Re: [PATCH] mmc: sdhci at91: add suspend/resume

[Ulf Hansson]

On 16 October 2015 at 17:01, Ludovic Desroches
<ludovic.desroches@xxxxxxxxx> wrote:
> Add suspend and resume PM ops.
>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>

I have no problem with this patch, nice and easy.

Although it would be interesting to see how runtime PM would be
supported for this driver and device. What I have in mind is whether
we can take a runtime PM centric approach and thus more or less get
system PM for "free" via the pm_runtime_force_suspend|resume()
helpers. Care to have a look?

Kind regards
Uffe

> ---
>  drivers/mmc/host/sdhci-of-at91.c | 55 +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 54 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 06d0b50..b9751f2 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -51,6 +51,59 @@ static const struct of_device_id sdhci_at91_dt_match[] = {
>         {}
>  };
>
> +#ifdef CONFIG_PM_SLEEP
> +static int sdhci_at91_suspend(struct device *dev)
> +{
> +       struct platform_device *pdev = to_platform_device(dev);
> +       struct sdhci_host *host = platform_get_drvdata(pdev);
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +       struct sdhci_at91_priv *priv = pltfm_host->priv;
> +       int ret;
> +
> +       ret = sdhci_suspend_host(host);
> +       if (ret)
> +               return ret;
> +
> +       clk_disable_unprepare(priv->gck);
> +       clk_disable_unprepare(priv->hclock);
> +       clk_disable_unprepare(priv->mainck);
> +
> +       return 0;
> +}
> +
> +static int sdhci_at91_resume(struct device *dev)
> +{
> +       struct platform_device *pdev = to_platform_device(dev);
> +       struct sdhci_host *host = platform_get_drvdata(pdev);
> +       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> +       struct sdhci_at91_priv *priv = pltfm_host->priv;
> +       int ret;
> +
> +       ret = clk_prepare_enable(priv->mainck);
> +       if (ret) {
> +               dev_err(dev, "can't enable mainck\n");
> +               return ret;
> +       }
> +
> +       ret = clk_prepare_enable(priv->hclock);
> +       if (ret) {
> +               dev_err(dev, "can't enable hclock\n");
> +               return ret;
> +       }
> +
> +       ret = clk_prepare_enable(priv->gck);
> +       if (ret) {
> +               dev_err(dev, "can't enable gck\n");
> +               return ret;
> +       }
> +
> +       return sdhci_resume_host(host);
> +}
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static SIMPLE_DEV_PM_OPS(sdhci_at91_dev_pm_ops, sdhci_at91_suspend,
> +                        sdhci_at91_resume);
> +
>  static int sdhci_at91_probe(struct platform_device *pdev)
>  {
>         const struct of_device_id       *match;
> @@ -178,7 +231,7 @@ static struct platform_driver sdhci_at91_driver = {
>         .driver         = {
>                 .name   = "sdhci-at91",
>                 .of_match_table = sdhci_at91_dt_match,
> -               .pm     = SDHCI_PLTFM_PMOPS,
> +               .pm     = &sdhci_at91_dev_pm_ops,
>         },
>         .probe          = sdhci_at91_probe,
>         .remove         = sdhci_at91_remove,
> --
> 2.5.0
>
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