Re: [PATCH v2 3/3] leds: leds-pwm: Add device tree bindings

[Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>]

On Mon, 12 Nov 2012 15:41:10 +0100, Peter Ujfalusi <peter.ujfalusi-l0cyMroinI0@public.gmane.org> wrote:
> Support for device tree booted kernel.
> When the kernel is booted with DeviceTree blob we support one led per
> leds-pwm device to have cleaner integration with the PWM subsystem.
> 
> For usage see:
> Documentation/devicetree/bindings/leds/leds-pwm.txt
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi-l0cyMroinI0@public.gmane.org>
> ---
>  .../devicetree/bindings/leds/leds-pwm.txt          |  34 ++++++
>  drivers/leds/leds-pwm.c                            | 125 +++++++++++++++------
>  2 files changed, 127 insertions(+), 32 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-pwm.txt
> 
> diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt
> new file mode 100644
> index 0000000..9fe3040
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt
> @@ -0,0 +1,34 @@
> +LED connected to PWM
> +
> +Required properties:
> +- compatible : should be "pwm-leds".
> +- pwms : PWM property, please refer to: 
> +  Documentation/devicetree/bindings/pwm/pwm.txt
> +- pwm-names : (optional) Name to be used by the PWM subsystem for the PWM device
> +- label : (optional) The label for this LED.  If omitted, the label is
> +  taken from the node name (excluding the unit address).
> +- max-brightness : Maximum brightness possible for the LED
> +- linux,default-trigger :  (optional) This parameter, if present, is a
> +  string defining the trigger assigned to the LED.  Current triggers are:
> +    "backlight" - LED will act as a back-light, controlled by the framebuffer
> +		  system
> +    "default-on" - LED will turn on, but see "default-state" below
> +    "heartbeat" - LED "double" flashes at a load average based rate
> +    "ide-disk" - LED indicates disk activity
> +    "timer" - LED flashes at a fixed, configurable rate

The binding mostly looks good. However, it seems to be gratuitously
different from the gpio-leds binding and it duplicates property
definitions. Please match the gpio-leds behaviour with each led defined
as a sub node of the pwm-leds node.

Also, please reference the common properties in bindings/leds/common.txt
(This is a new file in linux-next. See how leds-gpio references it).

Otherwise the binding looks okay to me.