Merge branch 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - API for late atomic transfers (e.g. to shut down via PMIC). We have a
   seperate callback now which is called under clearly defined
   conditions. In-kernel users are converted, too.

 - new driver for the AMD PCIe MP2 I2C controller

 - large refactoring for at91 and bcm-iproc (both gain slave support due
   to this)

 - and a good share of various driver improvements anf fixes

* 'i2c/for-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (57 commits)
  dt-bindings: i2c: riic: document r7s9210 support
  i2c: imx-lpi2c: Use __maybe_unused instead of #if CONFIG_PM_SLEEP
  i2c-piix4: Add Hygon Dhyana SMBus support
  i2c: core: apply 'is_suspended' check for SMBus, too
  i2c: core: ratelimit 'transfer when suspended' errors
  i2c: iproc: Change driver to use 'BIT' macro
  i2c: riic: Add Runtime PM support
  i2c: mux: demux-pinctrl: use struct_size() in devm_kzalloc()
  i2c: mux: pca954x: allow management of device idle state via sysfs
  i2c: mux: pca9541: remove support for unused platform data
  i2c: mux: pca954x: remove support for unused platform data
  dt-bindings: i2c: i2c-mtk: add support for MT8516
  i2c: axxia: use auto cmd for last message
  i2c: gpio: flag atomic capability if possible
  i2c: algo: bit: add flag to whitelist atomic transfers
  i2c: stu300: use xfer_atomic callback to bail out early
  i2c: ocores: enable atomic xfers
  i2c: ocores: refactor setup for polling
  i2c: tegra-bpmp: convert to use new atomic callbacks
  i2c: omap: Add the master_xfer_atomic hook
  ...

Documentation/ABI/testing/sysfs-bus-i2c-devices-pca954x

@@ -0,0 +1,20 @@
+What:		/sys/bus/i2c/.../idle_state
+Date:		January 2019
+KernelVersion:	5.2
+Contact:	Robert Shearman <robert.shearman@att.com>
+Description:
+		Value that exists only for mux devices that can be
+		written to control the behaviour of the multiplexer on
+		idle. Possible values:
+		-2 - disconnect on idle, i.e. deselect the last used
+		     channel, which is useful when there is a device
+		     with an address that conflicts with another
+		     device on another mux on the same parent bus.
+		-1 - leave the mux as-is, which is the most optimal
+		     setting in terms of I2C operations and is the
+		     default mode.
+		0..<nchans> - set the mux to a predetermined channel,
+		     which is useful if there is one channel that is
+		     used almost always, and you want to reduce the
+		     latency for normal operations after rare
+		     transactions on other channels

Documentation/devicetree/bindings/eeprom/at24.txt

@@ -50,6 +50,7 @@ Required properties:
 
                 "nxp,se97b" - the fallback is "atmel,24c02",
                 "renesas,r1ex24002" - the fallback is "atmel,24c02"
+                "renesas,r1ex24016" - the fallback is "atmel,24c16"
                 "renesas,r1ex24128" - the fallback is "atmel,24c128"
                 "rohm,br24t01" - the fallback is "atmel,24c01"
 

Documentation/devicetree/bindings/i2c/brcm,iproc-i2c.txt

@@ -3,15 +3,12 @@ Broadcom iProc I2C controller
 Required properties:
 
 - compatible:
-    Must be "brcm,iproc-i2c"
+    Must be "brcm,iproc-i2c" or "brcm,iproc-nic-i2c"
 
 - reg:
     Define the base and range of the I/O address space that contain the iProc
     I2C controller registers
 
-- interrupts:
-    Should contain the I2C interrupt
-
 - clock-frequency:
     This is the I2C bus clock. Need to be either 100000 or 400000
 
@@ -21,6 +18,18 @@ Required properties:
 - #size-cells:
     Always 0
 
+Optional properties:
+
+- interrupts:
+    Should contain the I2C interrupt. For certain revisions of the I2C
+    controller, I2C interrupt is unwired to the interrupt controller. In such
+    case, this property should be left unspecified, and driver will fall back
+    to polling mode
+
+- brcm,ape-hsls-addr-mask:
+    Required for "brcm,iproc-nic-i2c". Host view of address mask into the
+    'APE' co-processor. Value must be unsigned, 32-bit
+
 Example:
 	i2c0: i2c@18008000 {
 		compatible = "brcm,iproc-i2c";

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

@@ -6,12 +6,21 @@ Required properties :
                 or "mscc,ocelot-i2c" with "snps,designware-i2c" for fallback
  - reg : Offset and length of the register set for the device
  - interrupts : <IRQ> where IRQ is the interrupt number.
+ - clocks : phandles for the clocks, see the description of clock-names below.
+   The phandle for the "ic_clk" clock is required. The phandle for the "pclk"
+   clock is optional. If a single clock is specified but no clock-name, it is
+   the "ic_clk" clock. If both clocks are listed, the "ic_clk" must be first.
 
 Recommended properties :
 
  - clock-frequency : desired I2C bus clock frequency in Hz.
 
 Optional properties :
+
+ - clock-names : Contains the names of the clocks:
+    "ic_clk", for the core clock used to generate the external I2C clock.
+    "pclk", the interface clock, required for register access.
+
  - reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold
    time, named ICPU_CFG:TWI_DELAY in the datasheet.
 

Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt

@@ -12,13 +12,16 @@ Required properties:
       "mediatek,mt7623-i2c", "mediatek,mt6577-i2c": for MediaTek MT7623
       "mediatek,mt7629-i2c", "mediatek,mt2712-i2c": for MediaTek MT7629
       "mediatek,mt8173-i2c": for MediaTek MT8173
+      "mediatek,mt8183-i2c": for MediaTek MT8183
+      "mediatek,mt8516-i2c", "mediatek,mt2712-i2c": for MediaTek MT8516
   - reg: physical base address of the controller and dma base, length of memory
     mapped region.
   - interrupts: interrupt number to the cpu.
   - clock-div: the fixed value for frequency divider of clock source in i2c
     module. Each IC may be different.
   - clocks: clock name from clock manager
-  - clock-names: Must include "main" and "dma", if enable have-pmic need include
+  - clock-names: Must include "main" and "dma", "arb" is for multi-master that
+    one bus has more than two i2c controllers, if enable have-pmic need include
     "pmic" extra.
 
 Optional properties:

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

@@ -1,7 +1,10 @@
 Device tree configuration for Renesas RIIC driver
 
 Required properties:
-- compatible      : "renesas,riic-<soctype>". "renesas,riic-rz" as fallback
+- compatible      :
+	"renesas,riic-r7s72100" if the device is a part of a R7S72100 SoC.
+	"renesas,riic-r7s9210" if the device is a part of a R7S9210 SoC.
+	"renesas,riic-rz" for a generic RZ/A compatible device.
 - reg             : address start and address range size of device
 - interrupts      : 8 interrupts (TEI, RI, TI, SPI, STI, NAKI, ALI, TMOI)
 - clock-frequency : frequency of bus clock in Hz

Documentation/devicetree/bindings/i2c/i2c-stm32.txt

@@ -1,11 +1,11 @@
 * I2C controller embedded in STMicroelectronics STM32 I2C platform
 
-Required properties :
+Required properties:
-- compatible : Must be one of the following
+- compatible: Must be one of the following
   - "st,stm32f4-i2c"
   - "st,stm32f7-i2c"
-- reg : Offset and length of the register set for the device
+- reg: Offset and length of the register set for the device
-- interrupts : Must contain the interrupt id for I2C event and then the
+- interrupts: Must contain the interrupt id for I2C event and then the
   interrupt id for I2C error.
 - resets: Must contain the phandle to the reset controller.
 - clocks: Must contain the input clock of the I2C instance.
@@ -14,25 +14,26 @@ Required properties :
 - #address-cells = <1>;
 - #size-cells = <0>;
 
-Optional properties :
+Optional properties:
-- clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
+- clock-frequency: Desired I2C bus clock frequency in Hz. If not specified,
   the default 100 kHz frequency will be used.
   For STM32F4 SoC Standard-mode and Fast-mode are supported, possible values are
   100000 and 400000.
-  For STM32F7 SoC, Standard-mode, Fast-mode and Fast-mode Plus are supported,
+  For STM32F7, STM32H7 and STM32MP1 SoCs, Standard-mode, Fast-mode and Fast-mode
-  possible values are 100000, 400000 and 1000000.
+  Plus are supported, possible values are 100000, 400000 and 1000000.
-- i2c-scl-rising-time-ns : Only for STM32F7, I2C SCL Rising time for the board
+- i2c-scl-rising-time-ns: I2C SCL Rising time for the board (default: 25)
-  (default: 25)
+  For STM32F7, STM32H7 and STM32MP1 only.
-- i2c-scl-falling-time-ns : Only for STM32F7, I2C SCL Falling time for the board
+- i2c-scl-falling-time-ns: I2C SCL Falling time for the board (default: 10)
-  (default: 10)
+  For STM32F7, STM32H7 and STM32MP1 only.
   I2C Timings are derived from these 2 values
-- st,syscfg-fmp:  Only for STM32F7, use to set Fast Mode Plus bit within SYSCFG
+- st,syscfg-fmp: Use to set Fast Mode Plus bit within SYSCFG when Fast Mode
-  whether Fast Mode Plus speed is selected by slave.
+  Plus speed is selected by slave.
-	1st cell : phandle to syscfg
+	1st cell: phandle to syscfg
-	2nd cell : register offset within SYSCFG
+	2nd cell: register offset within SYSCFG
-	3rd cell : register bitmask for FMP bit
+	3rd cell: register bitmask for FMP bit
+  For STM32F7, STM32H7 and STM32MP1 only.
 
-Example :
+Example:
 
 	i2c@40005400 {
 		compatible = "st,stm32f4-i2c";

Documentation/i2c/busses/i2c-amd-mp2

@@ -0,0 +1,23 @@
+Kernel driver i2c-amd-mp2
+
+Supported adapters:
+  * AMD MP2 PCIe interface
+
+Datasheet: not publicly available.
+
+Authors:
+	Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+	Nehal Shah <nehal-bakulchandra.shah@amd.com>
+	Elie Morisse <syniurge@gmail.com>
+
+Description
+-----------
+
+The MP2 is an ARM processor programmed as an I2C controller and communicating
+with the x86 host through PCI.
+
+If you see something like this:
+
+03:00.7 MP2 I2C controller: Advanced Micro Devices, Inc. [AMD] Device 15e6
+
+in your 'lspci -v', then this driver is for your device.

Documentation/i2c/busses/i2c-piix4

@@ -15,6 +15,8 @@ Supported adapters:
     http://support.amd.com/us/Embedded_TechDocs/44413.pdf
   * AMD Hudson-2, ML, CZ
     Datasheet: Not publicly available
+  * Hygon CZ
+    Datasheet: Not publicly available
   * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge
     Datasheet: Publicly available at the SMSC website http://www.smsc.com
 

MAINTAINERS

@@ -826,6 +826,14 @@ F:	drivers/gpu/drm/amd/include/vi_structs.h
 F:	drivers/gpu/drm/amd/include/v9_structs.h
 F:	include/uapi/linux/kfd_ioctl.h
 
+AMD MP2 I2C DRIVER
+M:	Elie Morisse <syniurge@gmail.com>
+M:	Nehal Shah <nehal-bakulchandra.shah@amd.com>
+M:	Shyam Sundar S K <shyam-sundar.s-k@amd.com>
+L:	linux-i2c@vger.kernel.org
+S:	Maintained
+F:	drivers/i2c/busses/i2c-amd-mp2*
+
 AMD POWERPLAY
 M:	Rex Zhu <rex.zhu@amd.com>
 M:	Evan Quan <evan.quan@amd.com>
@@ -2582,7 +2590,7 @@ F:	include/linux/dmaengine.h
 F:	include/linux/async_tx.h
 
 AT24 EEPROM DRIVER
-M:	Bartosz Golaszewski <brgl@bgdev.pl>
+M:	Bartosz Golaszewski <bgolaszewski@baylibre.com>
 L:	linux-i2c@vger.kernel.org
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git
 S:	Maintained
@@ -10207,7 +10215,8 @@ MICROCHIP I2C DRIVER
 M:	Ludovic Desroches <ludovic.desroches@microchip.com>
 L:	linux-i2c@vger.kernel.org
 S:	Supported
-F:	drivers/i2c/busses/i2c-at91.c
+F:	drivers/i2c/busses/i2c-at91.h
+F:	drivers/i2c/busses/i2c-at91-*.c
 
 MICROCHIP ISC DRIVER
 M:	Eugen Hristev <eugen.hristev@microchip.com>

drivers/i2c/algos/i2c-algo-bit.c

@@ -603,6 +603,23 @@ bailout:
 	return ret;
 }
 
+/*
+ * We print a warning when we are not flagged to support atomic transfers but
+ * will try anyhow. That's what the I2C core would do as well. Sadly, we can't
+ * modify the algorithm struct at probe time because this struct is exported
+ * 'const'.
+ */
+static int bit_xfer_atomic(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[],
+			   int num)
+{
+	struct i2c_algo_bit_data *adap = i2c_adap->algo_data;
+
+	if (!adap->can_do_atomic)
+		dev_warn(&i2c_adap->dev, "not flagged for atomic transfers\n");
+
+	return bit_xfer(i2c_adap, msgs, num);
+}
+
 static u32 bit_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL |
@@ -615,8 +632,9 @@ static u32 bit_func(struct i2c_adapter *adap)
 /* -----exported algorithm data: -------------------------------------	*/
 
 const struct i2c_algorithm i2c_bit_algo = {
-	.master_xfer	= bit_xfer,
+	.master_xfer = bit_xfer,
-	.functionality	= bit_func,
+	.master_xfer_atomic = bit_xfer_atomic,
+	.functionality = bit_func,
 };
 EXPORT_SYMBOL(i2c_bit_algo);
 

drivers/i2c/busses/Kconfig

@@ -77,6 +77,16 @@ config I2C_AMD8111
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-amd8111.
 
+config I2C_AMD_MP2
+	tristate "AMD MP2 PCIe"
+	depends on PCI && ACPI
+	help
+	  If you say yes to this option, support will be included for the AMD
+	  MP2 PCIe I2C adapter.
+
+	  This driver can also be built as modules.  If so, the modules will
+	  be called i2c-amd-mp2-pci and i2c-amd-mp2-plat.
+
 config I2C_HIX5HD2
 	tristate "Hix5hd2 high-speed I2C driver"
 	depends on ARCH_HISI || ARCH_HIX5HD2 || COMPILE_TEST
@@ -176,6 +186,7 @@ config I2C_PIIX4
 	    AMD Hudson-2
 	    AMD ML
 	    AMD CZ
+	    Hygon CZ
 	    Serverworks OSB4
 	    Serverworks CSB5
 	    Serverworks CSB6
@@ -388,6 +399,19 @@ config I2C_AT91
 	  the latency to fill the transmission register is too long. If you
 	  are facing this situation, use the i2c-gpio driver.
 
+config I2C_AT91_SLAVE_EXPERIMENTAL
+	tristate "Microchip AT91 I2C experimental slave mode"
+	depends on I2C_AT91
+	select I2C_SLAVE
+	help
+	  If you say yes to this option, support for the slave mode will be
+	  added. Caution: do not use it for production. This feature has not
+	  been tested in a heavy way, help wanted.
+	  There are known bugs:
+	    - It can hang, on a SAMA5D4, after several transfers.
+	    - There are some mismtaches with a SAMA5D4 as slave and a SAMA5D2 as
+	    master.
+
 config I2C_AU1550
 	tristate "Au1550/Au1200/Au1300 SMBus interface"
 	depends on MIPS_ALCHEMY
@@ -425,6 +449,7 @@ config I2C_BCM_IPROC
 	tristate "Broadcom iProc I2C controller"
 	depends on ARCH_BCM_IPROC || COMPILE_TEST
 	default ARCH_BCM_IPROC
+	select I2C_SLAVE
 	help
 	  If you say yes to this option, support will be included for the
 	  Broadcom iProc I2C controller.

drivers/i2c/busses/Makefile

@@ -33,8 +33,13 @@ obj-$(CONFIG_I2C_POWERMAC)	+= i2c-powermac.o
 
 # Embedded system I2C/SMBus host controller drivers
 obj-$(CONFIG_I2C_ALTERA)	+= i2c-altera.o
+obj-$(CONFIG_I2C_AMD_MP2)	+= i2c-amd-mp2-pci.o i2c-amd-mp2-plat.o
 obj-$(CONFIG_I2C_ASPEED)	+= i2c-aspeed.o
 obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
+i2c-at91-objs			:= i2c-at91-core.o i2c-at91-master.o
+ifeq ($(CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL),y)
+	i2c-at91-objs		+= i2c-at91-slave.o
+endif
 obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_AXXIA)		+= i2c-axxia.o
 obj-$(CONFIG_I2C_BCM2835)	+= i2c-bcm2835.o

