Hi Laurent, On Fri, Mar 28, 2014 at 5:53 PM, Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: >> --- a/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt >> +++ b/Documentation/devicetree/bindings/gpio/renesas,gpio-rcar.txt >> @@ -21,6 +21,10 @@ Required Properties: >> GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. >> - gpio-ranges: Range of pins managed by the GPIO controller. >> >> +Optional properties: >> + >> + - clocks: Must contain a reference to the functional clock. >> + > > I would make the property mandatory. Obviously the driver needs to consider it > as optional in order not to break the DT ABI, but the specification should > make it mandatory in order to ensure that all future implementations will > specify the clock. I think it has to stay optional: unless I misinterpreted the datasheet, r8a7778 doesn't have MSTP bits for the GPIO modules. I guess it's the same for other R-Car Gen1 like r8a7779. So it looks like the bits were added in R-Car Gen2. Hence I'll just add ", if present", unless the Best Practice is to put such properties under "Required properties" or "Recommended properties"? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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