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i2c-nomadik: add code to retry on timeout failure

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It is seen that i2c-nomadik controller randomly stops generating the
interrupts leading to a i2c timeout. As a workaround to this problem,
add retries to the on going transfer on failure.

Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Reviewed-by: Jonas ABERG <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This commit is contained in:
Virupax Sadashivpetimath 2011-05-13 12:30:23 +02:00 committed by Ben Dooks
parent b0e751a925
commit ebd10e0783
1 changed files with 49 additions and 48 deletions
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97
drivers/i2c/busses/i2c-nomadik.c
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@ -255,8 +255,6 @@ static int init_hw(struct nmk_i2c_dev *dev)
{ {
int stat; int stat;
clk_enable(dev->clk);
stat = flush_i2c_fifo(dev); stat = flush_i2c_fifo(dev);
if (stat) if (stat)
goto exit; goto exit;
@ -271,8 +269,6 @@ static int init_hw(struct nmk_i2c_dev *dev)
dev->cli.operation = I2C_NO_OPERATION; dev->cli.operation = I2C_NO_OPERATION;
exit: exit:
/* TODO: Why disable clocks after init hw? */
clk_disable(dev->clk);
/* /*
* TODO: What is this delay for? * TODO: What is this delay for?
* Must be pretty pointless since the hw block * Must be pretty pointless since the hw block
@ -572,6 +568,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
u32 cause; u32 cause;
struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap); struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
u32 i2c_sr; u32 i2c_sr;
int j;
dev->busy = true; dev->busy = true;
@ -579,63 +576,67 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
regulator_enable(dev->regulator); regulator_enable(dev->regulator);
pm_runtime_get_sync(&dev->pdev->dev); pm_runtime_get_sync(&dev->pdev->dev);
status = init_hw(dev);
if (status)
goto out2;
clk_enable(dev->clk); clk_enable(dev->clk);
/* setup the i2c controller */ status = init_hw(dev);
setup_i2c_controller(dev); if (status)
goto out;
for (i = 0; i < num_msgs; i++) { for (j = 0; j < 3; j++) {
if (unlikely(msgs[i].flags & I2C_M_TEN)) { /* setup the i2c controller */
dev_err(&dev->pdev->dev, "10 bit addressing" setup_i2c_controller(dev);
"not supported\n");
status = -EINVAL; for (i = 0; i < num_msgs; i++) {
goto out; if (unlikely(msgs[i].flags & I2C_M_TEN)) {
} dev_err(&dev->pdev->dev, "10 bit addressing"
dev->cli.slave_adr = msgs[i].addr; "not supported\n");
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) { status = -EINVAL;
/* it is a read operation */ goto out;
dev->cli.operation = I2C_READ; }
status = read_i2c(dev); dev->cli.slave_adr = msgs[i].addr;
} else { dev->cli.buffer = msgs[i].buf;
/* write operation */ dev->cli.count = msgs[i].len;
dev->cli.operation = I2C_WRITE; dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
status = write_i2c(dev); dev->result = 0;
}
if (status || (dev->result)) { if (msgs[i].flags & I2C_M_RD) {
i2c_sr = readl(dev->virtbase + I2C_SR); /* it is a read operation */
/* dev->cli.operation = I2C_READ;
* Check if the controller I2C operation status is set status = read_i2c(dev);
* to ABORT(11b). } else {
*/ /* write operation */
if (((i2c_sr >> 2) & 0x3) == 0x3) { dev->cli.operation = I2C_WRITE;
/* get the abort cause */ status = write_i2c(dev);
cause = (i2c_sr >> 4) }
& 0x7; if (status || (dev->result)) {
dev_err(&dev->pdev->dev, "%s\n", cause >= i2c_sr = readl(dev->virtbase + I2C_SR);
ARRAY_SIZE(abort_causes) ? /*
* Check if the controller I2C operation status
* is set to ABORT(11b).
*/
if (((i2c_sr >> 2) & 0x3) == 0x3) {
/* get the abort cause */
cause = (i2c_sr >> 4)
& 0x7;
dev_err(&dev->pdev->dev, "%s\n", cause
>= ARRAY_SIZE(abort_causes) ?
"unknown reason" : "unknown reason" :
abort_causes[cause]); abort_causes[cause]);
} }
status = status ? status : dev->result; status = status ? status : dev->result;
goto out;
break;
}
udelay(I2C_DELAY);
} }
udelay(I2C_DELAY); if (status == 0)
break;
} }
out: out:
clk_disable(dev->clk); clk_disable(dev->clk);
out2:
pm_runtime_put_sync(&dev->pdev->dev); pm_runtime_put_sync(&dev->pdev->dev);
if (dev->regulator) if (dev->regulator)
regulator_disable(dev->regulator); regulator_disable(dev->regulator);