On Fri, Dec 14, 2018 at 1:25 AM Sean Paul <sean@xxxxxxxxxx> wrote:
>
> On Fri, Dec 14, 2018 at 12:56:03AM +0530, Jagan Teki wrote:
> > On Thu, Dec 13, 2018 at 8:37 PM Sean Paul <sean@xxxxxxxxxx> wrote:
> > >
> > > On Fri, Nov 16, 2018 at 10:09:15PM +0530, Jagan Teki wrote:
> > > > Feiyang FY07024DI26A30-D is 1024x600, 4-lane MIPI-DSI LCD panel.
> > > >
> > > > Add panel driver for it.
> > > >
> > > > Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> > > > ---
> > > > MAINTAINERS | 6 +
> > > > drivers/gpu/drm/panel/Kconfig | 9 +
> > > > drivers/gpu/drm/panel/Makefile | 1 +
> > > > .../drm/panel/panel-feiyang-fy07024di26a30d.c | 286 ++++++++++++++++++
> > > > 4 files changed, 302 insertions(+)
> > > > create mode 100644 drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
> > > >
>
> /snip
>
> > > > diff --git a/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
> > > > new file mode 100644
> > > > index 000000000000..a4b46bd8fdbe
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
>
> /snip
>
> > > > +static int feiyang_prepare(struct drm_panel *panel)
> > > > +{
> > > > + struct feiyang *ctx = panel_to_feiyang(panel);
> > > > + struct mipi_dsi_device *dsi = ctx->dsi;
> > > > + unsigned int i;
> > > > + int ret;
> > > > +
> > > > + ret = regulator_enable(ctx->dvdd);
> > > > + if (ret)
> > > > + return ret;
> > > > +
> > > > + msleep(100);
> > >
> > > nit: You should do your best to correlate the sleeps with the timing parameters
> > > from the datasheet with a comment.
> > >
> > > ie:
> > > /* T1: > 100ms */
> > > msleep(100);
> >
> > Sorry, what does this mean?
>
> On page 9 of the datasheet you sent me [1], it has the delays required to safely
> power up the panel. This delay is the time between dvdd going high and avdd
> going high. On the figure in the datasheet, this would be T2 (T1 is dvdd rise
time between dvdd going high and avdd going high is T1 + T3 right?
T2 > 0ms
T3 > 20ms
In this case the delay can be msleep(20) ?
> time and should be handled in the regulator subsystem (iirc)). Also according to
> the datasheet, T2 just needs to be > 0, so you don't even need this delay. You
> could replace this with a comment like:
>
> /* T1 (dvdd rise time) + T2 (dvdd->avdd) > 0 */
>
> So for all of the msleeps below you should get the delays from the datasheet and
> add a comment referencing them.
T5 and T6 are delay between avdd to reset enable it can be 10 + 10
=> 20ms and finally T12 which is 200 after reset.
What about the delay between resets, I need to understand it a bit.
