[PATCH v3 2/6] dt-bindings: display: Add Synopsys DW MIPI DSI DRM bridge driver

[Jose Abreu]

Hello,


On 09-06-2017 05:11, Archit Taneja wrote:
> Hi Philippe, Rob,
>
> On 06/08/2017 09:10 PM, Rob Herring wrote:
>> Seems strange there's not also a pixel or bit clock? Or this
>> gets driven
>> from the phy?
>
> Since you mention phy here, I wanted to share a concern with
> the bindings.
> These bindings don't have a separate PHY DT node. The PHY is
> assumed as a
> part of the IP when integrated by a SoC. There are already
> rockchip and
> hisil DSI bindings that use this IP but don't define a PHY node.
>
> It's a similar situation with the DW-HDMI bindings.
>
> For example, when the DW HDMI is integrated in rockchip or
> renesas SoC, the
> bindings "rockchip,rk3288-dw-hdmi" or "renesas,r8a7795-dw-hdmi"
> are used,
> and they don't have a separate PHY DT node.
>
> I wasn't sure whether this is the right way to proceed or not
> for such IPs.
> Some advice would help us here.
>
> Thanks,
> Archit
>

I just want to add that read/writes from/to phy are done using
the controller (in HDMI and in MIPI DSI Host), so the only way to
have a phy driver is that if some custom callbacks are provided
or if the memory region is shared.

Anyway, I agree with Archit in the sense that phy + controller
are highly tied. Also, these two "pieces" are SoC specific and
sometimes very different between SoC's because they can be
customized so I think a different compatible string suits well here.

Best regards,
Jose Miguel Abreu