !bri->get_sda(adap))
+	if (ret == -EOPNOTSUPP)
-		ret = -EBUSY;
+		ret = 0;
-
-	/* If all went well, send STOP for a sane bus state. */
-	if (ret == 0 && bri->set_sda) {
-		bri->set_scl(adap, 0);
-		ndelay(RECOVERY_NDELAY / 2);
-		bri->set_sda(adap, 0);
-		ndelay(RECOVERY_NDELAY / 2);
-		bri->set_scl(adap, 1);
-		ndelay(RECOVERY_NDELAY / 2);
-		bri->set_sda(adap, 1);
-		ndelay(RECOVERY_NDELAY / 2);
-	}
 
 	if (bri->unprepare_recovery)
 		bri->unprepare_recovery(adap);
@@ -274,6 +283,10 @@ static void i2c_init_recovery(struct i2c_adapter *adap)
 			err_str = "no {get|set}_scl() found";
 			goto err;
 		}
+		if (!bri->set_sda && !bri->get_sda) {
+			err_str = "either get_sda() or set_sda() needed";
+			goto err;
+		}
 	}
 
 	return;
@@ -1563,6 +1576,8 @@ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_de
 	ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns);
 	if (ret && use_defaults)
 		t->sda_fall_ns = t->scl_fall_ns;
+
+	device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns);
 }
 EXPORT_SYMBOL_GPL(i2c_parse_fw_timings);
 
@@ -1826,9 +1841,15 @@ static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs,
 		if (msgs[i].flags & I2C_M_RD) {
 			if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
 				return i2c_quirk_error(adap, &msgs[i], "msg too long");
+
+			if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0)
+				return i2c_quirk_error(adap, &msgs[i], "no zero length");
 		} else {
 			if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
 				return i2c_quirk_error(adap, &msgs[i], "msg too long");
+
+			if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0)
+				return i2c_quirk_error(adap, &msgs[i], "no zero length");
 		}
 	}
 

drivers/i2c/i2c-core-slave.c

@@ -47,9 +47,9 @@ int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
 
 	client->slave_cb = slave_cb;
 
-	i2c_lock_adapter(client->adapter);
+	i2c_lock_bus(client->adapter, I2C_LOCK_ROOT_ADAPTER);
 	ret = client->adapter->algo->reg_slave(client);
-	i2c_unlock_adapter(client->adapter);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	if (ret) {
 		client->slave_cb = NULL;
@@ -69,9 +69,9 @@ int i2c_slave_unregister(struct i2c_client *client)
 		return -EOPNOTSUPP;
 	}
 
-	i2c_lock_adapter(client->adapter);
+	i2c_lock_bus(client->adapter, I2C_LOCK_ROOT_ADAPTER);
 	ret = client->adapter->algo->unreg_slave(client);
-	i2c_unlock_adapter(client->adapter);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	if (ret == 0)
 		client->slave_cb = NULL;

drivers/i2c/i2c-mux.c

@@ -87,8 +87,8 @@ static int __i2c_mux_smbus_xfer(struct i2c_adapter *adap,
 
 	ret = muxc->select(muxc, priv->chan_id);
 	if (ret >= 0)
-		ret = parent->algo->smbus_xfer(parent, addr, flags,
+		ret = __i2c_smbus_xfer(parent, addr, flags,
-					read_write, command, size, data);
+				       read_write, command, size, data);
 	if (muxc->deselect)
 		muxc->deselect(muxc, priv->chan_id);
 

drivers/i2c/muxes/i2c-mux-mlxcpld.c

@@ -94,31 +94,11 @@ static int mlxcpld_mux_reg_write(struct i2c_adapter *adap,
 				 struct i2c_client *client, u8 val)
 {
 	struct mlxcpld_mux_plat_data *pdata = dev_get_platdata(&client->dev);
-	int ret = -ENODEV;
+	union i2c_smbus_data data = { .byte = val };
 
