On Wed, 30 Nov 2016 11:52:25 +0200
Laurent Pinchart <laurent.pinchart at ideasonboard.com> wrote:
> Hi Jean-François,
>
> On Wednesday 30 Nov 2016 10:27:57 Jean-Francois Moine wrote:
> > On Wed, 30 Nov 2016 10:20:21 +0200 Laurent Pinchart wrote:
> > >> Well, I don't see what this connector can be.
> > >> May you give me a DT example?
> > >
> > > Sure.
> > >
> > > arch/arm/boot/dts/r8a7791-koelsch.dts
> > >
> > > /* HDMI encoder */
[snip]
> > > /* HDMI connector */
> > >
> > > hdmi-out {
> > > compatible = "hdmi-connector";
> > > type = "a";
> > >
> > > port {
> > > hdmi_con: endpoint {
> > > remote-endpoint = <&adv7511_out>;
> > > };
> > > };
> > > };
[snip]
> > - what does the software do with the connector type?
>
> That's up to the software to decide, the DT bindings should describe the
> hardware in the most accurate and usable way for the OS as possible. One of
> my
> longer term goals is to add connector drivers to handle DDC and HPD when
> they're not handled by the encoder (they are in the above example).
>
> If the DDC was connected to a general-purpose I2C bus of the SoC, and the HPD
> to a GPIO, we would have
>
> hdmi-out {
> compatible = "hdmi-connector";
> type = "a";
> /* I2C bus and GPIO references are made up for the example */
> ddc-i2c-bus = <&i2c4>;
> hpd-gpios = <&gpio4 7 GPIO_ACTIVE_HIGH>
>
> port {
> hdmi_con: endpoint {
> remote-endpoint = <&adv7511_out>;
> };
> };
> };
>
> and both HPD and EDID reading should be handled by the connector driver.
[snip]
Hi Laurent,
OK. I understand. This connector complexity should be added in all DTs,
and the same code would be used.
Actually, for component binding, I use drm_of_component_probe():
- from the DRM master, loop on the "ports" phandle array and bind the
CRTCs,
- for each CRTC, loop on the first remote port level and bind the
encoders/connectors
Now, this should be:
- from the DRM master, loop on the first remote ports level and bind
the CRTCs,
- for each CRTC, loop on the second remote port level and bind the
encoders (and bridges?),
- for each encoder, loop on the third remote port level and bind the
connectors.
Then, it would be nice to have a generic function for doing this job.
Otherwise, from your description:
> hdmi-out {
> compatible = "hdmi-connector";
> type = "a";
> /* I2C bus and GPIO references are made up for the example */
> ddc-i2c-bus = <&i2c4>;
> hpd-gpios = <&gpio4 7 GPIO_ACTIVE_HIGH>
the "hdmi-connector" is a big piece of software. It must handle a lot
of more and more exotic connectors.
So, I hope that you have written a "simple-hdmi-connector" which does
nothing but setting the connector type.
Where is it?
--
Ken ar c'hentañ | ** Breizh ha Linux atav! **
Jef | http://moinejf.free.fr/
