Re: [RFC PATCH 2/5] dt-bindings: an30259a: example for using fixed LED node names.

From: Rob Herring
Date: Tue Nov 05 2019 - 22:42:10 EST


On Tue, Oct 29, 2019 at 02:47:26PM +0200, Matti Vaittinen wrote:
> Use predefined LED node name to match the LED node in driver.
>
> It would be nice to offload common LED property parsing to
> LED core driver. One of the key things to allow this is somehow
> 'pair' the LED DT node with LED driver initialization data.
>
> This patch uses LED node name as a 'key' in a same fashion
> as regulators do. The an30259a was selected as demonstration
> example and this change may not be really feasible for an30259a
> as I have no idea whether the existing DTs for devices out there
> have specific node names (or can be changed). This servers just
> as an example to initiate discussion as to how we could pair the
> driver data and DT node.
>
> Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/leds/leds-an30259a.txt | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/leds-an30259a.txt b/Documentation/devicetree/bindings/leds/leds-an30259a.txt
> index cbd833906b2b..bd1a2d11a0ad 100644
> --- a/Documentation/devicetree/bindings/leds/leds-an30259a.txt
> +++ b/Documentation/devicetree/bindings/leds/leds-an30259a.txt
> @@ -9,7 +9,8 @@ Required properties:
> - #address-cells: Must be 1.
> - #size-cells: Must be 0.
>
> -Each LED is represented as a sub-node of the panasonic,an30259a node.
> +Each LED is represented as a sub-node of the panasonic,an30259a node. LED nodes
> +must be named as led1 led2 and led3.
>
> Required sub-node properties:
> - reg: Pin that the LED is connected to. Must be 1, 2, or 3.
> @@ -34,20 +35,20 @@ led-controller@30 {
> #address-cells = <1>;
> #size-cells = <0>;
>
> - led@1 {
> + led1 {
> reg = <1>;

This is wrong. reg requires a unit-address and vice-versa.

> linux,default-trigger = "heartbeat";
> function = LED_FUNCTION_INDICATOR;
> color = <LED_COLOR_ID_RED>;
> };
>
> - led@2 {
> + led2 {
> reg = <2>;
> function = LED_FUNCTION_INDICATOR;
> color = <LED_COLOR_ID_GREEN>;
> };
>
> - led@3 {
> + led3 {
> reg = <3>;
> function = LED_FUNCTION_INDICATOR;
> color = <LED_COLOR_ID_BLUE>;
> --
> 2.21.0
>
>
> --
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
>
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> Simon says - in Latin please.
> ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
> Thanks to Simon Glass for the translation =]