-	if (adap->algo->master_xfer) {
+	return __i2c_smbus_xfer(adap, client->addr, client->flags,
-		struct i2c_msg msg;
+				I2C_SMBUS_WRITE, pdata->sel_reg_addr,
-		u8 msgbuf[] = {pdata->sel_reg_addr, val};
+				I2C_SMBUS_BYTE_DATA, &data);
-
-		msg.addr = client->addr;
-		msg.flags = 0;
-		msg.len = 2;
-		msg.buf = msgbuf;
-		ret = __i2c_transfer(adap, &msg, 1);
-
-		if (ret >= 0 && ret != 1)
-			ret = -EREMOTEIO;
-	} else if (adap->algo->smbus_xfer) {
-		union i2c_smbus_data data;
-
-		data.byte = val;
-		ret = adap->algo->smbus_xfer(adap, client->addr,
-					     client->flags, I2C_SMBUS_WRITE,
-					     pdata->sel_reg_addr,
-					     I2C_SMBUS_BYTE_DATA, &data);
-	}
-
-	return ret;
 }
 
 static int mlxcpld_mux_select_chan(struct i2c_mux_core *muxc, u32 chan)

drivers/i2c/muxes/i2c-mux-pca9541.c

@@ -99,31 +99,11 @@ MODULE_DEVICE_TABLE(of, pca9541_of_match);
 static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
 {
 	struct i2c_adapter *adap = client->adapter;
-	int ret;
+	union i2c_smbus_data data = { .byte = val };
 
-	if (adap->algo->master_xfer) {
+	return __i2c_smbus_xfer(adap, client->addr, client->flags,
-		struct i2c_msg msg;
+				I2C_SMBUS_WRITE, command,
-		char buf[2];
+				I2C_SMBUS_BYTE_DATA, &data);
-
-		msg.addr = client->addr;
-		msg.flags = 0;
-		msg.len = 2;
-		buf[0] = command;
-		buf[1] = val;
-		msg.buf = buf;
-		ret = __i2c_transfer(adap, &msg, 1);
-	} else {
-		union i2c_smbus_data data;
-
-		data.byte = val;
-		ret = adap->algo->smbus_xfer(adap, client->addr,
-					     client->flags,
-					     I2C_SMBUS_WRITE,
-					     command,
-					     I2C_SMBUS_BYTE_DATA, &data);
-	}
-
-	return ret;
 }
 
 /*
@@ -133,41 +113,14 @@ static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
 static int pca9541_reg_read(struct i2c_client *client, u8 command)
 {
 	struct i2c_adapter *adap = client->adapter;
+	union i2c_smbus_data data;
 	int ret;
-	u8 val;
 
-	if (adap->algo->master_xfer) {
+	ret = __i2c_smbus_xfer(adap, client->addr, client->flags,
-		struct i2c_msg msg[2] = {
+			       I2C_SMBUS_READ, command,
-			{
+			       I2C_SMBUS_BYTE_DATA, &data);
-				.addr = client->addr,
-				.flags = 0,
-				.len = 1,
-				.buf = &command
-			},
-			{
-				.addr = client->addr,
-				.flags = I2C_M_RD,
-				.len = 1,
-				.buf = &val
-			}
-		};
-		ret = __i2c_transfer(adap, msg, 2);
-		if (ret == 2)
-			ret = val;
-		else if (ret >= 0)
-			ret = -EIO;
-	} else {
-		union i2c_smbus_data data;
 
-		ret = adap->algo->smbus_xfer(adap, client->addr,
+	return ret ?: data.byte;
-					     client->flags,
-					     I2C_SMBUS_READ,
-					     command,
-					     I2C_SMBUS_BYTE_DATA, &data);
-		if (!ret)
-			ret = data.byte;
-	}
-	return ret;
 }
 
 /*
@@ -345,11 +298,11 @@ static int pca9541_probe(struct i2c_client *client,
 
 	/*
 	 * I2C accesses are unprotected here.
-	 * We have to lock the adapter before releasing the bus.
+	 * We have to lock the I2C segment before releasing the bus.
 	 */
-	i2c_lock_adapter(adap);
+	i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
 	pca9541_release_bus(client);
-	i2c_unlock_adapter(adap);
+	i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
 
 	/* Create mux adapter */
 

drivers/i2c/muxes/i2c-mux-pca954x.c

@@ -220,30 +220,11 @@ MODULE_DEVICE_TABLE(of, pca954x_of_match);
 static int pca954x_reg_write(struct i2c_adapter *adap,
 			     struct i2c_client *client, u8 val)
 {
-	int ret = -ENODEV;
+	union i2c_smbus_data dummy;
 
