[PATCH v2 04/16] drm: bridge: thc63: Restrict modes based on hardware operating frequency
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Mon Sep 17 12:23:28 UTC 2018
Hi Ulrich,
On Monday, 17 September 2018 13:53:43 EEST Ulrich Hecht wrote:
> > On September 14, 2018 at 11:10 AM Laurent Pinchart wrote:
> >
> > The THC63LVD1024 is restricted to a pixel clock frequency in the range
> > of 8 to 135 MHz. Implement the bridge .mode_valid() operation
> > accordingly.
> >
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas at ideasonboard.com>
> > Reviewed-by: Andrzej Hajda <a.hajda at samsung.com>
> > Tested-by: Jacopo Mondi <jacopo+renesas at jmondi.org>
> > ---
> >
> > drivers/gpu/drm/bridge/thc63lvd1024.c | 18 ++++++++++++++++++
> > 1 file changed, 18 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/bridge/thc63lvd1024.c
> > b/drivers/gpu/drm/bridge/thc63lvd1024.c index c8b9edd5a7f4..63609ba16b6d
> > 100644
> > --- a/drivers/gpu/drm/bridge/thc63lvd1024.c
> > +++ b/drivers/gpu/drm/bridge/thc63lvd1024.c
> > @@ -45,6 +45,23 @@ static int thc63_attach(struct drm_bridge *bridge)
> > return drm_bridge_attach(bridge->encoder, thc63->next, bridge);
> > }
> >
> > +static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge,
> > + const struct drm_display_mode *mode)
> > +{
> > + /*
> > + * The THC63LVD0124 clock frequency range is 8 to 135 MHz in single-in,
>
> That should be THC63LVD1024.
Will be fixed in v3.
> > + * single-out mode.
>
> For the input clock (that's what we're talking about, right?), that also
> applies to single-in/dual-out. Maybe just omit the "single-out" clause?
Good point, I'll change that in v3.
> > Note that the limits depends on the mode and will
> > + * need to be adjusted accordingly.
> > + */
>
> I don't quite understand. Does that refer to the THC63 mode, or the DRM
> mode?
This refers to the THC63 mode, I'll clarify this in v3 as well.
> > + if (mode->clock < 8000)
> > + return MODE_CLOCK_LOW;
> > +
> > + if (mode->clock > 135000)
> > + return MODE_CLOCK_HIGH;
> > +
> > + return MODE_OK;
> > +}
> > +
> > static void thc63_enable(struct drm_bridge *bridge)
> > {
> > struct thc63_dev *thc63 = to_thc63(bridge);
> > @@ -77,6 +94,7 @@ static void thc63_disable(struct drm_bridge *bridge)
> >
> > static const struct drm_bridge_funcs thc63_bridge_func = {
> > .attach = thc63_attach,
> > + .mode_valid = thc63_mode_valid,
> > .enable = thc63_enable,
> > .disable = thc63_disable,
> > };
--
Regards,
Laurent Pinchart
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