[PATCH 06/11] mfd: bcm2835-pm: Use 'reg-names' to get resources

[Peter Robinson]

On Sun, May 15, 2022 at 9:21 PM Stefan Wahren <stefan.wahren at i2se.com> wrote:
>
> From: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
>
> If available in firmware, find resources by their 'reg-names' position
> instead of relying on hardcoded offsets. Care is taken to support old
> firmware nonetheless.

So this patch has changed a little over Nicolas's last one, which was
what I based my patch on [1] but there's no changelog

[1] https://patchwork.kernel.org/project/linux-arm-kernel/patch/20220213225646.67761-7-pbrobinson@gmail.com/

> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
> Signed-off-by: Stefan Wahren <stefan.wahren at i2se.com>
Minor comment inline, else:
Reviewed-by: Peter Robinson <pbrobinson at gmail.com>
> ---
>  drivers/mfd/bcm2835-pm.c | 59 +++++++++++++++++++++++++++-------------
>  1 file changed, 40 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
> index 42fe67f1538e..1656d786993a 100644
> --- a/drivers/mfd/bcm2835-pm.c
> +++ b/drivers/mfd/bcm2835-pm.c
> @@ -25,9 +25,41 @@ static const struct mfd_cell bcm2835_power_devs[] = {
>         { .name = "bcm2835-power" },
>  };
>
> +static int bcm2835_pm_get_pdata(struct platform_device *pdev,
> +                               struct bcm2835_pm *pm)
> +{
> +       /* If no 'reg-names' property is found we can assume we're using old
> +        * firmware.
> +        */
> +       if (!of_find_property(pm->dev->of_node, "reg-names", NULL)) {
> +               dev_warn(pm->dev, "Old devicetree detected, please update your firmware.\n");

If they're using an upstream kernel DT and an old firmware this may be
confusing, maybe tweak the wording a little?

> +
> +               pm->base = devm_platform_ioremap_resource(pdev, 0);
> +               if (IS_ERR(pm->base))
> +                       return PTR_ERR(pm->base);
> +
> +               pm->asb = devm_platform_ioremap_resource(pdev, 1);
> +       } else {
> +               struct resource *res;
> +
> +               pm->base = devm_platform_ioremap_resource_byname(pdev, "pm");
> +               if (IS_ERR(pm->base))
> +                       return PTR_ERR(pm->base);
> +
> +               res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
> +                                                   "asb");
> +               if (res)
> +                       pm->asb = devm_ioremap_resource(&pdev->dev, res);
> +       }
> +
> +       if (IS_ERR(pm->asb))
> +               pm->asb = NULL;
> +
> +       return 0;
> +}
> +
>  static int bcm2835_pm_probe(struct platform_device *pdev)
>  {
> -       struct resource *res;
>         struct device *dev = &pdev->dev;
>         struct bcm2835_pm *pm;
>         int ret;
> @@ -39,10 +71,9 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
>
>         pm->dev = dev;
>
> -       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -       pm->base = devm_ioremap_resource(dev, res);
> -       if (IS_ERR(pm->base))
> -               return PTR_ERR(pm->base);
> +       ret = bcm2835_pm_get_pdata(pdev, pm);
> +       if (ret)
> +               return ret;
>
>         ret = devm_mfd_add_devices(dev, -1,
>                                    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
> @@ -54,20 +85,10 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
>          * bcm2835-pm binding as the key for whether we can reference
>          * the full PM register range and support power domains.
>          */
> -       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> -       if (res) {
> -               pm->asb = devm_ioremap_resource(dev, res);
> -               if (IS_ERR(pm->asb))
> -                       return PTR_ERR(pm->asb);
> -
> -               ret = devm_mfd_add_devices(dev, -1,
> -                                          bcm2835_power_devs,
> -                                          ARRAY_SIZE(bcm2835_power_devs),
> -                                          NULL, 0, NULL);
> -               if (ret)
> -                       return ret;
> -       }
> -
> +       if (pm->asb)
> +               return devm_mfd_add_devices(dev, -1, bcm2835_power_devs,
> +                                           ARRAY_SIZE(bcm2835_power_devs),
> +                                           NULL, 0, NULL);
>         return 0;
>  }
>
> --
> 2.25.1
>