On Sun, Sep 18, 2016 at 01:04:17PM +0300, Laurent Pinchart wrote: > On Sunday 18 Sep 2016 13:01:16 Laurent Pinchart wrote: > > On Thursday 08 Sep 2016 14:17:48 Maxime Ripard wrote: > > > Some boards have an entirely passive RGB to VGA bridge, based on either > > > DACs or resistor ladders. > > > > > > Those might or might not have an i2c bus routed to the VGA connector in > > > order to access the screen EDIDs. > > > > > > Add a bridge that doesn't do anything but expose the modes available on > > > the screen, either based on the EDIDs if available, or based on the XGA > > > standards. > > > > > > Acked-by: Rob Herring <robh@xxxxxxxxxx> > > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > > --- > > > > > > .../bindings/display/bridge/rgb-to-vga-bridge.txt | 52 +++++ > > > drivers/gpu/drm/bridge/Kconfig | 6 + > > > drivers/gpu/drm/bridge/Makefile | 1 + > > > drivers/gpu/drm/bridge/rgb-to-vga.c | 232 ++++++++++++++++ > > > 4 files changed, 291 insertions(+) > > > create mode 100644 > > > > > > Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > create mode 100644 drivers/gpu/drm/bridge/rgb-to-vga.c > > > > > > diff --git > > > a/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > new file mode 100644 > > > index 000000000000..83a053fb51a0 > > > --- /dev/null > > > +++ > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > @@ -0,0 +1,52 @@ > > > +Passive RGB to VGA bridge > > > +------------------------- > > > + > > > +This binding is aimed for entirely passive RGB to VGA bridges that do not > > > +require any configuration. > > > > Couldn't it also support active RGB to VGA bridges that don't require any > > configuration ? It would seem a bit pointless to define a separate DT > > binding for them. > > I'm thinking in particular about the ADV7123 > (http://www.analog.com/media/en/technical-documentation/data-sheets/ADV7123.pdf) > that already has a DT binding. I guess we don't have the same definition of passive, but I was thinking of devices that do not need any configuration in order to operate properly. And this one seems to fall in that category. > Would it be feasible to combine the two, and support both devices > with a single driver ? I don't see why not. But converting the renesas DRM driver seems a bit out of scope, and the ADV compatible can definitely be added later. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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