-	if (adap->algo->master_xfer) {
+	return __i2c_smbus_xfer(adap, client->addr, client->flags,
-		struct i2c_msg msg;
+				I2C_SMBUS_WRITE, val,
-		char buf[1];
+				I2C_SMBUS_BYTE, &dummy);
-
-		msg.addr = client->addr;
-		msg.flags = 0;
-		msg.len = 1;
-		buf[0] = val;
-		msg.buf = buf;
-		ret = __i2c_transfer(adap, &msg, 1);
-
-		if (ret >= 0 && ret != 1)
-			ret = -EREMOTEIO;
-	} else {
-		union i2c_smbus_data data;
-		ret = adap->algo->smbus_xfer(adap, client->addr,
-					     client->flags,
-					     I2C_SMBUS_WRITE,
-					     val, I2C_SMBUS_BYTE, &data);
-	}
-
-	return ret;
 }
 
 static int pca954x_select_chan(struct i2c_mux_core *muxc, u32 chan)
@@ -368,7 +349,8 @@ static int pca954x_probe(struct i2c_client *client,
 {
 	struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
 	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
-	struct device_node *of_node = client->dev.of_node;
+	struct device *dev = &client->dev;
+	struct device_node *np = dev->of_node;
 	bool idle_disconnect_dt;
 	struct gpio_desc *gpio;
 	int num, force, class;
@@ -379,8 +361,7 @@ static int pca954x_probe(struct i2c_client *client,
 	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
 		return -ENODEV;
 
-	muxc = i2c_mux_alloc(adap, &client->dev,
+	muxc = i2c_mux_alloc(adap, dev, PCA954X_MAX_NCHANS, sizeof(*data), 0,
-			     PCA954X_MAX_NCHANS, sizeof(*data), 0,
 			     pca954x_select_chan, pca954x_deselect_mux);
 	if (!muxc)
 		return -ENOMEM;
@@ -390,7 +371,7 @@ static int pca954x_probe(struct i2c_client *client,
 	data->client = client;
 
 	/* Reset the mux if a reset GPIO is specified. */
-	gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_HIGH);
+	gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(gpio))
 		return PTR_ERR(gpio);
 	if (gpio) {
@@ -400,7 +381,7 @@ static int pca954x_probe(struct i2c_client *client,
 		udelay(1);
 	}
 
-	data->chip = of_device_get_match_data(&client->dev);
+	data->chip = of_device_get_match_data(dev);
 	if (!data->chip)
 		data->chip = &chips[id->driver_data];
 
@@ -414,8 +395,7 @@ static int pca954x_probe(struct i2c_client *client,
 		if (!ret &&
 		    (id.manufacturer_id != data->chip->id.manufacturer_id ||
 		     id.part_id != data->chip->id.part_id)) {
-			dev_warn(&client->dev,
+			dev_warn(dev, "unexpected device id %03x-%03x-%x\n",
-				 "unexpected device id %03x-%03x-%x\n",
 				 id.manufacturer_id, id.part_id,
 				 id.die_revision);
 			return -ENODEV;
@@ -427,14 +407,14 @@ static int pca954x_probe(struct i2c_client *client,
 	 * initializes the mux to disconnected state.
 	 */
 	if (i2c_smbus_write_byte(client, 0) < 0) {
-		dev_warn(&client->dev, "probe failed\n");
+		dev_warn(dev, "probe failed\n");
 		return -ENODEV;
 	}
 
 	data->last_chan = 0;		   /* force the first selection */
 
-	idle_disconnect_dt = of_node &&
+	idle_disconnect_dt = np &&
-		of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
+		of_property_read_bool(np, "i2c-mux-idle-disconnect");
 
 	ret = pca954x_irq_setup(muxc);
 	if (ret)
@@ -465,7 +445,7 @@ static int pca954x_probe(struct i2c_client *client,
 	}
 
 	if (data->irq) {
-		ret = devm_request_threaded_irq(&client->dev, data->client->irq,
+		ret = devm_request_threaded_irq(dev, data->client->irq,
 						NULL, pca954x_irq_handler,
 						IRQF_ONESHOT | IRQF_SHARED,
 						"pca954x", data);
@@ -473,8 +453,7 @@ static int pca954x_probe(struct i2c_client *client,
 			goto fail_cleanup;
 	}
 
-	dev_info(&client->dev,
+	dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
-		 "registered %d multiplexed busses for I2C %s %s\n",
 		 num, data->chip->muxtype == pca954x_ismux
 				? "mux" : "switch", client->name);
 

drivers/iio/temperature/mlx90614.c

@@ -433,11 +433,11 @@ static int mlx90614_wakeup(struct mlx90614_data *data)
 
 	dev_dbg(&data->client->dev, "Requesting wake-up");
 
