[PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable

From: Jan Glauber
Date: Mon Mar 07 2016 - 10:12:00 EST


From: Peter Swain <pswain@xxxxxxxxxx>

Make the i2c adapter timeout a module parameter to allow upper-level
target device drivers to retry with their own logic before their own
timeouts abort operations.

For example, at24 eeprom driver retries for 25ms when -EAGAIN
indicates that an eeprom has gone unresponsive while committing
a newly written page (5ms on typical devices).

Signed-off-by: Peter Swain <pswain@xxxxxxxxxx>
Signed-off-by: Jan Glauber <jglauber@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-octeon.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 6041cd7..ef1720f 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -72,6 +72,10 @@ struct octeon_i2c {
struct device *dev;
};

+static int timeout = 2;
+module_param(timeout, int, 0444);
+MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
+
/**
* octeon_i2c_write_sw - write an I2C core register
* @i2c: The struct octeon_i2c
@@ -425,7 +429,6 @@ static struct i2c_adapter octeon_i2c_ops = {
.owner = THIS_MODULE,
.name = "OCTEON adapter",
.algo = &octeon_i2c_algo,
- .timeout = HZ / 50,
};

/* calculate and set clock divisors */
@@ -561,6 +564,8 @@ static int octeon_i2c_probe(struct platform_device *pdev)
octeon_i2c_setclock(i2c);

i2c->adap = octeon_i2c_ops;
+ i2c->adap.timeout = msecs_to_jiffies(timeout);
+ i2c->adap.retries = 10;
i2c->adap.dev.parent = &pdev->dev;
i2c->adap.dev.of_node = node;
i2c_set_adapdata(&i2c->adap, i2c);
--
1.9.1