Re: [PATCH v3 2/9] drm/sun4i: tcon: Add TCON LCD support for R40

[Jagan Teki <jagan@amarulasolutions.com>]

On Thu, Jan 2, 2020 at 4:24 PM Maxime Ripard <mripard@kernel.org> wrote:
>
> On Tue, Dec 31, 2019 at 06:35:21PM +0530, Jagan Teki wrote:
> > TCON LCD0, LCD1 in allwinner R40, are used for managing
> > LCD interfaces like RGB, LVDS and DSI.
> >
> > Like TCON TV0, TV1 these LCD0, LCD1 are also managed via
> > tcon top.
> >
> > Add support for it, in tcon driver.
> >
> > Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
> > ---
> > Changes for v3:
> > - none
> >
> >  drivers/gpu/drm/sun4i/sun4i_tcon.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > index fad72799b8df..69611d38c844 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -1470,6 +1470,13 @@ static const struct sun4i_tcon_quirks sun8i_a83t_tv_quirks = {
> >       .has_channel_1          = true,
> >  };
> >
> > +static const struct sun4i_tcon_quirks sun8i_r40_lcd_quirks = {
> > +     .supports_lvds          = true,
> > +     .has_channel_0          = true,
> > +     /* TODO Need to support TCON output muxing via GPIO pins */
> > +     .set_mux                = sun8i_r40_tcon_tv_set_mux,
>
> What is this muking about? And why is it a TODO?

Muxing similar like how TCON TOP handle TV0, TV1 I have reused the
same so-that it would configure de port selection via
sun8i_tcon_top_de_config

TCON output muxing have gpio with GPIOD and GPIOH bits, which select
which of LCD or TV TCON outputs to the LCD function pins. I have
marked these has TODO for further support as mentioned by Chen-Yu in
v1[1].

[1] https://patchwork.freedesktop.org/patch/310210/?series=62062&rev=1