On Thu, 15 Mar 2012 11:27:36 +0100, Thierry Reding <[email protected]> wrote: > * Arnd Bergmann wrote: > > On Thursday 15 March 2012, Nicolas Ferre wrote: > [...] > > > + i2c1: i2c@1 { > > > + ... > > > + dma-request = <&sdma 2 &sdma 3>; > > > + dma-request-names = "tx", "rx"; > > > + ... > > > + }; > > > > This is slightly different from how the proposed pwm binding works that > > Thierry is working on, which uses an arbitrary property name instead of > > requiring the use of a specific property but then allowing to give names > > in another property. > > > > I don't care much which way it's done, but please try to agree on one > > approach that is used for both. > > > > The one you have here is already used by reg and irq, while the other > > one is used in gpio. > > I think we can just use pwm as the fixed property name. Or alternatively do > something along the lines of the regulator bindings, where we use "-pwm" as > the suffix for specifying PWM devices. For instance if a named PWM is > requested, the OF support code would look for a <name>-pwm property, while > requesting an unnamed PWM would simply look at the pwm property. > > When it comes to the labelling of PWM devices, I don't think both variants > are exclusive. Currently the PWM framework uses name of the user OF device > node for the PWM label. That is, if I have the following in the DTS: > > pwm { > .. > }; > > backlight { > compatible = "pwm-backlight"; > pwm = <&pwm 0 5000000>; > ... > }; > > Then the PWM will be labelled "backlight": > > $ cat cat /sys/kernel/debug/pwm > platform/tegra-pwm, 4 PWM devices > pwm-0 (backlight ): requested enabled > pwm-1 ((null) ): > pwm-2 ((null) ): > pwm-3 ((null) ): > > So if we decide to explicitly allow specifying names, then we can always add > a pwm-names property (or <name>-pwm-names respectively) to use as label and > fallback to the user OF device node name if that property is not present.
After implementing both schemes (ie. interrupts+interrupt-names && [*-]gpios) I definitely prefer the fixed property name plus a separate names property. It is easier to use common code with that scheme, and easier to statically check for correctness. g. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