drivers/i2c/busses/i2c-amd-mp2-pci.c

@@ -0,0 +1,483 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * AMD MP2 PCIe communication driver
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *          Elie Morisse <syniurge@gmail.com>
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+
+#include "i2c-amd-mp2.h"
+
+#include <linux/io-64-nonatomic-lo-hi.h>
+
+static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+	/* there is only one data mailbox for two i2c adapters */
+	mutex_lock(&privdata->c2p_lock);
+	privdata->c2p_lock_busid = i2c_common->bus_id;
+}
+
+static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+	if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) {
+		dev_warn(ndev_dev(privdata),
+			 "bus %d attempting to unlock C2P locked by bus %d\n",
+			 i2c_common->bus_id, privdata->c2p_lock_busid);
+		return;
+	}
+
+	mutex_unlock(&privdata->c2p_lock);
+}
+
+static int amd_mp2_cmd(struct amd_i2c_common *i2c_common,
+		       union i2c_cmd_base i2c_cmd_base)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+	void __iomem *reg;
+
+	i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd;
+
+	reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ?
+				AMD_C2P_MSG1 : AMD_C2P_MSG0);
+	writel(i2c_cmd_base.ul, reg);
+
+	return 0;
+}
+
+int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+	union i2c_cmd_base i2c_cmd_base;
+
+	dev_dbg(ndev_dev(privdata), "%s id: %d\n", __func__,
+		i2c_common->bus_id);
+
+	i2c_cmd_base.ul = 0;
+	i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable;
+	i2c_cmd_base.s.bus_id = i2c_common->bus_id;
+	i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed;
+
+	amd_mp2_c2p_mutex_lock(i2c_common);
+
+	return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set);
+
+static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common,
+				union i2c_cmd_base *i2c_cmd_base,
+				enum i2c_cmd reqcmd)
+{
+	i2c_cmd_base->s.i2c_cmd = reqcmd;
+	i2c_cmd_base->s.bus_id = i2c_common->bus_id;
+	i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed;
+	i2c_cmd_base->s.slave_addr = i2c_common->msg->addr;
+	i2c_cmd_base->s.length = i2c_common->msg->len;
+}
+
+int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+	union i2c_cmd_base i2c_cmd_base;
+
+	amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd);
+	amd_mp2_c2p_mutex_lock(i2c_common);
+
+	if (i2c_common->msg->len <= 32) {
+		i2c_cmd_base.s.mem_type = use_c2pmsg;
+		if (reqcmd == i2c_write)
+			memcpy_toio(privdata->mmio + AMD_C2P_MSG2,
+				    i2c_common->msg->buf,
+				    i2c_common->msg->len);
+	} else {
+		i2c_cmd_base.s.mem_type = use_dram;
+		writeq((u64)i2c_common->dma_addr,
+		       privdata->mmio + AMD_C2P_MSG2);
+	}
+
+	return amd_mp2_cmd(i2c_common, i2c_cmd_base);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw);
+
+static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+	int len = i2c_common->eventval.r.length;
+	u32 slave_addr = i2c_common->eventval.r.slave_addr;
+	bool err = false;
+
+	if (unlikely(len != i2c_common->msg->len)) {
+		dev_err(ndev_dev(privdata),
+			"length %d in event doesn't match buffer length %d!\n",
+			len, i2c_common->msg->len);
+		err = true;
+	}
+
+	if (unlikely(slave_addr != i2c_common->msg->addr)) {
+		dev_err(ndev_dev(privdata),
+			"unexpected slave address %x (expected: %x)!\n",
+			slave_addr, i2c_common->msg->addr);
+		err = true;
+	}
+
+	if (!err)
+		i2c_common->cmd_success = true;
+}
+
+static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+	enum status_type sts = i2c_common->eventval.r.status;
+	enum response_type res = i2c_common->eventval.r.response;
+	int len = i2c_common->eventval.r.length;
+
+	if (res != command_success) {
+		if (res != command_failed)
+			dev_err(ndev_dev(privdata), "invalid response to i2c command!\n");
+		return;
+	}
+
+	switch (i2c_common->reqcmd) {
+	case i2c_read:
+		if (sts == i2c_readcomplete_event) {
+			amd_mp2_pci_check_rw_event(i2c_common);
+			if (len <= 32)
+				memcpy_fromio(i2c_common->msg->buf,
+					      privdata->mmio + AMD_C2P_MSG2,
+					      len);
+		} else if (sts != i2c_readfail_event) {
+			dev_err(ndev_dev(privdata),
+				"invalid i2c status after read (%d)!\n", sts);
+		}
+		break;
+	case i2c_write:
+		if (sts == i2c_writecomplete_event)
+			amd_mp2_pci_check_rw_event(i2c_common);
+		else if (sts != i2c_writefail_event)
+			dev_err(ndev_dev(privdata),
+				"invalid i2c status after write (%d)!\n", sts);
+		break;
+	case i2c_enable:
+		if (sts == i2c_busenable_complete)
+			i2c_common->cmd_success = true;
+		else if (sts != i2c_busenable_failed)
+			dev_err(ndev_dev(privdata),
+				"invalid i2c status after bus enable (%d)!\n",
+				sts);
+		break;
+	case i2c_disable:
+		if (sts == i2c_busdisable_complete)
+			i2c_common->cmd_success = true;
+		else if (sts != i2c_busdisable_failed)
+			dev_err(ndev_dev(privdata),
+				"invalid i2c status after bus disable (%d)!\n",
+				sts);
+		break;
+	default:
+		break;
+	}
+}
+
+void amd_mp2_process_event(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+	if (unlikely(i2c_common->reqcmd == i2c_none)) {
+		dev_warn(ndev_dev(privdata),
+			 "received msg but no cmd was sent (bus = %d)!\n",
+			 i2c_common->bus_id);
+		return;
+	}
+
+	__amd_mp2_process_event(i2c_common);
+
+	i2c_common->reqcmd = i2c_none;
+	amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_process_event);
+
+static irqreturn_t amd_mp2_irq_isr(int irq, void *dev)
+{
+	struct amd_mp2_dev *privdata = dev;
+	struct amd_i2c_common *i2c_common;
+	u32 val;
+	unsigned int bus_id;
+	void __iomem *reg;
+	enum irqreturn ret = IRQ_NONE;
+
+	for (bus_id = 0; bus_id < 2; bus_id++) {
+		i2c_common = privdata->busses[bus_id];
+		if (!i2c_common)
+			continue;
+
+		reg = privdata->mmio + ((bus_id == 0) ?
+					AMD_P2C_MSG1 : AMD_P2C_MSG2);
+		val = readl(reg);
+		if (val != 0) {
+			writel(0, reg);
+			writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+			i2c_common->eventval.ul = val;
+			i2c_common->cmd_completion(i2c_common);
+
+			ret = IRQ_HANDLED;
+		}
+	}
+
+	if (ret != IRQ_HANDLED) {
+		val = readl(privdata->mmio + AMD_P2C_MSG_INTEN);
+		if (val != 0) {
+			writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+			dev_warn(ndev_dev(privdata),
+				 "received irq without message\n");
+			ret = IRQ_HANDLED;
+		}
+	}
+
+	return ret;
+}
+
+void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common)
+{
+	i2c_common->reqcmd = i2c_none;
+	amd_mp2_c2p_mutex_unlock(i2c_common);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout);
+
+int amd_mp2_register_cb(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+	if (i2c_common->bus_id > 1)
+		return -EINVAL;
+
+	if (privdata->busses[i2c_common->bus_id]) {
+		dev_err(ndev_dev(privdata),
+			"Bus %d already taken!\n", i2c_common->bus_id);
+		return -EINVAL;
+	}
+
+	privdata->busses[i2c_common->bus_id] = i2c_common;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_register_cb);
+
+int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common)
+{
+	struct amd_mp2_dev *privdata = i2c_common->mp2_dev;
+
+	privdata->busses[i2c_common->bus_id] = NULL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb);
+
+static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)
+{
+	int reg;
+
+	for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4)
+		writel(0, privdata->mmio + reg);
+
+	for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4)
+		writel(0, privdata->mmio + reg);
+}
+
+static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
+			    struct pci_dev *pci_dev)
+{
+	int rc;
+
+	pci_set_drvdata(pci_dev, privdata);
+
+	rc = pcim_enable_device(pci_dev);
+	if (rc) {
+		dev_err(ndev_dev(privdata), "Failed to enable MP2 PCI device\n");
+		goto err_pci_enable;
+	}
+
+	rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev));
+	if (rc) {
+		dev_err(ndev_dev(privdata), "I/O memory remapping failed\n");
+		goto err_pci_enable;
+	}
+	privdata->mmio = pcim_iomap_table(pci_dev)[2];
+
+	pci_set_master(pci_dev);
+
+	rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(64));
+	if (rc) {
+		rc = pci_set_dma_mask(pci_dev, DMA_BIT_MASK(32));
+		if (rc)
+			goto err_dma_mask;
+	}
+
+	/* Set up intx irq */
+	writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);
+	pci_intx(pci_dev, 1);
+	rc = devm_request_irq(&pci_dev->dev, pci_dev->irq, amd_mp2_irq_isr,
+			      IRQF_SHARED, dev_name(&pci_dev->dev), privdata);
+	if (rc)
+		dev_err(&pci_dev->dev, "Failure requesting irq %i: %d\n",
+			pci_dev->irq, rc);
+
+	return rc;
+
+err_dma_mask:
+	pci_clear_master(pci_dev);
+err_pci_enable:
+	pci_set_drvdata(pci_dev, NULL);
+	return rc;
+}
+
+static int amd_mp2_pci_probe(struct pci_dev *pci_dev,
+			     const struct pci_device_id *id)
+{
+	struct amd_mp2_dev *privdata;
+	int rc;
+
+	privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL);
+	if (!privdata)
+		return -ENOMEM;
+
+	rc = amd_mp2_pci_init(privdata, pci_dev);
+	if (rc)
+		return rc;
+
+	mutex_init(&privdata->c2p_lock);
+	privdata->pci_dev = pci_dev;
+
+	pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);
+	pm_runtime_use_autosuspend(&pci_dev->dev);
+	pm_runtime_put_autosuspend(&pci_dev->dev);
+	pm_runtime_allow(&pci_dev->dev);
+
+	privdata->probed = true;
+
+	dev_info(&pci_dev->dev, "MP2 device registered.\n");
+	return 0;
+}
+
+static void amd_mp2_pci_remove(struct pci_dev *pci_dev)
+{
+	struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+
+	pm_runtime_forbid(&pci_dev->dev);
+	pm_runtime_get_noresume(&pci_dev->dev);
+
+	pci_intx(pci_dev, 0);
+	pci_clear_master(pci_dev);
+
+	amd_mp2_clear_reg(privdata);
+}
+
+#ifdef CONFIG_PM
+static int amd_mp2_pci_suspend(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+	struct amd_i2c_common *i2c_common;
+	unsigned int bus_id;
+	int ret = 0;
+
+	for (bus_id = 0; bus_id < 2; bus_id++) {
+		i2c_common = privdata->busses[bus_id];
+		if (i2c_common)
+			i2c_common->suspend(i2c_common);
+	}
+
+	ret = pci_save_state(pci_dev);
+	if (ret) {
+		dev_err(ndev_dev(privdata),
+			"pci_save_state failed = %d\n", ret);
+		return ret;
+	}
+
+	pci_disable_device(pci_dev);
+	return ret;
+}
+
+static int amd_mp2_pci_resume(struct device *dev)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);
+	struct amd_i2c_common *i2c_common;
+	unsigned int bus_id;
+	int ret = 0;
+
+	pci_restore_state(pci_dev);
+	ret = pci_enable_device(pci_dev);
+	if (ret < 0) {
+		dev_err(ndev_dev(privdata),
+			"pci_enable_device failed = %d\n", ret);
+		return ret;
+	}
+
+	for (bus_id = 0; bus_id < 2; bus_id++) {
+		i2c_common = privdata->busses[bus_id];
+		if (i2c_common) {
+			ret = i2c_common->resume(i2c_common);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return ret;
+}
+
+static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend,
+			    amd_mp2_pci_resume, NULL);
+#endif /* CONFIG_PM */
+
+static const struct pci_device_id amd_mp2_pci_tbl[] = {
+	{PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)},
+	{0}
+};
+MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);
+
+static struct pci_driver amd_mp2_pci_driver = {
+	.name		= "i2c_amd_mp2",
+	.id_table	= amd_mp2_pci_tbl,
+	.probe		= amd_mp2_pci_probe,
+	.remove		= amd_mp2_pci_remove,
+#ifdef CONFIG_PM
+	.driver = {
+		.pm	= &amd_mp2_pci_pm_ops,
+	},
+#endif
+};
+module_pci_driver(amd_mp2_pci_driver);
+
+static int amd_mp2_device_match(struct device *dev, void *data)
+{
+	return 1;
+}
+
+struct amd_mp2_dev *amd_mp2_find_device(void)
+{
+	struct device *dev;
+	struct pci_dev *pci_dev;
+
+	dev = driver_find_device(&amd_mp2_pci_driver.driver, NULL, NULL,
+				 amd_mp2_device_match);
+	if (!dev)
+		return NULL;
+
+	pci_dev = to_pci_dev(dev);
+	return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);
+}
+EXPORT_SYMBOL_GPL(amd_mp2_find_device);
+
+MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver");
+MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>");
+MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");
+MODULE_LICENSE("Dual BSD/GPL");

drivers/i2c/busses/i2c-amd-mp2-plat.c

@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * AMD MP2 platform driver
+ *
+ * Setup the I2C adapters enumerated in the ACPI namespace.
+ * MP2 controllers have 2 separate busses, up to 2 I2C adapters may be listed.
+ *
+ * Authors: Nehal Bakulchandra Shah <Nehal-bakulchandra.shah@amd.com>
+ *          Elie Morisse <syniurge@gmail.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "i2c-amd-mp2.h"
+
+#define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1)
+#define AMD_I2C_TIMEOUT (msecs_to_jiffies(250))
+
+/**
+ * struct amd_i2c_dev - MP2 bus/i2c adapter context
+ * @common: shared context with the MP2 PCI driver
+ * @pdev: platform driver node
+ * @adap: i2c adapter
+ * @cmd_complete: xfer completion object
+ */
+struct amd_i2c_dev {
+	struct amd_i2c_common common;
+	struct platform_device *pdev;
+	struct i2c_adapter adap;
+	struct completion cmd_complete;
+};
+
+#define amd_i2c_dev_common(__common) \
+	container_of(__common, struct amd_i2c_dev, common)
+
+static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common)
+{
+	struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
+	struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+	enum dma_data_direction dma_direction =
+			i2c_common->msg->flags & I2C_M_RD ?
+			DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0);
+	i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf,
+					      i2c_common->msg->len,
+					      dma_direction);
+
+	if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) {
+		dev_err(&i2c_dev->pdev->dev,
+			"Error while mapping dma buffer %p\n",
+			i2c_common->dma_buf);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common)
+{
+	struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;
+	enum dma_data_direction dma_direction =
+			i2c_common->msg->flags & I2C_M_RD ?
+			DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	dma_unmap_single(dev_pci, i2c_common->dma_addr,
+			 i2c_common->msg->len, dma_direction);
+
+	i2c_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true);
+}
+
+static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev)
+{
+	struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+	reinit_completion(&i2c_dev->cmd_complete);
+	i2c_common->cmd_success = false;
+}
+
+static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common)
+{
+	struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+	union i2c_event *event = &i2c_common->eventval;
+
+	if (event->r.status == i2c_readcomplete_event)
+		dev_dbg(&i2c_dev->pdev->dev, "%s readdata:%*ph\n",
+			__func__, event->r.length,
+			i2c_common->msg->buf);
+
+	complete(&i2c_dev->cmd_complete);
+}
+
+static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev)
+{
+	struct amd_i2c_common *i2c_common = &i2c_dev->common;
+	unsigned long timeout;
+
+	timeout = wait_for_completion_timeout(&i2c_dev->cmd_complete,
+					      i2c_dev->adap.timeout);
+
+	if ((i2c_common->reqcmd == i2c_read ||
+	     i2c_common->reqcmd == i2c_write) &&
+	    i2c_common->msg->len > 32)
+		i2c_amd_dma_unmap(i2c_common);
+
+	if (timeout == 0) {
+		amd_mp2_rw_timeout(i2c_common);
+		return -ETIMEDOUT;
+	}
+
+	amd_mp2_process_event(i2c_common);
+
+	if (!i2c_common->cmd_success)
+		return -EIO;
+
+	return 0;
+}
+
+static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable)
+{
+	struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+	i2c_amd_start_cmd(i2c_dev);
+	amd_mp2_bus_enable_set(i2c_common, enable);
+
+	return i2c_amd_check_cmd_completion(i2c_dev);
+}
+
+static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg)
+{
+	struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+	i2c_amd_start_cmd(i2c_dev);
+	i2c_common->msg = pmsg;
+
+	if (pmsg->len > 32)
+		if (i2c_amd_dma_map(i2c_common))
+			return -EIO;
+
+	if (pmsg->flags & I2C_M_RD)
+		amd_mp2_rw(i2c_common, i2c_read);
+	else
+		amd_mp2_rw(i2c_common, i2c_write);
+
+	return i2c_amd_check_cmd_completion(i2c_dev);
+}
+
+static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+	int i;
+	struct i2c_msg *pmsg;
+	int err;
+
+	/* the adapter might have been deleted while waiting for the bus lock */
+	if (unlikely(!i2c_dev->common.mp2_dev))
+		return -EINVAL;
+
+	amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev);
+
+	for (i = 0; i < num; i++) {
+		pmsg = &msgs[i];
+		err = i2c_amd_xfer_msg(i2c_dev, pmsg);
+		if (err)
+			break;
+	}
+
+	amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev);
+	return err ? err : num;
+}
+
+static u32 i2c_amd_func(struct i2c_adapter *a)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm i2c_amd_algorithm = {
+	.master_xfer = i2c_amd_xfer,
+	.functionality = i2c_amd_func,
+};
+
+#ifdef CONFIG_PM
+static int i2c_amd_suspend(struct amd_i2c_common *i2c_common)
+{
+	struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+
+	i2c_amd_enable_set(i2c_dev, false);
+	return 0;
+}
+
+static int i2c_amd_resume(struct amd_i2c_common *i2c_common)
+{
+	struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);
+
+	return i2c_amd_enable_set(i2c_dev, true);
+}
+#endif
+
+static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev)
+{
+	u32 acpi_speed;
+	int i;
+	static const u32 supported_speeds[] = {
+		0, 100000, 400000, 1000000, 1400000, 3400000
+	};
+
+	acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);
+	/* round down to the lowest standard speed */
+	for (i = 1; i < ARRAY_SIZE(supported_speeds); i++) {
+		if (acpi_speed < supported_speeds[i])
+			break;
+	}
+	acpi_speed = supported_speeds[i - 1];
+
+	switch (acpi_speed) {
+	case 100000:
+		return speed100k;
+	case 400000:
+		return speed400k;
+	case 1000000:
+		return speed1000k;
+	case 1400000:
+		return speed1400k;
+	case 3400000:
+		return speed3400k;
+	default:
+		return speed400k;
+	}
+}
+
+static const struct i2c_adapter_quirks amd_i2c_dev_quirks = {
+	.max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH,
+	.max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH,
+};
+
+static int i2c_amd_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct amd_i2c_dev *i2c_dev;
+	acpi_handle handle = ACPI_HANDLE(&pdev->dev);
+	struct acpi_device *adev;
+	struct amd_mp2_dev *mp2_dev;
+	const char *uid;
+
+	if (acpi_bus_get_device(handle, &adev))
+		return -ENODEV;
+
+	/* The ACPI namespace doesn't contain information about which MP2 PCI
+	 * device an AMDI0011 ACPI device is related to, so assume that there's
+	 * only one MP2 PCI device per system.
+	 */
+	mp2_dev = amd_mp2_find_device();
+	if (!mp2_dev || !mp2_dev->probed)
+		/* The MP2 PCI device should get probed later */
+		return -EPROBE_DEFER;
+
+	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+	if (!i2c_dev)
+		return -ENOMEM;
+
+	i2c_dev->common.mp2_dev = mp2_dev;
+	i2c_dev->pdev = pdev;
+	platform_set_drvdata(pdev, i2c_dev);
+
+	i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion;
+#ifdef CONFIG_PM
+	i2c_dev->common.suspend = &i2c_amd_suspend;
+	i2c_dev->common.resume = &i2c_amd_resume;
+#endif
+
+	uid = adev->pnp.unique_id;
+	if (!uid) {
+		dev_err(&pdev->dev, "missing UID/bus id!\n");
+		return -EINVAL;
+	} else if (strcmp(uid, "0") == 0) {
+		i2c_dev->common.bus_id = 0;
+	} else if (strcmp(uid, "1") == 0) {
+		i2c_dev->common.bus_id = 1;
+	} else {
+		dev_err(&pdev->dev, "incorrect UID/bus id \"%s\"!\n", uid);
+		return -EINVAL;
+	}
+	dev_dbg(&pdev->dev, "bus id is %u\n", i2c_dev->common.bus_id);
+
+	/* Register the adapter */
+	amd_mp2_pm_runtime_get(mp2_dev);
+
+	i2c_dev->common.reqcmd = i2c_none;
+	if (amd_mp2_register_cb(&i2c_dev->common))
+		return -EINVAL;
+	device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev,
+			DL_FLAG_AUTOREMOVE_CONSUMER);
+
+	i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev);
+
+	/* Setup i2c adapter description */
+	i2c_dev->adap.owner = THIS_MODULE;
+	i2c_dev->adap.algo = &i2c_amd_algorithm;
+	i2c_dev->adap.quirks = &amd_i2c_dev_quirks;
+	i2c_dev->adap.dev.parent = &pdev->dev;
+	i2c_dev->adap.algo_data = i2c_dev;
+	i2c_dev->adap.timeout = AMD_I2C_TIMEOUT;
+	ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev));
+	i2c_dev->adap.dev.of_node = pdev->dev.of_node;
+	snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),
+		 "AMD MP2 i2c bus %u", i2c_dev->common.bus_id);
+	i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+
+	init_completion(&i2c_dev->cmd_complete);
+
+	/* Enable the bus */
+	if (i2c_amd_enable_set(i2c_dev, true))
+		dev_err(&pdev->dev, "initial bus enable failed\n");
+
+	/* Attach to the i2c layer */
+	ret = i2c_add_adapter(&i2c_dev->adap);
+
+	amd_mp2_pm_runtime_put(mp2_dev);
+
+	if (ret < 0)
+		dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);
+
+	return ret;
+}
+
+static int i2c_amd_remove(struct platform_device *pdev)
+{
+	struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+	struct amd_i2c_common *i2c_common = &i2c_dev->common;
+
+	i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
+
+	i2c_amd_enable_set(i2c_dev, false);
+	amd_mp2_unregister_cb(i2c_common);
+	i2c_common->mp2_dev = NULL;
+
+	i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);
+
+	i2c_del_adapter(&i2c_dev->adap);
+	return 0;
+}
+
+static const struct acpi_device_id i2c_amd_acpi_match[] = {
+	{ "AMDI0011" },
+	{ },
+};
+MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match);
+
+static struct platform_driver i2c_amd_plat_driver = {
+	.probe = i2c_amd_probe,
+	.remove = i2c_amd_remove,
+	.driver = {
+		.name = "i2c_amd_mp2",
+		.acpi_match_table = ACPI_PTR(i2c_amd_acpi_match),
+	},
+};
+module_platform_driver(i2c_amd_plat_driver);
+
+MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver");
+MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@amd.com>");
+MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");
+MODULE_LICENSE("Dual BSD/GPL");

