[PATCH v2 1/3] dt-bindings: Add doc for the ingenic-drm driver
Paul Cercueil
paul at crapouillou.net
Sat Mar 16 21:56:35 UTC 2019
Hi Sam,
Le sam. 16 mars 2019 à 21:59, Sam Ravnborg <sam at ravnborg.org> a écrit
:
> Hi Paul.
>
> On Fri, Mar 15, 2019 at 06:06:59PM +0100, Paul Cercueil wrote:
>> Add documentation for the devicetree bindings of the DRM driver for
>> the
>> JZ47xx family of SoCs from Ingenic.
>>
>> Signed-off-by: Paul Cercueil <paul at crapouillou.net>
>> Tested-by: Artur Rojek <contact at artur-rojek.eu>
>> ---
>>
>> Notes:
>> v2: Remove ingenic,panel property.
>>
>> .../devicetree/bindings/display/ingenic,drm.txt | 29
>> ++++++++++++++++++++++
>> 1 file changed, 29 insertions(+)
>> create mode 100644
>> Documentation/devicetree/bindings/display/ingenic,drm.txt
>>
>> diff --git
>> a/Documentation/devicetree/bindings/display/ingenic,drm.txt
>> b/Documentation/devicetree/bindings/display/ingenic,drm.txt
>> new file mode 100644
>> index 000000000000..f57a4ae0f7ac
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/ingenic,drm.txt
>> @@ -0,0 +1,29 @@
>> +Ingenic JZ47xx DRM driver
>> +
>> +Required properties:
>> +- compatible: one of:
>> + * ingenic,jz4740-drm
>> + * ingenic,jz4725b-drm
>> +- reg: LCD registers location and length
>> +- clocks: LCD pixclock and device clock specifiers.
>> + The device clock is only required on the JZ4740.
>> +- clock-names: "lcd_pclk" and "lcd"
>> +- interrupts: Specifies the interrupt line the LCD controller is
>> connected to.
>> +
>> +Optional properties:
>> +- ingenic,lcd-mode: LCD mode to use with the display panel.
>> + See <dt-bindings/display/ingenic,drm.h> for all the
>> + possible values.
>
> The value of the ingenic,lcd-mode depends on the panel used.
> So this looks like a panel property and not a display property.
>
> The panel should be specified using an OF graph binding
> in a port sub-node.
> The remote-endpoint will specifify the panel properties
> and if the panel requires something special from the display driver,
> the panle should specify this.
> So one can change panel without touching the display node
> in the DT.
Then the 'ingenic,lcd-mode' property would be in the panel node,
even though it's not used by the panel driver but by the DRM driver?
That sounds strange to me.
>> +
>> +Example:
>> +
>> +lcd: lcd-controller at 13050000 {
>> + compatible = "ingenic,jz4725b-drm";
>> + reg = <0x13050000 0x1000>;
>> +
>> + interrupt-parent = <&intc>;
>> + interrupts = <31>;
>> +
>> + clocks = <&cgu JZ4725B_CLK_LCD>;
>> + clock-names = "lcd";
>> +};
>
> As hinted above the panel is not specified above and to follow the
> modern way to do so would be to use a OF graph binding.
It's done this way in the DRM driver now, but I didn't update the
example. I will update it in the next version.
-Paul
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