Re: [PATCH v2 2/7] ARM: Exynos: add support for sub-power domains

[Marek Szyprowski <m.szyprowski@samsung.com>]

Hello,

On 2014-12-03 13:36, Geert Uytterhoeven wrote:
> Hi Marek,
>
> On Wed, Dec 3, 2014 at 1:33 PM, Marek Szyprowski
> <m.szyprowski@samsung.com> wrote:
>> diff --git a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
>> index abde1ea8a119..b884358ebb1a 100644
>> --- a/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
>> +++ b/Documentation/devicetree/bindings/arm/exynos/power_domain.txt
>> @@ -22,6 +22,8 @@ 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.
>> +- samsung,power-domain: phandle to a master power domain that the given domain
>> +                      is a part of
> For new DTSes I'd recommend using the generic "power-domains" only.

I think that some consistency in dts style will be really an added 
value. In my opinion for
all existing DTSes we should keep using 'samsung,power-domain' (even for 
defining a parent
power domains) and for all new DTSes, the generic 'power-domains' 
binding should be used.

> Or do you already have a DTS where tv-power-domain@10023C20 uses
> "samsung,power-domain" in the wild?

Not yet. We only used in private repositories, which can be changed.

>
>>   Node of a device using power domains must have a samsung,power-domain property
>>   defined with a phandle to respective power domain.
>> diff --git a/arch/arm/mach-exynos/pm_domains.c b/arch/arm/mach-exynos/pm_domains.c
>> index 20f267121b3e..fa9a47ddad81 100644
>> --- a/arch/arm/mach-exynos/pm_domains.c
>> +++ b/arch/arm/mach-exynos/pm_domains.c
>> @@ -108,7 +108,7 @@ static int exynos_pd_power_off(struct generic_pm_domain *domain)
>>   static __init int exynos4_pm_init_power_domain(void)
>>   {
>>          struct platform_device *pdev;
>> -       struct device_node *np;
>> +       struct device_node *np, *master_np;
>>
>>          for_each_compatible_node(np, NULL, "samsung,exynos4210-pd") {
>>                  struct exynos_pm_domain *pd;
>> @@ -159,6 +159,15 @@ no_clk:
>>
>>                  pm_genpd_init(&pd->pd, NULL, !on);
>>                  of_genpd_add_provider_simple(np, &pd->pd);
>> +
>> +               /* make master and slave hierarchy */
>> +               master_np = of_parse_phandle(np, "samsung,power-domain", 0);
>> +               if (!master_np)
>> +                       master_np = of_parse_phandle(np, "power-domains", 0);
>> +               if (master_np) {
>> +                       pm_genpd_add_subdomain_names(master_np->name, np->name);
>> +                       of_node_put(master_np);
>> +               }
>>

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland