starred/linux-legacy
1
0
Fork 0
mirror of https://github.com/genesi/linux-legacy.git synced 2026-07-08 17:56:55 +00:00
Code Issues 2 Packages Projects Releases Wiki Activity

Get i2c-imx up to a mainline revision (2.6.34)

Browse Source
This commit is contained in:
Matt Sealey
2010-08-14 12:32:44 -05:00
parent 8d96bbe76a
commit 7fa0618862
1 changed files with 74 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

118
drivers/i2c/busses/i2c-imx.c
View File

@@ -120,28 +120,35 @@ struct imx_i2c_struct {
wait_queue_head_t queue;
unsigned long i2csr;
unsigned int disable_delay;
int stopped;
unsigned int ifdr; /* IMX_I2C_IFDR */
};
/** Functions for IMX I2C adapter driver ***************************************
*******************************************************************************/
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx)
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
unsigned int temp;
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
/* wait for bus not busy */
while (readb(i2c_imx->base + IMX_I2C_I2SR) & I2SR_IBB) {
while (1) {
temp = readb(i2c_imx->base + IMX_I2C_I2SR);
if (for_busy && (temp & I2SR_IBB))
break;
if (!for_busy && !(temp & I2SR_IBB))
break;
if (signal_pending(current)) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> I2C Interrupted\n", __func__);
return -EINTR;
}
if (time_after(jiffies, orig_jiffies + HZ / 1000)) {
if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> I2C bus is busy\n", __func__);
return -EIO;
return -ETIMEDOUT;
}
schedule();
}
@@ -179,41 +186,63 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
return 0;
}
static void i2c_imx_start(struct imx_i2c_struct *i2c_imx)
static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
{
unsigned int temp = 0;
int result;
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
clk_enable(i2c_imx->clk);
writeb(i2c_imx->ifdr, i2c_imx->base + IMX_I2C_IFDR);
/* Enable I2C controller */
writeb(0, i2c_imx->base + IMX_I2C_I2SR);
writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
/* Wait controller to be stable */
udelay(50);
/* Start I2C transaction */
temp = readb(i2c_imx->base + IMX_I2C_I2CR);
temp |= I2CR_MSTA;
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
result = i2c_imx_bus_busy(i2c_imx, 1);
if (result)
return result;
i2c_imx->stopped = 0;
temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
return result;
}
static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
{
unsigned int temp = 0;
/* Stop I2C transaction */
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
temp = readb(i2c_imx->base + IMX_I2C_I2CR);
temp &= ~I2CR_MSTA;
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
/* setup chip registers to defaults */
writeb(I2CR_IEN, i2c_imx->base + IMX_I2C_I2CR);
writeb(0, i2c_imx->base + IMX_I2C_I2SR);
/*
* This delay caused by an i.MXL hardware bug.
* If no (or too short) delay, no "STOP" bit will be generated.
*/
udelay(i2c_imx->disable_delay);
if (!i2c_imx->stopped) {
/* Stop I2C transaction */
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
temp = readb(i2c_imx->base + IMX_I2C_I2CR);
temp &= ~(I2CR_MSTA | I2CR_MTX);
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
}
if (cpu_is_mx1()) {
/*
* This delay caused by an i.MXL hardware bug.
* If no (or too short) delay, no "STOP" bit will be generated.
*/
udelay(i2c_imx->disable_delay);
}
if (!i2c_imx->stopped) {
i2c_imx_bus_busy(i2c_imx, 0);
i2c_imx->stopped = 1;
}
/* Disable I2C controller */
writeb(0, i2c_imx->base + IMX_I2C_I2CR);
clk_disable(i2c_imx->clk);
}
static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
@@ -233,8 +262,8 @@ static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
else
for (i = 0; i2c_clk_div[i][0] < div; i++);
