On 01/29/2013 08:02 PM, Alexandre Courbot wrote: > Add support for the Chunghwa CLAA101WA01A display panel. > diff --git a/Documentation/devicetree/bindings/video/display/chunghwa,claa101wa01a.txt b/Documentation/devicetree/bindings/video/display/chunghwa,claa101wa01a.txt > +Chunghwa CLAA101WA01A Display Panel > + > +Required properties: > +- compatible: "chunghwa,claa101wa01a" > +- pnl-supply: regulator controlling power supply to the panel > +- bl-supply: regulator controlling power supply to the backlight > +- pnl-enable-gpios: GPIO that enables the panel > +- bl-enable-gpios: GPIO that enables the backlight So this looks like a reasonable binding to me. The one issue is that it's very generic, and if we go this route, we'll probably end up with tens or hundreds of identical or extremely similar simple bindings, and associated drivers. We can avoid this instead by defining something like a "simple-lcd" binding, and associated driver, that will work for perhaps 90%, 95%, 99%, even 100%(?) of panels. Just like the above, but with: compatible="simple-panel", "chunghwa,claa101wa01a" instead, and the driver binding to "simple-panel" rather than "chunghwa,claa101wa01a". The driver can assume that a specific set of supplies (and perhaps GPIOs) is always present, and that the /sequence/ of manipulating those is fixed. This will avoid the need for anything like the power sequences code. If a particular panel doesn't fit those assumptions, including the exact sequence of manipulations for each state transition (which should be documented in the binding) then it can get a custom driver, this also avoiding having to define custom sequences in DT. Things that might be parameterized/optional: * Perhaps some GPIOs aren't always present. * If some regulators aren't SW-controllable, DT should still provide a fixed/dummy regulator so the driver doesn't care. * Wait times between regulator/GPIO/... manipulation could be specified in DT. * For panels without EDID, CDF DT bindings can provide the list of supported modes, otherwise we assume that the display controller that drives the panel has been told how to access the EDID, just like it would for an "external" display. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
