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Merge branch 'for-linus/i2c' of git://git.fluff.org/bjdooks/linux 

* 'for-linus/i2c' of git://git.fluff.org/bjdooks/linux:
  i2c: Add support for Xilinx XPS IIC Bus Interface
  i2c: omap: Add support for 16-bit registers
  i2c-pnx: fix setting start/stop condition
  powerpc: doc/dts-bindings: update doc of FSL I2C bindings
  i2c-mpc: add support for the MPC512x processors from Freescale
  i2c-mpc: rename "setclock" initialization functions to "setup"
  i2c-mpc: use __devinit[data] for initialization functions and data
  i2c/imx: don't add probe function to the driver struct
  i2c: Add support for Ux500/Nomadik I2C controller
This commit is contained in:
Linus Torvalds 2010-03-07 15:56:25 -08:00
parent 6dc3eb5c1f 3f4ae86052
commit dd04265b02
9 changed files with 1973 additions and 116 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
Documentation/powerpc/dts-bindings/fsl/i2c.txt
View File

@ -2,15 +2,14 @@
Required properties :
- device_type : Should be "i2c"
- reg : Offset and length of the register set for the device
- compatible : should be "fsl,CHIP-i2c" where CHIP is the name of a
compatible processor, e.g. mpc8313, mpc8543, mpc8544, mpc5121,
mpc5200 or mpc5200b. For the mpc5121, an additional node
"fsl,mpc5121-i2c-ctrl" is required as shown in the example below.
Recommended properties :
- compatible : compatibility list with 2 entries, the first should
be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor,
e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one
should be "fsl-i2c".
- interrupts : <a b> where a is the interrupt number and b is a
field that represents an encoding of the sense and level
information for the interrupt. This should be encoded based on
@ -24,25 +23,40 @@ Recommended properties :
Examples :
/* MPC5121 based board */
i2c@1740 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,mpc5121-i2c", "fsl-i2c";
reg = <0x1740 0x20>;
interrupts = <11 0x8>;
interrupt-parent = <&ipic>;
clock-frequency = <100000>;
};
i2ccontrol@1760 {
compatible = "fsl,mpc5121-i2c-ctrl";
reg = <0x1760 0x8>;
};
/* MPC5200B based board */
i2c@3d00 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,mpc5200b-i2c","fsl,mpc5200-i2c","fsl-i2c";
cell-index = <0>;
reg = <0x3d00 0x40>;
interrupts = <2 15 0>;
interrupt-parent = <&mpc5200_pic>;
fsl,preserve-clocking;
};
/* MPC8544 base board */
i2c@3100 {
#address-cells = <1>;
#size-cells = <0>;
cell-index = <1>;
compatible = "fsl,mpc8544-i2c", "fsl-i2c";
reg = <0x3100 0x100>;
interrupts = <43 2>;
interrupt-parent = <&mpic>;
clock-frequency = <400000>;
};

24
drivers/i2c/busses/Kconfig
View File

@ -421,13 +421,12 @@ config I2C_IXP2000
instead.
config I2C_MPC
tristate "MPC107/824x/85xx/52xx/86xx"
tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
depends on PPC32
help
If you say yes to this option, support will be included for the
built-in I2C interface on the MPC107/Tsi107/MPC8240/MPC8245 and
MPC85xx/MPC8641 family processors. The driver may also work on 52xx
family processors, though interrupts are known not to work.
built-in I2C interface on the MPC107, Tsi107, MPC512x, MPC52xx,
MPC8240, MPC8245, MPC83xx, MPC85xx and MPC8641 family processors.
This driver can also be built as a module. If so, the module
will be called i2c-mpc.
@ -442,6 +441,13 @@ config I2C_MV64XXX
This driver can also be built as a module. If so, the module
will be called i2c-mv64xxx.
config I2C_NOMADIK
tristate "ST-Ericsson Nomadik/Ux500 I2C Controller"
depends on PLAT_NOMADIK
help
If you say yes to this option, support will be included for the
I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
config I2C_OCORES
tristate "OpenCores I2C Controller"
depends on EXPERIMENTAL
@ -577,6 +583,16 @@ config I2C_OCTEON
This driver can also be built as a module. If so, the module
will be called i2c-octeon.
config I2C_XILINX
tristate "Xilinx I2C Controller"
depends on EXPERIMENTAL && HAS_IOMEM
help
If you say yes to this option, support will be included for the
Xilinx I2C controller.
This driver can also be built as a module. If so, the module
will be called xilinx_i2c.
comment "External I2C/SMBus adapter drivers"
config I2C_PARPORT

2
drivers/i2c/busses/Makefile
View File

@ -42,6 +42,7 @@ obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
@ -55,6 +56,7 @@ obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
# External I2C/SMBus adapter drivers
obj-$(CONFIG_I2C_PARPORT) += i2c-parport.o

1
drivers/i2c/busses/i2c-imx.c
View File

@ -627,7 +627,6 @@ static int __exit i2c_imx_remove(struct platform_device *pdev)
}
static struct platform_driver i2c_imx_driver = {
.probe = i2c_imx_probe,
.remove = __exit_p(i2c_imx_remove),
.driver = {
.name = DRIVER_NAME,

