[PATCH 2/2] dt-bindings: panel-simple-dsi: Add generic panel-dsi

[Johan Adolfsson]

>-----Original Message-----
>From: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org> 
>Sent: den 22 april 2024 22:57
>To: Johan Adolfsson <Johan.Adolfsson at axis.com>; Neil Armstrong <neil.armstrong at linaro.org>; Jessica Zhang <quic_jesszhan at quicinc.com>; Sam Ravnborg <sam at ravnborg.org>; Maarten Lankhorst <maarten.lankhorst at linux.intel.com>; Maxime Ripard <mripard at kernel.org>; Thomas Zimmermann <tzimmermann at suse.de>; David Airlie <airlied at gmail.com>; Daniel Vetter <daniel at ffwll.ch>; Rob Herring <robh+dt at kernel.org>; Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>; Conor Dooley <conor+dt at kernel.org>; Thierry Reding <thierry.reding at gmail.com>
>Cc: dri-devel at lists.freedesktop.org; linux-kernel at vger.kernel.org; devicetree at vger.kernel.org; kernel <kernel at axis.com>
>Subject: Re: [PATCH 2/2] dt-bindings: panel-simple-dsi: Add generic panel-dsi>
>
>On 22/04/2024 16:34, Johan Adolfsson wrote:
>> 
>> 
>> -----Original Message-----
>> From: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
>> Sent: den 19 april 2024 01:05
>> To: Johan Adolfsson <Johan.Adolfsson at axis.com>; Neil Armstrong 
..
>> Subject: Re: [PATCH 2/2] dt-bindings: panel-simple-dsi: Add generic 
>> panel-dsi
>> 
>>> On 18/04/2024 16:01, Johan Adolfsson wrote:
>>>> panel-dsi is similar to panel-dpi with overridable timings
>>>
>>> ???
>> 
>> I guess a more correct description would be "panel-dsi is a fallback 
>> in a similar way that panel-dpi is in panel-dpi.yaml .."?
>
>I meant how does it explain the hardware.

In our case it's actually an FPGA that takes MIPI DSI input and can support multiple different kind of displays, and what I want to achieve
is to avoid specifying a lot of different panel timings in the driver and have that in devicetree instead. 
I appreciate any suggestions on how to phrase that in an acceptable manner.

>> ...
>>>> a/Documentation/devicetree/bindings/display/panel/panel-simple-dsi.y
>>>> am
>>>> l
>>>> +++ b/Documentation/devicetree/bindings/display/panel/panel-simple-d
>>>> +++ si
>>>> +++ .yaml
>>>> @@ -56,6 +56,8 @@ properties:
>>>>        - samsung,sofef00
>>>>          # Shangai Top Display Optoelectronics 7" TL070WSH30 1024x600 TFT LCD panel
>>>>        - tdo,tl070wsh30
>>>> +        # Generic dsi panel with timing overridable
>>>> +      - panel-dsi
>>>
>>> ? Devices are not generic. This is very confusing and commit msg does not help me. Compatibles *must* be specific, see writing-bindings.
>> 
>> I guess I see this a generic fallback, that handles any dsi panel as 
>> long as the correct timing etc is specified in devictree, similar to what panel-dpi is in panel-dpi.yaml Maybe phrasing it similar to panel-dpi.yaml is better?
>
>But panel-dpi is quite different. You always have two compatibles. I don't see two compatibles here.

It doesn't really need two compatibles (in practice at least), the new generic panel-dsi could be enough - I do believe that devices can be generic,
but I admit that I'm not really "fluent" in devicetree and binding descriptions.

>Best regards,
>Krzysztof

Best regards
/Johan