On Thu, Oct 04, 2012 at 11:35:35PM +0200, Guennadi Liakhovetski wrote: > Hi Steffen > > Sorry for chiming in so late in the game, but I've long been wanting to > have a look at this and compare with what we do for V4L2, so, this seems a > great opportunity to me:-) > > On Thu, 4 Oct 2012, Steffen Trumtrar wrote: > > > Signed-off-by: Steffen Trumtrar <s.trumtrar@xxxxxxxxxxxxxx> > > --- > > .../devicetree/bindings/video/display-timings.txt | 222 ++++++++++++++++++++ > > drivers/of/Kconfig | 5 + > > drivers/of/Makefile | 1 + > > drivers/of/of_display_timings.c | 183 ++++++++++++++++ > > include/linux/of_display_timings.h | 85 ++++++++ > > 5 files changed, 496 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/video/display-timings.txt > > create mode 100644 drivers/of/of_display_timings.c > > create mode 100644 include/linux/of_display_timings.h > > > > diff --git a/Documentation/devicetree/bindings/video/display-timings.txt b/Documentation/devicetree/bindings/video/display-timings.txt > > new file mode 100644 > > index 0000000..45e39bd > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/video/display-timings.txt > > @@ -0,0 +1,222 @@ > > +display-timings bindings > > +================== > > + > > +display-timings-node > > +------------ > > + > > +required properties: > > + - none > > + > > +optional properties: > > + - default-timing: the default timing value > > + > > +timings-subnode > > +--------------- > > + > > +required properties: > > + - hactive, vactive: Display resolution > > + - hfront-porch, hback-porch, hsync-len: Horizontal Display timing parameters > > + in pixels > > + vfront-porch, vback-porch, vsync-len: Vertical display timing parameters in > > + lines > > + - clock: displayclock in Hz > > You're going to hate me for this, but eventually we want to actually > reference clock objects in our DT bindings. For now, even if you don't > want to actually add clock phandles and stuff here, I think, using the > standard "clock-frequency" property would be much better! > Well, that shouldn't be a big deal, the "clock-frequency" property I mean :-) > > + > > +optional properties: > > + - hsync-active-high (bool): Hsync pulse is active high > > + - vsync-active-high (bool): Vsync pulse is active high > > For the above two we also considered using bool properties but eventually > settled down with integer ones: > > - hsync-active = <1> > > for active-high and 0 for active low. This has the added advantage of > being able to omit this property in the .dts, which then doesn't mean, > that the polarity is active low, but rather, that the hsync line is not > used on this hardware. So, maybe it would be good to use the same binding > here too? > Never really thought about it that way. But the argument sounds convincing. > > + - de-active-high (bool): Data-Enable pulse is active high > > + - pixelclk-inverted (bool): pixelclock is inverted > > We don't (yet) have a de-active property in V4L, don't know whether we'll > ever have to distingsuish between what some datasheets call "HREF" and > HSYNC in DT, but maybe similarly to the above an integer would be > preferred. As for pixclk, we call the property "pclk-sample" and it's also > an integer. > > > + - interlaced (bool) > > Is "interlaced" a property of the hardware, i.e. of the board? Can the > same display controller on one board require interlaced data and on > another board - progressive? BTW, I'm not very familiar with display > interfaces, but for interlaced you probably sometimes use a field signal, > whose polarity you also want to specify here? We use a "field-even-active" > integer property for it. > I don't really know about that; have to collect some info first. > Thanks > Guennadi Thank you. Regards, Steffen -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