166
drivers/i2c/busses/i2c-mpc.c
View File

@ -31,6 +31,9 @@
#define DRV_NAME "mpc-i2c"
#define MPC_I2C_CLOCK_LEGACY 0
#define MPC_I2C_CLOCK_PRESERVE (~0U)
#define MPC_I2C_FDR 0x04
#define MPC_I2C_CR 0x08
#define MPC_I2C_SR 0x0c
@ -66,9 +69,8 @@ struct mpc_i2c_divider {
u16 fdr; /* including dfsrr */
};
struct mpc_i2c_match_data {
void (*setclock)(struct device_node *node,
struct mpc_i2c *i2c,
struct mpc_i2c_data {
void (*setup)(struct device_node *node, struct mpc_i2c *i2c,
u32 clock, u32 prescaler);
u32 prescaler;
};
@ -164,8 +166,8 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
return 0;
}
#ifdef CONFIG_PPC_MPC52xx
static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
#if defined(CONFIG_PPC_MPC52xx) || defined(CONFIG_PPC_MPC512x)
static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] __devinitconst = {
{20, 0x20}, {22, 0x21}, {24, 0x22}, {26, 0x23},
{28, 0x24}, {30, 0x01}, {32, 0x25}, {34, 0x02},
{36, 0x26}, {40, 0x27}, {44, 0x04}, {48, 0x28},
@ -186,14 +188,15 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_52xx[] = {
{10240, 0x9d}, {12288, 0x9e}, {15360, 0x9f}
};
int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, int prescaler)
static int __devinit mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock,
int prescaler)
{
const struct mpc_i2c_divider *div = NULL;
unsigned int pvr = mfspr(SPRN_PVR);
u32 divider;
int i;
if (!clock)
if (clock == MPC_I2C_CLOCK_LEGACY)
return -EINVAL;
/* Determine divider value */
@ -215,12 +218,18 @@ int mpc_i2c_get_fdr_52xx(struct device_node *node, u32 clock, int prescaler)
return div ? (int)div->fdr : -EINVAL;
}
static void mpc_i2c_setclock_52xx(struct device_node *node,
static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
int ret, fdr;
if (clock == MPC_I2C_CLOCK_PRESERVE) {
dev_dbg(i2c->dev, "using fdr %d\n",
readb(i2c->base + MPC_I2C_FDR));
return;
}
ret = mpc_i2c_get_fdr_52xx(node, clock, prescaler);
fdr = (ret >= 0) ? ret : 0x3f; /* backward compatibility */
@ -229,16 +238,52 @@ static void mpc_i2c_setclock_52xx(struct device_node *node,
if (ret >= 0)
dev_info(i2c->dev, "clock %d Hz (fdr=%d)\n", clock, fdr);
}
#else /* !CONFIG_PPC_MPC52xx */
static void mpc_i2c_setclock_52xx(struct device_node *node,
#else /* !(CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x) */
static void __devinit mpc_i2c_setup_52xx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
}
#endif /* CONFIG_PPC_MPC52xx*/
#endif /* CONFIG_PPC_MPC52xx || CONFIG_PPC_MPC512x */
#ifdef CONFIG_PPC_MPC512x
static void __devinit mpc_i2c_setup_512x(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
struct device_node *node_ctrl;
void __iomem *ctrl;
const u32 *pval;
u32 idx;
/* Enable I2C interrupts for mpc5121 */
node_ctrl = of_find_compatible_node(NULL, NULL,
"fsl,mpc5121-i2c-ctrl");
if (node_ctrl) {
ctrl = of_iomap(node_ctrl, 0);
if (ctrl) {
/* Interrupt enable bits for i2c-0/1/2: bit 24/26/28 */
pval = of_get_property(node, "reg", NULL);
idx = (*pval & 0xff) / 0x20;
setbits32(ctrl, 1 << (24 + idx * 2));
iounmap(ctrl);
}
of_node_put(node_ctrl);
}
/* The clock setup for the 52xx works also fine for the 512x */
mpc_i2c_setup_52xx(node, i2c, clock, prescaler);
}
#else /* CONFIG_PPC_MPC512x */
static void __devinit mpc_i2c_setup_512x(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
}
#endif /* CONFIG_PPC_MPC512x */
#ifdef CONFIG_FSL_SOC
static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] __devinitconst = {
{160, 0x0120}, {192, 0x0121}, {224, 0x0122}, {256, 0x0123},
{288, 0x0100}, {320, 0x0101}, {352, 0x0601}, {384, 0x0102},
{416, 0x0602}, {448, 0x0126}, {480, 0x0103}, {512, 0x0127},
@ -258,7 +303,7 @@ static const struct mpc_i2c_divider mpc_i2c_dividers_8xxx[] = {
{49152, 0x011e}, {61440, 0x011f}
};
u32 mpc_i2c_get_sec_cfg_8xxx(void)
static u32 __devinit mpc_i2c_get_sec_cfg_8xxx(void)
{
struct device_node *node = NULL;
u32 __iomem *reg;
@ -287,13 +332,14 @@ u32 mpc_i2c_get_sec_cfg_8xxx(void)
return val;
}
int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, u32 prescaler)
static int __devinit mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock,
u32 prescaler)
{
const struct mpc_i2c_divider *div = NULL;
u32 divider;
int i;
if (!clock)
if (clock == MPC_I2C_CLOCK_LEGACY)
return -EINVAL;
/* Determine proper divider value */
@ -320,12 +366,19 @@ int mpc_i2c_get_fdr_8xxx(struct device_node *node, u32 clock, u32 prescaler)
return div ? (int)div->fdr : -EINVAL;
}
static void mpc_i2c_setclock_8xxx(struct device_node *node,
static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
int ret, fdr;
if (clock == MPC_I2C_CLOCK_PRESERVE) {
dev_dbg(i2c->dev, "using dfsrr %d, fdr %d\n",
readb(i2c->base + MPC_I2C_DFSRR),
readb(i2c->base + MPC_I2C_FDR));
return;
}
ret = mpc_i2c_get_fdr_8xxx(node, clock, prescaler);
fdr = (ret >= 0) ? ret : 0x1031; /* backward compatibility */
@ -338,7 +391,7 @@ static void mpc_i2c_setclock_8xxx(struct device_node *node,
}
#else /* !CONFIG_FSL_SOC */
static void mpc_i2c_setclock_8xxx(struct device_node *node,
static void __devinit mpc_i2c_setup_8xxx(struct device_node *node,
struct mpc_i2c *i2c,
u32 clock, u32 prescaler)
{
@ -494,7 +547,7 @@ static int __devinit fsl_i2c_probe(struct of_device *op,
{
struct mpc_i2c *i2c;
const u32 *prop;
u32 clock = 0;
u32 clock = MPC_I2C_CLOCK_LEGACY;
int result = 0;
int plen;
@ -523,21 +576,21 @@ static int __devinit fsl_i2c_probe(struct of_device *op,
}
}
if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) {
clock = MPC_I2C_CLOCK_PRESERVE;
} else {
prop = of_get_property(op->node, "clock-frequency", &plen);
if (prop && plen == sizeof(u32))
clock = *prop;
}
if (match->data) {
struct mpc_i2c_match_data *data =
(struct mpc_i2c_match_data *)match->data;
data->setclock(op->node, i2c, clock, data->prescaler);
struct mpc_i2c_data *data = match->data;
data->setup(op->node, i2c, clock, data->prescaler);
} else {
/* Backwards compatibility */
if (of_get_property(op->node, "dfsrr", NULL))
mpc_i2c_setclock_8xxx(op->node, i2c,
clock, 0);
}
mpc_i2c_setup_8xxx(op->node, i2c, clock, 0);
}
dev_set_drvdata(&op->dev, i2c);
@ -582,47 +635,42 @@ static int __devexit fsl_i2c_remove(struct of_device *op)
return 0;
};
static const struct of_device_id mpc_i2c_of_match[] = {
{.compatible = "mpc5200-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_52xx,
},
},
{.compatible = "fsl,mpc5200b-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_52xx,
},
},
{.compatible = "fsl,mpc5200-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_52xx,
},
},
{.compatible = "fsl,mpc8313-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_8xxx,
},
},
{.compatible = "fsl,mpc8543-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_8xxx,
static struct mpc_i2c_data mpc_i2c_data_512x __devinitdata = {
.setup = mpc_i2c_setup_512x,
};
static struct mpc_i2c_data mpc_i2c_data_52xx __devinitdata = {
.setup = mpc_i2c_setup_52xx,
};
static struct mpc_i2c_data mpc_i2c_data_8313 __devinitdata = {
.setup = mpc_i2c_setup_8xxx,
};
static struct mpc_i2c_data mpc_i2c_data_8543 __devinitdata = {
.setup = mpc_i2c_setup_8xxx,
.prescaler = 2,
},
},
{.compatible = "fsl,mpc8544-i2c",
.data = &(struct mpc_i2c_match_data) {
.setclock = mpc_i2c_setclock_8xxx,
};
static struct mpc_i2c_data mpc_i2c_data_8544 __devinitdata = {
.setup = mpc_i2c_setup_8xxx,
.prescaler = 3,
},
};
static const struct of_device_id mpc_i2c_of_match[] = {
{.compatible = "mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5200b-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5200-i2c", .data = &mpc_i2c_data_52xx, },
{.compatible = "fsl,mpc5121-i2c", .data = &mpc_i2c_data_512x, },
{.compatible = "fsl,mpc8313-i2c", .data = &mpc_i2c_data_8313, },
{.compatible = "fsl,mpc8543-i2c", .data = &mpc_i2c_data_8543, },
{.compatible = "fsl,mpc8544-i2c", .data = &mpc_i2c_data_8544, },
/* Backward compatibility */
},
{.compatible = "fsl-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
/* Structure for a device driver */
static struct of_platform_driver mpc_i2c_driver = {
.match_table = mpc_i2c_of_match,
@ -655,5 +703,5 @@ module_exit(fsl_i2c_exit);
MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
MODULE_DESCRIPTION("I2C-Bus adapter for MPC107 bridge and "
"MPC824x/85xx/52xx processors");
"MPC824x/83xx/85xx/86xx/512x/52xx processors");
MODULE_LICENSE("GPL");

