[PATCH/RFC 4/5] ARM: shmobile: R-Mobile: Add DT support for PM domains

[Kevin Hilman]

Geert Uytterhoeven <geert+renesas at glider.be> writes:

> Populate the PM domains from DT, and provide support to hook up devices
> to their respective PM domain.
>
> The always-on power area (e.g. C5 on r8a7740) is created as a PM domain
> without software control, to allow Run-Time management of module clocks
> for hardware blocks inside this area in the future.
> Power-on/off latencies are supported.
>
> Limitations and special cases in the non-DT case are handled through
> rmobile_pm_quirks(). Checks for hardcoded PM domain indices should be
> replaced by the analysis of relations between devices and PM domains in
> DT.
>
> Initialization is done from core_initcall(), as the
> "renesas,intc-irqpin" driver uses postcore_initcall().
>
> This is functionally almost equivalent to the non-DT case. Missing are
> Run-Time management of the module clocks (pm_clk_*()), and device
> latencies.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas at glider.be>

[...]

This series looks really good to me.  Just a minor question about a
possible next step...

> +static int r8a7740_pd_a4s_suspend(void)
> +{
> +	/*
> +	 * The A4S domain contains the CPU core and therefore it should
> +	 * only be turned off if the CPU is in use.
> +	 */
> +	return -EBUSY;
> +}


Do you have plans to use pm_genpd_attach_cpuidle() for this eventually,
maybe by checking if the enclosing node is a CPU?  If not, are there
other plans to handle idle for the power domains that contain CPUs?

Kevin