drivers/i2c/busses/i2c-amd-mp2.h

@@ -0,0 +1,219 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * AMD MP2 I2C adapter driver
+ *
+ * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ *          Elie Morisse <syniurge@gmail.com>
+ */
+
+#ifndef I2C_AMD_PCI_MP2_H
+#define I2C_AMD_PCI_MP2_H
+
+#include <linux/i2c.h>
+#include <linux/pci.h>
+#include <linux/pm_runtime.h>
+
+#define PCI_DEVICE_ID_AMD_MP2	0x15E6
+
+struct amd_i2c_common;
+struct amd_mp2_dev;
+
+enum {
+	/* MP2 C2P Message Registers */
+	AMD_C2P_MSG0 = 0x10500,			/* MP2 Message for I2C0 */
+	AMD_C2P_MSG1 = 0x10504,			/* MP2 Message for I2C1 */
+	AMD_C2P_MSG2 = 0x10508,			/* DRAM Address Lo / Data 0 */
+	AMD_C2P_MSG3 = 0x1050c,			/* DRAM Address HI / Data 1 */
+	AMD_C2P_MSG4 = 0x10510,			/* Data 2 */
+	AMD_C2P_MSG5 = 0x10514,			/* Data 3 */
+	AMD_C2P_MSG6 = 0x10518,			/* Data 4 */
+	AMD_C2P_MSG7 = 0x1051c,			/* Data 5 */
+	AMD_C2P_MSG8 = 0x10520,			/* Data 6 */
+	AMD_C2P_MSG9 = 0x10524,			/* Data 7 */
+
+	/* MP2 P2C Message Registers */
+	AMD_P2C_MSG0 = 0x10680,			/* Do not use */
+	AMD_P2C_MSG1 = 0x10684,			/* I2C0 interrupt register */
+	AMD_P2C_MSG2 = 0x10688,			/* I2C1 interrupt register */
+	AMD_P2C_MSG3 = 0x1068C,			/* MP2 debug info */
+	AMD_P2C_MSG_INTEN = 0x10690,		/* MP2 interrupt gen register */
+	AMD_P2C_MSG_INTSTS = 0x10694,		/* Interrupt status */
+};
+
+/* Command register data structures */
+
+#define i2c_none (-1)
+enum i2c_cmd {
+	i2c_read = 0,
+	i2c_write,
+	i2c_enable,
+	i2c_disable,
+	number_of_sensor_discovered,
+	is_mp2_active,
+	invalid_cmd = 0xF,
+};
+
+enum speed_enum {
+	speed100k = 0,
+	speed400k = 1,
+	speed1000k = 2,
+	speed1400k = 3,
+	speed3400k = 4
+};
+
+enum mem_type {
+	use_dram = 0,
+	use_c2pmsg = 1,
+};
+
+/**
+ * union i2c_cmd_base : bit access of C2P commands
+ * @i2c_cmd: bit 0..3 i2c R/W command
+ * @bus_id: bit 4..7 i2c bus index
+ * @slave_addr: bit 8..15 slave address
+ * @length: bit 16..27 read/write length
+ * @i2c_speed: bit 28..30 bus speed
+ * @mem_type: bit 31 0-DRAM; 1-C2P msg o/p
+ */
+union i2c_cmd_base {
+	u32 ul;
+	struct {
+		enum i2c_cmd i2c_cmd : 4;
+		u8 bus_id : 4;
+		u32 slave_addr : 8;
+		u32 length : 12;
+		enum speed_enum i2c_speed : 3;
+		enum mem_type mem_type : 1;
+	} s;
+};
+
+enum response_type {
+	invalid_response = 0,
+	command_success = 1,
+	command_failed = 2,
+};
+
+enum status_type {
+	i2c_readcomplete_event = 0,
+	i2c_readfail_event = 1,
+	i2c_writecomplete_event = 2,
+	i2c_writefail_event = 3,
+	i2c_busenable_complete = 4,
+	i2c_busenable_failed = 5,
+	i2c_busdisable_complete = 6,
+	i2c_busdisable_failed = 7,
+	invalid_data_length = 8,
+	invalid_slave_address = 9,
+	invalid_i2cbus_id = 10,
+	invalid_dram_addr = 11,
+	invalid_command = 12,
+	mp2_active = 13,
+	numberof_sensors_discovered_resp = 14,
+	i2c_bus_notinitialized
+};
+
+/**
+ * union i2c_event : bit access of P2C events
+ * @response: bit 0..1 i2c response type
+ * @status: bit 2..6 status_type
+ * @mem_type: bit 7 0-DRAM; 1-C2P msg o/p
+ * @bus_id: bit 8..11 i2c bus id
+ * @length: bit 12..23 message length
+ * @slave_addr: bit 24-31 slave address
+ */
+union i2c_event {
+	u32 ul;
+	struct {
+		enum response_type response : 2;
+		enum status_type status : 5;
+		enum mem_type mem_type : 1;
+		u8 bus_id : 4;
+		u32 length : 12;
+		u32 slave_addr : 8;
+	} r;
+};
+
+/**
+ * struct amd_i2c_common - per bus/i2c adapter context, shared
+ *	between the pci and the platform driver
+ * @eventval: MP2 event value set by the IRQ handler
+ * @mp2_dev: MP2 pci device this adapter is part of
+ * @msg: i2c message
+ * @cmd_completion: function called by the IRQ handler to signal
+ *		    the platform driver
+ * @reqcmd: requested i2c command type
+ * @cmd_success: set to true if the MP2 responded to a command with
+ *		 the expected status and response type
+ * @bus_id: bus index
+ * @i2c_speed: i2c bus speed determined by the slowest slave
+ * @dma_buf: if msg length > 32, holds the DMA buffer virtual address
+ * @dma_addr: if msg length > 32, holds the DMA buffer address
+ */
+struct amd_i2c_common {
+	union i2c_event eventval;
+	struct amd_mp2_dev *mp2_dev;
+	struct i2c_msg *msg;
+	void (*cmd_completion)(struct amd_i2c_common *i2c_common);
+	enum i2c_cmd reqcmd;
+	u8 cmd_success;
+	u8 bus_id;
+	enum speed_enum i2c_speed;
+	u8 *dma_buf;
+	dma_addr_t dma_addr;
+#ifdef CONFIG_PM
+	int (*suspend)(struct amd_i2c_common *i2c_common);
+	int (*resume)(struct amd_i2c_common *i2c_common);
+#endif /* CONFIG_PM */
+};
+
+/**
+ * struct amd_mp2_dev - per PCI device context
+ * @pci_dev: PCI driver node
+ * @busses: MP2 devices may have up to two busses,
+ *	    each bus corresponding to an i2c adapter
+ * @mmio: iommapped registers
+ * @c2p_lock: controls access to the C2P mailbox shared between
+ *	      the two adapters
+ * @c2p_lock_busid: id of the adapter which locked c2p_lock
+ */
+struct amd_mp2_dev {
+	struct pci_dev *pci_dev;
+	struct amd_i2c_common *busses[2];
+	void __iomem *mmio;
+	struct mutex c2p_lock;
+	u8 c2p_lock_busid;
+	unsigned int probed;
+};
+
+#define ndev_pdev(ndev) ((ndev)->pci_dev)
+#define ndev_name(ndev) pci_name(ndev_pdev(ndev))
+#define ndev_dev(ndev) (&ndev_pdev(ndev)->dev)
+#define work_amd_i2c_common(__work) \
+	container_of(__work, struct amd_i2c_common, work.work)
+
+/* PCIe communication driver */
+
+int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd);
+int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable);
+
+void amd_mp2_process_event(struct amd_i2c_common *i2c_common);
+
+void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common);
+
+int amd_mp2_register_cb(struct amd_i2c_common *i2c_common);
+int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common);
+
+struct amd_mp2_dev *amd_mp2_find_device(void);
+
+static inline void amd_mp2_pm_runtime_get(struct amd_mp2_dev *mp2_dev)
+{
+	pm_runtime_get_sync(&mp2_dev->pci_dev->dev);
+}
+
+static inline void amd_mp2_pm_runtime_put(struct amd_mp2_dev *mp2_dev)
+{
+	pm_runtime_mark_last_busy(&mp2_dev->pci_dev->dev);
+	pm_runtime_put_autosuspend(&mp2_dev->pci_dev->dev);
+}
+
+#endif

drivers/i2c/busses/i2c-at91-core.c

@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
+ *
+ *  Copyright (C) 2011 Weinmann Medical GmbH
+ *  Author: Nikolaus Voss <n.voss@weinmann.de>
+ *
+ *  Evolved from original work by:
+ *  Copyright (C) 2004 Rick Bronson
+ *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
+ *
+ *  Borrowed heavily from original work by:
+ *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
+
+#include "i2c-at91.h"
+
+unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
+{
+	return readl_relaxed(dev->base + reg);
+}
+
+void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
+{
+	writel_relaxed(val, dev->base + reg);
+}
+
+void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
+{
+	at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
+}
+
+void at91_twi_irq_save(struct at91_twi_dev *dev)
+{
+	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
+	at91_disable_twi_interrupts(dev);
+}
+
+void at91_twi_irq_restore(struct at91_twi_dev *dev)
+{
+	at91_twi_write(dev, AT91_TWI_IER, dev->imr);
+}
+
+void at91_init_twi_bus(struct at91_twi_dev *dev)
+{
+	at91_disable_twi_interrupts(dev);
+	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
+	if (dev->slave_detected)
+		at91_init_twi_bus_slave(dev);
+	else
+		at91_init_twi_bus_master(dev);
+}
+
+static struct at91_twi_pdata at91rm9200_config = {
+	.clk_max_div = 5,
+	.clk_offset = 3,
+	.has_unre_flag = true,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9261_config = {
+	.clk_max_div = 5,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9260_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9g20_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static struct at91_twi_pdata at91sam9g10_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static const struct platform_device_id at91_twi_devtypes[] = {
+	{
+		.name = "i2c-at91rm9200",
+		.driver_data = (unsigned long) &at91rm9200_config,
+	}, {
+		.name = "i2c-at91sam9261",
+		.driver_data = (unsigned long) &at91sam9261_config,
+	}, {
+		.name = "i2c-at91sam9260",
+		.driver_data = (unsigned long) &at91sam9260_config,
+	}, {
+		.name = "i2c-at91sam9g20",
+		.driver_data = (unsigned long) &at91sam9g20_config,
+	}, {
+		.name = "i2c-at91sam9g10",
+		.driver_data = (unsigned long) &at91sam9g10_config,
+	}, {
+		/* sentinel */
+	}
+};
+
+#if defined(CONFIG_OF)
+static struct at91_twi_pdata at91sam9x5_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = false,
+};
+
+static struct at91_twi_pdata sama5d4_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = false,
+	.has_alt_cmd = false,
+	.has_hold_field = true,
+};
+
+static struct at91_twi_pdata sama5d2_config = {
+	.clk_max_div = 7,
+	.clk_offset = 4,
+	.has_unre_flag = true,
+	.has_alt_cmd = true,
+	.has_hold_field = true,
+};
+
+static const struct of_device_id atmel_twi_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-i2c",
+		.data = &at91rm9200_config,
+	}, {
+		.compatible = "atmel,at91sam9260-i2c",
+		.data = &at91sam9260_config,
+	}, {
+		.compatible = "atmel,at91sam9261-i2c",
+		.data = &at91sam9261_config,
+	}, {
+		.compatible = "atmel,at91sam9g20-i2c",
+		.data = &at91sam9g20_config,
+	}, {
+		.compatible = "atmel,at91sam9g10-i2c",
+		.data = &at91sam9g10_config,
+	}, {
+		.compatible = "atmel,at91sam9x5-i2c",
+		.data = &at91sam9x5_config,
+	}, {
+		.compatible = "atmel,sama5d4-i2c",
+		.data = &sama5d4_config,
+	}, {
+		.compatible = "atmel,sama5d2-i2c",
+		.data = &sama5d2_config,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
+#endif
+
+static struct at91_twi_pdata *at91_twi_get_driver_data(
+					struct platform_device *pdev)
+{
+	if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
+		if (!match)
+			return NULL;
+		return (struct at91_twi_pdata *)match->data;
+	}
+	return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
+}
+
+static int at91_twi_probe(struct platform_device *pdev)
+{
+	struct at91_twi_dev *dev;
+	struct resource *mem;
+	int rc;
+	u32 phy_addr;
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->dev = &pdev->dev;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem)
+		return -ENODEV;
+	phy_addr = mem->start;
+
+	dev->pdata = at91_twi_get_driver_data(pdev);
+	if (!dev->pdata)
+		return -ENODEV;
+
+	dev->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(dev->base))
+		return PTR_ERR(dev->base);
+
+	dev->irq = platform_get_irq(pdev, 0);
+	if (dev->irq < 0)
+		return dev->irq;
+
+	platform_set_drvdata(pdev, dev);
+
+	dev->clk = devm_clk_get(dev->dev, NULL);
+	if (IS_ERR(dev->clk)) {
+		dev_err(dev->dev, "no clock defined\n");
+		return -ENODEV;
+	}
+	clk_prepare_enable(dev->clk);
+
+	snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
+	i2c_set_adapdata(&dev->adapter, dev);
+	dev->adapter.owner = THIS_MODULE;
+	dev->adapter.class = I2C_CLASS_DEPRECATED;
+	dev->adapter.dev.parent = dev->dev;
+	dev->adapter.nr = pdev->id;
+	dev->adapter.timeout = AT91_I2C_TIMEOUT;
+	dev->adapter.dev.of_node = pdev->dev.of_node;
+
+	dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
+
+	if (dev->slave_detected)
+		rc = at91_twi_probe_slave(pdev, phy_addr, dev);
+	else
+		rc = at91_twi_probe_master(pdev, phy_addr, dev);
+	if (rc)
+		return rc;
+
+	at91_init_twi_bus(dev);
+
+	pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(dev->dev);
+	pm_runtime_set_active(dev->dev);
+	pm_runtime_enable(dev->dev);
+
+	rc = i2c_add_numbered_adapter(&dev->adapter);
+	if (rc) {
+		clk_disable_unprepare(dev->clk);
+
+		pm_runtime_disable(dev->dev);
+		pm_runtime_set_suspended(dev->dev);
+
+		return rc;
+	}
+
+	dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
+		 at91_twi_read(dev, AT91_TWI_VER));
+	return 0;
+}
+
+static int at91_twi_remove(struct platform_device *pdev)
+{
+	struct at91_twi_dev *dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&dev->adapter);
+	clk_disable_unprepare(dev->clk);
+
+	pm_runtime_disable(dev->dev);
+	pm_runtime_set_suspended(dev->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int at91_twi_runtime_suspend(struct device *dev)
+{
+	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(twi_dev->clk);
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int at91_twi_runtime_resume(struct device *dev)
+{
+	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
+
+	pinctrl_pm_select_default_state(dev);
+
+	return clk_prepare_enable(twi_dev->clk);
+}
+
+static int at91_twi_suspend_noirq(struct device *dev)
+{
+	if (!pm_runtime_status_suspended(dev))
+		at91_twi_runtime_suspend(dev);
+
+	return 0;
+}
+
+static int at91_twi_resume_noirq(struct device *dev)
+{
+	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
+	int ret;
+
+	if (!pm_runtime_status_suspended(dev)) {
+		ret = at91_twi_runtime_resume(dev);
+		if (ret)
+			return ret;
+	}
+
+	pm_runtime_mark_last_busy(dev);
+	pm_request_autosuspend(dev);
+
+	at91_init_twi_bus(twi_dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops at91_twi_pm = {
+	.suspend_noirq	= at91_twi_suspend_noirq,
+	.resume_noirq	= at91_twi_resume_noirq,
+	.runtime_suspend	= at91_twi_runtime_suspend,
+	.runtime_resume		= at91_twi_runtime_resume,
+};
+
+#define at91_twi_pm_ops (&at91_twi_pm)
+#else
+#define at91_twi_pm_ops NULL
+#endif
+
+static struct platform_driver at91_twi_driver = {
+	.probe		= at91_twi_probe,
+	.remove		= at91_twi_remove,
+	.id_table	= at91_twi_devtypes,
+	.driver		= {
+		.name	= "at91_i2c",
+		.of_match_table = of_match_ptr(atmel_twi_dt_ids),
+		.pm	= at91_twi_pm_ops,
+	},
+};
+
+static int __init at91_twi_init(void)
+{
+	return platform_driver_register(&at91_twi_driver);
+}
+
+static void __exit at91_twi_exit(void)
+{
+	platform_driver_unregister(&at91_twi_driver);
+}
+
+subsys_initcall(at91_twi_init);
+module_exit(at91_twi_exit);
+
+MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
+MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:at91_i2c");

drivers/i2c/busses/i2c-at91-master.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
  *
@@ -10,11 +11,6 @@
  *
  *  Borrowed heavily from original work by:
  *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
- *
- *  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/clk.h>
@@ -25,159 +21,16 @@
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
-#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
-#include <linux/slab.h>
 #include <linux/platform_data/dma-atmel.h>
 #include <linux/pm_runtime.h>
-#include <linux/pinctrl/consumer.h>
 
-#define DEFAULT_TWI_CLK_HZ		100000		/* max 400 Kbits/s */
+#include "i2c-at91.h"
-#define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
-#define AT91_I2C_DMA_THRESHOLD	8			/* enable DMA if transfer size is bigger than this threshold */
-#define AUTOSUSPEND_TIMEOUT		2000
-#define AT91_I2C_MAX_ALT_CMD_DATA_SIZE	256
 
