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i2c: add CSR SiRFprimaII on-chip I2C controllers driver

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SiRFprimaII is the latest generation application processor from CSR’s
multi-function SoC product family.
The SoC support codes are in arch/arm/mach-prima2 from Linux mainline
3.0.
There are two I2C controllers on primaII, features include:
* Two I2C controller modules are on chip
* RISC I/O bus read write register
* Up to 16 bytes data buffer for issuing commands and writing data
  at the same time
* Up to 16 commands, and receiving read data 16 bytes at a time
* Error INT report (ACK check)
* No-ACK bus protocols (SCCB bus protocols)

Signed-off-by: Zhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: Xiangzhen Ye <Xiangzhen.Ye@csr.com>
Signed-off-by: Yuping Luo <Yuping.Luo@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Zhiwu Song 2012-02-08 23:28:35 +08:00 committed by Wolfram Sang
parent bf6c2de11c
commit 979b907fa5
4 changed files with 489 additions and 0 deletions
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19
Documentation/devicetree/bindings/i2c/sirf-i2c.txt Normal file
View file

@ -0,0 +1,19 @@
I2C for SiRFprimaII platforms
Required properties :
- compatible : Must be "sirf,prima2-i2c"
- reg: physical base address of the controller and length of memory mapped
region.
- interrupts: interrupt number to the cpu.
Optional properties:
- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
The absence of the propoerty indicates the default frequency 100 kHz.
Examples :
i2c0: i2c@b00e0000 {
compatible = "sirf,prima2-i2c";
reg = <0xb00e0000 0x10000>;
interrupts = <24>;
};

10
drivers/i2c/busses/Kconfig
View file

@ -645,6 +645,16 @@ config I2C_SIMTEC
This driver can also be built as a module. If so, the module
will be called i2c-simtec.
config I2C_SIRF
tristate "CSR SiRFprimaII I2C interface"
depends on ARCH_PRIMA2
help
If you say yes to this option, support will be included for the
CSR SiRFprimaII I2C interface.
This driver can also be built as a module. If so, the module
will be called i2c-sirf.
config I2C_STU300
tristate "ST Microelectronics DDC I2C interface"
depends on MACH_U300

1
drivers/i2c/busses/Makefile
View file

@ -64,6 +64,7 @@ obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_SIRF) += i2c-sirf.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o

