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

[Marek Szyprowski]

Hello,

On 2014-12-04 04:45, amit daniel kachhap wrote:
> On Wed, Dec 3, 2014 at 6:03 PM, Marek Szyprowski
> <m.szyprowski@xxxxxxxxxxx> wrote:
> > This patch adds support for making one power domain a sub-domain of
> > other domain. This is useful for modeling power dependences for devices
> > like TV Mixer or Camera ISP, which needs to have more than one power
> > domain enabled to be operational.
> >
> > Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > ---
> >   Documentation/devicetree/bindings/arm/exynos/power_domain.txt |  2 ++
> >   arch/arm/mach-exynos/pm_domains.c                             | 11 ++++++++++-
> >   2 files changed, 12 insertions(+), 1 deletion(-)
> >
> > 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
> >
> >   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);
> > +               }
> >          }
> Hi Marek,
>
> In the my patch series posted earlier i added this feature in a
> slightly different way. (https://lkml.org/lkml/2014/11/24/320)
> Parent PD's are not added in the same loop but in the second loop.
> This will make sure that the parents PD are registered before the
> child PD's and we can get away from the assumption of child/parent
> PD's position in the Device Tree. This is a still a work in progress.
> Also posted a patch earlier regarding this,
> http://www.spinics.net/lists/linux-samsung-soc/msg39836.html.

Right, your approach seems to be more error prone. Do you plan to resend 
your
patch with the parent domain phandle renamed to generic 'power-domains' 
property,
like Geert suggested?

I would like to send Exynos4 HDMI patches based on top of your work and 
have them
finally merged (they are waiting since v3.17...)

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

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