On Fri, Feb 28, 2014 at 10:25 AM, Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote:
> Am Freitag, den 28.02.2014, 15:59 +0000 schrieb Russell King - ARM
> Linux:
>> On Fri, Feb 28, 2014 at 02:20:10PM +0200, Tomi Valkeinen wrote:
>> > Add DT binding documentation for DVI Connector.
>> >
>> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
>> > Reviewed-by: Archit Taneja <archit@xxxxxx>
>> > ---
>> > .../devicetree/bindings/video/dvi-connector.txt | 26 ++++++++++++++++++++++
>> > 1 file changed, 26 insertions(+)
>> > create mode 100644 Documentation/devicetree/bindings/video/dvi-connector.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/video/dvi-connector.txt b/Documentation/devicetree/bindings/video/dvi-connector.txt
>> > new file mode 100644
>> > index 000000000000..6a0aff866c78
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/video/dvi-connector.txt
>> > @@ -0,0 +1,26 @@
>> > +DVI Connector
>> > +==============
>> > +
>> > +Required properties:
>> > +- compatible: "dvi-connector"
>> > +
>> > +Optional properties:
>> > +- label: a symbolic name for the connector
>> > +- i2c-bus: phandle to the i2c bus that is connected to DVI DDC
>> > +
>> > +Required nodes:
>> > +- Video port for DVI input
>> > +
>> > +Example
>> > +-------
>> > +
>> > +dvi0: connector@0 {
>> > + compatible = "dvi-connector";
>> > + label = "dvi";
>> > +
>> > + i2c-bus = <&i2c3>;
>> > +
>> > + dvi_connector_in: endpoint {
>> > + remote-endpoint = <&tfp410_out>;
>> > + };
>> > +};
>>
>> This looks far too simplistic. There are different classes of DVI
>> connector - there is:
>>
>> DVI A - analogue only
>> DVI D - digital only (single and dual link)
>> DVI I - both (single and dual digital link)
>>
>> DRM at least makes a distinction between these three classes, and this
>> disctinction is part of the user API. How would a display system know
>> which kind of DVI connector is wired up on the board from this DT
>> description?
>
> Maybe this could be inferred from the sources connected to it. For
> example a i.MX5 board with the SoC internal TV Encoder and an external
> SiI902x HDMI encoder connected to the same DVI I connector:
>
> ipu {
> port@2 {
> ipu_di0_disp0: endpoint {
> remote-endpoint = <&sii902x_in>;
> };
> };
> port@3 {
> ipu_di1_tve: endpoint {
> remote-endpoint = <&tve_in>;
> };
> };
> };
>
> &sii902x {
> compatible = "si,sii9022";
>
> port@0 {
> sii902x_in: endpoint {
> remote-endpoint = <&ipu_di0>;
> };
> };
> port@1 {
> sii902x_out: endpoint {
> remote-endpoint = <&dvi_d_in>;
> };
> };
> };
>
> &tve {
> compatible = "fsl,imx53-tve";
> port@0 {
> tve_in: endpoint {
> remote-endpoint = <&ipu_di1>;
> };
> };
> port@1 {
> tve_out: endpoint {
> remote-endpoint = <&dvi_a_in>;
> };
> };
> };
>
> dvi-connector {
> compatible = "dvi-connector";
> ddc-i2c-bus = <&i2c3>;
>
> port {
> dvi_d_in: endpoint@0 {
> remote-endpoint = <&sii902x_out>;
> };
> dvi_a_in: endpoint@1 {
> remote-endpoint = <&tve_out>;
> };
> };
> };
>
> It should be possible to let the connector know that those two endpoints
> are connected to a TMDS source and to a VGA source, respectively.
I like this proposal over the others. Although, would dual link be a
single endpoint or 2 endpoints? How would you differentiate that?
The port node seems a bit pointless.
Rob
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