459
drivers/i2c/busses/i2c-sirf.c Normal file
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@ -0,0 +1,459 @@
/*
* I2C bus driver for CSR SiRFprimaII
*
* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2 or later.
*/
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#define SIRFSOC_I2C_CLK_CTRL 0x00
#define SIRFSOC_I2C_STATUS 0x0C
#define SIRFSOC_I2C_CTRL 0x10
#define SIRFSOC_I2C_IO_CTRL 0x14
#define SIRFSOC_I2C_SDA_DELAY 0x18
#define SIRFSOC_I2C_CMD_START 0x1C
#define SIRFSOC_I2C_CMD_BUF 0x30
#define SIRFSOC_I2C_DATA_BUF 0x80
#define SIRFSOC_I2C_CMD_BUF_MAX 16
#define SIRFSOC_I2C_DATA_BUF_MAX 16
#define SIRFSOC_I2C_CMD(x) (SIRFSOC_I2C_CMD_BUF + (x)*0x04)
#define SIRFSOC_I2C_DATA_MASK(x) (0xFF<<(((x)&3)*8))
#define SIRFSOC_I2C_DATA_SHIFT(x) (((x)&3)*8)
#define SIRFSOC_I2C_DIV_MASK (0xFFFF)
/* I2C status flags */
#define SIRFSOC_I2C_STAT_BUSY BIT(0)
#define SIRFSOC_I2C_STAT_TIP BIT(1)
#define SIRFSOC_I2C_STAT_NACK BIT(2)
#define SIRFSOC_I2C_STAT_TR_INT BIT(4)
#define SIRFSOC_I2C_STAT_STOP BIT(6)
#define SIRFSOC_I2C_STAT_CMD_DONE BIT(8)
#define SIRFSOC_I2C_STAT_ERR BIT(9)
#define SIRFSOC_I2C_CMD_INDEX (0x1F<<16)
/* I2C control flags */
#define SIRFSOC_I2C_RESET BIT(0)
#define SIRFSOC_I2C_CORE_EN BIT(1)
#define SIRFSOC_I2C_MASTER_MODE BIT(2)
#define SIRFSOC_I2C_CMD_DONE_EN BIT(11)
#define SIRFSOC_I2C_ERR_INT_EN BIT(12)
#define SIRFSOC_I2C_SDA_DELAY_MASK (0xFF)
#define SIRFSOC_I2C_SCLF_FILTER (3<<8)
#define SIRFSOC_I2C_START_CMD BIT(0)
#define SIRFSOC_I2C_CMD_RP(x) ((x)&0x7)
#define SIRFSOC_I2C_NACK BIT(3)
#define SIRFSOC_I2C_WRITE BIT(4)
#define SIRFSOC_I2C_READ BIT(5)
#define SIRFSOC_I2C_STOP BIT(6)
#define SIRFSOC_I2C_START BIT(7)
#define SIRFSOC_I2C_DEFAULT_SPEED 100000
struct sirfsoc_i2c {
void __iomem *base;
struct clk *clk;
u32 cmd_ptr; /* Current position in CMD buffer */
u8 *buf; /* Buffer passed by user */
u32 msg_len; /* Message length */
u32 finished_len; /* number of bytes read/written */
u32 read_cmd_len; /* number of read cmd sent */
int msg_read; /* 1 indicates a read message */
int err_status; /* 1 indicates an error on bus */
u32 sda_delay; /* For suspend/resume */
u32 clk_div;
int last; /* Last message in transfer, STOP cmd can be sent */
struct completion done; /* indicates completion of message transfer */
struct i2c_adapter adapter;
};
static void i2c_sirfsoc_read_data(struct sirfsoc_i2c *siic)
{
u32 data = 0;
int i;
for (i = 0; i < siic->read_cmd_len; i++) {
if (!(i & 0x3))
data = readl(siic->base + SIRFSOC_I2C_DATA_BUF + i);
siic->buf[siic->finished_len++] =
(u8)((data & SIRFSOC_I2C_DATA_MASK(i)) >>
SIRFSOC_I2C_DATA_SHIFT(i));
}
}
static void i2c_sirfsoc_queue_cmd(struct sirfsoc_i2c *siic)
{
u32 regval;
int i = 0;
if (siic->msg_read) {
while (((siic->finished_len + i) < siic->msg_len)
&& (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0);
if (((siic->finished_len + i) ==
(siic->msg_len - 1)) && siic->last)
regval |= SIRFSOC_I2C_STOP | SIRFSOC_I2C_NACK;
writel(regval,
siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
i++;
}
siic->read_cmd_len = i;
} else {
while ((siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX - 1)
&& (siic->finished_len < siic->msg_len)) {
regval = SIRFSOC_I2C_WRITE | SIRFSOC_I2C_CMD_RP(0);
if ((siic->finished_len == (siic->msg_len - 1))
&& siic->last)
regval |= SIRFSOC_I2C_STOP;
writel(regval,
siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
writel(siic->buf[siic->finished_len++],
siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
}
}
siic->cmd_ptr = 0;
/* Trigger the transfer */
writel(SIRFSOC_I2C_START_CMD, siic->base + SIRFSOC_I2C_CMD_START);
}
static irqreturn_t i2c_sirfsoc_irq(int irq, void *dev_id)
{