959
drivers/i2c/busses/i2c-nomadik.c Normal file
View File

@ -0,0 +1,959 @@
/*
* Copyright (C) 2009 ST-Ericsson
* Copyright (C) 2009 STMicroelectronics
*
* I2C master mode controller driver, used in Nomadik 8815
* and Ux500 platforms.
*
* Author: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
* Author: Sachin Verma <sachin.verma@st.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2, as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <plat/i2c.h>
#define DRIVER_NAME "nmk-i2c"
/* I2C Controller register offsets */
#define I2C_CR (0x000)
#define I2C_SCR (0x004)
#define I2C_HSMCR (0x008)
#define I2C_MCR (0x00C)
#define I2C_TFR (0x010)
#define I2C_SR (0x014)
#define I2C_RFR (0x018)
#define I2C_TFTR (0x01C)
#define I2C_RFTR (0x020)
#define I2C_DMAR (0x024)
#define I2C_BRCR (0x028)
#define I2C_IMSCR (0x02C)
#define I2C_RISR (0x030)
#define I2C_MISR (0x034)
#define I2C_ICR (0x038)
/* Control registers */
#define I2C_CR_PE (0x1 << 0) /* Peripheral Enable */
#define I2C_CR_OM (0x3 << 1) /* Operating mode */
#define I2C_CR_SAM (0x1 << 3) /* Slave addressing mode */
#define I2C_CR_SM (0x3 << 4) /* Speed mode */
#define I2C_CR_SGCM (0x1 << 6) /* Slave general call mode */
#define I2C_CR_FTX (0x1 << 7) /* Flush Transmit */
#define I2C_CR_FRX (0x1 << 8) /* Flush Receive */
#define I2C_CR_DMA_TX_EN (0x1 << 9) /* DMA Tx enable */
#define I2C_CR_DMA_RX_EN (0x1 << 10) /* DMA Rx Enable */
#define I2C_CR_DMA_SLE (0x1 << 11) /* DMA sync. logic enable */
#define I2C_CR_LM (0x1 << 12) /* Loopback mode */
#define I2C_CR_FON (0x3 << 13) /* Filtering on */
#define I2C_CR_FS (0x3 << 15) /* Force stop enable */
/* Master controller (MCR) register */
#define I2C_MCR_OP (0x1 << 0) /* Operation */
#define I2C_MCR_A7 (0x7f << 1) /* 7-bit address */
#define I2C_MCR_EA10 (0x7 << 8) /* 10-bit Extended address */
#define I2C_MCR_SB (0x1 << 11) /* Extended address */
#define I2C_MCR_AM (0x3 << 12) /* Address type */
#define I2C_MCR_STOP (0x1 << 14) /* Stop condition */
#define I2C_MCR_LENGTH (0x7ff << 15) /* Transaction length */
/* Status register (SR) */
#define I2C_SR_OP (0x3 << 0) /* Operation */
#define I2C_SR_STATUS (0x3 << 2) /* controller status */
#define I2C_SR_CAUSE (0x7 << 4) /* Abort cause */
#define I2C_SR_TYPE (0x3 << 7) /* Receive type */
#define I2C_SR_LENGTH (0x7ff << 9) /* Transfer length */
/* Interrupt mask set/clear (IMSCR) bits */
#define I2C_IT_TXFE (0x1 << 0)
#define I2C_IT_TXFNE (0x1 << 1)
#define I2C_IT_TXFF (0x1 << 2)
#define I2C_IT_TXFOVR (0x1 << 3)
#define I2C_IT_RXFE (0x1 << 4)
#define I2C_IT_RXFNF (0x1 << 5)
#define I2C_IT_RXFF (0x1 << 6)
#define I2C_IT_RFSR (0x1 << 16)
#define I2C_IT_RFSE (0x1 << 17)
#define I2C_IT_WTSR (0x1 << 18)
#define I2C_IT_MTD (0x1 << 19)
#define I2C_IT_STD (0x1 << 20)
#define I2C_IT_MAL (0x1 << 24)
#define I2C_IT_BERR (0x1 << 25)
#define I2C_IT_MTDWS (0x1 << 28)
#define GEN_MASK(val, mask, sb) (((val) << (sb)) & (mask))
/* some bits in ICR are reserved */
#define I2C_CLEAR_ALL_INTS 0x131f007f
/* first three msb bits are reserved */
#define IRQ_MASK(mask) (mask & 0x1fffffff)
/* maximum threshold value */
#define MAX_I2C_FIFO_THRESHOLD 15
enum i2c_status {
I2C_NOP,
I2C_ON_GOING,
I2C_OK,
I2C_ABORT
};
/* operation */
enum i2c_operation {
I2C_NO_OPERATION = 0xff,
I2C_WRITE = 0x00,
I2C_READ = 0x01
};
/* controller response timeout in ms */
#define I2C_TIMEOUT_MS 500
/**
* struct i2c_nmk_client - client specific data
* @slave_adr: 7-bit slave address
* @count: no. bytes to be transfered
* @buffer: client data buffer
* @xfer_bytes: bytes transfered till now
* @operation: current I2C operation
*/
struct i2c_nmk_client {
unsigned short slave_adr;
unsigned long count;
unsigned char *buffer;
unsigned long xfer_bytes;
enum i2c_operation operation;
};
/**
* struct nmk_i2c_dev - private data structure of the controller
* @pdev: parent platform device
* @adap: corresponding I2C adapter
* @irq: interrupt line for the controller
* @virtbase: virtual io memory area
* @clk: hardware i2c block clock
* @cfg: machine provided controller configuration
* @cli: holder of client specific data
* @stop: stop condition
* @xfer_complete: acknowledge completion for a I2C message
* @result: controller propogated result
*/
struct nmk_i2c_dev {
struct platform_device *pdev;
struct i2c_adapter adap;
int irq;
void __iomem *virtbase;
struct clk *clk;
struct nmk_i2c_controller cfg;
struct i2c_nmk_client cli;
int stop;
struct completion xfer_complete;
int result;
};
/* controller's abort causes */
static const char *abort_causes[] = {
"no ack received after address transmission",
"no ack received during data phase",
"ack received after xmission of master code",
"master lost arbitration",
"slave restarts",
"slave reset",
"overflow, maxsize is 2047 bytes",
};
static inline void i2c_set_bit(void __iomem *reg, u32 mask)
{
writel(readl(reg) | mask, reg);
}
static inline void i2c_clr_bit(void __iomem *reg, u32 mask)
{
writel(readl(reg) & ~mask, reg);
}
/**
* flush_i2c_fifo() - This function flushes the I2C FIFO
* @dev: private data of I2C Driver
*
* This function flushes the I2C Tx and Rx FIFOs. It returns
* 0 on successful flushing of FIFO
*/
static int flush_i2c_fifo(struct nmk_i2c_dev *dev)
{
#define LOOP_ATTEMPTS 10
int i;
unsigned long timeout;
/*
* flush the transmit and receive FIFO. The flushing
* operation takes several cycles before to be completed.
* On the completion, the I2C internal logic clears these
* bits, until then no one must access Tx, Rx FIFO and
* should poll on these bits waiting for the completion.
*/
writel((I2C_CR_FTX | I2C_CR_FRX), dev->virtbase + I2C_CR);
for (i = 0; i < LOOP_ATTEMPTS; i++) {
timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT_MS);
while (!time_after(jiffies, timeout)) {
if ((readl(dev->virtbase + I2C_CR) &
(I2C_CR_FTX | I2C_CR_FRX)) == 0)
return 0;
}
}
dev_err(&dev->pdev->dev, "flushing operation timed out "
"giving up after %d attempts", LOOP_ATTEMPTS);
return -ETIMEDOUT;
}
/**
* disable_all_interrupts() - Disable all interrupts of this I2c Bus
* @dev: private data of I2C Driver
*/
static void disable_all_interrupts(struct nmk_i2c_dev *dev)
{
u32 mask = IRQ_MASK(0);
writel(mask, dev->virtbase + I2C_IMSCR);
}
/**
* clear_all_interrupts() - Clear all interrupts of I2C Controller
* @dev: private data of I2C Driver
*/
static void clear_all_interrupts(struct nmk_i2c_dev *dev)
{
u32 mask;
mask = IRQ_MASK(I2C_CLEAR_ALL_INTS);
writel(mask, dev->virtbase + I2C_ICR);
}
/**
* init_hw() - initialize the I2C hardware
* @dev: private data of I2C Driver
*/
static int init_hw(struct nmk_i2c_dev *dev)
{
int stat;
stat = flush_i2c_fifo(dev);
if (stat)
return stat;
/* disable the controller */
i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
disable_all_interrupts(dev);
clear_all_interrupts(dev);
dev->cli.operation = I2C_NO_OPERATION;
return 0;
}
/* enable peripheral, master mode operation */
#define DEFAULT_I2C_REG_CR ((1 << 1) | I2C_CR_PE)
/**
* load_i2c_mcr_reg() - load the MCR register
* @dev: private data of controller
*/
static u32 load_i2c_mcr_reg(struct nmk_i2c_dev *dev)
{
u32 mcr = 0;
/* 7-bit address transaction */
mcr |= GEN_MASK(1, I2C_MCR_AM, 12);
mcr |= GEN_MASK(dev->cli.slave_adr, I2C_MCR_A7, 1);
/* start byte procedure not applied */
mcr |= GEN_MASK(0, I2C_MCR_SB, 11);
/* check the operation, master read/write? */
if (dev->cli.operation == I2C_WRITE)
mcr |= GEN_MASK(I2C_WRITE, I2C_MCR_OP, 0);
else
mcr |= GEN_MASK(I2C_READ, I2C_MCR_OP, 0);
/* stop or repeated start? */
if (dev->stop)
mcr |= GEN_MASK(1, I2C_MCR_STOP, 14);
else
mcr &= ~(GEN_MASK(1, I2C_MCR_STOP, 14));
mcr |= GEN_MASK(dev->cli.count, I2C_MCR_LENGTH, 15);
return mcr;
}
/**
* setup_i2c_controller() - setup the controller
* @dev: private data of controller
