On 2018-04-18 09:16, Boris Brezillon wrote:
> Hi Peter,
>
> On Tue, 17 Apr 2018 15:10:48 +0200
> Peter Rosin <peda@xxxxxxxxxx> wrote:
>
>> With bus-type/bus-width properties in the endpoint nodes, the video-
>> interface of the connection can be specified for cases where the
>> heuristic fails to select the correct output mode. This can happen
>> e.g. if not all RGB pins are routed on the PCB; the driver has no
>> way of knowing this, and needs to be told explicitly.
>>
>> This is critical for the devices that have the "conflicting output
>> formats" issue (SAM9N12, SAM9X5, SAMA5D3), since the most significant
>> RGB bits move around depending on the selected output mode. For
>> devices that do not have the "conflicting output formats" issue
>> (SAMA5D2, SAMA5D4), this is completely irrelevant.
>>
>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>> ---
>> Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt | 8 ++++++++
>> 1 file changed, 8 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>> index 82f2acb3d374..244b48869eb4 100644
>> --- a/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>> +++ b/Documentation/devicetree/bindings/display/atmel/hlcdc-dc.txt
>> @@ -15,6 +15,14 @@ Required children nodes:
>> to external devices using the OF graph reprensentation (see ../graph.txt).
>> At least one port node is required.
>>
>> +Optional properties in grandchild nodes:
>> + Any endpoint grandchild node may specify a desired video interface
>> + according to ../../media/video-interfaces.txt, specifically
>> + - bus-type: must be <0>.
>> + - bus-width: recognized values are <12>, <16>, <18> and <24>, and
>> + override any output mode selection hueristic, forcing "rgb444",
heuristic, I'll fix that for v3, so please review as if it wasn't there...
>> + "rgb565", "rgb666" and "rgb888" respectively.
>> +
>
> Can you add an example or update the existing one to show how this
> should be defined?
For v3, I'll extend the binding with this after the preexisting example:
------------------8<-----------------
Example 2: With a video interface override to force rgb565, as above
but with these changes/additions:
&hlcdc {
hlcdc-display-controller {
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lcd_base &pinctrl_lcd_rgb565>;
port@0 {
hlcdc_panel_output: endpoint@0 {
bus-type = <0>;
bus-width = <16>;
};
};
};
};
------------------8<-----------------
Is that a good plan, or should I perhaps duplicate the whole example?
Cheers,
Peter
>> Example:
>>
>> hlcdc: hlcdc@f0030000 {
>
>
> Thanks,
>
> Boris
>
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