Re: [PATCH v6 04/18] video: tegra20: dc: pass DC id to internal devices

Svyatoslav Ryhel
2024-04-19T16:45:06Z

пт, 19 квіт. 2024 р. о 19:38 Thierry Reding <thierry.reding@gmail.com> пише:
>
> On Tue Jan 23, 2024 at 6:16 PM CET, Svyatoslav Ryhel wrote:
> > Tegra SoC has 2 independent display controllers called DC_A and
> > DC_B, they are handled differently by internal video devices like
> > DSI and HDMI controllers so it is important for last to know
> > which display controller is used to properly set up registers.
> > To achieve this, a pipe field was added to pdata to pass display
> > controller id to internal Tegra SoC devices.
> >
> > Tested-by: Agneli <poczt@protonmail.ch> # Toshiba AC100 T20
> > Tested-by: Robert Eckelmann <longnoserob@gmail.com> # ASUS TF101
> > Tested-by: Andreas Westman Dorcsak <hedmoo@yahoo.com> # ASUS Grouper E1565
> > Tested-by: Ion Agorria <ion@agorria.com> # HTC One X
> > Tested-by: Svyatoslav Ryhel <clamor95@gmail.com> # Nvidia Tegratab T114
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > ---
> > drivers/video/tegra20/tegra-dc.c | 6 ++++++
> > drivers/video/tegra20/tegra-dc.h | 3 +++
> > 2 files changed, 9 insertions(+)
> >
> > diff --git a/drivers/video/tegra20/tegra-dc.c b/drivers/video/tegra20/tegra-dc.c
> > index 5d8874f323..0e94e665ef 100644
> > --- a/drivers/video/tegra20/tegra-dc.c
> > +++ b/drivers/video/tegra20/tegra-dc.c
> > @@ -45,6 +45,7 @@ struct tegra_lcd_priv {
> > unsigned pixel_clock; /* Pixel clock in Hz */
> > int dc_clk[2]; /* Contains clk and its parent */
> > bool rotation; /* 180 degree panel turn */
> > + bool pipe; /* DC controller: 0 for A, 1 for B */
>
> Bool is a poor choice, even if there's only two of them. This is a
> proper index, so it should be some sort of integer.
>
> Also, the device tree bindings for the display controller specify a
> "nvidia,head" property that can be used to identify these. If you add
> that to the U-Boot DT you can avoid looking up by name to map this
> value.
>

Thanks for pointing to this property. May we apply this patch set as is
since it is well tested and confirmed to work and I will prepare a follow
up patches to adjust device tree relations? Would what be ok?

> Thierry