-/* AT91 TWI register definitions */
+void at91_init_twi_bus_master(struct at91_twi_dev *dev)
-#define	AT91_TWI_CR		0x0000	/* Control Register */
-#define	AT91_TWI_START		BIT(0)	/* Send a Start Condition */
-#define	AT91_TWI_STOP		BIT(1)	/* Send a Stop Condition */
-#define	AT91_TWI_MSEN		BIT(2)	/* Master Transfer Enable */
-#define	AT91_TWI_MSDIS		BIT(3)	/* Master Transfer Disable */
-#define	AT91_TWI_SVEN		BIT(4)	/* Slave Transfer Enable */
-#define	AT91_TWI_SVDIS		BIT(5)	/* Slave Transfer Disable */
-#define	AT91_TWI_QUICK		BIT(6)	/* SMBus quick command */
-#define	AT91_TWI_SWRST		BIT(7)	/* Software Reset */
-#define	AT91_TWI_ACMEN		BIT(16) /* Alternative Command Mode Enable */
-#define	AT91_TWI_ACMDIS		BIT(17) /* Alternative Command Mode Disable */
-#define	AT91_TWI_THRCLR		BIT(24) /* Transmit Holding Register Clear */
-#define	AT91_TWI_RHRCLR		BIT(25) /* Receive Holding Register Clear */
-#define	AT91_TWI_LOCKCLR	BIT(26) /* Lock Clear */
-#define	AT91_TWI_FIFOEN		BIT(28) /* FIFO Enable */
-#define	AT91_TWI_FIFODIS	BIT(29) /* FIFO Disable */
-
-#define	AT91_TWI_MMR		0x0004	/* Master Mode Register */
-#define	AT91_TWI_IADRSZ_1	0x0100	/* Internal Device Address Size */
-#define	AT91_TWI_MREAD		BIT(12)	/* Master Read Direction */
-
-#define	AT91_TWI_IADR		0x000c	/* Internal Address Register */
-
-#define	AT91_TWI_CWGR		0x0010	/* Clock Waveform Generator Reg */
-#define	AT91_TWI_CWGR_HOLD_MAX	0x1f
-#define	AT91_TWI_CWGR_HOLD(x)	(((x) & AT91_TWI_CWGR_HOLD_MAX) << 24)
-
-#define	AT91_TWI_SR		0x0020	/* Status Register */
-#define	AT91_TWI_TXCOMP		BIT(0)	/* Transmission Complete */
-#define	AT91_TWI_RXRDY		BIT(1)	/* Receive Holding Register Ready */
-#define	AT91_TWI_TXRDY		BIT(2)	/* Transmit Holding Register Ready */
-#define	AT91_TWI_OVRE		BIT(6)	/* Overrun Error */
-#define	AT91_TWI_UNRE		BIT(7)	/* Underrun Error */
-#define	AT91_TWI_NACK		BIT(8)	/* Not Acknowledged */
-#define	AT91_TWI_LOCK		BIT(23) /* TWI Lock due to Frame Errors */
-
-#define	AT91_TWI_INT_MASK \
-	(AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK)
-
-#define	AT91_TWI_IER		0x0024	/* Interrupt Enable Register */
-#define	AT91_TWI_IDR		0x0028	/* Interrupt Disable Register */
-#define	AT91_TWI_IMR		0x002c	/* Interrupt Mask Register */
-#define	AT91_TWI_RHR		0x0030	/* Receive Holding Register */
-#define	AT91_TWI_THR		0x0034	/* Transmit Holding Register */
-
-#define	AT91_TWI_ACR		0x0040	/* Alternative Command Register */
-#define	AT91_TWI_ACR_DATAL(len)	((len) & 0xff)
-#define	AT91_TWI_ACR_DIR	BIT(8)
-
-#define	AT91_TWI_FMR		0x0050	/* FIFO Mode Register */
-#define	AT91_TWI_FMR_TXRDYM(mode)	(((mode) & 0x3) << 0)
-#define	AT91_TWI_FMR_TXRDYM_MASK	(0x3 << 0)
-#define	AT91_TWI_FMR_RXRDYM(mode)	(((mode) & 0x3) << 4)
-#define	AT91_TWI_FMR_RXRDYM_MASK	(0x3 << 4)
-#define	AT91_TWI_ONE_DATA	0x0
-#define	AT91_TWI_TWO_DATA	0x1
-#define	AT91_TWI_FOUR_DATA	0x2
-
-#define	AT91_TWI_FLR		0x0054	/* FIFO Level Register */
-
-#define	AT91_TWI_FSR		0x0060	/* FIFO Status Register */
-#define	AT91_TWI_FIER		0x0064	/* FIFO Interrupt Enable Register */
-#define	AT91_TWI_FIDR		0x0068	/* FIFO Interrupt Disable Register */
-#define	AT91_TWI_FIMR		0x006c	/* FIFO Interrupt Mask Register */
-
-#define	AT91_TWI_VER		0x00fc	/* Version Register */
-
-struct at91_twi_pdata {
-	unsigned clk_max_div;
-	unsigned clk_offset;
-	bool has_unre_flag;
-	bool has_alt_cmd;
-	bool has_hold_field;
-	struct at_dma_slave dma_slave;
-};
-
-struct at91_twi_dma {
-	struct dma_chan *chan_rx;
-	struct dma_chan *chan_tx;
-	struct scatterlist sg[2];
-	struct dma_async_tx_descriptor *data_desc;
-	enum dma_data_direction direction;
-	bool buf_mapped;
-	bool xfer_in_progress;
-};
-
-struct at91_twi_dev {
-	struct device *dev;
-	void __iomem *base;
-	struct completion cmd_complete;
-	struct clk *clk;
-	u8 *buf;
-	size_t buf_len;
-	struct i2c_msg *msg;
-	int irq;
-	unsigned imr;
-	unsigned transfer_status;
-	struct i2c_adapter adapter;
-	unsigned twi_cwgr_reg;
-	struct at91_twi_pdata *pdata;
-	bool use_dma;
-	bool use_alt_cmd;
-	bool recv_len_abort;
-	u32 fifo_size;
-	struct at91_twi_dma dma;
-};
-
-static unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
 {
-	return readl_relaxed(dev->base + reg);
-}
-
-static void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
-{
-	writel_relaxed(val, dev->base + reg);
-}
-
-static void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
-{
-	at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
-}
-
-static void at91_twi_irq_save(struct at91_twi_dev *dev)
-{
-	dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK;
-	at91_disable_twi_interrupts(dev);
-}
-
-static void at91_twi_irq_restore(struct at91_twi_dev *dev)
-{
-	at91_twi_write(dev, AT91_TWI_IER, dev->imr);
-}
-
-static void at91_init_twi_bus(struct at91_twi_dev *dev)
-{
-	at91_disable_twi_interrupts(dev);
-	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST);
 	/* FIFO should be enabled immediately after the software reset */
 	if (dev->fifo_size)
 		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN);
@@ -190,16 +43,18 @@ static void at91_init_twi_bus(struct at91_twi_dev *dev)
  * Calculate symmetric clock as stated in datasheet:
  * twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset))
  */
-static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
+static void at91_calc_twi_clock(struct at91_twi_dev *dev)
 {
 	int ckdiv, cdiv, div, hold = 0;
 	struct at91_twi_pdata *pdata = dev->pdata;
 	int offset = pdata->clk_offset;
 	int max_ckdiv = pdata->clk_max_div;
-	u32 twd_hold_time_ns = 0;
+	struct i2c_timings timings, *t = &timings;
+
+	i2c_parse_fw_timings(dev->dev, t, true);
 
 	div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk),
-				       2 * twi_clk) - offset);
+				       2 * t->bus_freq_hz) - offset);
 	ckdiv = fls(div >> 8);
 	cdiv = div >> ckdiv;
 
@@ -211,15 +66,12 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
 	}
 
 	if (pdata->has_hold_field) {
-		of_property_read_u32(dev->dev->of_node, "i2c-sda-hold-time-ns",
-				     &twd_hold_time_ns);
-
 		/*
 		 * hold time = HOLD + 3 x T_peripheral_clock
 		 * Use clk rate in kHz to prevent overflows when computing
 		 * hold.
 		 */
-		hold = DIV_ROUND_UP(twd_hold_time_ns
+		hold = DIV_ROUND_UP(t->sda_hold_ns
 				    * (clk_get_rate(dev->clk) / 1000), 1000000);
 		hold -= 3;
 		if (hold < 0)
@@ -236,7 +88,7 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
 			    | AT91_TWI_CWGR_HOLD(hold);
 
 	dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns)\n",
-		cdiv, ckdiv, hold, twd_hold_time_ns);
+		cdiv, ckdiv, hold, t->sda_hold_ns);
 }
 
 static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)
@@ -833,124 +685,6 @@ static const struct i2c_algorithm at91_twi_algorithm = {
 	.functionality	= at91_twi_func,
 };
 
-static struct at91_twi_pdata at91rm9200_config = {
-	.clk_max_div = 5,
-	.clk_offset = 3,
-	.has_unre_flag = true,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static struct at91_twi_pdata at91sam9261_config = {
-	.clk_max_div = 5,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static struct at91_twi_pdata at91sam9260_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static struct at91_twi_pdata at91sam9g20_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static struct at91_twi_pdata at91sam9g10_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static const struct platform_device_id at91_twi_devtypes[] = {
-	{
-		.name = "i2c-at91rm9200",
-		.driver_data = (unsigned long) &at91rm9200_config,
-	}, {
-		.name = "i2c-at91sam9261",
-		.driver_data = (unsigned long) &at91sam9261_config,
-	}, {
-		.name = "i2c-at91sam9260",
-		.driver_data = (unsigned long) &at91sam9260_config,
-	}, {
-		.name = "i2c-at91sam9g20",
-		.driver_data = (unsigned long) &at91sam9g20_config,
-	}, {
-		.name = "i2c-at91sam9g10",
-		.driver_data = (unsigned long) &at91sam9g10_config,
-	}, {
-		/* sentinel */
-	}
-};
-
-#if defined(CONFIG_OF)
-static struct at91_twi_pdata at91sam9x5_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = false,
-};
-
-static struct at91_twi_pdata sama5d4_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = false,
-	.has_alt_cmd = false,
-	.has_hold_field = true,
-};
-
-static struct at91_twi_pdata sama5d2_config = {
-	.clk_max_div = 7,
-	.clk_offset = 4,
-	.has_unre_flag = true,
-	.has_alt_cmd = true,
-	.has_hold_field = true,
-};
-
-static const struct of_device_id atmel_twi_dt_ids[] = {
-	{
-		.compatible = "atmel,at91rm9200-i2c",
-		.data = &at91rm9200_config,
-	} , {
-		.compatible = "atmel,at91sam9260-i2c",
-		.data = &at91sam9260_config,
-	} , {
-		.compatible = "atmel,at91sam9261-i2c",
-		.data = &at91sam9261_config,
-	} , {
-		.compatible = "atmel,at91sam9g20-i2c",
-		.data = &at91sam9g20_config,
-	} , {
-		.compatible = "atmel,at91sam9g10-i2c",
-		.data = &at91sam9g10_config,
-	}, {
-		.compatible = "atmel,at91sam9x5-i2c",
-		.data = &at91sam9x5_config,
-	}, {
-		.compatible = "atmel,sama5d4-i2c",
-		.data = &sama5d4_config,
-	}, {
-		.compatible = "atmel,sama5d2-i2c",
-		.data = &sama5d2_config,
-	}, {
-		/* sentinel */
-	}
-};
-MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
-#endif
-
 static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
 {
 	int ret = 0;
@@ -1033,74 +767,24 @@ error:
 	return ret;
 }
 
-static struct at91_twi_pdata *at91_twi_get_driver_data(
+int at91_twi_probe_master(struct platform_device *pdev,
-					struct platform_device *pdev)
+			  u32 phy_addr, struct at91_twi_dev *dev)
 {
-	if (pdev->dev.of_node) {
-		const struct of_device_id *match;
-		match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node);
-		if (!match)
-			return NULL;
-		return (struct at91_twi_pdata *)match->data;
-	}
-	return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data;
-}
-
-static int at91_twi_probe(struct platform_device *pdev)
-{
-	struct at91_twi_dev *dev;
-	struct resource *mem;
 	int rc;
-	u32 phy_addr;
-	u32 bus_clk_rate;
 
-	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
-	if (!dev)
-		return -ENOMEM;
 	init_completion(&dev->cmd_complete);
-	dev->dev = &pdev->dev;
-
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!mem)
-		return -ENODEV;
-	phy_addr = mem->start;
-
-	dev->pdata = at91_twi_get_driver_data(pdev);
-	if (!dev->pdata)
-		return -ENODEV;
-
-	dev->base = devm_ioremap_resource(&pdev->dev, mem);
-	if (IS_ERR(dev->base))
-		return PTR_ERR(dev->base);
-
-	dev->irq = platform_get_irq(pdev, 0);
-	if (dev->irq < 0)
-		return dev->irq;
 
 	rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt, 0,
-			 dev_name(dev->dev), dev);
+			      dev_name(dev->dev), dev);
 	if (rc) {
 		dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc);
 		return rc;
 	}
 
-	platform_set_drvdata(pdev, dev);
-
-	dev->clk = devm_clk_get(dev->dev, NULL);
-	if (IS_ERR(dev->clk)) {
-		dev_err(dev->dev, "no clock defined\n");
-		return -ENODEV;
-	}
-	rc = clk_prepare_enable(dev->clk);
-	if (rc)
-		return rc;
-
 	if (dev->dev->of_node) {
 		rc = at91_twi_configure_dma(dev, phy_addr);
-		if (rc == -EPROBE_DEFER) {
+		if (rc == -EPROBE_DEFER)
-			clk_disable_unprepare(dev->clk);
 			return rc;
-		}
 	}
 
 	if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size",
@@ -1108,144 +792,10 @@ static int at91_twi_probe(struct platform_device *pdev)
 		dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size);
 	}
 
-	rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
+	at91_calc_twi_clock(dev);
-			&bus_clk_rate);
-	if (rc)
-		bus_clk_rate = DEFAULT_TWI_CLK_HZ;
 
-	at91_calc_twi_clock(dev, bus_clk_rate);
-	at91_init_twi_bus(dev);
-
-	snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");
-	i2c_set_adapdata(&dev->adapter, dev);
-	dev->adapter.owner = THIS_MODULE;
-	dev->adapter.class = I2C_CLASS_DEPRECATED;
 	dev->adapter.algo = &at91_twi_algorithm;
 	dev->adapter.quirks = &at91_twi_quirks;
-	dev->adapter.dev.parent = dev->dev;
-	dev->adapter.nr = pdev->id;
-	dev->adapter.timeout = AT91_I2C_TIMEOUT;
-	dev->adapter.dev.of_node = pdev->dev.of_node;
-
-	pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);
-	pm_runtime_use_autosuspend(dev->dev);
-	pm_runtime_set_active(dev->dev);
-	pm_runtime_enable(dev->dev);
-
-	rc = i2c_add_numbered_adapter(&dev->adapter);
-	if (rc) {
-		clk_disable_unprepare(dev->clk);
-
-		pm_runtime_disable(dev->dev);
-		pm_runtime_set_suspended(dev->dev);
-
-		return rc;
-	}
-
-	dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",
-		 at91_twi_read(dev, AT91_TWI_VER));
-	return 0;
-}
-
-static int at91_twi_remove(struct platform_device *pdev)
-{
-	struct at91_twi_dev *dev = platform_get_drvdata(pdev);
-
-	i2c_del_adapter(&dev->adapter);
-	clk_disable_unprepare(dev->clk);
-
-	pm_runtime_disable(dev->dev);
-	pm_runtime_set_suspended(dev->dev);
 
 	return 0;
 }
-
-#ifdef CONFIG_PM
-
-static int at91_twi_runtime_suspend(struct device *dev)
-{
-	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
-
-	clk_disable_unprepare(twi_dev->clk);
-
-	pinctrl_pm_select_sleep_state(dev);
-
-	return 0;
-}
-
-static int at91_twi_runtime_resume(struct device *dev)
-{
-	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
-
-	pinctrl_pm_select_default_state(dev);
-
-	return clk_prepare_enable(twi_dev->clk);
-}
-
-static int at91_twi_suspend_noirq(struct device *dev)
-{
-	if (!pm_runtime_status_suspended(dev))
-		at91_twi_runtime_suspend(dev);
-
-	return 0;
-}
-
-static int at91_twi_resume_noirq(struct device *dev)
-{
-	struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
-	int ret;
-
-	if (!pm_runtime_status_suspended(dev)) {
-		ret = at91_twi_runtime_resume(dev);
-		if (ret)
-			return ret;
-	}
-
-	pm_runtime_mark_last_busy(dev);
-	pm_request_autosuspend(dev);
-
-	at91_init_twi_bus(twi_dev);
-
-	return 0;
-}
-
-static const struct dev_pm_ops at91_twi_pm = {
-	.suspend_noirq	= at91_twi_suspend_noirq,
-	.resume_noirq	= at91_twi_resume_noirq,
-	.runtime_suspend	= at91_twi_runtime_suspend,
-	.runtime_resume		= at91_twi_runtime_resume,
-};
-
-#define at91_twi_pm_ops (&at91_twi_pm)
-#else
-#define at91_twi_pm_ops NULL
-#endif
-
-static struct platform_driver at91_twi_driver = {
-	.probe		= at91_twi_probe,
-	.remove		= at91_twi_remove,
-	.id_table	= at91_twi_devtypes,
-	.driver		= {
-		.name	= "at91_i2c",
-		.of_match_table = of_match_ptr(atmel_twi_dt_ids),
-		.pm	= at91_twi_pm_ops,
-	},
-};
-
-static int __init at91_twi_init(void)
-{
-	return platform_driver_register(&at91_twi_driver);
-}
-
-static void __exit at91_twi_exit(void)
-{
-	platform_driver_unregister(&at91_twi_driver);
-}
-
-subsys_initcall(at91_twi_init);
-module_exit(at91_twi_exit);
-
-MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
-MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:at91_i2c");

drivers/i2c/busses/i2c-at91-slave.c

@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  i2c slave support for Atmel's AT91 Two-Wire Interface (TWI)
+ *
+ *  Copyright (C) 2017 Juergen Fitschen <me@jue.yt>
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+
+#include "i2c-at91.h"
+
+static irqreturn_t atmel_twi_interrupt_slave(int irq, void *dev_id)
+{
+	struct at91_twi_dev *dev = dev_id;
+	const unsigned status = at91_twi_read(dev, AT91_TWI_SR);
+	const unsigned irqstatus = status & at91_twi_read(dev, AT91_TWI_IMR);
+	u8 value;
+
+	if (!irqstatus)
+		return IRQ_NONE;
+
+	/* slave address has been detected on I2C bus */
+	if (irqstatus & AT91_TWI_SVACC) {
+		if (status & AT91_TWI_SVREAD) {
+			i2c_slave_event(dev->slave,
+					I2C_SLAVE_READ_REQUESTED, &value);
+			writeb_relaxed(value, dev->base + AT91_TWI_THR);
+			at91_twi_write(dev, AT91_TWI_IER,
+				       AT91_TWI_TXRDY | AT91_TWI_EOSACC);
+		} else {
+			i2c_slave_event(dev->slave,
+					I2C_SLAVE_WRITE_REQUESTED, &value);
+			at91_twi_write(dev, AT91_TWI_IER,
+				       AT91_TWI_RXRDY | AT91_TWI_EOSACC);
+		}
+		at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_SVACC);
+	}
+
+	/* byte transmitted to remote master */
+	if (irqstatus & AT91_TWI_TXRDY) {
+		i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, &value);
+		writeb_relaxed(value, dev->base + AT91_TWI_THR);
+	}
+
+	/* byte received from remote master */
+	if (irqstatus & AT91_TWI_RXRDY) {
+		value = readb_relaxed(dev->base + AT91_TWI_RHR);
+		i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
+	}
+
+	/* master sent stop */
+	if (irqstatus & AT91_TWI_EOSACC) {
+		at91_twi_write(dev, AT91_TWI_IDR,
+			       AT91_TWI_TXRDY | AT91_TWI_RXRDY | AT91_TWI_EOSACC);
+		at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_SVACC);
+		i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &value);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int at91_reg_slave(struct i2c_client *slave)
+{
+	struct at91_twi_dev *dev = i2c_get_adapdata(slave->adapter);
+
+	if (dev->slave)
+		return -EBUSY;
+
+	if (slave->flags & I2C_CLIENT_TEN)
+		return -EAFNOSUPPORT;
+
+	/* Make sure twi_clk doesn't get turned off! */
+	pm_runtime_get_sync(dev->dev);
+
+	dev->slave = slave;
+	dev->smr = AT91_TWI_SMR_SADR(slave->addr);
+
+	at91_init_twi_bus(dev);
+	at91_twi_write(dev, AT91_TWI_IER, AT91_TWI_SVACC);
+
+	dev_info(dev->dev, "entered slave mode (ADR=%d)\n", slave->addr);
+
+	return 0;
+}
+
+static int at91_unreg_slave(struct i2c_client *slave)
+{
+	struct at91_twi_dev *dev = i2c_get_adapdata(slave->adapter);
+
+	WARN_ON(!dev->slave);
+
+	dev_info(dev->dev, "leaving slave mode\n");
+
+	dev->slave = NULL;
+	dev->smr = 0;
+
+	at91_init_twi_bus(dev);
+
+	pm_runtime_put(dev->dev);
+
+	return 0;
+}
+
+static u32 at91_twi_func(struct i2c_adapter *adapter)
+{
+	return I2C_FUNC_SLAVE | I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
+		| I2C_FUNC_SMBUS_READ_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm at91_twi_algorithm_slave = {
+	.reg_slave	= at91_reg_slave,
+	.unreg_slave	= at91_unreg_slave,
+	.functionality	= at91_twi_func,
+};
+
+int at91_twi_probe_slave(struct platform_device *pdev,
+			 u32 phy_addr, struct at91_twi_dev *dev)
+{
+	int rc;
+
+	rc = devm_request_irq(&pdev->dev, dev->irq, atmel_twi_interrupt_slave,
+			      0, dev_name(dev->dev), dev);
+	if (rc) {
+		dev_err(dev->dev, "Cannot get irq %d: %d\n", dev->irq, rc);
+		return rc;
+	}
+
+	dev->adapter.algo = &at91_twi_algorithm_slave;
+
+	return 0;
+}
+
+void at91_init_twi_bus_slave(struct at91_twi_dev *dev)
+{
+	at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSDIS);
+	if (dev->slave_detected && dev->smr) {
+		at91_twi_write(dev, AT91_TWI_SMR, dev->smr);
+		at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVEN);
+	}
+}

