Re: [PATCH v2 1/4] dt-bindings: rtc: ingenic: Rework compatible strings and add #clock-cells

From: Rob Herring
Date: Mon Oct 31 2022 - 15:23:45 EST


On Fri, Oct 28, 2022 at 11:55:16PM +0100, Paul Cercueil wrote:
> The RTC in the JZ4770 is compatible with the JZ4760, but has an extra
> register that permits to configure the behaviour of the CLK32K pin. The
> same goes for the RTC in the JZ4780.
>
> Therefore, the ingenic,jz4770-rtc and ingenic,jz4780-rtc strings do not
> fall back anymore to ingenic,jz4760-rtc. The ingenic,jz4780-rtc string
> now falls back to the ingenic,jz4770-rtc string.

This is a compatibility mess. There is no driver support in v6.1-rc for
ingenic,jz4770-rtc, so a new DT would not work with existing kernels. It
sounds like you need 3 compatibles for 4780.

>
> Additionally, since the RTCs in the JZ4770 and JZ4780 support outputting
> the input oscillator's clock to the CLK32K pin, the RTC node is now also
> a clock provider on these SoCs, so a #clock-cells property is added.
>
> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> ---
>
> v2: - add constraint on which SoCs can have the #clock-cells property
> - add JZ4780 example which has a #clock-cells
>
> .../devicetree/bindings/rtc/ingenic,rtc.yaml | 32 +++++++++++++++++--
> 1 file changed, 30 insertions(+), 2 deletions(-)