struct sirfsoc_i2c *siic = (struct sirfsoc_i2c *)dev_id;
u32 i2c_stat = readl(siic->base + SIRFSOC_I2C_STATUS);
if (i2c_stat & SIRFSOC_I2C_STAT_ERR) {
/* Error conditions */
siic->err_status = 1;
writel(SIRFSOC_I2C_STAT_ERR, siic->base + SIRFSOC_I2C_STATUS);
if (i2c_stat & SIRFSOC_I2C_STAT_NACK)
dev_err(&siic->adapter.dev, "ACK not received\n");
else
dev_err(&siic->adapter.dev, "I2C error\n");
complete(&siic->done);
} else if (i2c_stat & SIRFSOC_I2C_STAT_CMD_DONE) {
/* CMD buffer execution complete */
if (siic->msg_read)
i2c_sirfsoc_read_data(siic);
if (siic->finished_len == siic->msg_len)
complete(&siic->done);
else /* Fill a new CMD buffer for left data */
i2c_sirfsoc_queue_cmd(siic);
writel(SIRFSOC_I2C_STAT_CMD_DONE, siic->base + SIRFSOC_I2C_STATUS);
}
return IRQ_HANDLED;
}
static void i2c_sirfsoc_set_address(struct sirfsoc_i2c *siic,
struct i2c_msg *msg)
{
unsigned char addr;
u32 regval = SIRFSOC_I2C_START | SIRFSOC_I2C_CMD_RP(0) | SIRFSOC_I2C_WRITE;
/* no data and last message -> add STOP */
if (siic->last && (msg->len == 0))
regval |= SIRFSOC_I2C_STOP;
writel(regval, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
addr = msg->addr << 1; /* Generate address */
if (msg->flags & I2C_M_RD)
addr |= 1;
writel(addr, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
}
static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
{
u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL);
/* timeout waiting for the xfer to finish or fail */
int timeout = msecs_to_jiffies((msg->len + 1) * 50);
int ret = 0;
i2c_sirfsoc_set_address(siic, msg);
writel(regval | SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN,
siic->base + SIRFSOC_I2C_CTRL);
i2c_sirfsoc_queue_cmd(siic);
if (wait_for_completion_timeout(&siic->done, timeout) == 0) {
siic->err_status = 1;
dev_err(&siic->adapter.dev, "Transfer timeout\n");
}
writel(regval & ~(SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN),
siic->base + SIRFSOC_I2C_CTRL);
writel(0, siic->base + SIRFSOC_I2C_CMD_START);
if (siic->err_status) {
writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
siic->base + SIRFSOC_I2C_CTRL);
while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
cpu_relax();
ret = -EIO;
}
return ret;
}
static u32 i2c_sirfsoc_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
static int i2c_sirfsoc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int num)
{
struct sirfsoc_i2c *siic = adap->algo_data;
int i, ret;
clk_enable(siic->clk);
for (i = 0; i < num; i++) {
siic->buf = msgs[i].buf;
siic->msg_len = msgs[i].len;
siic->msg_read = !!(msgs[i].flags & I2C_M_RD);
siic->err_status = 0;
siic->cmd_ptr = 0;
siic->finished_len = 0;
siic->last = (i == (num - 1));
ret = i2c_sirfsoc_xfer_msg(siic, &msgs[i]);
if (ret) {
clk_disable(siic->clk);
return ret;
}
}
clk_disable(siic->clk);
return num;
}
/* I2C algorithms associated with this master controller driver */
static const struct i2c_algorithm i2c_sirfsoc_algo = {
.master_xfer = i2c_sirfsoc_xfer,
.functionality = i2c_sirfsoc_func,
};
static int __devinit i2c_sirfsoc_probe(struct platform_device *pdev)
{
struct sirfsoc_i2c *siic;
struct i2c_adapter *adap;
struct resource *mem_res;
struct clk *clk;
int bitrate;
int ctrl_speed;
int irq;
int err;
u32 regval;
clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
err = PTR_ERR(clk);
dev_err(&pdev->dev, "Clock get failed\n");
goto err_get_clk;
}
err = clk_prepare(clk);
if (err) {
dev_err(&pdev->dev, "Clock prepare failed\n");
goto err_clk_prep;
}
err = clk_enable(clk);
if (err) {
dev_err(&pdev->dev, "Clock enable failed\n");
goto err_clk_en;
}
ctrl_speed = clk_get_rate(clk);
siic = devm_kzalloc(&pdev->dev, sizeof(*siic), GFP_KERNEL);
if (!siic) {
