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Message-ID: <06a726ec-5423-c2e9-5b98-4eb36607a16e@pengutronix.de>
Date:   Fri, 28 Jul 2023 10:36:02 +0200
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Subject: Re: [PATCH v2 2/3] dt-bindings: display: simple: support non-default
 data-mapping
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To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Thierry Reding <thierry.reding@gmail.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        kernel test robot <lkp@intel.com>,
        Dan Carpenter <error27@gmail.com>,
        patchwork-jzi@pengutronix.de, kernel@pengutronix.de,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230523-simplepanel_support_nondefault_datamapping-v2-0-87196f0d0b64@pengutronix.de>
 <20230523-simplepanel_support_nondefault_datamapping-v2-2-87196f0d0b64@pengutronix.de>
 <20230602153525.GB3343@pendragon.ideasonboard.com>
From:   Johannes Zink <j.zink@pengutronix.de>
In-Reply-To: <20230602153525.GB3343@pendragon.ideasonboard.com>
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Hi Laurent,

thank you for your review.

On 6/2/23 17:35, Laurent Pinchart wrote:
> Hi Johannes,
> 
> Thank you for the patch.
> 
> On Tue, May 23, 2023 at 10:19:42AM +0200, Johannes Zink wrote:
>> Some Displays support more than just a single default lvds data mapping,
> 
> s/lvds/LVDS/

ack, gonna fix in V3

> 
>> which can be used to run displays on only 3 LVDS lanes in the jeida-18
>> data-mapping mode.
>>
>> Add an optional data-mapping property to allow overriding the default
>> data mapping. As it does not generally apply to any display and bus: use
> 
> s/bus:/bus,/

ack, gonna fix in V3

> 
>> it selectively on the innolux,g101ice-l01, which supports changing the
>> data mapping via a strapping pin.
>>
>> Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
>> ---
>>
>> Changes:
>>
>> v1 -> v2: - worked in Rob's review findings (thanks for reviewing my
>>              work): use extracted common property instead of duplicating
>> 	    the property
>> 	  - refined commit message
>> 	  - add an example dts for automated checking
>> ---
>>   .../bindings/display/panel/panel-simple.yaml       | 26 +++++++++++++++++++++-
>>   1 file changed, 25 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
>> index ec50dd268314..698301c8c920 100644
>> --- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
>> +++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
>> @@ -21,9 +21,9 @@ description: |
>>   
>>   allOf:
>>     - $ref: panel-common.yaml#
>> +  - $ref: ../lvds-data-mapping.yaml#
>>   
>>   properties:
>> -
>>     compatible:
>>       enum:
>>       # compatible must be listed in alphabetical order, ordered by compatible.
>> @@ -353,6 +353,17 @@ properties:
>>     power-supply: true
>>     no-hpd: true
>>     hpd-gpios: true
>> +  data-mapping: true
> 
> As the property is optional, don't you need a default value ?

as the simple-bus implicitely assumes default data mappings for LVDS panels, I 
think this is not necessary. If the property is not used in a DT, the default 
data mapping is used.

Best regards
Johannes

> 
>> +
>> +if:
>> +  not:
>> +    properties:
>> +      compatible:
>> +        contains:
>> +          const: innolux,g101ice-l01
>> +then:
>> +  properties:
>> +    data-mapping: false
>>   
>>   additionalProperties: false
>>   
>> @@ -372,3 +383,16 @@ examples:
>>           };
>>         };
>>       };
>> +  - |
>> +    panel_lvds: panel-lvds {
>> +      compatible = "innolux,g101ice-l01";
>> +      power-supply = <&vcc_lcd_reg>;
>> +
>> +      data-mapping = "jeida-24";
>> +
>> +      port {
>> +        panel_in_lvds: endpoint {
>> +          remote-endpoint = <&ltdc_out_lvds>;
>> +        };
>> +      };
>> +    };
>>
> 

-- 
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