Re: [PATCH v1 2/6] drm: panel-simple: add Seiko 70WVW2T 7" simple panel

From: Emil Velikov <emil.l.velikov@gmail.com>
To: Doug Anderson <dianders@chromium.org>
Cc: "Sam Ravnborg" <sam@ravnborg.org>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	"Sebastian Reichel" <sebastian.reichel@collabora.com>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	"Bjorn Andersson" <bjorn.andersson@linaro.org>,
	"Thierry Reding" <thierry.reding@gmail.com>,
	"Søren Andersen" <san@skov.dk>
Subject: Re: [PATCH v1 2/6] drm: panel-simple: add Seiko 70WVW2T 7" simple panel
Date: Tue, 2 Jun 2020 15:55:29 +0100	[thread overview]
Message-ID: <CACvgo52e_VE=oPz=A_rc=gkiSx+TqgPUm7smfe8yG6YYLHn+pA@mail.gmail.com> (raw)
In-Reply-To: <CAD=FV=VSyODjtVtEe6H46U6xNraD2LUUi+xt8cxraaqXom=64g@mail.gmail.com>

On Tue, 2 Jun 2020 at 01:31, Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Mon, Jun 1, 2020 at 1:33 AM Sam Ravnborg <sam@ravnborg.org> wrote:
> >
> > The Seiko 70WVW2T is a discontinued product, but may be used somewhere.
> > Tested on a proprietary product.
> >
> > Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
> > Cc: Søren Andersen <san@skov.dk>
> > Cc: Thierry Reding <thierry.reding@gmail.com>
> > Cc: Sam Ravnborg <sam@ravnborg.org>
> > ---
> >  drivers/gpu/drm/panel/panel-simple.c | 28 ++++++++++++++++++++++++++++
> >  1 file changed, 28 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> > index b067f66cea0e..8624bb80108c 100644
> > --- a/drivers/gpu/drm/panel/panel-simple.c
> > +++ b/drivers/gpu/drm/panel/panel-simple.c
> > @@ -3194,6 +3194,31 @@ static const struct panel_desc shelly_sca07010_bfn_lnn = {
> >         .bus_format = MEDIA_BUS_FMT_RGB666_1X18,
> >  };
> >
> > +static const struct drm_display_mode sii_70wvw2t_mode = {
> > +       .clock = 33000,
> > +       .hdisplay = 800,
> > +       .hsync_start = 800 + 256,
> > +       .hsync_end = 800 + 256 + 0,
> > +       .htotal = 800 + 256 + 0 + 0,
> > +       .vdisplay = 480,
> > +       .vsync_start = 480 + 0,
> > +       .vsync_end = 480 + 0 + 0,
> > +       .vtotal = 480 + 0 + 0 + 45,
>
> Important to have a "vrefresh"?
>
Ville posted a series (most of which already landed) getting removing
vrefresh all together. The overall idea is to compute it, in the rare
case it's needed.

>
> > +       .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
> > +};
> > +
> > +static const struct panel_desc sii_70wvw2t = {
> > +       .modes = &sii_70wvw2t_mode,
> > +       .num_modes = 1,
>
> Do we want "bpc = 6"?
>
The largest user of bpc is userspace - the data gets copied via the ioctls.

A secondary, and quite limited, user are drivers exposing the "max
bpc" connector property. From a quick look: amdgpu, the synopsys
dw-hdmi bridge and i915 do so. In case the data missing, atomics
assume a max 8 bpc.

>
> > +       .size = {
> > +               .width = 152,
> > +               .height = 91,
> > +       },
> > +       .bus_format = MEDIA_BUS_FMT_RGB888_1X24,
>
> Should this be a 666 format?  Random internet-found data sheet says
> 262K colors...

Good catch. Would be nice to have a spec sheet link (even if random)
in the commit message.

HTH
-Emil