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

Ludovic Desroches
2017-02-17T08:24:39Z

On Thu, Feb 16, 2017 at 06:27:59PM +0100, Alexandre Belloni wrote:
> 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>

Acked-by: Ludovic Desroches <ludovic.desroches@microchip.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
>