*/
static void setup_i2c_controller(struct nmk_i2c_dev *dev)
{
u32 brcr1, brcr2;
u32 i2c_clk, div;
writel(0x0, dev->virtbase + I2C_CR);
writel(0x0, dev->virtbase + I2C_HSMCR);
writel(0x0, dev->virtbase + I2C_TFTR);
writel(0x0, dev->virtbase + I2C_RFTR);
writel(0x0, dev->virtbase + I2C_DMAR);
/*
* set the slsu:
*
* slsu defines the data setup time after SCL clock
* stretching in terms of i2c clk cycles. The
* needed setup time for the three modes are 250ns,
* 100ns, 10ns repectively thus leading to the values
* of 14, 6, 2 for a 48 MHz i2c clk.
*/
writel(dev->cfg.slsu << 16, dev->virtbase + I2C_SCR);
i2c_clk = clk_get_rate(dev->clk);
/* fallback to std. mode if machine has not provided it */
if (dev->cfg.clk_freq == 0)
dev->cfg.clk_freq = 100000;
/*
* The spec says, in case of std. mode the divider is
* 2 whereas it is 3 for fast and fastplus mode of
* operation. TODO - high speed support.
*/
div = (dev->cfg.clk_freq > 100000) ? 3 : 2;
/*
* generate the mask for baud rate counters. The controller
* has two baud rate counters. One is used for High speed
* operation, and the other is for std, fast mode, fast mode
* plus operation. Currently we do not supprt high speed mode
* so set brcr1 to 0.
*/
brcr1 = 0 << 16;
brcr2 = (i2c_clk/(dev->cfg.clk_freq * div)) & 0xffff;
/* set the baud rate counter register */
writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
/*
* set the speed mode. Currently we support
* only standard and fast mode of operation
* TODO - support for fast mode plus (upto 1Mb/s)
* and high speed (up to 3.4 Mb/s)
*/
if (dev->cfg.sm > I2C_FREQ_MODE_FAST) {
dev_err(&dev->pdev->dev, "do not support this mode "
"defaulting to std. mode\n");
brcr2 = i2c_clk/(100000 * 2) & 0xffff;
writel((brcr1 | brcr2), dev->virtbase + I2C_BRCR);
writel(I2C_FREQ_MODE_STANDARD << 4,
dev->virtbase + I2C_CR);
}
writel(dev->cfg.sm << 4, dev->virtbase + I2C_CR);
/* set the Tx and Rx FIFO threshold */
writel(dev->cfg.tft, dev->virtbase + I2C_TFTR);
writel(dev->cfg.rft, dev->virtbase + I2C_RFTR);
}
/**
* read_i2c() - Read from I2C client device
* @dev: private data of I2C Driver
*
* This function reads from i2c client device when controller is in
* master mode. There is a completion timeout. If there is no transfer
* before timeout error is returned.
*/
static int read_i2c(struct nmk_i2c_dev *dev)
{
u32 status = 0;
u32 mcr;
u32 irq_mask = 0;
int timeout;
mcr = load_i2c_mcr_reg(dev);
writel(mcr, dev->virtbase + I2C_MCR);
/* load the current CR value */
writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
dev->virtbase + I2C_CR);
/* enable the controller */
i2c_set_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
init_completion(&dev->xfer_complete);
/* enable interrupts by setting the mask */
irq_mask = (I2C_IT_RXFNF | I2C_IT_RXFF |
I2C_IT_MAL | I2C_IT_BERR);
if (dev->stop)
irq_mask |= I2C_IT_MTD;
else
irq_mask |= I2C_IT_MTDWS;
irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);
writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
dev->virtbase + I2C_IMSCR);
timeout = wait_for_completion_interruptible_timeout(
&dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
if (timeout < 0) {
dev_err(&dev->pdev->dev,
"wait_for_completion_interruptible_timeout"
"returned %d waiting for event\n", timeout);
status = timeout;
}
if (timeout == 0) {
/* controler has timedout, re-init the h/w */
dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
(void) init_hw(dev);
status = -ETIMEDOUT;
}
return status;
}
/**
* write_i2c() - Write data to I2C client.
* @dev: private data of I2C Driver
*
* This function writes data to I2C client
*/
static int write_i2c(struct nmk_i2c_dev *dev)
{
u32 status = 0;
u32 mcr;
u32 irq_mask = 0;
int timeout;
mcr = load_i2c_mcr_reg(dev);
writel(mcr, dev->virtbase + I2C_MCR);
/* load the current CR value */
writel(readl(dev->virtbase + I2C_CR) | DEFAULT_I2C_REG_CR,
dev->virtbase + I2C_CR);
/* enable the controller */
i2c_set_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
init_completion(&dev->xfer_complete);
/* enable interrupts by settings the masks */
irq_mask = (I2C_IT_TXFNE | I2C_IT_TXFOVR |
I2C_IT_MAL | I2C_IT_BERR);
/*
* check if we want to transfer a single or multiple bytes, if so
* set the MTDWS bit (Master Transaction Done Without Stop)
* to start repeated start operation
*/
if (dev->stop)
irq_mask |= I2C_IT_MTD;
else
irq_mask |= I2C_IT_MTDWS;
irq_mask = I2C_CLEAR_ALL_INTS & IRQ_MASK(irq_mask);
writel(readl(dev->virtbase + I2C_IMSCR) | irq_mask,
dev->virtbase + I2C_IMSCR);
timeout = wait_for_completion_interruptible_timeout(
&dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
if (timeout < 0) {
dev_err(&dev->pdev->dev,
"wait_for_completion_interruptible_timeout"
"returned %d waiting for event\n", timeout);
status = timeout;
}
if (timeout == 0) {
/* controler has timedout, re-init the h/w */
dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
(void) init_hw(dev);
status = -ETIMEDOUT;
}
return status;
}
/**
* nmk_i2c_xfer() - I2C transfer function used by kernel framework
* @i2c_adap - Adapter pointer to the controller
* @msgs[] - Pointer to data to be written.
* @num_msgs - Number of messages to be executed
*
* This is the function called by the generic kernel i2c_transfer()
* or i2c_smbus...() API calls. Note that this code is protected by the
* semaphore set in the kernel i2c_transfer() function.
*
* NOTE:
* READ TRANSFER : We impose a restriction of the first message to be the
* index message for any read transaction.
* - a no index is coded as '0',
* - 2byte big endian index is coded as '3'
* !!! msg[0].buf holds the actual index.
* This is compatible with generic messages of smbus emulator
* that send a one byte index.
* eg. a I2C transation to read 2 bytes from index 0
* idx = 0;
* msg[0].addr = client->addr;
* msg[0].flags = 0x0;
* msg[0].len = 1;
* msg[0].buf = &idx;
*
* msg[1].addr = client->addr;
* msg[1].flags = I2C_M_RD;
* msg[1].len = 2;
* msg[1].buf = rd_buff
* i2c_transfer(adap, msg, 2);
*
* WRITE TRANSFER : The I2C standard interface interprets all data as payload.
* If you want to emulate an SMBUS write transaction put the
* index as first byte(or first and second) in the payload.
* eg. a I2C transation to write 2 bytes from index 1
* wr_buff[0] = 0x1;
* wr_buff[1] = 0x23;
* wr_buff[2] = 0x46;
* msg[0].flags = 0x0;
* msg[0].len = 3;
* msg[0].buf = wr_buff;
* i2c_transfer(adap, msg, 1);
*
* To read or write a block of data (multiple bytes) using SMBUS emulation
* please use the i2c_smbus_read_i2c_block_data()
* or i2c_smbus_write_i2c_block_data() API
*/
static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
struct i2c_msg msgs[], int num_msgs)
{
int status;
int i;
u32 cause;
struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
status = init_hw(dev);
if (status)
return status;
/* setup the i2c controller */
setup_i2c_controller(dev);
for (i = 0; i < num_msgs; i++) {
if (unlikely(msgs[i].flags & I2C_M_TEN)) {
dev_err(&dev->pdev->dev, "10 bit addressing"
"not supported\n");
return -EINVAL;
}
dev->cli.slave_adr = msgs[i].addr;
dev->cli.buffer = msgs[i].buf;
dev->cli.count = msgs[i].len;
dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
dev->result = 0;
if (msgs[i].flags & I2C_M_RD) {
/* it is a read operation */
dev->cli.operation = I2C_READ;
status = read_i2c(dev);
} else {
/* write operation */
dev->cli.operation = I2C_WRITE;
status = write_i2c(dev);
}
if (status || (dev->result)) {
/* get the abort cause */
cause = (readl(dev->virtbase + I2C_SR) >> 4) & 0x7;
dev_err(&dev->pdev->dev, "error during I2C"
"message xfer: %d\n", cause);
dev_err(&dev->pdev->dev, "%s\n",
cause >= ARRAY_SIZE(abort_causes)
? "unknown reason" : abort_causes[cause]);
return status;
}
mdelay(1);
}
/* return the no. messages processed */