drivers/i2c/busses/i2c-at91.h

@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  i2c Support for Atmel's AT91 Two-Wire Interface (TWI)
+ *
+ *  Copyright (C) 2011 Weinmann Medical GmbH
+ *  Author: Nikolaus Voss <n.voss@weinmann.de>
+ *
+ *  Evolved from original work by:
+ *  Copyright (C) 2004 Rick Bronson
+ *  Converted to 2.6 by Andrew Victor <andrew@sanpeople.com>
+ *
+ *  Borrowed heavily from original work by:
+ *  Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/i2c.h>
+#include <linux/platform_data/dma-atmel.h>
+#include <linux/platform_device.h>
+
+#define AT91_I2C_TIMEOUT	msecs_to_jiffies(100)	/* transfer timeout */
+#define AT91_I2C_DMA_THRESHOLD	8			/* enable DMA if transfer size is bigger than this threshold */
+#define AUTOSUSPEND_TIMEOUT		2000
+#define AT91_I2C_MAX_ALT_CMD_DATA_SIZE	256
+
+/* AT91 TWI register definitions */
+#define	AT91_TWI_CR		0x0000	/* Control Register */
+#define	AT91_TWI_START		BIT(0)	/* Send a Start Condition */
+#define	AT91_TWI_STOP		BIT(1)	/* Send a Stop Condition */
+#define	AT91_TWI_MSEN		BIT(2)	/* Master Transfer Enable */
+#define	AT91_TWI_MSDIS		BIT(3)	/* Master Transfer Disable */
+#define	AT91_TWI_SVEN		BIT(4)	/* Slave Transfer Enable */
+#define	AT91_TWI_SVDIS		BIT(5)	/* Slave Transfer Disable */
+#define	AT91_TWI_QUICK		BIT(6)	/* SMBus quick command */
+#define	AT91_TWI_SWRST		BIT(7)	/* Software Reset */
+#define	AT91_TWI_ACMEN		BIT(16) /* Alternative Command Mode Enable */
+#define	AT91_TWI_ACMDIS		BIT(17) /* Alternative Command Mode Disable */
+#define	AT91_TWI_THRCLR		BIT(24) /* Transmit Holding Register Clear */
+#define	AT91_TWI_RHRCLR		BIT(25) /* Receive Holding Register Clear */
+#define	AT91_TWI_LOCKCLR	BIT(26) /* Lock Clear */
+#define	AT91_TWI_FIFOEN		BIT(28) /* FIFO Enable */
+#define	AT91_TWI_FIFODIS	BIT(29) /* FIFO Disable */
+
+#define	AT91_TWI_MMR		0x0004	/* Master Mode Register */
+#define	AT91_TWI_IADRSZ_1	0x0100	/* Internal Device Address Size */
+#define	AT91_TWI_MREAD		BIT(12)	/* Master Read Direction */
+
+#define	AT91_TWI_SMR		0x0008	/* Slave Mode Register */
+#define	AT91_TWI_SMR_SADR_MAX	0x007f
+#define	AT91_TWI_SMR_SADR(x)	(((x) & AT91_TWI_SMR_SADR_MAX) << 16)
+
+#define	AT91_TWI_IADR		0x000c	/* Internal Address Register */
+
+#define	AT91_TWI_CWGR		0x0010	/* Clock Waveform Generator Reg */
+#define	AT91_TWI_CWGR_HOLD_MAX	0x1f
+#define	AT91_TWI_CWGR_HOLD(x)	(((x) & AT91_TWI_CWGR_HOLD_MAX) << 24)
+
+#define	AT91_TWI_SR		0x0020	/* Status Register */
+#define	AT91_TWI_TXCOMP		BIT(0)	/* Transmission Complete */
+#define	AT91_TWI_RXRDY		BIT(1)	/* Receive Holding Register Ready */
+#define	AT91_TWI_TXRDY		BIT(2)	/* Transmit Holding Register Ready */
+#define	AT91_TWI_SVREAD		BIT(3)	/* Slave Read */
+#define	AT91_TWI_SVACC		BIT(4)	/* Slave Access */
+#define	AT91_TWI_OVRE		BIT(6)	/* Overrun Error */
+#define	AT91_TWI_UNRE		BIT(7)	/* Underrun Error */
+#define	AT91_TWI_NACK		BIT(8)	/* Not Acknowledged */
+#define	AT91_TWI_EOSACC		BIT(11)	/* End Of Slave Access */
+#define	AT91_TWI_LOCK		BIT(23) /* TWI Lock due to Frame Errors */
+
+#define	AT91_TWI_INT_MASK \
+	(AT91_TWI_TXCOMP | AT91_TWI_RXRDY | AT91_TWI_TXRDY | AT91_TWI_NACK \
+	| AT91_TWI_SVACC | AT91_TWI_EOSACC)
+
+#define	AT91_TWI_IER		0x0024	/* Interrupt Enable Register */
+#define	AT91_TWI_IDR		0x0028	/* Interrupt Disable Register */
+#define	AT91_TWI_IMR		0x002c	/* Interrupt Mask Register */
+#define	AT91_TWI_RHR		0x0030	/* Receive Holding Register */
+#define	AT91_TWI_THR		0x0034	/* Transmit Holding Register */
+
+#define	AT91_TWI_ACR		0x0040	/* Alternative Command Register */
+#define	AT91_TWI_ACR_DATAL(len)	((len) & 0xff)
+#define	AT91_TWI_ACR_DIR	BIT(8)
+
+#define	AT91_TWI_FMR		0x0050	/* FIFO Mode Register */
+#define	AT91_TWI_FMR_TXRDYM(mode)	(((mode) & 0x3) << 0)
+#define	AT91_TWI_FMR_TXRDYM_MASK	(0x3 << 0)
+#define	AT91_TWI_FMR_RXRDYM(mode)	(((mode) & 0x3) << 4)
+#define	AT91_TWI_FMR_RXRDYM_MASK	(0x3 << 4)
+#define	AT91_TWI_ONE_DATA	0x0
+#define	AT91_TWI_TWO_DATA	0x1
+#define	AT91_TWI_FOUR_DATA	0x2
+
+#define	AT91_TWI_FLR		0x0054	/* FIFO Level Register */
+
+#define	AT91_TWI_FSR		0x0060	/* FIFO Status Register */
+#define	AT91_TWI_FIER		0x0064	/* FIFO Interrupt Enable Register */
+#define	AT91_TWI_FIDR		0x0068	/* FIFO Interrupt Disable Register */
+#define	AT91_TWI_FIMR		0x006c	/* FIFO Interrupt Mask Register */
+
+#define	AT91_TWI_VER		0x00fc	/* Version Register */
+
+struct at91_twi_pdata {
+	unsigned clk_max_div;
+	unsigned clk_offset;
+	bool has_unre_flag;
+	bool has_alt_cmd;
+	bool has_hold_field;
+	struct at_dma_slave dma_slave;
+};
+
+struct at91_twi_dma {
+	struct dma_chan *chan_rx;
+	struct dma_chan *chan_tx;
+	struct scatterlist sg[2];
+	struct dma_async_tx_descriptor *data_desc;
+	enum dma_data_direction direction;
+	bool buf_mapped;
+	bool xfer_in_progress;
+};
+
+struct at91_twi_dev {
+	struct device *dev;
+	void __iomem *base;
+	struct completion cmd_complete;
+	struct clk *clk;
+	u8 *buf;
+	size_t buf_len;
+	struct i2c_msg *msg;
+	int irq;
+	unsigned imr;
+	unsigned transfer_status;
+	struct i2c_adapter adapter;
+	unsigned twi_cwgr_reg;
+	struct at91_twi_pdata *pdata;
+	bool use_dma;
+	bool use_alt_cmd;
+	bool recv_len_abort;
+	u32 fifo_size;
+	struct at91_twi_dma dma;
+	bool slave_detected;
+#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
+	unsigned smr;
+	struct i2c_client *slave;
+#endif
+};
+
+unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg);
+void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val);
+void at91_disable_twi_interrupts(struct at91_twi_dev *dev);
+void at91_twi_irq_save(struct at91_twi_dev *dev);
+void at91_twi_irq_restore(struct at91_twi_dev *dev);
+void at91_init_twi_bus(struct at91_twi_dev *dev);
+
+void at91_init_twi_bus_master(struct at91_twi_dev *dev);
+int at91_twi_probe_master(struct platform_device *pdev, u32 phy_addr,
+			  struct at91_twi_dev *dev);
+
+#ifdef CONFIG_I2C_AT91_SLAVE_EXPERIMENTAL
+void at91_init_twi_bus_slave(struct at91_twi_dev *dev);
+int at91_twi_probe_slave(struct platform_device *pdev, u32 phy_addr,
+			 struct at91_twi_dev *dev);
+
+#else
+static inline void at91_init_twi_bus_slave(struct at91_twi_dev *dev) {}
+static inline int at91_twi_probe_slave(struct platform_device *pdev,
+				       u32 phy_addr, struct at91_twi_dev *dev)
+{
+	return -EINVAL;
+}
+
+#endif

drivers/i2c/busses/i2c-axxia.c

@@ -99,6 +99,7 @@
  * @adapter: core i2c abstraction
  * @i2c_clk: clock reference for i2c input clock
  * @bus_clk_rate: current i2c bus clock rate
+ * @last: a flag indicating is this is last message in transfer
  */
 struct axxia_i2c_dev {
 	void __iomem *base;
@@ -112,6 +113,7 @@ struct axxia_i2c_dev {
 	struct i2c_adapter adapter;
 	struct clk *i2c_clk;
 	u32 bus_clk_rate;
+	bool last;
 };
 
 static void i2c_int_disable(struct axxia_i2c_dev *idev, u32 mask)
@@ -324,15 +326,14 @@ static irqreturn_t axxia_i2c_isr(int irq, void *_dev)
 		/* Stop completed */
 		i2c_int_disable(idev, ~MST_STATUS_TSS);
 		complete(&idev->msg_complete);
-	} else if (status & MST_STATUS_SNS) {
+	} else if (status & (MST_STATUS_SNS | MST_STATUS_SS)) {
 		/* Transfer done */
-		i2c_int_disable(idev, ~MST_STATUS_TSS);
+		int mask = idev->last ? ~0 : ~MST_STATUS_TSS;
+
+		i2c_int_disable(idev, mask);
 		if (i2c_m_rd(idev->msg_r) && idev->msg_xfrd_r < idev->msg_r->len)
 			axxia_i2c_empty_rx_fifo(idev);
 		complete(&idev->msg_complete);
-	} else if (status & MST_STATUS_SS) {
-		/* Auto/Sequence transfer done */
-		complete(&idev->msg_complete);
 	} else if (status & MST_STATUS_TSS) {
 		/* Transfer timeout */
 		idev->msg_err = -ETIMEDOUT;
@@ -405,6 +406,7 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
 	idev->msg_r = &msgs[1];
 	idev->msg_xfrd = 0;
 	idev->msg_xfrd_r = 0;
+	idev->last = true;
 	axxia_i2c_fill_tx_fifo(idev);
 
 	writel(CMD_SEQUENCE, idev->base + MST_COMMAND);
@@ -415,10 +417,6 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
 	time_left = wait_for_completion_timeout(&idev->msg_complete,
 						I2C_XFER_TIMEOUT);
 
-	i2c_int_disable(idev, int_mask);
-
-	axxia_i2c_empty_rx_fifo(idev);
-
 	if (idev->msg_err == -ENXIO) {
 		if (axxia_i2c_handle_seq_nak(idev))
 			axxia_i2c_init(idev);
@@ -438,9 +436,10 @@ static int axxia_i2c_xfer_seq(struct axxia_i2c_dev *idev, struct i2c_msg msgs[])
 	return idev->msg_err;
 }
 
-static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
+static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg,
+			      bool last)
 {
-	u32 int_mask = MST_STATUS_ERR | MST_STATUS_SNS;
+	u32 int_mask = MST_STATUS_ERR;
 	u32 rx_xfer, tx_xfer;
 	unsigned long time_left;
 	unsigned int wt_value;
@@ -449,6 +448,7 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 	idev->msg_r = msg;
 	idev->msg_xfrd = 0;
 	idev->msg_xfrd_r = 0;
+	idev->last = last;
 	reinit_completion(&idev->msg_complete);
 
 	axxia_i2c_set_addr(idev, msg);
@@ -478,8 +478,13 @@ static int axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct i2c_msg *msg)
 	if (idev->msg_err)
 		goto out;
 
-	/* Start manual mode */
+	if (!last) {
-	writel(CMD_MANUAL, idev->base + MST_COMMAND);
+		writel(CMD_MANUAL, idev->base + MST_COMMAND);
+		int_mask |= MST_STATUS_SNS;
+	} else {
+		writel(CMD_AUTO, idev->base + MST_COMMAND);
+		int_mask |= MST_STATUS_SS;
+	}
 
 	writel(WT_EN | wt_value, idev->base + WAIT_TIMER_CONTROL);
 
@@ -507,28 +512,6 @@ out:
 	return idev->msg_err;
 }
 
-static int axxia_i2c_stop(struct axxia_i2c_dev *idev)
-{
-	u32 int_mask = MST_STATUS_ERR | MST_STATUS_SCC | MST_STATUS_TSS;
-	unsigned long time_left;
-
-	reinit_completion(&idev->msg_complete);
-
-	/* Issue stop */
-	writel(0xb, idev->base + MST_COMMAND);
-	i2c_int_enable(idev, int_mask);
-	time_left = wait_for_completion_timeout(&idev->msg_complete,
-					      I2C_STOP_TIMEOUT);
-	i2c_int_disable(idev, int_mask);
-	if (time_left == 0)
-		return -ETIMEDOUT;
-
-	if (readl(idev->base + MST_COMMAND) & CMD_BUSY)
-		dev_warn(idev->dev, "busy after stop\n");
-
-	return 0;
-}
-
 /* This function checks if the msgs[] array contains messages compatible with
  * Sequence mode of operation. This mode assumes there will be exactly one
  * write of non-zero length followed by exactly one read of non-zero length,
@@ -558,9 +541,7 @@ axxia_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	i2c_int_enable(idev, MST_STATUS_TSS);
 
 	for (i = 0; ret == 0 && i < num; ++i)
-		ret = axxia_i2c_xfer_msg(idev, &msgs[i]);
+		ret = axxia_i2c_xfer_msg(idev, &msgs[i], i == (num - 1));
-
-	axxia_i2c_stop(idev);
 
 	return ret ? : i;
 }

drivers/i2c/busses/i2c-brcmstb.c

@@ -165,7 +165,6 @@ static const struct bsc_clk_param bsc_clk[] = {
 struct brcmstb_i2c_dev {
 	struct device *device;
 	void __iomem *base;
-	void __iomem *irq_base;
 	int irq;
 	struct bsc_regs *bsc_regmap;
 	struct i2c_adapter adapter;

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

@@ -251,13 +251,27 @@ unsigned long i2c_dw_clk_rate(struct dw_i2c_dev *dev)
 
 int i2c_dw_prepare_clk(struct dw_i2c_dev *dev, bool prepare)
 {
+	int ret;
+
 	if (IS_ERR(dev->clk))
 		return PTR_ERR(dev->clk);
 
-	if (prepare)
+	if (prepare) {
-		return clk_prepare_enable(dev->clk);
+		/* Optional interface clock */
+		ret = clk_prepare_enable(dev->pclk);
+		if (ret)
+			return ret;
+
+		ret = clk_prepare_enable(dev->clk);
+		if (ret)
+			clk_disable_unprepare(dev->pclk);
+
+		return ret;
+	}
 
 	clk_disable_unprepare(dev->clk);
+	clk_disable_unprepare(dev->pclk);
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(i2c_dw_prepare_clk);

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

@@ -177,6 +177,7 @@
  * @base: IO registers pointer
  * @cmd_complete: tx completion indicator
  * @clk: input reference clock
+ * @pclk: clock required to access the registers
  * @slave: represent an I2C slave device
  * @cmd_err: run time hadware error code
  * @msgs: points to an array of messages currently being transferred
@@ -227,6 +228,7 @@ struct dw_i2c_dev {
 	void __iomem		*ext;
 	struct completion	cmd_complete;
 	struct clk		*clk;
+	struct clk		*pclk;
 	struct reset_control	*rst;
 	struct i2c_client		*slave;
 	u32			(*get_clk_rate_khz) (struct dw_i2c_dev *dev);

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

@@ -344,6 +344,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	else
 		i2c_dw_configure_master(dev);
 
+	/* Optional interface clock */
+	dev->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
+	if (IS_ERR(dev->pclk))
+		return PTR_ERR(dev->pclk);
+
 	dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (!i2c_dw_prepare_clk(dev, true)) {
 		u64 clk_khz;

drivers/i2c/busses/i2c-gpio.c

@@ -413,6 +413,8 @@ static int i2c_gpio_probe(struct platform_device *pdev)
 
 	if (gpiod_cansleep(priv->sda) || gpiod_cansleep(priv->scl))
 		dev_warn(dev, "Slow GPIO pins might wreak havoc into I2C/SMBus bus timing");
+	else
+		bit_data->can_do_atomic = true;
 
 	bit_data->setsda = i2c_gpio_setsda_val;
 	bit_data->setscl = i2c_gpio_setscl_val;

drivers/i2c/busses/i2c-imx-lpi2c.c

@@ -639,8 +639,7 @@ static int lpi2c_imx_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM_SLEEP
+static int __maybe_unused lpi2c_runtime_suspend(struct device *dev)
-static int lpi2c_runtime_suspend(struct device *dev)
 {
 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
 
@@ -650,7 +649,7 @@ static int lpi2c_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int lpi2c_runtime_resume(struct device *dev)
+static int __maybe_unused lpi2c_runtime_resume(struct device *dev)
 {
 	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
 	int ret;
@@ -671,10 +670,6 @@ static const struct dev_pm_ops lpi2c_pm_ops = {
 	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,
 			   lpi2c_runtime_resume, NULL)
 };
-#define IMX_LPI2C_PM      (&lpi2c_pm_ops)
-#else
-#define IMX_LPI2C_PM      NULL
-#endif
 
 static struct platform_driver lpi2c_imx_driver = {
 	.probe = lpi2c_imx_probe,
@@ -682,7 +677,7 @@ static struct platform_driver lpi2c_imx_driver = {
 	.driver = {
 		.name = DRIVER_NAME,
 		.of_match_table = lpi2c_imx_of_match,
-		.pm = IMX_LPI2C_PM,
+		.pm = &lpi2c_pm_ops,
 	},
 };
 

drivers/i2c/busses/i2c-isch.c

@@ -30,7 +30,6 @@
 #include <linux/ioport.h>
 #include <linux/i2c.h>
 #include <linux/io.h>
-#include <linux/acpi.h>
 
