Re: [PATCH] spi/pl022: get/put resources on suspend/resume

[Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>]

I can agree with the code as such. One issue remains though.

You will have compile warnings when not having CONFIG_SUSPEND and
CONFIG_RUNTIME_PM, due to unused code/functions.

Otherwise you have my ack.

Kind regards
Ulf Hansson


On 26 September 2012 17:08, Linus Walleij <linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org> wrote:
> This factors out the resource handling in runtime
> suspend/resume and also calls it from the ordinary suspend
> and resume hooks.
>
> The semantics require that ordinary PM op suspend is called
> with runtime PM in resumed mode, so that ordinary suspend
> can assume that it will e.g. decrease the clock reference
> counter to 0, runtime resume having previously increased it
> to 1.
>
> Cc: Ulf Hansson <ulf.hansson-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Cc: Vipul Kumar Samar <vipulkumar.samar-qxv4g6HH51o@public.gmane.org>
> Cc: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> Signed-off-by: Linus Walleij <linus.walleij-0IS4wlFg1OjSUeElwK9/Pw@public.gmane.org>
> ---
> Vipin: can you confirm that this approach works for your
> case with only suspend/resume but no runtime PM?
>
> Question: can I be sure that the above semantics is taken
> care of by runtime PM, or will I have to add kludges to
> the ordinary suspend/resume hooks to make sure that the
> device is out of runtime suspend before suspending?
> ---
>  drivers/spi/spi-pl022.c | 64 ++++++++++++++++++++++++++++++++-----------------
>  1 file changed, 42 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 15737bc..63cd7c6 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -2300,6 +2300,43 @@ pl022_remove(struct amba_device *adev)
>         return 0;
>  }
>
> +/*
> + * These two functions are used from both suspend/resume and
> + * the runtime counterparts to handle external resources like
> + * clocks, pins and regulators when going to sleep.
> + */
> +static void pl022_suspend_resources(struct pl022 *pl022)
> +{
> +       int ret;
> +
> +       clk_disable(pl022->clk);
> +
> +       /* Optionally let pins go into sleep states */
> +       if (!IS_ERR(pl022->pins_sleep)) {
> +               ret = pinctrl_select_state(pl022->pinctrl,
> +                                          pl022->pins_sleep);
> +               if (ret)
> +                       dev_err(&pl022->adev->dev,
> +                               "could not set pins to sleep state\n");
> +       }
> +}
> +
> +static void pl022_resume_resources(struct pl022 *pl022)
> +{
> +       int ret;
> +
> +       /* Optionaly enable pins to be muxed in and configured */
> +       if (!IS_ERR(pl022->pins_default)) {
> +               ret = pinctrl_select_state(pl022->pinctrl,
> +                                          pl022->pins_default);
> +               if (ret)
> +                       dev_err(&pl022->adev->dev,
> +                               "could not set default pins\n");
> +       }
> +
> +       clk_enable(pl022->clk);
> +}
> +
>  #ifdef CONFIG_SUSPEND
>  static int pl022_suspend(struct device *dev)
>  {
> @@ -2311,6 +2348,7 @@ static int pl022_suspend(struct device *dev)
>                 dev_warn(dev, "cannot suspend master\n");
>                 return ret;
>         }
> +       pl022_suspend_resources(pl022);
>
>         dev_dbg(dev, "suspended\n");
>         return 0;
> @@ -2321,6 +2359,8 @@ static int pl022_resume(struct device *dev)
>         struct pl022 *pl022 = dev_get_drvdata(dev);
>         int ret;
>
> +       pl022_resume_resources(pl022);
> +
>         /* Start the queue running */
>         ret = spi_master_resume(pl022->master);
>         if (ret)
> @@ -2336,36 +2376,16 @@ static int pl022_resume(struct device *dev)
>  static int pl022_runtime_suspend(struct device *dev)
>  {
>         struct pl022 *pl022 = dev_get_drvdata(dev);
> -       int status = 0;
> -
> -       clk_disable(pl022->clk);
> -
> -       /* Optionally let pins go into sleep states */
> -       if (!IS_ERR(pl022->pins_sleep)) {
> -               status = pinctrl_select_state(pl022->pinctrl,
> -                               pl022->pins_sleep);
> -               if (status)
> -                       dev_err(dev, "could not set pins to sleep state\n");
> -       }
>
> +       pl022_suspend_resources(pl022);
>         return 0;
>  }
>
>  static int pl022_runtime_resume(struct device *dev)
>  {
>         struct pl022 *pl022 = dev_get_drvdata(dev);
> -       int status = 0;
> -
> -       /* Optionaly enable pins to be muxed in and configured */
> -       if (!IS_ERR(pl022->pins_default)) {
> -               status = pinctrl_select_state(pl022->pinctrl,
> -                               pl022->pins_default);
> -               if (status)
> -                       dev_err(dev, "could not set default pins\n");
> -       }
> -
> -       clk_enable(pl022->clk);
>
> +       pl022_resume_resources(pl022);
>         return 0;
>  }
>  #endif
> --
> 1.7.11.3
>

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