if (status)
return status;
else
return num_msgs;
}
/**
* disable_interrupts() - disable the interrupts
* @dev: private data of controller
*/
static int disable_interrupts(struct nmk_i2c_dev *dev, u32 irq)
{
irq = IRQ_MASK(irq);
writel(readl(dev->virtbase + I2C_IMSCR) & ~(I2C_CLEAR_ALL_INTS & irq),
dev->virtbase + I2C_IMSCR);
return 0;
}
/**
* i2c_irq_handler() - interrupt routine
* @irq: interrupt number
* @arg: data passed to the handler
*
* This is the interrupt handler for the i2c driver. Currently
* it handles the major interrupts like Rx & Tx FIFO management
* interrupts, master transaction interrupts, arbitration and
* bus error interrupts. The rest of the interrupts are treated as
* unhandled.
*/
static irqreturn_t i2c_irq_handler(int irq, void *arg)
{
struct nmk_i2c_dev *dev = arg;
u32 tft, rft;
u32 count;
u32 misr;
u32 src = 0;
/* load Tx FIFO and Rx FIFO threshold values */
tft = readl(dev->virtbase + I2C_TFTR);
rft = readl(dev->virtbase + I2C_RFTR);
/* read interrupt status register */
misr = readl(dev->virtbase + I2C_MISR);
src = __ffs(misr);
switch ((1 << src)) {
/* Transmit FIFO nearly empty interrupt */
case I2C_IT_TXFNE:
{
if (dev->cli.operation == I2C_READ) {
/*
* in read operation why do we care for writing?
* so disable the Transmit FIFO interrupt
*/
disable_interrupts(dev, I2C_IT_TXFNE);
} else {
for (count = (MAX_I2C_FIFO_THRESHOLD - tft - 2);
(count > 0) &&
(dev->cli.count != 0);
count--) {
/* write to the Tx FIFO */
writeb(*dev->cli.buffer,
dev->virtbase + I2C_TFR);
dev->cli.buffer++;
dev->cli.count--;
dev->cli.xfer_bytes++;
}
/*
* if done, close the transfer by disabling the
* corresponding TXFNE interrupt
*/
if (dev->cli.count == 0)
disable_interrupts(dev, I2C_IT_TXFNE);
}
}
break;
/*
* Rx FIFO nearly full interrupt.
* This is set when the numer of entries in Rx FIFO is
* greater or equal than the threshold value programmed
* in RFT
*/
case I2C_IT_RXFNF:
for (count = rft; count > 0; count--) {
/* Read the Rx FIFO */
*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
dev->cli.buffer++;
}
dev->cli.count -= rft;
dev->cli.xfer_bytes += rft;
break;
/* Rx FIFO full */
case I2C_IT_RXFF:
for (count = MAX_I2C_FIFO_THRESHOLD; count > 0; count--) {
*dev->cli.buffer = readb(dev->virtbase + I2C_RFR);
dev->cli.buffer++;
}
dev->cli.count -= MAX_I2C_FIFO_THRESHOLD;
dev->cli.xfer_bytes += MAX_I2C_FIFO_THRESHOLD;
break;
/* Master Transaction Done with/without stop */
case I2C_IT_MTD:
case I2C_IT_MTDWS:
if (dev->cli.operation == I2C_READ) {
while (!readl(dev->virtbase + I2C_RISR) & I2C_IT_RXFE) {
if (dev->cli.count == 0)
break;
*dev->cli.buffer =
readb(dev->virtbase + I2C_RFR);
dev->cli.buffer++;
dev->cli.count--;
dev->cli.xfer_bytes++;
}
}
i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTD);
i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTDWS);
disable_interrupts(dev,
(I2C_IT_TXFNE | I2C_IT_TXFE | I2C_IT_TXFF
| I2C_IT_TXFOVR | I2C_IT_RXFNF
| I2C_IT_RXFF | I2C_IT_RXFE));
if (dev->cli.count) {
dev->result = -1;
dev_err(&dev->pdev->dev, "%lu bytes still remain to be"
"xfered\n", dev->cli.count);
(void) init_hw(dev);
}
complete(&dev->xfer_complete);
break;
/* Master Arbitration lost interrupt */
case I2C_IT_MAL:
dev->result = -1;
(void) init_hw(dev);
i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MAL);
complete(&dev->xfer_complete);
break;
/*
* Bus Error interrupt.
* This happens when an unexpected start/stop condition occurs
* during the transaction.
*/
case I2C_IT_BERR:
dev->result = -1;
/* get the status */
if (((readl(dev->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT)
(void) init_hw(dev);
i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_BERR);
complete(&dev->xfer_complete);
break;
/*
* Tx FIFO overrun interrupt.
* This is set when a write operation in Tx FIFO is performed and
* the Tx FIFO is full.
*/
case I2C_IT_TXFOVR:
dev->result = -1;
(void) init_hw(dev);
dev_err(&dev->pdev->dev, "Tx Fifo Over run\n");
complete(&dev->xfer_complete);
break;
/* unhandled interrupts by this driver - TODO*/
case I2C_IT_TXFE:
case I2C_IT_TXFF:
case I2C_IT_RXFE:
case I2C_IT_RFSR:
case I2C_IT_RFSE:
case I2C_IT_WTSR:
case I2C_IT_STD:
dev_err(&dev->pdev->dev, "unhandled Interrupt\n");
break;
default:
dev_err(&dev->pdev->dev, "spurious Interrupt..\n");
break;
}
return IRQ_HANDLED;
}
static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK;
}
static const struct i2c_algorithm nmk_i2c_algo = {
.master_xfer = nmk_i2c_xfer,
.functionality = nmk_i2c_functionality
};
static int __devinit nmk_i2c_probe(struct platform_device *pdev)
{
int ret = 0;
struct resource *res;
struct nmk_i2c_controller *pdata =
pdev->dev.platform_data;
struct nmk_i2c_dev *dev;
struct i2c_adapter *adap;
dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
if (!dev) {
dev_err(&pdev->dev, "cannot allocate memory\n");
ret = -ENOMEM;
goto err_no_mem;
}
dev->pdev = pdev;
platform_set_drvdata(pdev, dev);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENOENT;
goto err_no_resource;
}
if (request_mem_region(res->start, resource_size(res),
DRIVER_NAME "I/O region") == NULL) {
ret = -EBUSY;
goto err_no_region;
}
dev->virtbase = ioremap(res->start, resource_size(res));
if (!dev->virtbase) {
ret = -ENOMEM;
goto err_no_ioremap;
}
dev->irq = platform_get_irq(pdev, 0);
ret = request_irq(dev->irq, i2c_irq_handler, IRQF_DISABLED,
DRIVER_NAME, dev);
if (ret) {
dev_err(&pdev->dev, "cannot claim the irq %d\n", dev->irq);
goto err_irq;
}
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
dev_err(&pdev->dev, "could not get i2c clock\n");
ret = PTR_ERR(dev->clk);
goto err_no_clk;
}
clk_enable(dev->clk);
adap = &dev->adap;
adap->dev.parent = &pdev->dev;
adap->owner = THIS_MODULE;
adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
adap->algo = &nmk_i2c_algo;
/* fetch the controller id */
adap->nr = pdev->id;
/* fetch the controller configuration from machine */
dev->cfg.clk_freq = pdata->clk_freq;
dev->cfg.slsu = pdata->slsu;
dev->cfg.tft = pdata->tft;
dev->cfg.rft = pdata->rft;
dev->cfg.sm = pdata->sm;
i2c_set_adapdata(adap, dev);
ret = init_hw(dev);
if (ret != 0) {
dev_err(&pdev->dev, "error in initializing i2c hardware\n");
goto err_init_hw;
}
dev_dbg(&pdev->dev, "initialize I2C%d bus on virtual "
"base %p\n", pdev->id, dev->virtbase);
ret = i2c_add_numbered_adapter(adap);
if (ret) {
dev_err(&pdev->dev, "failed to add adapter\n");
goto err_add_adap;
}
return 0;
err_init_hw:
clk_disable(dev->clk);
err_add_adap:
clk_put(dev->clk);
err_no_clk:
free_irq(dev->irq, dev);
err_irq:
iounmap(dev->virtbase);
err_no_ioremap:
release_mem_region(res->start, resource_size(res));
err_no_region:
platform_set_drvdata(pdev, NULL);
err_no_resource:
kfree(dev);
err_no_mem:
return ret;
}
static int __devexit nmk_i2c_remove(struct platform_device *pdev)
{
struct nmk_i2c_dev *dev = platform_get_drvdata(pdev);
i2c_del_adapter(&dev->adap);
flush_i2c_fifo(dev);
disable_all_interrupts(dev);
clear_all_interrupts(dev);
/* disable the controller */
i2c_clr_bit(dev->virtbase + I2C_CR, I2C_CR_PE);
free_irq(dev->irq, dev);
iounmap(dev->virtbase);
clk_disable(dev->clk);
clk_put(dev->clk);
platform_set_drvdata(pdev, NULL);
kfree(dev);
return 0;
}
static struct platform_driver nmk_i2c_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRIVER_NAME,
},
.probe = nmk_i2c_probe,
.remove = __devexit_p(nmk_i2c_remove),
};
static int __init nmk_i2c_init(void)
{
return platform_driver_register(&nmk_i2c_driver);
}
static void __exit nmk_i2c_exit(void)
{
platform_driver_unregister(&nmk_i2c_driver);
}
subsys_initcall(nmk_i2c_init);
module_exit(nmk_i2c_exit);
MODULE_AUTHOR("Sachin Verma, Srinidhi KASAGAR");
MODULE_DESCRIPTION("Nomadik/Ux500 I2C driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);

