Re: [PATCH v2 1/3] dt-bindings: display: bridge: fork out ti,ds90c185 from lvds-transmitter

From: Peter Rosin
Date: Thu Dec 27 2018 - 17:54:18 EST


On 2018-12-27 22:27, Rob Herring wrote:
> On Wed, Dec 19, 2018 at 02:04:47PM +0100, Peter Rosin wrote:
>> From: Peter Rosin <peda@xxxxxxxxxx>
>>
>> DS90C185 has a shutdown pin which does not fit in the lvds-transmitter
>> binding, which is meant to be generic.
>>
>> The sister chip DS90C187 is similar to DS90C185, describe it here as well.
>>
>> Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
>> ---
>> .../bindings/display/bridge/lvds-transmitter.txt | 8 +---
>> .../bindings/display/bridge/ti,ds90c185.txt | 55 ++++++++++++++++++++++
>> 2 files changed, 56 insertions(+), 7 deletions(-)
>> create mode 100644 Documentation/devicetree/bindings/display/bridge/ti,ds90c185.txt
>>
>> diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
>> index 50220190c203..fd39ad34c383 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/lvds-transmitter.txt
>> @@ -22,13 +22,7 @@ among others.
>>
>> Required properties:
>>
>> -- compatible: Must be one or more of the following
>> - - "ti,ds90c185" for the TI DS90C185 FPD-Link Serializer
>> - - "lvds-encoder" for a generic LVDS encoder device
>> -
>> - When compatible with the generic version, nodes must list the
>> - device-specific version corresponding to the device first
>> - followed by the generic version.
>> +- compatible: Must be "lvds-encoder"
>>
>> Required nodes:
>>
>> diff --git a/Documentation/devicetree/bindings/display/bridge/ti,ds90c185.txt b/Documentation/devicetree/bindings/display/bridge/ti,ds90c185.txt
>> new file mode 100644
>> index 000000000000..a13e778503e6
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/display/bridge/ti,ds90c185.txt
>> @@ -0,0 +1,55 @@
>> +Texas Instruments FPD-Link (LVDS) Serializer
>> +--------------------------------------------
>> +
>> +The DS90C185 and DS90C187 are low-power serializers for portable
>> +battery-powered applications that reduces the size of the RGB
>> +interface between the host GPU and the display.
>> +
>> +Required properties:
>> +
>> +- compatible: Should be
>> + "ti,ds90c185", "lvds-encoder" for the TI DS90C185 FPD-Link Serializer
>> + "ti,ds90c187", "lvds-encoder" for the TI DS90C187 FPD-Link Serializer
>> +
>> +Optional properties:
>> +
>> +- pwdn-gpios: Power down control GPIO (the PDB pin, active-low)
>
> powerdown-gpios is the standard name.

The lvds-encoder driver handles this binding, and that driver incidentally
also implements the thine,thc63lvdm83d binding which already has a
pwdn-gpios property. Should the thine,thc63lvdm83d binding be updated and
the driver be made to support both properties?

Since the lvds-encoder driver never had support for the pwdn-gpios (at least
not upstream) I suppose there is also the option to simply go with
powerdown-gpios as you suggest and not bother with support for the
pwdn-gpios property.

I'm quite willing to send an updated series, but I don't know what is
preferred, and am in need of guidance.

Cheers,
Peter

>> +
>> +Required nodes:
>> +
>> +The devices have two video ports. Their connections are modeled using the OF
>> +graph bindings specified in Documentation/devicetree/bindings/graph.txt.
>> +
>> +- Video port 0 for parallel input
>> +- Video port 1 for LVDS output
>> +
>> +
>> +Example
>> +-------
>> +
>> +lvds-encoder {
>> + compatible = "ti,ds90c185", "lvds-encoder";
>> +
>> + pwdn-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
>> +
>> + ports {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> +
>> + port@0 {
>> + reg = <0>;
>> +
>> + lvds_enc_in: endpoint {
>> + remote-endpoint = <&lcdc_out_rgb>;
>> + };
>> + };
>> +
>> + port@1 {
>> + reg = <1>;
>> +
>> + lvds_enc_out: endpoint {
>> + remote-endpoint = <&lvds_panel_in>;
>> + };
>> + };
>> + };
>> +};
>> --
>> 2.11.0
>>