Re: [PATCH 07/21] dt-bindings: display: mediatek: dpi: add binding for MT8365

[Alexandre Mergnat]

Hi Chun-Kuang,

Le lun. 13 mars 2023 à 16:17, Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx> a écrit :
>
> Hi, Alexandre:
>
> Alexandre Mergnat <amergnat@xxxxxxxxxxxx> 於 2023年3月9日 週四 下午10:23寫道：
> >
> > From: Fabien Parent <fparent@xxxxxxxxxxxx>
> >
> > DPI for MT8365 is compatible with MT8192 but requires an additional
> > clock. Modify the documentation to requires this clock only on MT8365 SoCs.
>
> If MT8365 DPI has additional clock, why it is compatible with MT8192 DPI?
> I think some part of MT8165 DPI works under the speed control by the
> DPI clock and this is different with MT8192 DPI, how could these two
> are compatible?

AFAII, The mtk_dpi driver manage the 4th clock as optional
dpi->dpi_clk = devm_clk_get_optional(dev, "dpi");
And all configuration variables for mt8192 are the same for mt8365.
These configuration clock variables (like cal_factor) aren't
correlated with the 4th clock.
The clock number doesn't impact the configuration variable because the
4th clock is simply retrieved from DTS, saved in the driver structure
and prepare/unprepare/enable/disable, like other clocks.

Regards,
Alex