44
drivers/i2c/busses/i2c-omap.c
View File

@ -49,24 +49,24 @@
#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
#define OMAP_I2C_REV_REG 0x00
#define OMAP_I2C_IE_REG 0x04
#define OMAP_I2C_STAT_REG 0x08
#define OMAP_I2C_IV_REG 0x0c
#define OMAP_I2C_IE_REG 0x01
#define OMAP_I2C_STAT_REG 0x02
#define OMAP_I2C_IV_REG 0x03
/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
#define OMAP_I2C_WE_REG 0x0c
#define OMAP_I2C_SYSS_REG 0x10
#define OMAP_I2C_BUF_REG 0x14
#define OMAP_I2C_CNT_REG 0x18
#define OMAP_I2C_DATA_REG 0x1c
#define OMAP_I2C_SYSC_REG 0x20
#define OMAP_I2C_CON_REG 0x24
#define OMAP_I2C_OA_REG 0x28
#define OMAP_I2C_SA_REG 0x2c
#define OMAP_I2C_PSC_REG 0x30
#define OMAP_I2C_SCLL_REG 0x34
#define OMAP_I2C_SCLH_REG 0x38
#define OMAP_I2C_SYSTEST_REG 0x3c
#define OMAP_I2C_BUFSTAT_REG 0x40
#define OMAP_I2C_WE_REG 0x03
#define OMAP_I2C_SYSS_REG 0x04
#define OMAP_I2C_BUF_REG 0x05
#define OMAP_I2C_CNT_REG 0x06
#define OMAP_I2C_DATA_REG 0x07
#define OMAP_I2C_SYSC_REG 0x08
#define OMAP_I2C_CON_REG 0x09
#define OMAP_I2C_OA_REG 0x0a
#define OMAP_I2C_SA_REG 0x0b
#define OMAP_I2C_PSC_REG 0x0c
#define OMAP_I2C_SCLL_REG 0x0d
#define OMAP_I2C_SCLH_REG 0x0e
#define OMAP_I2C_SYSTEST_REG 0x0f
#define OMAP_I2C_BUFSTAT_REG 0x10
/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
@ -161,6 +161,7 @@ struct omap_i2c_dev {
struct device *dev;
void __iomem *base; /* virtual */
int irq;
int reg_shift; /* bit shift for I2C register addresses */
struct clk *iclk; /* Interface clock */
struct clk *fclk; /* Functional clock */
struct completion cmd_complete;
@ -189,12 +190,12 @@ struct omap_i2c_dev {
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
int reg, u16 val)
{
__raw_writew(val, i2c_dev->base + reg);
__raw_writew(val, i2c_dev->base + (reg << i2c_dev->reg_shift));
}
static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
{
return __raw_readw(i2c_dev->base + reg);
return __raw_readw(i2c_dev->base + (reg << i2c_dev->reg_shift));
}
static int __init omap_i2c_get_clocks(struct omap_i2c_dev *dev)
@ -924,6 +925,11 @@ omap_i2c_probe(struct platform_device *pdev)
dev->b_hw = 1; /* Enable hardware fixes */
}
if (cpu_is_omap7xx())
dev->reg_shift = 1;
else
dev->reg_shift = 2;
/* reset ASAP, clearing any IRQs */
omap_i2c_init(dev);

