Re: [linux-sunxi] Re: [PATCH 02/12] drm: sun4i: Add support for enabling DDC I2C bus to dw_hdmi glue

From: Chen-Yu Tsai
Date: Mon Apr 08 2019 - 03:28:43 EST


On Mon, Apr 8, 2019 at 3:23 PM Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
>
> On Sat, Apr 06, 2019 at 01:45:04AM +0200, megous@xxxxxxxxxx wrote:
> > From: Ondrej Jirman <megous@xxxxxxxxxx>
> >
> > Orange Pi 3 board requires enabling DDC I2C bus via some GPIO connected
> > transistors, before it can be used. Model this as a power supply for DDC
> > (via regulator framework).
> >
> > Signed-off-by: Ondrej Jirman <megous@xxxxxxxxxx>
>
> The DDC bus itself is usually attached to the HDMI connector, so it
> would make sense to make the supply also a property of the connector.

I believe these are separate things. What this patch covers is power for
a voltage shifter between the SoC and HDMI DDC pins. The HDMI connector's
5V supply to power the remote DDC chip is something else. And on the
Orange Pi 3 they are indeed separate supplies.

ChenYu