Re: [PATCH 2/2] ARM: Exynos: Hook up power domains to generic power domain infrastructure

[Sylwester Nawrocki <snjw23@gmail.com>]

Hi Thomas,

thank you for clarifying.

On 01/02/2012 03:14 AM, Thomas Abraham wrote:
> 
> The following is a snippet from the dts file used for testing.
> 
>    [...]
> 
>    lcd0:power-domain-lcd0 {
>             compatible = "samsung,exynos4210-pd";
>             reg = <0x10023C00 0x10>;
>    };
> 
>    [...]
> 
>    fimd0:display-controller {
>             compatible = "samsung,exynos4-fimd";
>             [...]
>             pd = <&lcd0>;
>    };
> 
> The fimd (display controller) driver would then do the following.
> 
> parp = of_get_property(pdev->dev.of_node, "pd", NULL);
> pd_np = of_find_node_by_phandle(be32_to_cpup(parp));
> pm_genpd_of_add_device(pd_np, &pdev->dev);

Sounds interesting. Currently it's platform code that adds devices to
a corresponding power domain. But doing it at drivers might be more
convenient for avoiding device/driver/power domain registration
synchronization issues, especially that knowledge about power domain
existence may be contained directly in DT description, not needing
drivers to carry platform specific data.

BTW, I have a feeling that "samsung" is a bit longish prefix for the bindings.
Didn't you initially consider "sec" for instance ? Probably it is already
too late for changing that though.

> The lookup is based on the node pointer of the power domain.

Thanks,
Sylwester