Re: [PATCH 2/3] i2c/at91: add support for system PM

Kevin Hilman
2014-10-20T18:15:41Z

Wenyou Yang <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org> writes:

Add a changelog here describing what you're doing, and why.

> Signed-off-by: Wenyou Yang <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-at91.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
> index 03b9f48..8f408f8 100644
> --- a/drivers/i2c/busses/i2c-at91.c
> +++ b/drivers/i2c/busses/i2c-at91.c
> @@ -845,6 +845,35 @@ static int at91_twi_remove(struct platform_device *pdev)
> }
>
> #ifdef CONFIG_PM
> +#ifdef CONFIG_PM_SLEEP
> +static int at91_twi_suspend(struct device *dev)
> +{
> + struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);
> +
> + if (!pm_runtime_suspended(dev))
> + clk_disable_unprepare(twi_dev->clk);

I would just call at91_twi_runtime_suspend() here.

Then, if you need to add additional steps, you only have to add them in
once place. This also makes it obvious that ->suspend and
->runtime_suspend are doing the exact same thing.

NOTE: you'll need to wrap the runtime_suspend|resume functions in just
CONFIG_PM instead of CONFIG_PM_RUNTIME for this to work.

Kevin