11
drivers/i2c/busses/i2c-pnx.c
View File

@ -172,12 +172,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
/* We still have something to talk about... */
val = *alg_data->mif.buf++;
if (alg_data->mif.len == 1) {
val |= stop_bit;
if (!alg_data->last)
val |= start_bit;
}
alg_data->mif.len--;
iowrite32(val, I2C_REG_TX(alg_data));
@ -251,11 +245,6 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
__func__);
if (alg_data->mif.len == 1) {
/* Last byte, do not acknowledge next rcv. */
val |= stop_bit;
if (!alg_data->last)
val |= start_bit;
/*
* Enable interrupt RFDAIE (data in Rx fifo),
* and disable DRMIE (need data for Tx)

824
drivers/i2c/busses/i2c-xiic.c Normal file
View File

@ -0,0 +1,824 @@
/*
* i2c-xiic.c
* Copyright (c) 2002-2007 Xilinx Inc.
* Copyright (c) 2009-2010 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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.
*
*
* This code was implemented by Mocean Laboratories AB when porting linux
* to the automotive development board Russellville. The copyright holder
* as seen in the header is Intel corporation.
* Mocean Laboratories forked off the GNU/Linux platform work into a
* separate company called Pelagicore AB, which commited the code to the
* kernel.
*/
/* Supports:
* Xilinx IIC
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/i2c-xiic.h>
#include <linux/io.h>
#define DRIVER_NAME "xiic-i2c"
enum xilinx_i2c_state {
STATE_DONE,
STATE_ERROR,
STATE_START
};
/**
* struct xiic_i2c - Internal representation of the XIIC I2C bus
* @base: Memory base of the HW registers
* @wait: Wait queue for callers
* @adap: Kernel adapter representation
* @tx_msg: Messages from above to be sent
* @lock: Mutual exclusion
* @tx_pos: Current pos in TX message
* @nmsgs: Number of messages in tx_msg
* @state: See STATE_
* @rx_msg: Current RX message
* @rx_pos: Position within current RX message
*/
struct xiic_i2c {
void __iomem *base;
wait_queue_head_t wait;
struct i2c_adapter adap;
struct i2c_msg *tx_msg;
spinlock_t lock;
unsigned int tx_pos;
unsigned int nmsgs;
enum xilinx_i2c_state state;
struct i2c_msg *rx_msg;
int rx_pos;
};
#define XIIC_MSB_OFFSET 0
#define XIIC_REG_OFFSET (0x100+XIIC_MSB_OFFSET)
/*
* Register offsets in bytes from RegisterBase. Three is added to the
* base offset to access LSB (IBM style) of the word
*/
#define XIIC_CR_REG_OFFSET (0x00+XIIC_REG_OFFSET) /* Control Register */
#define XIIC_SR_REG_OFFSET (0x04+XIIC_REG_OFFSET) /* Status Register */
#define XIIC_DTR_REG_OFFSET (0x08+XIIC_REG_OFFSET) /* Data Tx Register */
#define XIIC_DRR_REG_OFFSET (0x0C+XIIC_REG_OFFSET) /* Data Rx Register */
#define XIIC_ADR_REG_OFFSET (0x10+XIIC_REG_OFFSET) /* Address Register */
#define XIIC_TFO_REG_OFFSET (0x14+XIIC_REG_OFFSET) /* Tx FIFO Occupancy */
#define XIIC_RFO_REG_OFFSET (0x18+XIIC_REG_OFFSET) /* Rx FIFO Occupancy */
#define XIIC_TBA_REG_OFFSET (0x1C+XIIC_REG_OFFSET) /* 10 Bit Address reg */
#define XIIC_RFD_REG_OFFSET (0x20+XIIC_REG_OFFSET) /* Rx FIFO Depth reg */
#define XIIC_GPO_REG_OFFSET (0x24+XIIC_REG_OFFSET) /* Output Register */
/* Control Register masks */
#define XIIC_CR_ENABLE_DEVICE_MASK 0x01 /* Device enable = 1 */
#define XIIC_CR_TX_FIFO_RESET_MASK 0x02 /* Transmit FIFO reset=1 */
#define XIIC_CR_MSMS_MASK 0x04 /* Master starts Txing=1 */
#define XIIC_CR_DIR_IS_TX_MASK 0x08 /* Dir of tx. Txing=1 */
#define XIIC_CR_NO_ACK_MASK 0x10 /* Tx Ack. NO ack = 1 */
#define XIIC_CR_REPEATED_START_MASK 0x20 /* Repeated start = 1 */
#define XIIC_CR_GENERAL_CALL_MASK 0x40 /* Gen Call enabled = 1 */
/* Status Register masks */
#define XIIC_SR_GEN_CALL_MASK 0x01 /* 1=a mstr issued a GC */
#define XIIC_SR_ADDR_AS_SLAVE_MASK 0x02 /* 1=when addr as slave */
#define XIIC_SR_BUS_BUSY_MASK 0x04 /* 1 = bus is busy */
#define XIIC_SR_MSTR_RDING_SLAVE_MASK 0x08 /* 1=Dir: mstr <-- slave */
#define XIIC_SR_TX_FIFO_FULL_MASK 0x10 /* 1 = Tx FIFO full */
#define XIIC_SR_RX_FIFO_FULL_MASK 0x20 /* 1 = Rx FIFO full */
#define XIIC_SR_RX_FIFO_EMPTY_MASK 0x40 /* 1 = Rx FIFO empty */
#define XIIC_SR_TX_FIFO_EMPTY_MASK 0x80 /* 1 = Tx FIFO empty */
/* Interrupt Status Register masks Interrupt occurs when... */
#define XIIC_INTR_ARB_LOST_MASK 0x01 /* 1 = arbitration lost */
#define XIIC_INTR_TX_ERROR_MASK 0x02 /* 1=Tx error/msg complete */
#define XIIC_INTR_TX_EMPTY_MASK 0x04 /* 1 = Tx FIFO/reg empty */
#define XIIC_INTR_RX_FULL_MASK 0x08 /* 1=Rx FIFO/reg=OCY level */
#define XIIC_INTR_BNB_MASK 0x10 /* 1 = Bus not busy */
#define XIIC_INTR_AAS_MASK 0x20 /* 1 = when addr as slave */
#define XIIC_INTR_NAAS_MASK 0x40 /* 1 = not addr as slave */
#define XIIC_INTR_TX_HALF_MASK 0x80 /* 1 = TX FIFO half empty */
/* The following constants specify the depth of the FIFOs */
#define IIC_RX_FIFO_DEPTH 16 /* Rx fifo capacity */
#define IIC_TX_FIFO_DEPTH 16 /* Tx fifo capacity */
/* The following constants specify groups of interrupts that are typically
* enabled or disables at the same time
*/
#define XIIC_TX_INTERRUPTS \
(XIIC_INTR_TX_ERROR_MASK | XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)
#define XIIC_TX_RX_INTERRUPTS (XIIC_INTR_RX_FULL_MASK | XIIC_TX_INTERRUPTS)
/* The following constants are used with the following macros to specify the
* operation, a read or write operation.
*/
#define XIIC_READ_OPERATION 1
#define XIIC_WRITE_OPERATION 0
/*
* Tx Fifo upper bit masks.
*/
#define XIIC_TX_DYN_START_MASK 0x0100 /* 1 = Set dynamic start */
#define XIIC_TX_DYN_STOP_MASK 0x0200 /* 1 = Set dynamic stop */
/*
* The following constants define the register offsets for the Interrupt
* registers. There are some holes in the memory map for reserved addresses
* to allow other registers to be added and still match the memory map of the
* interrupt controller registers
*/
#define XIIC_DGIER_OFFSET 0x1C /* Device Global Interrupt Enable Register */
#define XIIC_IISR_OFFSET 0x20 /* Interrupt Status Register */
#define XIIC_IIER_OFFSET 0x28 /* Interrupt Enable Register */
#define XIIC_RESETR_OFFSET 0x40 /* Reset Register */
#define XIIC_RESET_MASK 0xAUL
/*
* The following constant is used for the device global interrupt enable
* register, to enable all interrupts for the device, this is the only bit
* in the register
*/
#define XIIC_GINTR_ENABLE_MASK 0x80000000UL
#define xiic_tx_space(i2c) ((i2c)->tx_msg->len - (i2c)->tx_pos)
#define xiic_rx_space(i2c) ((i2c)->rx_msg->len - (i2c)->rx_pos)
static void xiic_start_xfer(struct xiic_i2c *i2c);
static void __xiic_start_xfer(struct xiic_i2c *i2c);
static inline void xiic_setreg8(struct xiic_i2c *i2c, int reg, u8 value)
{
iowrite8(value, i2c->base + reg);
}
static inline u8 xiic_getreg8(struct xiic_i2c *i2c, int reg)
{
return ioread8(i2c->base + reg);
}
static inline void xiic_setreg16(struct xiic_i2c *i2c, int reg, u16 value)
{
iowrite16(value, i2c->base + reg);
}
static inline void xiic_setreg32(struct xiic_i2c *i2c, int reg, int value)
{
iowrite32(value, i2c->base + reg);
}
static inline int xiic_getreg32(struct xiic_i2c *i2c, int reg)
{
return ioread32(i2c->base + reg);
}
static inline void xiic_irq_dis(struct xiic_i2c *i2c, u32 mask)
{
u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier & ~mask);
}
static inline void xiic_irq_en(struct xiic_i2c *i2c, u32 mask)
{
u32 ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
xiic_setreg32(i2c, XIIC_IIER_OFFSET, ier | mask);
}
static inline void xiic_irq_clr(struct xiic_i2c *i2c, u32 mask)
{
u32 isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
xiic_setreg32(i2c, XIIC_IISR_OFFSET, isr & mask);
}
static inline void xiic_irq_clr_en(struct xiic_i2c *i2c, u32 mask)
{
xiic_irq_clr(i2c, mask);
xiic_irq_en(i2c, mask);
}
static void xiic_clear_rx_fifo(struct xiic_i2c *i2c)
{
u8 sr;
for (sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
!(sr & XIIC_SR_RX_FIFO_EMPTY_MASK);
sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET))
xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
}
static void xiic_reinit(struct xiic_i2c *i2c)
{
xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
/* Set receive Fifo depth to maximum (zero based). */
xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, IIC_RX_FIFO_DEPTH - 1);
/* Reset Tx Fifo. */
xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_TX_FIFO_RESET_MASK);
/* Enable IIC Device, remove Tx Fifo reset & disable general call. */
xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, XIIC_CR_ENABLE_DEVICE_MASK);
/* make sure RX fifo is empty */
xiic_clear_rx_fifo(i2c);
/* Enable interrupts */
xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
xiic_irq_clr_en(i2c, XIIC_INTR_AAS_MASK | XIIC_INTR_ARB_LOST_MASK);
}
static void xiic_deinit(struct xiic_i2c *i2c)
{
u8 cr;
xiic_setreg32(i2c, XIIC_RESETR_OFFSET, XIIC_RESET_MASK);
/* Disable IIC Device. */
cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr & ~XIIC_CR_ENABLE_DEVICE_MASK);
}
static void xiic_read_rx(struct xiic_i2c *i2c)
{
u8 bytes_in_fifo;
int i;
bytes_in_fifo = xiic_getreg8(i2c, XIIC_RFO_REG_OFFSET) + 1;
dev_dbg(i2c->adap.dev.parent, "%s entry, bytes in fifo: %d, msg: %d"
", SR: 0x%x, CR: 0x%x\n",
__func__, bytes_in_fifo, xiic_rx_space(i2c),
xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
if (bytes_in_fifo > xiic_rx_space(i2c))
bytes_in_fifo = xiic_rx_space(i2c);
for (i = 0; i < bytes_in_fifo; i++)
i2c->rx_msg->buf[i2c->rx_pos++] =
xiic_getreg8(i2c, XIIC_DRR_REG_OFFSET);
xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET,
(xiic_rx_space(i2c) > IIC_RX_FIFO_DEPTH) ?
IIC_RX_FIFO_DEPTH - 1 : xiic_rx_space(i2c) - 1);
}
static int xiic_tx_fifo_space(struct xiic_i2c *i2c)
{
/* return the actual space left in the FIFO */
return IIC_TX_FIFO_DEPTH - xiic_getreg8(i2c, XIIC_TFO_REG_OFFSET) - 1;
}
static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
{
u8 fifo_space = xiic_tx_fifo_space(i2c);
int len = xiic_tx_space(i2c);
len = (len > fifo_space) ? fifo_space : len;
dev_dbg(i2c->adap.dev.parent, "%s entry, len: %d, fifo space: %d\n",
__func__, len, fifo_space);
while (len--) {
u16 data = i2c->tx_msg->buf[i2c->tx_pos++];
if ((xiic_tx_space(i2c) == 0) && (i2c->nmsgs == 1)) {
/* last message in transfer -> STOP */
data |= XIIC_TX_DYN_STOP_MASK;
dev_dbg(i2c->adap.dev.parent, "%s TX STOP\n", __func__);
xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
} else
xiic_setreg8(i2c, XIIC_DTR_REG_OFFSET, data);
}
}
static void xiic_wakeup(struct xiic_i2c *i2c, int code)
{
i2c->tx_msg = NULL;
i2c->rx_msg = NULL;
i2c->nmsgs = 0;
i2c->state = code;
wake_up(&i2c->wait);
}
static void xiic_process(struct xiic_i2c *i2c)
{
u32 pend, isr, ier;
u32 clr = 0;
/* Get the interrupt Status from the IPIF. There is no clearing of
* interrupts in the IPIF. Interrupts must be cleared at the source.
* To find which interrupts are pending; AND interrupts pending with
* interrupts masked.
*/
isr = xiic_getreg32(i2c, XIIC_IISR_OFFSET);
ier = xiic_getreg32(i2c, XIIC_IIER_OFFSET);
pend = isr & ier;
dev_dbg(i2c->adap.dev.parent, "%s entry, IER: 0x%x, ISR: 0x%x, "
