Re: [PATCH RFC v2 08/12] soc: samsung: pm_domain: Add support for parent power domain

[Ulf Hansson <ulf.hansson@linaro.org>]

On 24 November 2014 at 14:04, Amit Daniel Kachhap
<amit.daniel@samsung.com> wrote:
> This patch adds supports for parent power domain. This will ensure
> invoking of parent/child power domain on/off in a correct sequence.
> In exynos7 SOC's, power domain controllers have parent and child
> hierarchy.
>
> Cc: Kukjin Kim <kgene.kim@samsung.com>
> Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com>
> ---
>  .../bindings/arm/exynos/power_domain.txt           |    2 +
>  drivers/soc/samsung/pm_domains.c                   |   43 +++++++++++++++++++-
>  2 files changed, 44 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
> index 00ebda1..0160bdc 100644
> --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
> +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
> @@ -24,6 +24,7 @@ Optional Properties:
>         - pclkN, clkN: Pairs of parent of input clock and input clock to the
>                 devices in this power domain. Maximum of 4 pairs (N = 0 to 3)
>                 are supported currently.
> +- parents: phandle of parent power domains.
>
>  Node of a device using power domains must have a samsung,power-domain property
>  defined with a phandle to respective power domain.
> @@ -48,6 +49,7 @@ Example:
>         mfc_pd: power-domain@10044060 {
>                 compatible = "samsung,exynos4210-pd", "samsung,exynos7-pd-mfc";
>                 reg = <0x10044060 0x20>;
> +               parents = <&pd_top>;
>                 #power-domain-cells = <0>;
>         };

This seems like a good and generic approach to describe that a PM
domain could have a parent. I would suggest to rename it, such it
reflects its a PM domain binding though.

So, maybe we can add this as a common DT binding for the generic PM
domain instead of having it as Exynos specific?

Kind regards
Uffe