 /* SCH SMBus address offsets */
 #define SMBHSTCNT	(0 + sch_smba)

drivers/i2c/busses/i2c-mt65xx.c

@@ -35,6 +35,7 @@
 #include <linux/slab.h>
 
 #define I2C_RS_TRANSFER			(1 << 4)
+#define I2C_ARB_LOST			(1 << 3)
 #define I2C_HS_NACKERR			(1 << 2)
 #define I2C_ACKERR			(1 << 1)
 #define I2C_TRANSAC_COMP		(1 << 0)
@@ -76,6 +77,8 @@
 #define I2C_CONTROL_DIR_CHANGE          (0x1 << 4)
 #define I2C_CONTROL_ACKERR_DET_EN       (0x1 << 5)
 #define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6)
+#define I2C_CONTROL_DMAACK_EN           (0x1 << 8)
+#define I2C_CONTROL_ASYNC_MODE          (0x1 << 9)
 #define I2C_CONTROL_WRAPPER             (0x1 << 0)
 
 #define I2C_DRV_NAME		"i2c-mt65xx"
@@ -106,40 +109,97 @@ enum mtk_trans_op {
 };
 
 enum I2C_REGS_OFFSET {
-	OFFSET_DATA_PORT = 0x0,
+	OFFSET_DATA_PORT,
-	OFFSET_SLAVE_ADDR = 0x04,
+	OFFSET_SLAVE_ADDR,
-	OFFSET_INTR_MASK = 0x08,
+	OFFSET_INTR_MASK,
-	OFFSET_INTR_STAT = 0x0c,
+	OFFSET_INTR_STAT,
-	OFFSET_CONTROL = 0x10,
+	OFFSET_CONTROL,
-	OFFSET_TRANSFER_LEN = 0x14,
+	OFFSET_TRANSFER_LEN,
-	OFFSET_TRANSAC_LEN = 0x18,
+	OFFSET_TRANSAC_LEN,
-	OFFSET_DELAY_LEN = 0x1c,
+	OFFSET_DELAY_LEN,
-	OFFSET_TIMING = 0x20,
+	OFFSET_TIMING,
-	OFFSET_START = 0x24,
+	OFFSET_START,
-	OFFSET_EXT_CONF = 0x28,
+	OFFSET_EXT_CONF,
-	OFFSET_FIFO_STAT = 0x30,
+	OFFSET_FIFO_STAT,
-	OFFSET_FIFO_THRESH = 0x34,
+	OFFSET_FIFO_THRESH,
-	OFFSET_FIFO_ADDR_CLR = 0x38,
+	OFFSET_FIFO_ADDR_CLR,
-	OFFSET_IO_CONFIG = 0x40,
+	OFFSET_IO_CONFIG,
-	OFFSET_RSV_DEBUG = 0x44,
+	OFFSET_RSV_DEBUG,
-	OFFSET_HS = 0x48,
+	OFFSET_HS,
-	OFFSET_SOFTRESET = 0x50,
+	OFFSET_SOFTRESET,
-	OFFSET_DCM_EN = 0x54,
+	OFFSET_DCM_EN,
-	OFFSET_PATH_DIR = 0x60,
+	OFFSET_PATH_DIR,
-	OFFSET_DEBUGSTAT = 0x64,
+	OFFSET_DEBUGSTAT,
-	OFFSET_DEBUGCTRL = 0x68,
+	OFFSET_DEBUGCTRL,
-	OFFSET_TRANSFER_LEN_AUX = 0x6c,
+	OFFSET_TRANSFER_LEN_AUX,
-	OFFSET_CLOCK_DIV = 0x70,
+	OFFSET_CLOCK_DIV,
+	OFFSET_LTIMING,
+};
+
+static const u16 mt_i2c_regs_v1[] = {
+	[OFFSET_DATA_PORT] = 0x0,
+	[OFFSET_SLAVE_ADDR] = 0x4,
+	[OFFSET_INTR_MASK] = 0x8,
+	[OFFSET_INTR_STAT] = 0xc,
+	[OFFSET_CONTROL] = 0x10,
+	[OFFSET_TRANSFER_LEN] = 0x14,
+	[OFFSET_TRANSAC_LEN] = 0x18,
+	[OFFSET_DELAY_LEN] = 0x1c,
+	[OFFSET_TIMING] = 0x20,
+	[OFFSET_START] = 0x24,
+	[OFFSET_EXT_CONF] = 0x28,
+	[OFFSET_FIFO_STAT] = 0x30,
+	[OFFSET_FIFO_THRESH] = 0x34,
+	[OFFSET_FIFO_ADDR_CLR] = 0x38,
+	[OFFSET_IO_CONFIG] = 0x40,
+	[OFFSET_RSV_DEBUG] = 0x44,
+	[OFFSET_HS] = 0x48,
+	[OFFSET_SOFTRESET] = 0x50,
+	[OFFSET_DCM_EN] = 0x54,
+	[OFFSET_PATH_DIR] = 0x60,
+	[OFFSET_DEBUGSTAT] = 0x64,
+	[OFFSET_DEBUGCTRL] = 0x68,
+	[OFFSET_TRANSFER_LEN_AUX] = 0x6c,
+	[OFFSET_CLOCK_DIV] = 0x70,
+};
+
+static const u16 mt_i2c_regs_v2[] = {
+	[OFFSET_DATA_PORT] = 0x0,
+	[OFFSET_SLAVE_ADDR] = 0x4,
+	[OFFSET_INTR_MASK] = 0x8,
+	[OFFSET_INTR_STAT] = 0xc,
+	[OFFSET_CONTROL] = 0x10,
+	[OFFSET_TRANSFER_LEN] = 0x14,
+	[OFFSET_TRANSAC_LEN] = 0x18,
+	[OFFSET_DELAY_LEN] = 0x1c,
+	[OFFSET_TIMING] = 0x20,
+	[OFFSET_START] = 0x24,
+	[OFFSET_EXT_CONF] = 0x28,
+	[OFFSET_LTIMING] = 0x2c,
+	[OFFSET_HS] = 0x30,
+	[OFFSET_IO_CONFIG] = 0x34,
+	[OFFSET_FIFO_ADDR_CLR] = 0x38,
+	[OFFSET_TRANSFER_LEN_AUX] = 0x44,
+	[OFFSET_CLOCK_DIV] = 0x48,
+	[OFFSET_SOFTRESET] = 0x50,
+	[OFFSET_DEBUGSTAT] = 0xe0,
+	[OFFSET_DEBUGCTRL] = 0xe8,
+	[OFFSET_FIFO_STAT] = 0xf4,
+	[OFFSET_FIFO_THRESH] = 0xf8,
+	[OFFSET_DCM_EN] = 0xf88,
 };
 
 struct mtk_i2c_compatible {
 	const struct i2c_adapter_quirks *quirks;
+	const u16 *regs;
 	unsigned char pmic_i2c: 1;
 	unsigned char dcm: 1;
 	unsigned char auto_restart: 1;
 	unsigned char aux_len_reg: 1;
 	unsigned char support_33bits: 1;
 	unsigned char timing_adjust: 1;
+	unsigned char dma_sync: 1;
+	unsigned char ltiming_adjust: 1;
 };
 
 struct mtk_i2c {
@@ -153,6 +213,7 @@ struct mtk_i2c {
 	struct clk *clk_main;		/* main clock for i2c bus */
 	struct clk *clk_dma;		/* DMA clock for i2c via DMA */
 	struct clk *clk_pmic;		/* PMIC clock for i2c from PMIC */
+	struct clk *clk_arb;		/* Arbitrator clock for i2c */
 	bool have_pmic;			/* can use i2c pins from PMIC */
 	bool use_push_pull;		/* IO config push-pull mode */
 
@@ -162,6 +223,7 @@ struct mtk_i2c {
 	enum mtk_trans_op op;
 	u16 timing_reg;
 	u16 high_speed_reg;
+	u16 ltiming_reg;
 	unsigned char auto_restart;
 	bool ignore_restart_irq;
 	const struct mtk_i2c_compatible *dev_comp;
@@ -181,51 +243,78 @@ static const struct i2c_adapter_quirks mt7622_i2c_quirks = {
 };
 
 static const struct mtk_i2c_compatible mt2712_compat = {
+	.regs = mt_i2c_regs_v1,
 	.pmic_i2c = 0,
 	.dcm = 1,
 	.auto_restart = 1,
 	.aux_len_reg = 1,
 	.support_33bits = 1,
 	.timing_adjust = 1,
+	.dma_sync = 0,
+	.ltiming_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt6577_compat = {
 	.quirks = &mt6577_i2c_quirks,
+	.regs = mt_i2c_regs_v1,
 	.pmic_i2c = 0,
 	.dcm = 1,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
 	.support_33bits = 0,
 	.timing_adjust = 0,
+	.dma_sync = 0,
+	.ltiming_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt6589_compat = {
 	.quirks = &mt6577_i2c_quirks,
+	.regs = mt_i2c_regs_v1,
 	.pmic_i2c = 1,
 	.dcm = 0,
 	.auto_restart = 0,
 	.aux_len_reg = 0,
 	.support_33bits = 0,
 	.timing_adjust = 0,
+	.dma_sync = 0,
+	.ltiming_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt7622_compat = {
 	.quirks = &mt7622_i2c_quirks,
+	.regs = mt_i2c_regs_v1,
 	.pmic_i2c = 0,
 	.dcm = 1,
 	.auto_restart = 1,
 	.aux_len_reg = 1,
 	.support_33bits = 0,
 	.timing_adjust = 0,
+	.dma_sync = 0,
+	.ltiming_adjust = 0,
 };
 
 static const struct mtk_i2c_compatible mt8173_compat = {
+	.regs = mt_i2c_regs_v1,
 	.pmic_i2c = 0,
 	.dcm = 1,
 	.auto_restart = 1,
 	.aux_len_reg = 1,
 	.support_33bits = 1,
 	.timing_adjust = 0,
+	.dma_sync = 0,
+	.ltiming_adjust = 0,
+};
+
+static const struct mtk_i2c_compatible mt8183_compat = {
+	.regs = mt_i2c_regs_v2,
+	.pmic_i2c = 0,
+	.dcm = 0,
+	.auto_restart = 1,
+	.aux_len_reg = 1,
+	.support_33bits = 1,
+	.timing_adjust = 1,
+	.dma_sync = 1,
+	.ltiming_adjust = 1,
 };
 
 static const struct of_device_id mtk_i2c_of_match[] = {
@@ -234,10 +323,22 @@ static const struct of_device_id mtk_i2c_of_match[] = {
 	{ .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat },
 	{ .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat },
 	{ .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat },
+	{ .compatible = "mediatek,mt8183-i2c", .data = &mt8183_compat },
 	{}
 };
 MODULE_DEVICE_TABLE(of, mtk_i2c_of_match);
 
+static u16 mtk_i2c_readw(struct mtk_i2c *i2c, enum I2C_REGS_OFFSET reg)
+{
+	return readw(i2c->base + i2c->dev_comp->regs[reg]);
+}
+
+static void mtk_i2c_writew(struct mtk_i2c *i2c, u16 val,
+			   enum I2C_REGS_OFFSET reg)
+{
+	writew(val, i2c->base + i2c->dev_comp->regs[reg]);
+}
+
 static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
 {
 	int ret;
@@ -255,8 +356,18 @@ static int mtk_i2c_clock_enable(struct mtk_i2c *i2c)
 		if (ret)
 			goto err_pmic;
 	}
+
+	if (i2c->clk_arb) {
+		ret = clk_prepare_enable(i2c->clk_arb);
+		if (ret)
+			goto err_arb;
+	}
+
 	return 0;
 
+err_arb:
+	if (i2c->have_pmic)
+		clk_disable_unprepare(i2c->clk_pmic);
 err_pmic:
 	clk_disable_unprepare(i2c->clk_main);
 err_main:
@@ -267,6 +378,9 @@ err_main:
 
 static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
 {
+	if (i2c->clk_arb)
+		clk_disable_unprepare(i2c->clk_arb);
+
 	if (i2c->have_pmic)
 		clk_disable_unprepare(i2c->clk_pmic);
 
@@ -278,31 +392,36 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 {
 	u16 control_reg;
 
-	writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET);
+	mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
 
 	/* Set ioconfig */
 	if (i2c->use_push_pull)
-		writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG);
+		mtk_i2c_writew(i2c, I2C_IO_CONFIG_PUSH_PULL, OFFSET_IO_CONFIG);
 	else
-		writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG);
+		mtk_i2c_writew(i2c, I2C_IO_CONFIG_OPEN_DRAIN, OFFSET_IO_CONFIG);
 
 	if (i2c->dev_comp->dcm)
-		writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN);
+		mtk_i2c_writew(i2c, I2C_DCM_DISABLE, OFFSET_DCM_EN);
 
 	if (i2c->dev_comp->timing_adjust)
-		writew(I2C_DEFAULT_CLK_DIV - 1, i2c->base + OFFSET_CLOCK_DIV);
+		mtk_i2c_writew(i2c, I2C_DEFAULT_CLK_DIV - 1, OFFSET_CLOCK_DIV);
 
-	writew(i2c->timing_reg, i2c->base + OFFSET_TIMING);
+	mtk_i2c_writew(i2c, i2c->timing_reg, OFFSET_TIMING);
-	writew(i2c->high_speed_reg, i2c->base + OFFSET_HS);
+	mtk_i2c_writew(i2c, i2c->high_speed_reg, OFFSET_HS);
+	if (i2c->dev_comp->ltiming_adjust)
+		mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
 
 	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
 	if (i2c->have_pmic)
-		writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR);
+		mtk_i2c_writew(i2c, I2C_CONTROL_WRAPPER, OFFSET_PATH_DIR);
 
 	control_reg = I2C_CONTROL_ACKERR_DET_EN |
 		      I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
-	writew(control_reg, i2c->base + OFFSET_CONTROL);
+	if (i2c->dev_comp->dma_sync)
-	writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
+		control_reg |= I2C_CONTROL_DMAACK_EN | I2C_CONTROL_ASYNC_MODE;
+
+	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
+	mtk_i2c_writew(i2c, I2C_DELAY_LEN, OFFSET_DELAY_LEN);
 
 	writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
 	udelay(50);
@@ -390,6 +509,8 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 	unsigned int clk_src;
 	unsigned int step_cnt;
 	unsigned int sample_cnt;
+	unsigned int l_step_cnt;
+	unsigned int l_sample_cnt;
 	unsigned int target_speed;
 	int ret;
 
@@ -399,11 +520,11 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 	if (target_speed > MAX_FS_MODE_SPEED) {
 		/* Set master code speed register */
 		ret = mtk_i2c_calculate_speed(i2c, clk_src, MAX_FS_MODE_SPEED,
-					      &step_cnt, &sample_cnt);
+					      &l_step_cnt, &l_sample_cnt);
 		if (ret < 0)
 			return ret;
 
-		i2c->timing_reg = (sample_cnt << 8) | step_cnt;
+		i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
 
 		/* Set the high speed mode register */
 		ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
@@ -413,6 +534,10 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 
 		i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
 			(sample_cnt << 12) | (step_cnt << 8);
+
+		if (i2c->dev_comp->ltiming_adjust)
+			i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt |
+					   (sample_cnt << 12) | (step_cnt << 9);
 	} else {
 		ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
 					      &step_cnt, &sample_cnt);
@@ -423,6 +548,9 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 
 		/* Disable the high speed transaction */
 		i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
+
+		if (i2c->dev_comp->ltiming_adjust)
+			i2c->ltiming_reg = (sample_cnt << 6) | step_cnt;
 	}
 
 	return 0;
@@ -454,7 +582,7 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 
 	reinit_completion(&i2c->msg_complete);
 
-	control_reg = readw(i2c->base + OFFSET_CONTROL) &
+	control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
 			~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
 	if ((i2c->speed_hz > MAX_FS_MODE_SPEED) || (left_num >= 1))
 		control_reg |= I2C_CONTROL_RS;
@@ -462,40 +590,41 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 	if (i2c->op == I2C_MASTER_WRRD)
 		control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS;
 
-	writew(control_reg, i2c->base + OFFSET_CONTROL);
+	mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL);
 
 	/* set start condition */
 	if (i2c->speed_hz <= I2C_DEFAULT_SPEED)
-		writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF);
+		mtk_i2c_writew(i2c, I2C_ST_START_CON, OFFSET_EXT_CONF);
 	else
-		writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF);
+		mtk_i2c_writew(i2c, I2C_FS_START_CON, OFFSET_EXT_CONF);
 
 	addr_reg = i2c_8bit_addr_from_msg(msgs);
-	writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR);
+	mtk_i2c_writew(i2c, addr_reg, OFFSET_SLAVE_ADDR);
 
 	/* Clear interrupt status */
-	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
-	       I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
+			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT);
-	writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR);
+
+	mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR);
 
 	/* Enable interrupt */
-	writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
-	       I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK);
+			    I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK);
 
 	/* Set transfer and transaction len */
 	if (i2c->op == I2C_MASTER_WRRD) {
 		if (i2c->dev_comp->aux_len_reg) {
-			writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
+			mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
-			writew((msgs + 1)->len, i2c->base +
+			mtk_i2c_writew(i2c, (msgs + 1)->len,
-			       OFFSET_TRANSFER_LEN_AUX);
+					    OFFSET_TRANSFER_LEN_AUX);
 		} else {
-			writew(msgs->len | ((msgs + 1)->len) << 8,
+			mtk_i2c_writew(i2c, msgs->len | ((msgs + 1)->len) << 8,
-			       i2c->base + OFFSET_TRANSFER_LEN);
+					    OFFSET_TRANSFER_LEN);
 		}
-		writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN);
+		mtk_i2c_writew(i2c, I2C_WRRD_TRANAC_VALUE, OFFSET_TRANSAC_LEN);
 	} else {
-		writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN);
+		mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN);
-		writew(num, i2c->base + OFFSET_TRANSAC_LEN);
+		mtk_i2c_writew(i2c, num, OFFSET_TRANSAC_LEN);
 	}
 
 	/* Prepare buffer data to start transfer */
@@ -607,14 +736,14 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 		if (left_num >= 1)
 			start_reg |= I2C_RS_MUL_CNFG;
 	}
-	writew(start_reg, i2c->base + OFFSET_START);
+	mtk_i2c_writew(i2c, start_reg, OFFSET_START);
 
 	ret = wait_for_completion_timeout(&i2c->msg_complete,
 					  i2c->adap.timeout);
 
 	/* Clear interrupt mask */
-	writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
+	mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR |
-	       I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK);
+			    I2C_ARB_LOST | I2C_TRANSAC_COMP), OFFSET_INTR_MASK);
 
 	if (i2c->op == I2C_MASTER_WR) {
 		dma_unmap_single(i2c->dev, wpaddr,
@@ -724,8 +853,8 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 	if (i2c->auto_restart)
 		restart_flag = I2C_RS_TRANSFER;
 
-	intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
+	intr_stat = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
-	writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
+	mtk_i2c_writew(i2c, intr_stat, OFFSET_INTR_STAT);
 
 	/*
 	 * when occurs ack error, i2c controller generate two interrupts
@@ -737,8 +866,8 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
 	if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) {
 		i2c->ignore_restart_irq = false;
 		i2c->irq_stat = 0;
-		writew(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START,
+		mtk_i2c_writew(i2c, I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG |
-		       i2c->base + OFFSET_START);
+				    I2C_TRANSAC_START, OFFSET_START);
 	} else {
 		if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
 			complete(&i2c->msg_complete);
@@ -839,6 +968,10 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 		return PTR_ERR(i2c->clk_dma);
 	}
 