dev_err(&pdev->dev, "Can't allocate driver data\n");
err = -ENOMEM;
goto out;
}
adap = &siic->adapter;
adap->class = I2C_CLASS_HWMON;
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (mem_res == NULL) {
dev_err(&pdev->dev, "Unable to get MEM resource\n");
err = -EINVAL;
goto out;
}
siic->base = devm_request_and_ioremap(&pdev->dev, mem_res);
if (siic->base == NULL) {
dev_err(&pdev->dev, "IO remap failed!\n");
err = -ENOMEM;
goto out;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
err = irq;
goto out;
}
err = devm_request_irq(&pdev->dev, irq, i2c_sirfsoc_irq, 0,
dev_name(&pdev->dev), siic);
if (err)
goto out;
adap->algo = &i2c_sirfsoc_algo;
adap->algo_data = siic;
adap->dev.parent = &pdev->dev;
adap->nr = pdev->id;
strlcpy(adap->name, "sirfsoc-i2c", sizeof(adap->name));
platform_set_drvdata(pdev, adap);
init_completion(&siic->done);
/* Controller Initalisation */
writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
cpu_relax();
writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
siic->base + SIRFSOC_I2C_CTRL);
siic->clk = clk;
err = of_property_read_u32(pdev->dev.of_node,
"clock-frequency", &bitrate);
if (err < 0)
bitrate = SIRFSOC_I2C_DEFAULT_SPEED;
if (bitrate < 100000)
regval =
(2 * ctrl_speed) / (2 * bitrate * 11);
else
regval = ctrl_speed / (bitrate * 5);
writel(regval, siic->base + SIRFSOC_I2C_CLK_CTRL);
if (regval > 0xFF)
writel(0xFF, siic->base + SIRFSOC_I2C_SDA_DELAY);
else
writel(regval, siic->base + SIRFSOC_I2C_SDA_DELAY);
err = i2c_add_numbered_adapter(adap);
if (err < 0) {
dev_err(&pdev->dev, "Can't add new i2c adapter\n");
goto out;
}
clk_disable(clk);
dev_info(&pdev->dev, " I2C adapter ready to operate\n");
return 0;
out:
clk_disable(clk);
err_clk_en:
clk_unprepare(clk);
err_clk_prep:
clk_put(clk);
err_get_clk:
return err;
}
static int __devexit i2c_sirfsoc_remove(struct platform_device *pdev)
{
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
struct sirfsoc_i2c *siic = adapter->algo_data;
writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
i2c_del_adapter(adapter);
clk_unprepare(siic->clk);
clk_put(siic->clk);
return 0;
}
#ifdef CONFIG_PM
static int i2c_sirfsoc_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
struct sirfsoc_i2c *siic = adapter->algo_data;
clk_enable(siic->clk);
siic->sda_delay = readl(siic->base + SIRFSOC_I2C_SDA_DELAY);
siic->clk_div = readl(siic->base + SIRFSOC_I2C_CLK_CTRL);
clk_disable(siic->clk);
return 0;
}
static int i2c_sirfsoc_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct i2c_adapter *adapter = platform_get_drvdata(pdev);
struct sirfsoc_i2c *siic = adapter->algo_data;
clk_enable(siic->clk);
writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
siic->base + SIRFSOC_I2C_CTRL);
writel(siic->clk_div, siic->base + SIRFSOC_I2C_CLK_CTRL);
writel(siic->sda_delay, siic->base + SIRFSOC_I2C_SDA_DELAY);
clk_disable(siic->clk);
return 0;
}
static const struct dev_pm_ops i2c_sirfsoc_pm_ops = {
.suspend = i2c_sirfsoc_suspend,
.resume = i2c_sirfsoc_resume,
};
#endif
static const struct of_device_id sirfsoc_i2c_of_match[] __devinitconst = {
{ .compatible = "sirf,prima2-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, sirfsoc_i2c_of_match);
static struct platform_driver i2c_sirfsoc_driver = {
.driver = {
.name = "sirfsoc_i2c",
.owner = THIS_MODULE,
#ifdef CONFIG_PM
.pm = &i2c_sirfsoc_pm_ops,
#endif
.of_match_table = sirfsoc_i2c_of_match,
},
.probe = i2c_sirfsoc_probe,
.remove = __devexit_p(i2c_sirfsoc_remove),
};
module_platform_driver(i2c_sirfsoc_driver);
MODULE_DESCRIPTION("SiRF SoC I2C master controller driver");
MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, "
"Xiangzhen Ye <Xiangzhen.Ye@csr.com>");
MODULE_LICENSE("GPL v2");