Re: [PATCH v4 1/2] arm64: dts: rockchip: add "rockchip, grf" property for RK3399 PMUCRU/CRU

[Doug Anderson]

Hi,

On Mon, Jan 9, 2017 at 10:15 PM, Xing Zheng <zhengxing@xxxxxxxxxxxxxx> wrote:
> The structure rockchip_clk_provider needs to refer the GRF regmap
> in somewhere, if the CRU node has not "rockchip,grf" property,
> calling syscon_regmap_lookup_by_phandle will return an invalid GRF
> regmap, and the MUXGRF type clock will be not supported.
>
> Therefore, we need to add them.
>
> Signed-off-by: Xing Zheng <zhengxing@xxxxxxxxxxxxxx>
> ---
>
> Changes in v4:
> - separte the binding patch
>
> Changes in v3:
> - add optional roperty rockchip,grf in rockchip,rk3399-cru.txt
>
> Changes in v2:
> - referring pmugrf for PMUGRU
> - fix the typo "invaild" in COMMIT message
>
>  arch/arm64/boot/dts/rockchip/rk3399.dtsi | 2 ++
>  1 file changed, 2 insertions(+)

This seems fine to me, so:

Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

...but I will say that before you actually add any real "MUXGRF"
clocks on rk3399 you _might_ need to rework the code to make things
truly "optional".  If it turns out that any existing clocks that
already exist today already go through one of these muxes in the GRF
and we've always been assuming one setting of the mux, we'll need to
make sure we keep assuming that setting of the mux even if the "grf"
isn't specified.

As I understand it, your motivation for this patch is to eventually be
able to model the EDP reference clock which can either be xin24 or
"edp osc".  Presumably the eDP "reference clock" isn't related to any
of the pre-existing eDP clocks so that one should be safe.

-Doug