On Tue, 2015-03-03 at 10:02 +0000, Pawel Moll wrote: > On Mon, 2015-03-02 at 19:09 +0000, Arun Ramamurthy wrote: > > > The existing bindings intentionally avoided quoting internal registers - > > > they are supposed to describe how the hardware is wired up... > > > > > > So how about something like "arm,pl11x,tft-invert-clac"? Then the driver > > > sets the bit or not, depending on the property existance? > > > > > Sure, I can change it to two properties called arm,pl11x,tft-invert-clac > > and arm,pl11x,tft-clksel. Would that be acceptable? > > That would be fine by me :-) Or (after having a look at the TRM) I should rather say: the invert-clac is fine by me :-) but the tft-clksel doesn't work, I afraid. If I'm not mistaken, there are two problems with it. Number one: it's not TFT-specific, is it? So it certainly should not have the "tft-" bit. Number two: setting this bit says "do not use CLCDCLK for the logic; use HCLK instead", correct? If so, have a look at the clock properties. They say: - clock-names: should contain "clcdclk" and "apb_pclk" - clocks: contains phandle and clock specifier pairs for the entries in the clock-names property. See So if your hardware has the reference clock wired to HCLK, and you defining the clocks as "clcdclk", you are (no offence meant ;-) lying :-) So how about solving the problem by extending the clock-names definition like this (feel free to use own wording): - clock-names: should contain two clocks, either "clcdclk" or "hclk" (depending on which input is to be used as a reference clock by the controller logic) and "apb_pclk" That way you're precisely describing the way the hardware is wired up. And the driver simply tries to get clcdclk first, if it's defined - cool, set clksel to 1, if not - try hclk and set clksel to 0. If neither of them is present - bail out. Does this make any sense? Pawel -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html