[PATCH v2] i2c: at91: ensure state is restored after suspending

Alexandre Belloni
2017-02-16T17:27:59Z

When going to suspend, the I2C registers may be lost because the power to
VDDcore is cut. Restore them when resuming.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
Changes in v2:
- don't cache unecessary registers and simply call at91_init_twi_bus()

drivers/i2c/busses/i2c-at91.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 0b86c6173e07..c925a690cb32 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -1180,6 +1180,7 @@ static int at91_twi_suspend_noirq(struct device *dev)

static int at91_twi_resume_noirq(struct device *dev)
{
+ struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
int ret;

if (!pm_runtime_status_suspended(dev)) {
@@ -1191,6 +1192,8 @@ static int at91_twi_resume_noirq(struct device *dev)
pm_runtime_mark_last_busy(dev);
pm_request_autosuspend(dev);

+ at91_init_twi_bus(twi_dev);
+
return 0;
}

--
2.11.0