"pend: 0x%x, SR: 0x%x, msg: %p, nmsgs: %d\n",
__func__, ier, isr, pend, xiic_getreg8(i2c, XIIC_SR_REG_OFFSET),
i2c->tx_msg, i2c->nmsgs);
/* Do not processes a devices interrupts if the device has no
* interrupts pending
*/
if (!pend)
return;
/* Service requesting interrupt */
if ((pend & XIIC_INTR_ARB_LOST_MASK) ||
((pend & XIIC_INTR_TX_ERROR_MASK) &&
!(pend & XIIC_INTR_RX_FULL_MASK))) {
/* bus arbritration lost, or...
* Transmit error _OR_ RX completed
* if this happens when RX_FULL is not set
* this is probably a TX error
*/
dev_dbg(i2c->adap.dev.parent, "%s error\n", __func__);
/* dynamic mode seem to suffer from problems if we just flushes
* fifos and the next message is a TX with len 0 (only addr)
* reset the IP instead of just flush fifos
*/
xiic_reinit(i2c);
if (i2c->tx_msg)
xiic_wakeup(i2c, STATE_ERROR);
} else if (pend & XIIC_INTR_RX_FULL_MASK) {
/* Receive register/FIFO is full */
clr = XIIC_INTR_RX_FULL_MASK;
if (!i2c->rx_msg) {
dev_dbg(i2c->adap.dev.parent,
"%s unexpexted RX IRQ\n", __func__);
xiic_clear_rx_fifo(i2c);
goto out;
}
xiic_read_rx(i2c);
if (xiic_rx_space(i2c) == 0) {
/* this is the last part of the message */
i2c->rx_msg = NULL;
/* also clear TX error if there (RX complete) */
clr |= (isr & XIIC_INTR_TX_ERROR_MASK);
dev_dbg(i2c->adap.dev.parent,
"%s end of message, nmsgs: %d\n",
__func__, i2c->nmsgs);
/* send next message if this wasn't the last,
* otherwise the transfer will be finialise when
* receiving the bus not busy interrupt
*/
if (i2c->nmsgs > 1) {
i2c->nmsgs--;
i2c->tx_msg++;
dev_dbg(i2c->adap.dev.parent,
"%s will start next...\n", __func__);
__xiic_start_xfer(i2c);
}
}
} else if (pend & XIIC_INTR_BNB_MASK) {
/* IIC bus has transitioned to not busy */
clr = XIIC_INTR_BNB_MASK;
/* The bus is not busy, disable BusNotBusy interrupt */
xiic_irq_dis(i2c, XIIC_INTR_BNB_MASK);
if (!i2c->tx_msg)
goto out;
if ((i2c->nmsgs == 1) && !i2c->rx_msg &&
xiic_tx_space(i2c) == 0)
xiic_wakeup(i2c, STATE_DONE);
else
xiic_wakeup(i2c, STATE_ERROR);
} else if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK)) {
/* Transmit register/FIFO is empty or ½ empty */
clr = pend &
(XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK);
if (!i2c->tx_msg) {
dev_dbg(i2c->adap.dev.parent,
"%s unexpexted TX IRQ\n", __func__);
goto out;
}
xiic_fill_tx_fifo(i2c);
/* current message sent and there is space in the fifo */
if (!xiic_tx_space(i2c) && xiic_tx_fifo_space(i2c) >= 2) {
dev_dbg(i2c->adap.dev.parent,
"%s end of message sent, nmsgs: %d\n",
__func__, i2c->nmsgs);
if (i2c->nmsgs > 1) {
i2c->nmsgs--;
i2c->tx_msg++;
__xiic_start_xfer(i2c);
} else {
xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
dev_dbg(i2c->adap.dev.parent,
"%s Got TX IRQ but no more to do...\n",
__func__);
}
} else if (!xiic_tx_space(i2c) && (i2c->nmsgs == 1))
/* current frame is sent and is last,
* make sure to disable tx half
*/
xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
} else {
/* got IRQ which is not acked */
dev_err(i2c->adap.dev.parent, "%s Got unexpected IRQ\n",
__func__);
clr = pend;
}
out:
dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
}
static int xiic_bus_busy(struct xiic_i2c *i2c)
{
u8 sr = xiic_getreg8(i2c, XIIC_SR_REG_OFFSET);
return (sr & XIIC_SR_BUS_BUSY_MASK) ? -EBUSY : 0;
}
static int xiic_busy(struct xiic_i2c *i2c)
{
int tries = 3;
int err;
if (i2c->tx_msg)
return -EBUSY;
/* for instance if previous transfer was terminated due to TX error
* it might be that the bus is on it's way to become available
* give it at most 3 ms to wake
*/
err = xiic_bus_busy(i2c);
while (err && tries--) {
mdelay(1);
err = xiic_bus_busy(i2c);
}
return err;
}
static void xiic_start_recv(struct xiic_i2c *i2c)
{
u8 rx_watermark;
struct i2c_msg *msg = i2c->rx_msg = i2c->tx_msg;
/* Clear and enable Rx full interrupt. */
xiic_irq_clr_en(i2c, XIIC_INTR_RX_FULL_MASK | XIIC_INTR_TX_ERROR_MASK);
/* we want to get all but last byte, because the TX_ERROR IRQ is used
* to inidicate error ACK on the address, and negative ack on the last
* received byte, so to not mix them receive all but last.
* In the case where there is only one byte to receive
* we can check if ERROR and RX full is set at the same time
*/
rx_watermark = msg->len;
if (rx_watermark > IIC_RX_FIFO_DEPTH)
rx_watermark = IIC_RX_FIFO_DEPTH;
xiic_setreg8(i2c, XIIC_RFD_REG_OFFSET, rx_watermark - 1);
if (!(msg->flags & I2C_M_NOSTART))
/* write the address */
xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
(msg->addr << 1) | XIIC_READ_OPERATION |
XIIC_TX_DYN_START_MASK);
xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET,
msg->len | ((i2c->nmsgs == 1) ? XIIC_TX_DYN_STOP_MASK : 0));
if (i2c->nmsgs == 1)
/* very last, enable bus not busy as well */
xiic_irq_clr_en(i2c, XIIC_INTR_BNB_MASK);
/* the message is tx:ed */
i2c->tx_pos = msg->len;
}
static void xiic_start_send(struct xiic_i2c *i2c)
{
struct i2c_msg *msg = i2c->tx_msg;
xiic_irq_clr(i2c, XIIC_INTR_TX_ERROR_MASK);
dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, len: %d, "
"ISR: 0x%x, CR: 0x%x\n",
__func__, msg, msg->len, xiic_getreg32(i2c, XIIC_IISR_OFFSET),
xiic_getreg8(i2c, XIIC_CR_REG_OFFSET));
if (!(msg->flags & I2C_M_NOSTART)) {
/* write the address */
u16 data = ((msg->addr << 1) & 0xfe) | XIIC_WRITE_OPERATION |
XIIC_TX_DYN_START_MASK;
if ((i2c->nmsgs == 1) && msg->len == 0)
/* no data and last message -> add STOP */
data |= XIIC_TX_DYN_STOP_MASK;
xiic_setreg16(i2c, XIIC_DTR_REG_OFFSET, data);
}
xiic_fill_tx_fifo(i2c);
/* Clear any pending Tx empty, Tx Error and then enable them. */
xiic_irq_clr_en(i2c, XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_ERROR_MASK |
XIIC_INTR_BNB_MASK);
}
static irqreturn_t xiic_isr(int irq, void *dev_id)
{
struct xiic_i2c *i2c = dev_id;
spin_lock(&i2c->lock);
/* disable interrupts globally */
xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0);
dev_dbg(i2c->adap.dev.parent, "%s entry\n", __func__);
xiic_process(i2c);
xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
spin_unlock(&i2c->lock);
return IRQ_HANDLED;
}
static void __xiic_start_xfer(struct xiic_i2c *i2c)
{
int first = 1;
int fifo_space = xiic_tx_fifo_space(i2c);
dev_dbg(i2c->adap.dev.parent, "%s entry, msg: %p, fifos space: %d\n",
__func__, i2c->tx_msg, fifo_space);
if (!i2c->tx_msg)
return;
i2c->rx_pos = 0;
i2c->tx_pos = 0;
i2c->state = STATE_START;
while ((fifo_space >= 2) && (first || (i2c->nmsgs > 1))) {
if (!first) {
i2c->nmsgs--;
i2c->tx_msg++;
i2c->tx_pos = 0;
} else
first = 0;
if (i2c->tx_msg->flags & I2C_M_RD) {
/* we dont date putting several reads in the FIFO */
xiic_start_recv(i2c);
return;
} else {
xiic_start_send(i2c);
if (xiic_tx_space(i2c) != 0) {
/* the message could not be completely sent */
break;
}
}
fifo_space = xiic_tx_fifo_space(i2c);
}
/* there are more messages or the current one could not be completely
* put into the FIFO, also enable the half empty interrupt
*/
if (i2c->nmsgs > 1 || xiic_tx_space(i2c))
xiic_irq_clr_en(i2c, XIIC_INTR_TX_HALF_MASK);
}
static void xiic_start_xfer(struct xiic_i2c *i2c)
{
unsigned long flags;
spin_lock_irqsave(&i2c->lock, flags);
xiic_reinit(i2c);
/* disable interrupts globally */
xiic_setreg32(i2c, XIIC_DGIER_OFFSET, 0);
spin_unlock_irqrestore(&i2c->lock, flags);
__xiic_start_xfer(i2c);
xiic_setreg32(i2c, XIIC_DGIER_OFFSET, XIIC_GINTR_ENABLE_MASK);
}
static int xiic_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
struct xiic_i2c *i2c = i2c_get_adapdata(adap);
int err;
dev_dbg(adap->dev.parent, "%s entry SR: 0x%x\n", __func__,
xiic_getreg8(i2c, XIIC_SR_REG_OFFSET));
err = xiic_busy(i2c);
if (err)
return err;
i2c->tx_msg = msgs;
i2c->nmsgs = num;
xiic_start_xfer(i2c);
if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
(i2c->state == STATE_DONE), HZ))
return (i2c->state == STATE_DONE) ? num : -EIO;
else {
i2c->tx_msg = NULL;
i2c->rx_msg = NULL;
i2c->nmsgs = 0;
return -ETIMEDOUT;
}
}
static u32 xiic_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static const struct i2c_algorithm xiic_algorithm = {
.master_xfer = xiic_xfer,
.functionality = xiic_func,
};
static struct i2c_adapter xiic_adapter = {
.owner = THIS_MODULE,
.name = DRIVER_NAME,
.class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
.algo = &xiic_algorithm,
};
static int __devinit xiic_i2c_probe(struct platform_device *pdev)
{
struct xiic_i2c *i2c;
struct xiic_i2c_platform_data *pdata;
struct resource *res;
int ret, irq;
u8 i;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
goto resource_missing;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
goto resource_missing;
pdata = (struct xiic_i2c_platform_data *) pdev->dev.platform_data;
if (!pdata)
return -EINVAL;
i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
dev_err(&pdev->dev, "Memory region busy\n");
ret = -EBUSY;
goto request_mem_failed;
}
i2c->base = ioremap(res->start, resource_size(res));
if (!i2c->base) {
dev_err(&pdev->dev, "Unable to map registers\n");
ret = -EIO;
goto map_failed;
}
/* hook up driver to tree */
platform_set_drvdata(pdev, i2c);
i2c->adap = xiic_adapter;
i2c_set_adapdata(&i2c->adap, i2c);
i2c->adap.dev.parent = &pdev->dev;
xiic_reinit(i2c);
spin_lock_init(&i2c->lock);
init_waitqueue_head(&i2c->wait);
ret = request_irq(irq, xiic_isr, 0, pdev->name, i2c);
if (ret) {
dev_err(&pdev->dev, "Cannot claim IRQ\n");
goto request_irq_failed;
}
/* add i2c adapter to i2c tree */
ret = i2c_add_adapter(&i2c->adap);
if (ret) {
dev_err(&pdev->dev, "Failed to add adapter\n");
goto add_adapter_failed;
}
/* add in known devices to the bus */
for (i = 0; i < pdata->num_devices; i++)
i2c_new_device(&i2c->adap, pdata->devices + i);
return 0;
add_adapter_failed:
free_irq(irq, i2c);
request_irq_failed:
xiic_deinit(i2c);
iounmap(i2c->base);
map_failed:
release_mem_region(res->start, resource_size(res));
request_mem_failed:
kfree(i2c);
return ret;
resource_missing:
dev_err(&pdev->dev, "IRQ or Memory resource is missing\n");
return -ENOENT;
}
static int __devexit xiic_i2c_remove(struct platform_device* pdev)
{
struct xiic_i2c *i2c = platform_get_drvdata(pdev);
struct resource *res;
/* remove adapter & data */
i2c_del_adapter(&i2c->adap);
xiic_deinit(i2c);
platform_set_drvdata(pdev, NULL);
free_irq(platform_get_irq(pdev, 0), i2c);
iounmap(i2c->base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res)
release_mem_region(res->start, resource_size(res));
kfree(i2c);
return 0;
}
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:"DRIVER_NAME);
static struct platform_driver xiic_i2c_driver = {
.probe = xiic_i2c_probe,
.remove = __devexit_p(xiic_i2c_remove),
.driver = {
.owner = THIS_MODULE,
.name = DRIVER_NAME,
},
};
static int __init xiic_i2c_init(void)
{
return platform_driver_register(&xiic_i2c_driver);
}
static void __exit xiic_i2c_exit(void)
{
platform_driver_unregister(&xiic_i2c_driver);
}
module_init(xiic_i2c_init);
module_exit(xiic_i2c_exit);
MODULE_AUTHOR("info@mocean-labs.com");
MODULE_DESCRIPTION("Xilinx I2C bus driver");
MODULE_LICENSE("GPL v2");