Re: [PATCH v8 05/10] pmdomain: samsung: convert to using regmap

[Ulf Hansson]

On Wed, 18 Mar 2026 at 16:28, André Draszik <andre.draszik@xxxxxxxxxx> wrote:
>
> On platforms such as Google gs101, direct mmio register access to the
> PMU registers doesn't necessarily work and access must happen via a
> regmap created by the PMU driver instead.
>
> In preparation for supporting such SoCs convert the existing mmio
> accesses to using a regmap wrapper.
>
> With this change in place, a follow-up patch can update the driver to
> optionally acquire the PMU-created regmap without having to change the
> rest of the code.
>
> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: André Draszik <andre.draszik@xxxxxxxxxx>

[...]

> @@ -36,31 +35,42 @@ struct exynos_pm_domain {
>  static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
>  {
>         struct exynos_pm_domain *pd;
> -       void __iomem *base;
>         u32 timeout, pwr;
> -       char *op;
> +       int err;
>
>         pd = container_of(domain, struct exynos_pm_domain, pd);
> -       base = pd->base;
>
>         pwr = power_on ? pd->local_pwr_cfg : 0;
> -       writel_relaxed(pwr, base);
> +       err = regmap_write(pd->regmap, 0, pwr);
> +       if (err) {
> +               pr_err("Regmap write for power domain %s %sable failed: %d\n",
> +                      domain->name, power_on ? "en" : "dis", err);
> +               return err;
> +       }
>
>         /* Wait max 1ms */
>         timeout = 10;
> -
> -       while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) {
> -               if (!timeout) {
> -                       op = (power_on) ? "enable" : "disable";
> -                       pr_err("Power domain %s %s failed\n", domain->name, op);
> -                       return -ETIMEDOUT;
> +       while (timeout-- > 0) {
> +               unsigned int val;
> +
> +               err = regmap_read(pd->regmap, 0x4, &val);
> +               if (err || ((val & pd->local_pwr_cfg) != pwr)) {
> +                       cpu_relax();
> +                       usleep_range(80, 100);
> +                       continue;
>                 }
> -               timeout--;
> -               cpu_relax();
> -               usleep_range(80, 100);
> +
> +               break;
>         }
>

[...]

As a follow-up patch on top, please consider converting the open-coded
polling loop above into a readx_poll_timeout_atomic().

That said, the series looks ready to me, but I am awaiting an ack from
a DT maintainer on patch4 before applying.

Kind regards
Uffe