On Wednesday 03 August 2011 04:53 AM, Kevin Hilman wrote:
Shubhrajyoti D<shubhrajy...@ti.com> writes:
Under some error conditions the i2c driver may do a reset.
^ ^
minor: extra whitespace
Adding a reset field and support in the platform.
s/platform/device-specific code/
Yes will fix these.
Signed-off-by: Shubhrajyoti D<shubhrajy...@ti.com>
That being said, omap_device_shutdown() should already do a clean
shutdown + reset for you, and i2c-omap.h already has a pointer for
->device_shutdown() so a new device_reset() should not be needed.
IOW, simply adding pdata->device_shutdown = omap_device_shutdown()
should work.
i2C has a special reset sequence ie Disable -> reset -> enable -> Poll
on reset done.
This function is implemented in omap_i2c_reset. The
omap_hwmod_reset calls -> _reset
which calls ocp_softrest or custom reset if it is present.The latter is
true for I2C.
However I see that
omap_device_shutdown -> _assert_hardreset However for I2c there doesnt seem to
be a HW reset line.
Am I missing something?
Kevin
---
arch/arm/plat-omap/i2c.c | 18 ++++++++++++++++++
include/linux/i2c-omap.h | 1 +
2 files changed, 19 insertions(+), 0 deletions(-)
diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index 2388b8e..be36cac 100644
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -146,6 +146,22 @@ static struct omap_device_pm_latency omap_i2c_latency[] = {
.flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
},
};
+/**
+ * omap2_i2c_reset - reset the omap i2c module.
+ * @dev: struct device*
+ */
+
+static int omap2_i2c_reset(struct device *dev)
+{
+ int r = 0;
+ struct platform_device *pdev = to_platform_device(dev);
+ struct omap_device *odev = to_omap_device(pdev);
+ struct omap_hwmod *oh;
+
+ oh = odev->hwmods[0];
+ r = omap_hwmod_reset(oh);
+ return r;
+}
static inline int omap2_i2c_add_bus(int bus_id)
{
@@ -187,6 +203,8 @@ static inline int omap2_i2c_add_bus(int bus_id)
*/
if (cpu_is_omap34xx())
pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
+
+ pdata->device_reset = omap2_i2c_reset;
od = omap_device_build(name, bus_id, oh, pdata,
sizeof(struct omap_i2c_bus_platform_data),
omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0);
diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h
index 98ae49b..8aa91b6 100644
--- a/include/linux/i2c-omap.h
+++ b/include/linux/i2c-omap.h
@@ -38,6 +38,7 @@ struct omap_i2c_bus_platform_data {
int (*device_enable) (struct platform_device *pdev);
int (*device_shutdown) (struct platform_device *pdev);
int (*device_idle) (struct platform_device *pdev);
+ int (*device_reset) (struct device *dev);
};
#endif
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