/* Write divider value to register */
writeb(i2c_clk_div[i][1], i2c_imx->base + IMX_I2C_IFDR);
/* Store divider value */
i2c_imx->ifdr = i2c_clk_div[i][1];
/*
* There dummy delay is calculated.
@@ -341,11 +370,15 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
if (result)
return result;
if (i == (msgs->len - 1)) {
/* It must generate STOP before read I2DR to prevent
controller from generating another clock cycle */
dev_dbg(&i2c_imx->adapter.dev,
"<%s> clear MSTA\n", __func__);
temp = readb(i2c_imx->base + IMX_I2C_I2CR);
temp &= ~I2CR_MSTA;
temp &= ~(I2CR_MSTA | I2CR_MTX);
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
i2c_imx_bus_busy(i2c_imx, 0);
i2c_imx->stopped = 1;
} else if (i == (msgs->len - 2)) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> set TXAK\n", __func__);
@@ -370,14 +403,11 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
/* Check if i2c bus is not busy */
result = i2c_imx_bus_busy(i2c_imx);
/* Start I2C transfer */
result = i2c_imx_start(i2c_imx);
if (result)
goto fail0;
/* Start I2C transfer */
i2c_imx_start(i2c_imx);
/* read/write data */
for (i = 0; i < num; i++) {
if (i) {
@@ -386,6 +416,9 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
temp = readb(i2c_imx->base + IMX_I2C_I2CR);
temp |= I2CR_RSTA;
writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
result = i2c_imx_bus_busy(i2c_imx, 1);
if (result)
goto fail0;
}
dev_dbg(&i2c_imx->adapter.dev,
"<%s> transfer message: %d\n", __func__, i);
@@ -410,6 +443,8 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
result = i2c_imx_read(i2c_imx, &msgs[i]);
else
result = i2c_imx_write(i2c_imx, &msgs[i]);
if (result)
goto fail0;
}
fail0:
@@ -464,22 +499,23 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
}
res_size = resource_size(res);
if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
ret = -EBUSY;
goto fail0;
}
base = ioremap(res->start, res_size);
if (!base) {
dev_err(&pdev->dev, "ioremap failed\n");
ret = -EIO;
goto fail0;
goto fail1;
}
i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
if (!i2c_imx) {
dev_err(&pdev->dev, "can't allocate interface\n");
ret = -ENOMEM;
goto fail1;
}
if (!request_mem_region(res->start, res_size, DRIVER_NAME)) {
ret = -EBUSY;
goto fail2;
}
@@ -500,7 +536,6 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "can't get I2C clock\n");
goto fail3;
}
clk_enable(i2c_imx->clk);
/* Request IRQ */
ret = request_irq(i2c_imx->irq, i2c_imx_isr, 0, pdev->name, i2c_imx);
@@ -549,14 +584,13 @@ static int __init i2c_imx_probe(struct platform_device *pdev)
fail5:
free_irq(i2c_imx->irq, i2c_imx);
fail4:
clk_disable(i2c_imx->clk);
clk_put(i2c_imx->clk);
fail3:
release_mem_region(i2c_imx->res->start, resource_size(res));
fail2:
kfree(i2c_imx);
fail1:
fail2:
iounmap(base);
fail1:
release_mem_region(res->start, resource_size(res));
fail0:
if (pdata && pdata->exit)
pdata->exit(&pdev->dev);
@@ -586,18 +620,15 @@ static int __exit i2c_imx_remove(struct platform_device *pdev)
if (pdata && pdata->exit)
pdata->exit(&pdev->dev);
/* Disable I2C clock */
clk_disable(i2c_imx->clk);
clk_put(i2c_imx->clk);
release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
iounmap(i2c_imx->base);
release_mem_region(i2c_imx->res->start, resource_size(i2c_imx->res));
kfree(i2c_imx);
return 0;
}
static struct platform_driver i2c_imx_driver = {
.probe = i2c_imx_probe,
.remove = __exit_p(i2c_imx_remove),
.driver = {
.name = DRIVER_NAME,
@@ -609,13 +640,12 @@ static int __init i2c_adap_imx_init(void)
{
return platform_driver_probe(&i2c_imx_driver, i2c_imx_probe);
}
subsys_initcall(i2c_adap_imx_init);
static void __exit i2c_adap_imx_exit(void)
{
platform_driver_unregister(&i2c_imx_driver);
}
module_init(i2c_adap_imx_init);
module_exit(i2c_adap_imx_exit);
MODULE_LICENSE("GPL");