+	i2c->clk_arb = devm_clk_get(&pdev->dev, "arb");
+	if (IS_ERR(i2c->clk_arb))
+		i2c->clk_arb = NULL;
+
 	clk = i2c->clk_main;
 	if (i2c->have_pmic) {
 		i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic");

drivers/i2c/busses/i2c-nomadik.c

@@ -1070,8 +1070,7 @@ static int nmk_i2c_remove(struct amba_device *adev)
 	/* disable the controller */
 	i2c_clr_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
 	clk_disable_unprepare(dev->clk);
-	if (res)
+	release_mem_region(res->start, resource_size(res));
-		release_mem_region(res->start, resource_size(res));
 
 	return 0;
 }

drivers/i2c/busses/i2c-ocores.c

@@ -26,8 +26,6 @@
 #include <linux/spinlock.h>
 #include <linux/jiffies.h>
 
-#define OCORES_FLAG_POLL BIT(0)
-
 /*
  * 'process_lock' exists because ocores_process() and ocores_process_timeout()
  * can't run in parallel.
@@ -37,7 +35,6 @@ struct ocores_i2c {
 	int iobase;
 	u32 reg_shift;
 	u32 reg_io_width;
-	unsigned long flags;
 	wait_queue_head_t wait;
 	struct i2c_adapter adap;
 	struct i2c_msg *msg;
@@ -403,11 +400,7 @@ static int ocores_xfer_polling(struct i2c_adapter *adap,
 static int ocores_xfer(struct i2c_adapter *adap,
 		       struct i2c_msg *msgs, int num)
 {
-	struct ocores_i2c *i2c = i2c_get_adapdata(adap);
+	return ocores_xfer_core(i2c_get_adapdata(adap), msgs, num, false);
-
-	if (i2c->flags & OCORES_FLAG_POLL)
-		return ocores_xfer_polling(adap, msgs, num);
-	return ocores_xfer_core(i2c, msgs, num, false);
 }
 
 static int ocores_init(struct device *dev, struct ocores_i2c *i2c)
@@ -447,8 +440,9 @@ static u32 ocores_func(struct i2c_adapter *adap)
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
-static const struct i2c_algorithm ocores_algorithm = {
+static struct i2c_algorithm ocores_algorithm = {
 	.master_xfer = ocores_xfer,
+	.master_xfer_atomic = ocores_xfer_polling,
 	.functionality = ocores_func,
 };
 
@@ -673,13 +667,13 @@ static int ocores_i2c_probe(struct platform_device *pdev)
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq == -ENXIO) {
-		i2c->flags |= OCORES_FLAG_POLL;
+		ocores_algorithm.master_xfer = ocores_xfer_polling;
 	} else {
 		if (irq < 0)
 			return irq;
 	}
 
-	if (!(i2c->flags & OCORES_FLAG_POLL)) {
+	if (ocores_algorithm.master_xfer != ocores_xfer_polling) {
 		ret = devm_request_irq(&pdev->dev, irq, ocores_isr, 0,
 				       pdev->name, i2c);
 		if (ret) {

drivers/i2c/busses/i2c-omap.c

@@ -269,6 +269,8 @@ static const u8 reg_map_ip_v2[] = {
 	[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
 };
 
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);
+
 static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,
 				      int reg, u16 val)
 {
@@ -648,15 +650,28 @@ static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx)
 			(1000 * omap->speed / 8);
 }
 
+static void omap_i2c_wait(struct omap_i2c_dev *omap)
+{
+	u16 stat;
+	u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+	int count = 0;
+
+	do {
+		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+		count++;
+	} while (!(stat & mask) && count < 5);
+}
+
 /*
  * Low level master read/write transaction.
  */
 static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
-			     struct i2c_msg *msg, int stop)
+			     struct i2c_msg *msg, int stop, bool polling)
 {
 	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
 	unsigned long timeout;
 	u16 w;
+	int ret;
 
 	dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
 		msg->addr, msg->len, msg->flags, stop);
@@ -680,7 +695,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
 	omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
 
-	reinit_completion(&omap->cmd_complete);
+	if (!polling)
+		reinit_completion(&omap->cmd_complete);
 	omap->cmd_err = 0;
 
 	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
@@ -732,8 +748,18 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
 	 * REVISIT: We should abort the transfer on signals, but the bus goes
 	 * into arbitration and we're currently unable to recover from it.
 	 */
-	timeout = wait_for_completion_timeout(&omap->cmd_complete,
+	if (!polling) {
-						OMAP_I2C_TIMEOUT);
+		timeout = wait_for_completion_timeout(&omap->cmd_complete,
+						      OMAP_I2C_TIMEOUT);
+	} else {
+		do {
+			omap_i2c_wait(omap);
+			ret = omap_i2c_xfer_data(omap);
+		} while (ret == -EAGAIN);
+
+		timeout = !ret;
+	}
+
 	if (timeout == 0) {
 		dev_err(omap->dev, "controller timed out\n");
 		omap_i2c_reset(omap);
@@ -772,7 +798,8 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
  * to do the work during IRQ processing.
  */
 static int
-omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,
+		     bool polling)
 {
 	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
 	int i;
@@ -794,7 +821,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 		omap->set_mpu_wkup_lat(omap->dev, omap->latency);
 
 	for (i = 0; i < num; i++) {
-		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),
+				      polling);
 		if (r != 0)
 			break;
 	}
@@ -813,6 +841,18 @@ out:
 	return r;
 }
 
+static int
+omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	return omap_i2c_xfer_common(adap, msgs, num, false);
+}
+
+static int
+omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	return omap_i2c_xfer_common(adap, msgs, num, true);
+}
+
 static u32
 omap_i2c_func(struct i2c_adapter *adap)
 {
@@ -1035,10 +1075,8 @@ omap_i2c_isr(int irq, void *dev_id)
 	return ret;
 }
 
-static irqreturn_t
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)
-omap_i2c_isr_thread(int this_irq, void *dev_id)
 {
-	struct omap_i2c_dev *omap = dev_id;
 	u16 bits;
 	u16 stat;
 	int err = 0, count = 0;
@@ -1056,7 +1094,8 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 
 		if (!stat) {
 			/* my work here is done */
-			goto out;
+			err = -EAGAIN;
+			break;
 		}
 
 		dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
@@ -1165,14 +1204,25 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 		}
 	} while (stat);
 
-	omap_i2c_complete_cmd(omap, err);
+	return err;
+}
+
+static irqreturn_t
+omap_i2c_isr_thread(int this_irq, void *dev_id)
+{
+	int ret;
+	struct omap_i2c_dev *omap = dev_id;
+
+	ret = omap_i2c_xfer_data(omap);
+	if (ret != -EAGAIN)
+		omap_i2c_complete_cmd(omap, ret);
 
-out:
 	return IRQ_HANDLED;
 }
 
 static const struct i2c_algorithm omap_i2c_algo = {
-	.master_xfer	= omap_i2c_xfer,
+	.master_xfer	= omap_i2c_xfer_irq,
+	.master_xfer_atomic	= omap_i2c_xfer_polling,
 	.functionality	= omap_i2c_func,
 };
 

drivers/i2c/busses/i2c-piix4.c

@@ -19,6 +19,7 @@
 	Serverworks OSB4, CSB5, CSB6, HT-1000, HT-1100
 	ATI IXP200, IXP300, IXP400, SB600, SB700/SP5100, SB800
 	AMD Hudson-2, ML, CZ
+	Hygon CZ
 	SMSC Victory66
 
    Note: we assume there can only be one device, with one or more
@@ -289,7 +290,9 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 	     PIIX4_dev->revision >= 0x41) ||
 	    (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD &&
 	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
-	     PIIX4_dev->revision >= 0x49))
+	     PIIX4_dev->revision >= 0x49) ||
+	    (PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON &&
+	     PIIX4_dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS))
 		smb_en = 0x00;
 	else
 		smb_en = (aux) ? 0x28 : 0x2c;
@@ -361,7 +364,8 @@ static int piix4_setup_sb800(struct pci_dev *PIIX4_dev,
 		 piix4_smba, i2ccfg >> 4);
 
 	/* Find which register is used for port selection */
-	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD) {
+	if (PIIX4_dev->vendor == PCI_VENDOR_ID_AMD ||
+	    PIIX4_dev->vendor == PCI_VENDOR_ID_HYGON) {
 		switch (PIIX4_dev->device) {
 		case PCI_DEVICE_ID_AMD_KERNCZ_SMBUS:
 			piix4_port_sel_sb800 = SB800_PIIX4_PORT_IDX_KERNCZ;
@@ -794,6 +798,7 @@ static const struct pci_device_id piix4_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
 		     PCI_DEVICE_ID_SERVERWORKS_OSB4) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_SERVERWORKS,
@@ -904,11 +909,13 @@ static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
 	     dev->revision >= 0x40) ||
-	    dev->vendor == PCI_VENDOR_ID_AMD) {
+	    dev->vendor == PCI_VENDOR_ID_AMD ||
+	    dev->vendor == PCI_VENDOR_ID_HYGON) {
 		bool notify_imc = false;
 		is_sb800 = true;
 
-		if (dev->vendor == PCI_VENDOR_ID_AMD &&
+		if ((dev->vendor == PCI_VENDOR_ID_AMD ||
+		     dev->vendor == PCI_VENDOR_ID_HYGON) &&
 		    dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS) {
 			u8 imc;
 

drivers/i2c/busses/i2c-rcar.c

@@ -85,6 +85,7 @@
 /* ICFBSCR */
 #define TCYC17	0x0f		/* 17*Tcyc delay 1st bit between SDA and SCL */
 
+#define RCAR_MIN_DMA_LEN	8
 
 #define RCAR_BUS_PHASE_START	(MDBS | MIE | ESG)
 #define RCAR_BUS_PHASE_DATA	(MDBS | MIE)
@@ -398,7 +399,7 @@ static void rcar_i2c_dma_callback(void *data)
 	rcar_i2c_dma_unmap(priv);
 }
 
-static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
+static bool rcar_i2c_dma(struct rcar_i2c_priv *priv)
 {
 	struct device *dev = rcar_i2c_priv_to_dev(priv);
 	struct i2c_msg *msg = priv->msg;
@@ -412,9 +413,9 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	int len;
 
 	/* Do various checks to see if DMA is feasible at all */
-	if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE) ||
+	if (IS_ERR(chan) || msg->len < RCAR_MIN_DMA_LEN ||
-	    (read && priv->flags & ID_P_NO_RXDMA))
+	    !(msg->flags & I2C_M_DMA_SAFE) || (read && priv->flags & ID_P_NO_RXDMA))
-		return;
+		return false;
 
 	if (read) {
 		/*
@@ -434,7 +435,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	dma_addr = dma_map_single(chan->device->dev, buf, len, dir);
 	if (dma_mapping_error(chan->device->dev, dma_addr)) {
 		dev_dbg(dev, "dma map failed, using PIO\n");
-		return;
+		return false;
 	}
 
 	sg_dma_len(&priv->sg) = len;
@@ -448,7 +449,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	if (!txdesc) {
 		dev_dbg(dev, "dma prep slave sg failed, using PIO\n");
 		rcar_i2c_cleanup_dma(priv);
-		return;
+		return false;
 	}
 
 	txdesc->callback = rcar_i2c_dma_callback;
@@ -458,7 +459,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 	if (dma_submit_error(cookie)) {
 		dev_dbg(dev, "submitting dma failed, using PIO\n");
 		rcar_i2c_cleanup_dma(priv);
-		return;
+		return false;
 	}
 
 	/* Enable DMA Master Received/Transmitted */
@@ -468,6 +469,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
 		rcar_i2c_write(priv, ICDMAER, TMDMAE);
 
 	dma_async_issue_pending(chan);
+	return true;
 }
 
 static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
@@ -478,6 +480,10 @@ static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
 	if (!(msr & MDE))
 		return;
 
+	/* Check if DMA can be enabled and take over */
+	if (priv->pos == 1 && rcar_i2c_dma(priv))
+		return;
+
 	if (priv->pos < msg->len) {
 		/*
 		 * Prepare next data to ICRXTX register.
@@ -488,13 +494,6 @@ static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
 		 */
 		rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
 		priv->pos++;
-
-		/*
-		 * Try to use DMA to transmit the rest of the data if
-		 * address transfer phase just finished.
-		 */
-		if (msr & MAT)
-			rcar_i2c_dma(priv);
 	} else {
 		/*
 		 * The last data was pushed to ICRXTX on _PREV_ empty irq.
@@ -921,6 +920,9 @@ static int rcar_i2c_probe(struct platform_device *pdev)
 	struct i2c_timings i2c_t;
 	int irq, ret;
 
+	/* Otherwise logic will break because some bytes must always use PIO */
+	BUILD_BUG_ON_MSG(RCAR_MIN_DMA_LEN < 3, "Invalid min DMA length");
+
 	priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
 	if (!priv)
 		return -ENOMEM;

drivers/i2c/busses/i2c-riic.c

@@ -43,6 +43,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 #define RIIC_ICCR1	0x00
 #define RIIC_ICCR2	0x04
@@ -112,12 +113,10 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 {
 	struct riic_dev *riic = i2c_get_adapdata(adap);
 	unsigned long time_left;
-	int i, ret;
+	int i;
 	u8 start_bit;
 
-	ret = clk_prepare_enable(riic->clk);
+	pm_runtime_get_sync(adap->dev.parent);
-	if (ret)
-		return ret;
 
 	if (readb(riic->base + RIIC_ICCR2) & ICCR2_BBSY) {
 		riic->err = -EBUSY;
@@ -150,7 +149,7 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	}
 
  out:
-	clk_disable_unprepare(riic->clk);
+	pm_runtime_put(adap->dev.parent);
 
 	return riic->err ?: num;
 }
@@ -281,20 +280,18 @@ static const struct i2c_algorithm riic_algo = {
 
 static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
 {
-	int ret;
+	int ret = 0;
 	unsigned long rate;
 	int total_ticks, cks, brl, brh;
 
-	ret = clk_prepare_enable(riic->clk);
+	pm_runtime_get_sync(riic->adapter.dev.parent);
-	if (ret)
-		return ret;
 
 	if (t->bus_freq_hz > 400000) {
 		dev_err(&riic->adapter.dev,
 			"unsupported bus speed (%dHz). 400000 max\n",
 			t->bus_freq_hz);
-		clk_disable_unprepare(riic->clk);
+		ret = -EINVAL;
-		return -EINVAL;
+		goto out;
 	}
 
 	rate = clk_get_rate(riic->clk);
@@ -332,8 +329,8 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
 	if (brl > (0x1F + 3)) {
 		dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
 			(unsigned long)t->bus_freq_hz);
-		clk_disable_unprepare(riic->clk);
+		ret = -EINVAL;
-		return -EINVAL;
+		goto out;
 	}
 
 	brh = total_ticks - brl;
@@ -378,9 +375,9 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
 
 	riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
 
-	clk_disable_unprepare(riic->clk);
+out:
-
+	pm_runtime_put(riic->adapter.dev.parent);
-	return 0;
+	return ret;
 }
 
 static struct riic_irq_desc riic_irqs[] = {
@@ -439,28 +436,36 @@ static int riic_i2c_probe(struct platform_device *pdev)
 
 	i2c_parse_fw_timings(&pdev->dev, &i2c_t, true);
 
+	pm_runtime_enable(&pdev->dev);
+
 	ret = riic_init_hw(riic, &i2c_t);
 	if (ret)
-		return ret;
+		goto out;
-
 
 	ret = i2c_add_adapter(adap);
 	if (ret)
-		return ret;
+		goto out;
 
 	platform_set_drvdata(pdev, riic);
 
 	dev_info(&pdev->dev, "registered with %dHz bus speed\n",
 		 i2c_t.bus_freq_hz);
 	return 0;
+
+out:
+	pm_runtime_disable(&pdev->dev);
+	return ret;
 }
 
 static int riic_i2c_remove(struct platform_device *pdev)
 {
 	struct riic_dev *riic = platform_get_drvdata(pdev);
 
+	pm_runtime_get_sync(&pdev->dev);
 	writeb(0, riic->base + RIIC_ICIER);
+	pm_runtime_put(&pdev->dev);
 	i2c_del_adapter(&riic->adapter);
+	pm_runtime_disable(&pdev->dev);
 
 	return 0;
 }

drivers/i2c/busses/i2c-stm32f7.c

@@ -476,8 +476,12 @@ static int stm32f7_i2c_compute_timing(struct stm32f7_i2c_dev *i2c_dev,
 
 					list_add_tail(&v->node,
 						      &solutions);
+					break;
 				}
 			}
+
+			if (p_prev == p)
+				break;
 		}
 	}
 

drivers/i2c/busses/i2c-stu300.c

@@ -328,12 +328,6 @@ static int stu300_start_and_await_event(struct stu300_dev *dev,
 {
 	int ret;
 
-	if (unlikely(irqs_disabled())) {
-		/* TODO: implement polling for this case if need be. */
-		WARN(1, "irqs are disabled, cannot poll for event\n");
-		return -EIO;
-	}
-
 	/* Lock command issue, fill in an event we wait for */
 	spin_lock_irq(&dev->cmd_issue_lock);
 	init_completion(&dev->cmd_complete);
@@ -380,13 +374,6 @@ static int stu300_await_event(struct stu300_dev *dev,
 {
 	int ret;
 
-	if (unlikely(irqs_disabled())) {
-		/* TODO: implement polling for this case if need be. */
-		dev_err(&dev->pdev->dev, "irqs are disabled on this "
-			"system!\n");
-		return -EIO;
-	}
-
 	/* Is it already here? */
 	spin_lock_irq(&dev->cmd_issue_lock);
 	dev->cmd_err = STU300_ERROR_NONE;
@@ -846,6 +833,13 @@ static int stu300_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 	return num;
 }
 
+static int stu300_xfer_todo(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	/* TODO: implement polling for this case if need be. */
+	WARN(1, "%s: atomic transfers not implemented\n", dev_name(&adap->dev));
+	return -EOPNOTSUPP;
+}
+
 static u32 stu300_func(struct i2c_adapter *adap)
 {
 	/* This is the simplest thing you can think of... */
@@ -853,8 +847,9 @@ static u32 stu300_func(struct i2c_adapter *adap)
 }
 
 static const struct i2c_algorithm stu300_algo = {
-	.master_xfer	= stu300_xfer,
+	.master_xfer = stu300_xfer,
-	.functionality	= stu300_func,
+	.master_xfer_atomic = stu300_xfer_todo,
+	.functionality = stu300_func,
 };
 
 static const struct i2c_adapter_quirks stu300_quirks = {

drivers/i2c/busses/i2c-tegra-bpmp.c

@@ -207,7 +207,8 @@ static int tegra_bpmp_i2c_msg_len_check(struct i2c_msg *msgs, unsigned int num)
 
 static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c,
 				   struct mrq_i2c_request *request,
-				   struct mrq_i2c_response *response)
+				   struct mrq_i2c_response *response,
+				   bool atomic)
 {
 	struct tegra_bpmp_message msg;
 	int err;
@@ -222,7 +223,7 @@ static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c,
 	msg.rx.data = response;
 	msg.rx.size = sizeof(*response);
 
-	if (irqs_disabled())
+	if (atomic)
 		err = tegra_bpmp_transfer_atomic(i2c->bpmp, &msg);
 	else
 		err = tegra_bpmp_transfer(i2c->bpmp, &msg);
@@ -230,8 +231,9 @@ static int tegra_bpmp_i2c_msg_xfer(struct tegra_bpmp_i2c *i2c,
 	return err;
 }
 