-	i2c_lock_adapter(data->client->adapter);
+	i2c_lock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
 	gpiod_direction_output(data->wakeup_gpio, 0);
 	msleep(MLX90614_TIMING_WAKEUP);
 	gpiod_direction_input(data->wakeup_gpio);
-	i2c_unlock_adapter(data->client->adapter);
+	i2c_unlock_bus(data->client->adapter, I2C_LOCK_ROOT_ADAPTER);
 
 	data->ready_timestamp = jiffies +
 			msecs_to_jiffies(MLX90614_TIMING_STARTUP);

drivers/input/touchscreen/rohm_bu21023.c

@@ -304,7 +304,7 @@ static int rohm_i2c_burst_read(struct i2c_client *client, u8 start, void *buf,
 	msg[1].len = len;
 	msg[1].buf = buf;
 
-	i2c_lock_adapter(adap);
+	i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
 
 	for (i = 0; i < 2; i++) {
 		if (__i2c_transfer(adap, &msg[i], 1) < 0) {
@@ -313,7 +313,7 @@ static int rohm_i2c_burst_read(struct i2c_client *client, u8 start, void *buf,
 		}
 	}
 
-	i2c_unlock_adapter(adap);
+	i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);
 
 	return ret;
 }

drivers/media/dvb-frontends/af9013.c

@@ -1311,10 +1311,10 @@ static int af9013_wregs(struct i2c_client *client, u8 cmd, u16 reg,
 	memcpy(&buf[3], val, len);
 
 	if (lock)
-		i2c_lock_adapter(client->adapter);
+		i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = __i2c_transfer(client->adapter, msg, 1);
 	if (lock)
-		i2c_unlock_adapter(client->adapter);
+		i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	if (ret < 0) {
 		goto err;
 	} else if (ret != 1) {
@@ -1352,10 +1352,10 @@ static int af9013_rregs(struct i2c_client *client, u8 cmd, u16 reg,
 	buf[2] = cmd;
 
 	if (lock)
-		i2c_lock_adapter(client->adapter);
+		i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = __i2c_transfer(client->adapter, msg, 2);
 	if (lock)
-		i2c_unlock_adapter(client->adapter);
+		i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	if (ret < 0) {
 		goto err;
 	} else if (ret != 2) {

drivers/media/dvb-frontends/drxk_hard.c

@@ -213,7 +213,7 @@ static inline u32 log10times100(u32 value)
 
 static int drxk_i2c_lock(struct drxk_state *state)
 {
-	i2c_lock_adapter(state->i2c);
+	i2c_lock_bus(state->i2c, I2C_LOCK_SEGMENT);
 	state->drxk_i2c_exclusive_lock = true;
 
 	return 0;
@@ -224,7 +224,7 @@ static void drxk_i2c_unlock(struct drxk_state *state)
 	if (!state->drxk_i2c_exclusive_lock)
 		return;
 
-	i2c_unlock_adapter(state->i2c);
+	i2c_unlock_bus(state->i2c, I2C_LOCK_SEGMENT);
 	state->drxk_i2c_exclusive_lock = false;
 }
 

drivers/media/dvb-frontends/rtl2830.c

@@ -24,9 +24,9 @@ static int rtl2830_bulk_write(struct i2c_client *client, unsigned int reg,
 	struct rtl2830_dev *dev = i2c_get_clientdata(client);
 	int ret;
 
-	i2c_lock_adapter(client->adapter);
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = regmap_bulk_write(dev->regmap, reg, val, val_count);
-	i2c_unlock_adapter(client->adapter);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	return ret;
 }
 
@@ -36,9 +36,9 @@ static int rtl2830_update_bits(struct i2c_client *client, unsigned int reg,
 	struct rtl2830_dev *dev = i2c_get_clientdata(client);
 	int ret;
 
-	i2c_lock_adapter(client->adapter);
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = regmap_update_bits(dev->regmap, reg, mask, val);
-	i2c_unlock_adapter(client->adapter);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	return ret;
 }
 
@@ -48,9 +48,9 @@ static int rtl2830_bulk_read(struct i2c_client *client, unsigned int reg,
 	struct rtl2830_dev *dev = i2c_get_clientdata(client);
 	int ret;
 
