Re: [PATCH 3/9] Doc/DT: Add DT binding documentation for DVI Connector

On Fri, Feb 28, 2014 at 10:25 AM, Philipp Zabel [off-list ref] wrote:

Am Freitag, den 28.02.2014, 15:59 +0000 schrieb Russell King - ARM
Linux:

quoted

On Fri, Feb 28, 2014 at 02:20:10PM +0200, Tomi Valkeinen wrote:

quoted

Add DT binding documentation for DVI Connector.

Signed-off-by: Tomi Valkeinen <redacted>
Reviewed-by: Archit Taneja <redacted>
---
 .../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>;
+

79 more quoted lines

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

On 10/03/14 23:45, Rob Herring wrote:

I like this proposal over the others. Although, would dual link be a

I don't like inferring the information. With the above, you can't find
out that the DVI connector has digital and analog support before all the
drivers are loaded.

single endpoint or 2 endpoints? How would you differentiate that?

Hmm, well endpoints for a single port are exclusive. So it's either a
single port and a single endpoint, or two ports and two endpoints. I
think dual link has to be single port & endpoint, as the TMDS links need
to be driven together as a single bus.

And dual-link is not really "two links". DVI dual-link means 1 clock
lane and 6 data lanes, compared to 1 clock lane and 3 data lanes for
single-link.

The port node seems a bit pointless.

There's another thread discussing the ports and endpoints.

The port node represents, for example, the pins for the connection for
that device. And an endpoint-endpoint link represents wires between two
ports.

 Tomi

On Tue, Mar 11, 2014 at 7:39 AM, Tomi Valkeinen [off-list ref] wrote:

On 10/03/14 23:45, Rob Herring wrote:

quoted

I like this proposal over the others. Although, would dual link be a

I don't like inferring the information. With the above, you can't find
out that the DVI connector has digital and analog support before all the
drivers are loaded.

quoted

single endpoint or 2 endpoints? How would you differentiate that?

Hmm, well endpoints for a single port are exclusive. So it's either a
single port and a single endpoint, or two ports and two endpoints. I
think dual link has to be single port & endpoint, as the TMDS links need
to be driven together as a single bus.

And dual-link is not really "two links". DVI dual-link means 1 clock
lane and 6 data lanes, compared to 1 clock lane and 3 data lanes for
single-link.

What about having a property for the number of data lanes?

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

On 11/03/14 10:00, Geert Uytterhoeven wrote:

On Tue, Mar 11, 2014 at 7:39 AM, Tomi Valkeinen [off-list ref] wrote:

quoted

On 10/03/14 23:45, Rob Herring wrote:

quoted

I like this proposal over the others. Although, would dual link be a

I don't like inferring the information. With the above, you can't find
out that the DVI connector has digital and analog support before all the
drivers are loaded.

quoted

single endpoint or 2 endpoints? How would you differentiate that?

Hmm, well endpoints for a single port are exclusive. So it's either a
single port and a single endpoint, or two ports and two endpoints. I
think dual link has to be single port & endpoint, as the TMDS links need
to be driven together as a single bus.

And dual-link is not really "two links". DVI dual-link means 1 clock
lane and 6 data lanes, compared to 1 clock lane and 3 data lanes for
single-link.

What about having a property for the number of data lanes?

That was already suggested by Philipp in this thread. I don't see
anything wrong with that, but I don't really see benefit either.
"dual-link" is a standard term for 6 data lanes for the DVI connector.
And the choices are 3 or 6 data lanes, nothing else.

 Tomi

Am Dienstag, den 11.03.2014, 10:04 +0200 schrieb Tomi Valkeinen:

On 11/03/14 10:00, Geert Uytterhoeven wrote:

quoted

On Tue, Mar 11, 2014 at 7:39 AM, Tomi Valkeinen [off-list ref] wrote:

quoted

On 10/03/14 23:45, Rob Herring wrote:

quoted

I like this proposal over the others. Although, would dual link be a

I don't like inferring the information. With the above, you can't find
out that the DVI connector has digital and analog support before all the
drivers are loaded.

quoted

single endpoint or 2 endpoints? How would you differentiate that?

Hmm, well endpoints for a single port are exclusive. So it's either a
single port and a single endpoint, or two ports and two endpoints. I
think dual link has to be single port & endpoint, as the TMDS links need
to be driven together as a single bus.

And dual-link is not really "two links". DVI dual-link means 1 clock
lane and 6 data lanes, compared to 1 clock lane and 3 data lanes for
single-link.

What about having a property for the number of data lanes?

That was already suggested by Philipp in this thread. I don't see
anything wrong with that, but I don't really see benefit either.
"dual-link" is a standard term for 6 data lanes for the DVI connector.
And the choices are 3 or 6 data lanes, nothing else.

The number of lanes of a DisplayPort connector could be 1 to 4. Also,
there's dual-mode DP which can use four lanes to drive
somewhat-like-HDMI single link TMDS signals.

regards
Philipp