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

[amit daniel kachhap]

On Tue, Nov 25, 2014 at 1:29 PM, Ulf Hansson <ulf.hansson at linaro.org> wrote:
> On 24 November 2014 at 14:04, Amit Daniel Kachhap
> <amit.daniel at 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 at samsung.com>
>> Signed-off-by: Amit Daniel Kachhap <amit.daniel at 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 at 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.
I am not sure if this is generic. I guess PD's represented like below
are more generic.
PD1 {
        PD2 {
                PD3 {
                };
        };
};

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

Regards,
Amit D
>
> Kind regards
> Uffe
>
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