Hi,

Am Donnerstag, den 06.03.2014, 10:52 +0200 schrieb Tomi Valkeinen:

On 06/03/14 10:39, Geert Uytterhoeven wrote:

quoted

On Wed, Mar 5, 2014 at 9:41 AM, Tomi Valkeinen [off-list ref] wrote:

quoted

On 28/02/14 18:23, Russell King - ARM Linux wrote:

quoted

That's rather a lot of compatible strings.  Another possibility is:

      compatible = "dvi-connector";
      analog;
      digital;
      single-link;
      dual-link;

I made the following changes compared to the posted version. I decided
to leave the "single-link" out, as it's implied if "digital" is set.

 Tomi

@@ -6,11 +6,16 @@ Required properties:

 Optional properties:
 - label: a symbolic name for the connector
-- i2c-bus: phandle to the i2c bus that is connected to DVI DDC
+- ddc-i2c-bus: phandle to the i2c bus that is connected to DVI DDC
+- analog: the connector has DVI analog pins
+- digital: the connector has DVI digital pins
+- dual-link: the connector has pins for DVI dual-link

 Required nodes:
 - Video port for DVI input

+Note: One (or both) of 'analog' or 'digital' must be set.

So dual-link needs both "digital" and "dual-link"?

Yes. It is extra, but it felt clearer to me to have 'digital' as a
matching property for 'analog'.

Alternatively we could have three options:

analog;
digital-single-link;
digital-dual-link;

My reasoning to the format I chose was basically that when a connector
supports 'digital', it contains TMDS clock and TMDS data for link 1.
Adding dual link to that adds only TMDS data for link 2, so the second
data link is kind of an additional feature, marked with a flag.

Not a very big argument, and I'm fine with other format suggestions.

I'd prefer the analog / digital / dual-link variant for aesthetic
reasons. But looking at other connector types, I wonder if this should
be generalized even more:

For HDMI/DVI (digital) single-link means one clock pair and 3 TMDS data
pairs, dual-link means one clock pair and 6 data pairs.

On LVDS connectors, there usually are one clock pair and three (18-bit)
or four (24-bit) LVDS data pairs, in dual channel configuration two
clock pairs and 6 or 8 data pairs are used.

For DisplayPort there is no separate clock pair, but 1 to 4 data pairs,
and MIPI DSI again has one clock pair and a one or more data pairs.

There are already optional endpoint configuration properties
'data-lanes' and 'clock-lanes' for MIPI CSI-2 defined in
Documentation/devicetree/bindings/media/video-interfaces.txt.
Could/should this be aligned with the same?

regards
Philipp