Hello, On 2014-11-25 10:19, Geert Uytterhoeven wrote:
On Tue, Nov 25, 2014 at 9:57 AM, amit daniel kachhap <amit.daniel@xxxxxxxxxxx> wrote: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.Why not using just "power-domains = <&pd_top>"? This is consistent with how clocks refer to their parent clocks.
I agree. The only question is weather exynos dts should keep using samsung,power-domain property, or switch to generic 'power-domains' approach. I assume that exynos-pm driver
should support both.
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.I am not sure if this is generic. I guess PD's represented like below are more generic. PD1 { PD2 { PD3 { }; }; };Such a representation is not always possible. If you have one power-controller for a hierarchy of PM domains, you can use it. If you have multiple power-controllers, the power controller nodes are at the same level in DT, so you'll have to use "power-domains" properties to link them together.
I agree. I will send updated patch for this purpose for existing exynos4 power domain driver.
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