-	i2c_lock_adapter(client->adapter);
+	i2c_lock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	ret = regmap_bulk_read(dev->regmap, reg, val, val_count);
-	i2c_unlock_adapter(client->adapter);
+	i2c_unlock_bus(client->adapter, I2C_LOCK_SEGMENT);
 	return ret;
 }
 

drivers/media/dvb-frontends/tda1004x.c

@@ -329,7 +329,7 @@ static int tda1004x_do_upload(struct tda1004x_state *state,
 	tda1004x_write_byteI(state, dspCodeCounterReg, 0);
 	fw_msg.addr = state->config->demod_address;
 
-	i2c_lock_adapter(state->i2c);
+	i2c_lock_bus(state->i2c, I2C_LOCK_SEGMENT);
 	buf[0] = dspCodeInReg;
 	while (pos != len) {
 		// work out how much to send this time
@@ -342,14 +342,14 @@ static int tda1004x_do_upload(struct tda1004x_state *state,
 		fw_msg.len = tx_size + 1;
 		if (__i2c_transfer(state->i2c, &fw_msg, 1) != 1) {
 			printk(KERN_ERR "tda1004x: Error during firmware upload\n");
-			i2c_unlock_adapter(state->i2c);
+			i2c_unlock_bus(state->i2c, I2C_LOCK_SEGMENT);
 			return -EIO;
 		}
 		pos += tx_size;
 
 		dprintk("%s: fw_pos=0x%x\n", __func__, pos);
 	}
-	i2c_unlock_adapter(state->i2c);
+	i2c_unlock_bus(state->i2c, I2C_LOCK_SEGMENT);
 
 	/* give the DSP a chance to settle 03/10/05 Hac */
 	msleep(100);

drivers/media/tuners/tda18271-common.c

@@ -225,7 +225,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
 	 */
 	if (lock_i2c) {
 		tda18271_i2c_gate_ctrl(fe, 1);
-		i2c_lock_adapter(priv->i2c_props.adap);
+		i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 	}
 	while (len) {
 		if (max > len)
@@ -246,7 +246,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
 		len -= max;
 	}
 	if (lock_i2c) {
-		i2c_unlock_adapter(priv->i2c_props.adap);
+		i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 		tda18271_i2c_gate_ctrl(fe, 0);
 	}
 
@@ -300,7 +300,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
 	 * as those could cause bad things
 	 */
 	tda18271_i2c_gate_ctrl(fe, 1);
-	i2c_lock_adapter(priv->i2c_props.adap);
+	i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 
 	/* initialize registers */
 	switch (priv->id) {
@@ -516,7 +516,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
 	/* synchronize */
 	__tda18271_write_regs(fe, R_EP1, 1, false);
 
-	i2c_unlock_adapter(priv->i2c_props.adap);
+	i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 	tda18271_i2c_gate_ctrl(fe, 0);
 
 	return 0;

drivers/mfd/88pm860x-i2c.c

@@ -146,14 +146,14 @@ int pm860x_page_reg_write(struct i2c_client *i2c, int reg,
 	unsigned char zero;
 	int ret;
 
-	i2c_lock_adapter(i2c->adapter);
+	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 	read_device(i2c, 0xFA, 0, &zero);
 	read_device(i2c, 0xFB, 0, &zero);
 	read_device(i2c, 0xFF, 0, &zero);
 	ret = write_device(i2c, reg, 1, &data);
 	read_device(i2c, 0xFE, 0, &zero);
 	read_device(i2c, 0xFC, 0, &zero);
-	i2c_unlock_adapter(i2c->adapter);
+	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 	return ret;
 }
 EXPORT_SYMBOL(pm860x_page_reg_write);
@@ -164,14 +164,14 @@ int pm860x_page_bulk_read(struct i2c_client *i2c, int reg,
 	unsigned char zero = 0;
 	int ret;
 
-	i2c_lock_adapter(i2c->adapter);
+	i2c_lock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 	read_device(i2c, 0xfa, 0, &zero);
 	read_device(i2c, 0xfb, 0, &zero);
 	read_device(i2c, 0xff, 0, &zero);
 	ret = read_device(i2c, reg, count, buf);
 	read_device(i2c, 0xFE, 0, &zero);
 	read_device(i2c, 0xFC, 0, &zero);
-	i2c_unlock_adapter(i2c->adapter);
+	i2c_unlock_bus(i2c->adapter, I2C_LOCK_SEGMENT);
 	return ret;
 }
 EXPORT_SYMBOL(pm860x_page_bulk_read);

drivers/misc/eeprom/at24.c

@@ -478,6 +478,23 @@ static void at24_properties_to_pdata(struct device *dev,
 	if (device_property_present(dev, "no-read-rollover"))
 		chip->flags |= AT24_FLAG_NO_RDROL;
 
