Re: [PATCH 2/4] drm: Add DT bindings documentation for ARC PGU display controller

[Rob Herring]

On Thu, Mar 3, 2016 at 7:58 AM, Alexey Brodkin
<Alexey.Brodkin@xxxxxxxxxxxx> wrote:
> Hi Rob,
>
> On Tue, 2016-02-23 at 14:38 -0600, Rob Herring wrote:
>> On Fri, Feb 19, 2016 at 04:03:52PM +0300, Alexey Brodkin wrote:
>> >
>> > This add DT bindings documentation for ARC PGU display controller.
>> >
>> > Signed-off-by: Alexey Brodkin <abrodkin@xxxxxxxxxxxx>
>> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
>> > Cc: Pawel Moll <pawel.moll@xxxxxxx>
>> > Cc: Mark Rutland <mark.rutland@xxxxxxx>
>> > Cc: Ian Campbell <ijc+devicetree@xxxxxxxxxxxxxx>
>> > Cc: Kumar Gala <galak@xxxxxxxxxxxxxx>
>> > Cc: devicetree@xxxxxxxxxxxxxxx
>> > Cc: linux-snps-arc@xxxxxxxxxxxxxxxxxxx
>> > ---
>> >  .../devicetree/bindings/display/snps,arcpgu.txt    | 74 ++++++++++++++++++++++
>> >  1 file changed, 74 insertions(+)
>> >  create mode 100644 Documentation/devicetree/bindings/display/snps,arcpgu.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/display/snps,arcpgu.txt
>> > b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
>> > new file mode 100644
>> > index 0000000..c8382fb
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/display/snps,arcpgu.txt
>> > @@ -0,0 +1,74 @@
>> > +ARC PGU
>> > +
>> > +This is a display controller found on several development boards produced
>> > +by Synopsys. The ARC PGU is an RGB streamer that reads the data from a
>> > +framebuffer and sends it to a single digital encoder (usually HDMI).
>> > +
>> > +Required properties:
>> > +  - compatible: "snps,arcpgu"
>> Seems like this should be more specific. Is there some sort or
>> versioning with ARC blocks?
>
> Well as of today there's only one and only version of PGU.
> So is there a real need for "snps,arcpgu-1.0"?
>
>> >
>> > +  - reg: Physical base address and length of the controller's registers.
>> > +  - clocks: A list of phandle + clock-specifier pairs, one for each
>> > +    entry in 'clock-names'.
>> > +  - clock-names: A list of clock names. For ARC PGU it should contain:
>> > +      - "pxlclk" for the clock feeding the output PLL of the controller.
>> > +  - encoder-slave: Phandle of encoder chip.
>> This is unnecessary with the OF graph.
>
> Do you mean I may drop "encoder-slave" from bindings description?

Yes, you should drop it.

> I actually thought about that because in case of simulation platform where
> this device is also used there's no encoder as well as no connector - we're
> dealing with memory area which is read by host and then displayed on host's
> display.
>