-static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
+static int tegra_bpmp_i2c_xfer_common(struct i2c_adapter *adapter,
-			       struct i2c_msg *msgs, int num)
+				      struct i2c_msg *msgs, int num,
+				      bool atomic)
 {
 	struct tegra_bpmp_i2c *i2c = i2c_get_adapdata(adapter);
 	struct mrq_i2c_response response;
@@ -253,7 +255,7 @@ static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
 		return err;
 	}
 
-	err = tegra_bpmp_i2c_msg_xfer(i2c, &request, &response);
+	err = tegra_bpmp_i2c_msg_xfer(i2c, &request, &response, atomic);
 	if (err < 0) {
 		dev_err(i2c->dev, "failed to transfer message: %d\n", err);
 		return err;
@@ -268,6 +270,18 @@ static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
 	return num;
 }
 
+static int tegra_bpmp_i2c_xfer(struct i2c_adapter *adapter,
+			       struct i2c_msg *msgs, int num)
+{
+	return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, false);
+}
+
+static int tegra_bpmp_i2c_xfer_atomic(struct i2c_adapter *adapter,
+				      struct i2c_msg *msgs, int num)
+{
+	return tegra_bpmp_i2c_xfer_common(adapter, msgs, num, true);
+}
+
 static u32 tegra_bpmp_i2c_func(struct i2c_adapter *adapter)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
@@ -276,6 +290,7 @@ static u32 tegra_bpmp_i2c_func(struct i2c_adapter *adapter)
 
 static const struct i2c_algorithm tegra_bpmp_i2c_algo = {
 	.master_xfer = tegra_bpmp_i2c_xfer,
+	.master_xfer_atomic = tegra_bpmp_i2c_xfer_atomic,
 	.functionality = tegra_bpmp_i2c_func,
 };
 

drivers/i2c/i2c-core-base.c

@@ -1871,8 +1871,10 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 
 	if (WARN_ON(!msgs || num < 1))
 		return -EINVAL;
-	if (WARN_ON(test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)))
+
-		return -ESHUTDOWN;
+	ret = __i2c_check_suspended(adap);
+	if (ret)
+		return ret;
 
 	if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
 		return -EOPNOTSUPP;
@@ -1894,7 +1896,11 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	/* Retry automatically on arbitration loss */
 	orig_jiffies = jiffies;
 	for (ret = 0, try = 0; try <= adap->retries; try++) {
-		ret = adap->algo->master_xfer(adap, msgs, num);
+		if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic)
+			ret = adap->algo->master_xfer_atomic(adap, msgs, num);
+		else
+			ret = adap->algo->master_xfer(adap, msgs, num);
+
 		if (ret != -EAGAIN)
 			break;
 		if (time_after(jiffies, orig_jiffies + adap->timeout))
@@ -1950,14 +1956,9 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 	 *    one (discarding status on the second message) or errno
 	 *    (discarding status on the first one).
 	 */
-	if (in_atomic() || irqs_disabled()) {
+	ret = __i2c_lock_bus_helper(adap);
-		ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
+	if (ret)
-		if (!ret)
+		return ret;
-			/* I2C activity is ongoing. */
-			return -EAGAIN;
-	} else {
-		i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
-	}
 
 	ret = __i2c_transfer(adap, msgs, num);
 	i2c_unlock_bus(adap, I2C_LOCK_SEGMENT);

drivers/i2c/i2c-core-smbus.c

@@ -20,6 +20,8 @@
 #include <linux/i2c-smbus.h>
 #include <linux/slab.h>
 
+#include "i2c-core.h"
+
 #define CREATE_TRACE_POINTS
 #include <trace/events/smbus.h>
 
@@ -530,7 +532,10 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 {
 	s32 res;
 
-	i2c_lock_bus(adapter, I2C_LOCK_SEGMENT);
+	res = __i2c_lock_bus_helper(adapter);
+	if (res)
+		return res;
+
 	res = __i2c_smbus_xfer(adapter, addr, flags, read_write,
 			       command, protocol, data);
 	i2c_unlock_bus(adapter, I2C_LOCK_SEGMENT);
@@ -543,10 +548,17 @@ s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 		     unsigned short flags, char read_write,
 		     u8 command, int protocol, union i2c_smbus_data *data)
 {
+	int (*xfer_func)(struct i2c_adapter *adap, u16 addr,
+			 unsigned short flags, char read_write,
+			 u8 command, int size, union i2c_smbus_data *data);
 	unsigned long orig_jiffies;
 	int try;
 	s32 res;
 
+	res = __i2c_check_suspended(adapter);
+	if (res)
+		return res;
+
 	/* If enabled, the following two tracepoints are conditional on
 	 * read_write and protocol.
 	 */
@@ -557,13 +569,20 @@ s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 
 	flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
 
-	if (adapter->algo->smbus_xfer) {
+	xfer_func = adapter->algo->smbus_xfer;
+	if (i2c_in_atomic_xfer_mode()) {
+		if (adapter->algo->smbus_xfer_atomic)
+			xfer_func = adapter->algo->smbus_xfer_atomic;
+		else if (adapter->algo->master_xfer_atomic)
+			xfer_func = NULL; /* fallback to I2C emulation */
+	}
+
+	if (xfer_func) {
 		/* Retry automatically on arbitration loss */
 		orig_jiffies = jiffies;
 		for (res = 0, try = 0; try <= adapter->retries; try++) {
-			res = adapter->algo->smbus_xfer(adapter, addr, flags,
+			res = xfer_func(adapter, addr, flags, read_write,
-							read_write, command,
+					command, protocol, data);
-							protocol, data);
 			if (res != -EAGAIN)
 				break;
 			if (time_after(jiffies,

drivers/i2c/i2c-core.h

@@ -29,6 +29,42 @@ extern int		__i2c_first_dynamic_bus_num;
 
 int i2c_check_7bit_addr_validity_strict(unsigned short addr);
 
+/*
+ * We only allow atomic transfers for very late communication, e.g. to send
+ * the powerdown command to a PMIC. Atomic transfers are a corner case and not
+ * for generic use!
+ */
+static inline bool i2c_in_atomic_xfer_mode(void)
+{
+	return system_state > SYSTEM_RUNNING && irqs_disabled();
+}
+
+static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap)
+{
+	int ret = 0;
+
+	if (i2c_in_atomic_xfer_mode()) {
+		WARN(!adap->algo->master_xfer_atomic && !adap->algo->smbus_xfer_atomic,
+		     "No atomic I2C transfer handler for '%s'\n", dev_name(&adap->dev));
+		ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT) ? 0 : -EAGAIN;
+	} else {
+		i2c_lock_bus(adap, I2C_LOCK_SEGMENT);
+	}
+
+	return ret;
+}
+
+static inline int __i2c_check_suspended(struct i2c_adapter *adap)
+{
+	if (test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)) {
+		if (!test_and_set_bit(I2C_ALF_SUSPEND_REPORTED, &adap->locked_flags))
+			dev_WARN(&adap->dev, "Transfer while suspended\n");
+		return -ESHUTDOWN;
+	}
+
+	return 0;
+}
+
 #ifdef CONFIG_ACPI
 const struct acpi_device_id *
 i2c_acpi_match_device(const struct acpi_device_id *matches,

drivers/i2c/i2c-mux.c

@@ -310,12 +310,18 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 		else
 			priv->algo.master_xfer = __i2c_mux_master_xfer;
 	}
+	if (parent->algo->master_xfer_atomic)
+		priv->algo.master_xfer_atomic = priv->algo.master_xfer;
+
 	if (parent->algo->smbus_xfer) {
 		if (muxc->mux_locked)
 			priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
 		else
 			priv->algo.smbus_xfer = __i2c_mux_smbus_xfer;
 	}
+	if (parent->algo->smbus_xfer_atomic)
+		priv->algo.smbus_xfer_atomic = priv->algo.smbus_xfer;
+
 	priv->algo.functionality = i2c_mux_functionality;
 
 	/* Now fill out new adapter structure */

drivers/i2c/muxes/i2c-demux-pinctrl.c

@@ -99,6 +99,8 @@ static int i2c_demux_activate_master(struct i2c_demux_pinctrl_priv *priv, u32 ne
 
 	/* Now fill out current adapter structure. cur_chan must be up to date */
 	priv->algo.master_xfer = i2c_demux_master_xfer;
+	if (adap->algo->master_xfer_atomic)
+		priv->algo.master_xfer_atomic = i2c_demux_master_xfer;
 	priv->algo.functionality = i2c_demux_functionality;
 
 	snprintf(priv->cur_adap.name, sizeof(priv->cur_adap.name),
@@ -219,8 +221,8 @@ static int i2c_demux_pinctrl_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	priv = devm_kzalloc(&pdev->dev, sizeof(*priv)
+	priv = devm_kzalloc(&pdev->dev, struct_size(priv, chan, num_chan),
-			   + num_chan * sizeof(struct i2c_demux_pinctrl_chan), GFP_KERNEL);
+			    GFP_KERNEL);
 
 	props = devm_kcalloc(&pdev->dev, num_chan, sizeof(*props), GFP_KERNEL);
 

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

@@ -22,7 +22,6 @@
 #include <linux/i2c-mux.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>
-#include <linux/platform_data/pca954x.h>
 #include <linux/slab.h>
 
 /*
@@ -287,10 +286,8 @@ static int pca9541_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adap = client->adapter;
-	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct i2c_mux_core *muxc;
 	struct pca9541 *data;
-	int force;
 	int ret;
 
 	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE_DATA))
@@ -306,9 +303,6 @@ static int pca9541_probe(struct i2c_client *client,
 
 	/* Create mux adapter */
 
-	force = 0;
-	if (pdata)
-		force = pdata->modes[0].adap_id;
 	muxc = i2c_mux_alloc(adap, &client->dev, 1, sizeof(*data),
 			     I2C_MUX_ARBITRATOR,
 			     pca9541_select_chan, pca9541_release_chan);
@@ -320,7 +314,7 @@ static int pca9541_probe(struct i2c_client *client,
 
 	i2c_set_clientdata(client, muxc);
 
-	ret = i2c_mux_add_adapter(muxc, force, 0, 0);
+	ret = i2c_mux_add_adapter(muxc, 0, 0, 0);
 	if (ret)
 		return ret;
 

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

@@ -46,10 +46,10 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
-#include <linux/platform_data/pca954x.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <dt-bindings/mux/mux.h>
 
 #define PCA954X_MAX_NCHANS 8
 
@@ -85,7 +85,9 @@ struct pca954x {
 	const struct chip_desc *chip;
 
 	u8 last_chan;		/* last register value */
-	u8 deselect;
+	/* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */
+	s8 idle_state;
+
 	struct i2c_client *client;
 
 	struct irq_domain *irq;
@@ -254,15 +256,71 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan)
 {
 	struct pca954x *data = i2c_mux_priv(muxc);
 	struct i2c_client *client = data->client;
+	s8 idle_state;
 
-	if (!(data->deselect & (1 << chan)))
+	idle_state = READ_ONCE(data->idle_state);
-		return 0;
+	if (idle_state >= 0)
+		/* Set the mux back to a predetermined channel */
+		return pca954x_select_chan(muxc, idle_state);
 
-	/* Deselect active channel */
+	if (idle_state == MUX_IDLE_DISCONNECT) {
-	data->last_chan = 0;
+		/* Deselect active channel */
-	return pca954x_reg_write(muxc->parent, client, data->last_chan);
+		data->last_chan = 0;
+		return pca954x_reg_write(muxc->parent, client,
+					 data->last_chan);
+	}
+
+	/* otherwise leave as-is */
+
+	return 0;
 }
 
+static ssize_t idle_state_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+	struct pca954x *data = i2c_mux_priv(muxc);
+
+	return sprintf(buf, "%d\n", READ_ONCE(data->idle_state));
+}
+
+static ssize_t idle_state_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
+	struct pca954x *data = i2c_mux_priv(muxc);
+	int val;
+	int ret;
+
+	ret = kstrtoint(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val != MUX_IDLE_AS_IS && val != MUX_IDLE_DISCONNECT &&
+	    (val < 0 || val >= data->chip->nchans))
+		return -EINVAL;
+
+	i2c_lock_bus(muxc->parent, I2C_LOCK_SEGMENT);
+
+	WRITE_ONCE(data->idle_state, val);
+	/*
+	 * Set the mux into a state consistent with the new
+	 * idle_state.
+	 */
+	if (data->last_chan || val != MUX_IDLE_DISCONNECT)
+		ret = pca954x_deselect_mux(muxc, 0);
+
+	i2c_unlock_bus(muxc->parent, I2C_LOCK_SEGMENT);
+
+	return ret < 0 ? ret : count;
+}
+
+static DEVICE_ATTR_RW(idle_state);
+
 static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
 {
 	struct pca954x *data = dev_id;
@@ -329,8 +387,11 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
 static void pca954x_cleanup(struct i2c_mux_core *muxc)
 {
 	struct pca954x *data = i2c_mux_priv(muxc);
+	struct i2c_client *client = data->client;
 	int c, irq;
 
+	device_remove_file(&client->dev, &dev_attr_idle_state);
+
 	if (data->irq) {
 		for (c = 0; c < data->chip->nchans; c++) {
 			irq = irq_find_mapping(data->irq, c);
@@ -348,14 +409,13 @@ static int pca954x_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adap = client->adapter;
-	struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
 	struct device *dev = &client->dev;
 	struct device_node *np = dev->of_node;
 	bool idle_disconnect_dt;
 	struct gpio_desc *gpio;
-	int num, force, class;
 	struct i2c_mux_core *muxc;
 	struct pca954x *data;
+	int num;
 	int ret;
 
 	if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
@@ -412,9 +472,12 @@ static int pca954x_probe(struct i2c_client *client,
 	}
 
 	data->last_chan = 0;		   /* force the first selection */
+	data->idle_state = MUX_IDLE_AS_IS;
 
 	idle_disconnect_dt = np &&
 		of_property_read_bool(np, "i2c-mux-idle-disconnect");
+	if (idle_disconnect_dt)
+		data->idle_state = MUX_IDLE_DISCONNECT;
 
 	ret = pca954x_irq_setup(muxc);
 	if (ret)
@@ -422,24 +485,7 @@ static int pca954x_probe(struct i2c_client *client,
 
 	/* Now create an adapter for each channel */
 	for (num = 0; num < data->chip->nchans; num++) {
-		bool idle_disconnect_pd = false;
+		ret = i2c_mux_add_adapter(muxc, 0, num, 0);
-
-		force = 0;			  /* dynamic adap number */
-		class = 0;			  /* no class by default */
-		if (pdata) {
-			if (num < pdata->num_modes) {
-				/* force static number */
-				force = pdata->modes[num].adap_id;
-				class = pdata->modes[num].class;
-			} else
-				/* discard unconfigured channels */
-				break;
-			idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
-		}
-		data->deselect |= (idle_disconnect_pd ||
-				   idle_disconnect_dt) << num;
-
-		ret = i2c_mux_add_adapter(muxc, force, num, class);
 		if (ret)
 			goto fail_cleanup;
 	}
@@ -453,6 +499,12 @@ static int pca954x_probe(struct i2c_client *client,
 			goto fail_cleanup;
 	}
 
+	/*
+	 * The attr probably isn't going to be needed in most cases,
+	 * so don't fail completely on error.
+	 */
+	device_create_file(dev, &dev_attr_idle_state);
+
 	dev_info(dev, "registered %d multiplexed busses for I2C %s %s\n",
 		 num, data->chip->muxtype == pca954x_ismux
 				? "mux" : "switch", client->name);

include/linux/i2c-algo-bit.h

@@ -33,6 +33,7 @@ struct i2c_algo_bit_data {
 				   minimum 5 us for standard-mode I2C and SMBus,
 				   maximum 50 us for SMBus */
 	int timeout;		/* in jiffies */
+	bool can_do_atomic;	/* callbacks don't sleep, we can be atomic */
 };
 
 int i2c_bit_add_bus(struct i2c_adapter *);

include/linux/i2c.h

@@ -499,9 +499,13 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
  *   defined by the msgs array, with num messages available to transfer via
  *   the adapter specified by adap.
+ * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
+ *   so e.g. PMICs can be accessed very late before shutdown. Optional.
  * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
  *   is not present, then the bus layer will try and convert the SMBus calls
  *   into I2C transfers instead.
+ * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
+ *   so e.g. PMICs can be accessed very late before shutdown. Optional.
  * @functionality: Return the flags that this algorithm/adapter pair supports
  *   from the I2C_FUNC_* flags.
  * @reg_slave: Register given client to I2C slave mode of this adapter
@@ -512,25 +516,33 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  * to name two of the most common.
  *
- * The return codes from the @master_xfer field should indicate the type of
+ * The return codes from the @master_xfer{_atomic} fields should indicate the
- * error code that occurred during the transfer, as documented in the kernel
+ * type of error code that occurred during the transfer, as documented in the
- * Documentation file Documentation/i2c/fault-codes.
+ * Kernel Documentation file Documentation/i2c/fault-codes.
  */
 struct i2c_algorithm {
-	/* If an adapter algorithm can't do I2C-level access, set master_xfer
+	/*
-	   to NULL. If an adapter algorithm can do SMBus access, set
+	 * If an adapter algorithm can't do I2C-level access, set master_xfer
-	   smbus_xfer. If set to NULL, the SMBus protocol is simulated
+	 * to NULL. If an adapter algorithm can do SMBus access, set
-	   using common I2C messages */
+	 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
-	/* master_xfer should return the number of messages successfully
+	 * using common I2C messages.
-	   processed, or a negative value on error */
+	 *
+	 * master_xfer should return the number of messages successfully
+	 * processed, or a negative value on error
+	 */
 	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
 			   int num);
-	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
+	int (*master_xfer_atomic)(struct i2c_adapter *adap,
-			   unsigned short flags, char read_write,
+				   struct i2c_msg *msgs, int num);
-			   u8 command, int size, union i2c_smbus_data *data);
+	int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr,
+			  unsigned short flags, char read_write,
+			  u8 command, int size, union i2c_smbus_data *data);
+	int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr,
+				 unsigned short flags, char read_write,
+				 u8 command, int size, union i2c_smbus_data *data);
 
 	/* To determine what the adapter supports */
-	u32 (*functionality) (struct i2c_adapter *);
+	u32 (*functionality)(struct i2c_adapter *adap);
 
 #if IS_ENABLED(CONFIG_I2C_SLAVE)
 	int (*reg_slave)(struct i2c_client *client);
@@ -682,7 +694,8 @@ struct i2c_adapter {
 	int retries;
 	struct device dev;		/* the adapter device */
 	unsigned long locked_flags;	/* owned by the I2C core */
-#define I2C_ALF_IS_SUSPENDED	0
+#define I2C_ALF_IS_SUSPENDED		0
+#define I2C_ALF_SUSPEND_REPORTED	1
 
 	int nr;
 	char name[48];

include/linux/platform_data/pca954x.h

@@ -1,48 +0,0 @@
-/*
- *
- * pca954x.h - I2C multiplexer/switch support
- *
- * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
- * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
- * Michael Lawnick <michael.lawnick.ext@nsn.com>
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-
-#ifndef _LINUX_I2C_PCA954X_H
-#define _LINUX_I2C_PCA954X_H
-
-/* Platform data for the PCA954x I2C multiplexers */
-
-/* Per channel initialisation data:
- * @adap_id: bus number for the adapter. 0 = don't care
- * @deselect_on_exit: set this entry to 1, if your H/W needs deselection
- *                    of this channel after transaction.
- *
- */
-struct pca954x_platform_mode {
-	int		adap_id;
-	unsigned int	deselect_on_exit:1;
-	unsigned int	class;
-};
-
-/* Per mux/switch data, used with i2c_register_board_info */
-struct pca954x_platform_data {
-	struct pca954x_platform_mode *modes;
-	int num_modes;
-};
-
-#endif /* _LINUX_I2C_PCA954X_H */