+	err = device_property_read_u32(dev, "address-width", &val);
+	if (!err) {
+		switch (val) {
+		case 8:
+			if (chip->flags & AT24_FLAG_ADDR16)
+				dev_warn(dev, "Override address width to be 8, while default is 16\n");
+			chip->flags &= ~AT24_FLAG_ADDR16;
+			break;
+		case 16:
+			chip->flags |= AT24_FLAG_ADDR16;
+			break;
+		default:
+			dev_warn(dev, "Bad \"address-width\" property: %u\n",
+				 val);
+		}
+	}
+
 	err = device_property_read_u32(dev, "size", &val);
 	if (!err)
 		chip->byte_len = val;

include/linux/i2c.h

@@ -564,6 +564,7 @@ struct i2c_lock_operations {
  * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
  * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
  * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
+ * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
  */
 struct i2c_timings {
 	u32 bus_freq_hz;
@@ -571,6 +572,7 @@ struct i2c_timings {
 	u32 scl_fall_ns;
 	u32 scl_int_delay_ns;
 	u32 sda_fall_ns;
+	u32 sda_hold_ns;
 };
 
 /**
@@ -581,12 +583,14 @@ struct i2c_timings {
  *      recovery. Populated internally for generic GPIO recovery.
  * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
  *      Populated internally for generic GPIO recovery.
- * @get_sda: This gets current value of SDA line. Optional for generic SCL
+ * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
- *      recovery. Populated internally, if sda_gpio is a valid GPIO, for generic
+ *	for generic SCL recovery. Populated internally, if sda_gpio is a valid
- *      GPIO recovery.
+ *	GPIO, for generic GPIO recovery.
- * @set_sda: This sets/clears the SDA line. Optional for generic SCL recovery.
+ * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
- *	Populated internally, if sda_gpio is a valid GPIO, for generic GPIO
+ *	generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
- *	recovery.
+ *	for generic GPIO recovery.
+ * @get_bus_free: Returns the bus free state as seen from the IP core in case it
+ *	has a more complex internal logic than just reading SDA. Optional.
  * @prepare_recovery: This will be called before starting recovery. Platform may
  *	configure padmux here for SDA/SCL line or something else they want.
  * @unprepare_recovery: This will be called after completing recovery. Platform
@@ -601,6 +605,7 @@ struct i2c_bus_recovery_info {
 	void (*set_scl)(struct i2c_adapter *adap, int val);
 	int (*get_sda)(struct i2c_adapter *adap);
 	void (*set_sda)(struct i2c_adapter *adap, int val);
+	int (*get_bus_free)(struct i2c_adapter *adap);
 
 	void (*prepare_recovery)(struct i2c_adapter *adap);
 	void (*unprepare_recovery)(struct i2c_adapter *adap);
@@ -658,6 +663,10 @@ struct i2c_adapter_quirks {
 					 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
 /* clock stretching is not supported */
 #define I2C_AQ_NO_CLK_STRETCH		BIT(4)
+/* message cannot have length of 0 */
+#define I2C_AQ_NO_ZERO_LEN_READ		BIT(5)
+#define I2C_AQ_NO_ZERO_LEN_WRITE	BIT(6)
+#define I2C_AQ_NO_ZERO_LEN		(I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
 
 /*
  * i2c_adapter is the structure used to identify a physical i2c bus along
@@ -759,18 +768,6 @@ i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
 	adapter->lock_ops->unlock_bus(adapter, flags);
 }
 
-static inline void
-i2c_lock_adapter(struct i2c_adapter *adapter)
-{
-	i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
-}
-
-static inline void
-i2c_unlock_adapter(struct i2c_adapter *adapter)
-{
-	i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
-}
-
 /*flags for the client struct: */
 #define I2C_CLIENT_PEC		0x04	/* Use Packet Error Checking */
 #define I2C_CLIENT_TEN		0x10	/* we have a ten bit chip address */