[PATCH V5 5/9] mmc: bcm2835: add suspend/resume pm support

[Ulf Hansson]

On Fri, 25 Oct 2024 at 12:36, Stefan Wahren <wahrenst at gmx.net> wrote:
>
> Add a minimalistic suspend/resume PM support.
>
> Signed-off-by: Stefan Wahren <wahrenst at gmx.net>
> ---
>  drivers/mmc/host/bcm2835.c | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
>
> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> index 107666b7c1c8..17c327b7b5cc 100644
> --- a/drivers/mmc/host/bcm2835.c
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -1343,6 +1343,30 @@ static int bcm2835_add_host(struct bcm2835_host *host)
>         return 0;
>  }
>
> +static int bcm2835_suspend(struct device *dev)
> +{
> +       struct bcm2835_host *host = dev_get_drvdata(dev);
> +
> +       if (!host->data_complete) {
> +               dev_warn(dev, "Suspend is prevented\n");
> +               return -EBUSY;
> +       }

This should not be needed.

The mmc core makes sure all outstanding requests have been flushed,
before the host controller becomes suspended.

> +
> +       clk_disable_unprepare(host->clk);
> +
> +       return 0;
> +}
> +
> +static int bcm2835_resume(struct device *dev)
> +{
> +       struct bcm2835_host *host = dev_get_drvdata(dev);
> +
> +       return clk_prepare_enable(host->clk);
> +}
> +
> +static DEFINE_SIMPLE_DEV_PM_OPS(bcm2835_pm_ops, bcm2835_suspend,
> +                               bcm2835_resume);
> +
>  static int bcm2835_probe(struct platform_device *pdev)
>  {
>         struct device *dev = &pdev->dev;
> @@ -1471,6 +1495,7 @@ static struct platform_driver bcm2835_driver = {
>                 .name           = "sdhost-bcm2835",
>                 .probe_type     = PROBE_PREFER_ASYNCHRONOUS,
>                 .of_match_table = bcm2835_match,
> +               .pm = pm_ptr(&bcm2835_pm_ops),
>         },
>  };
>  module_platform_driver(bcm2835_driver);

Kind regards
Uffe