[PATCH 2/6] led-uclass: honour ->label field populated by driver's own .bind

[Christian Gmeiner]

Am Mo., 23. Okt. 2023 um 11:30 Uhr schrieb Rasmus Villemoes
<rasmus.villemoes at prevas.dk>:
>
> On 19/10/2023 15.54, Marek Vasut wrote:
> > On 10/19/23 11:58, Rasmus Villemoes wrote:
> >> If the driver's own .bind method has populated uc_plat->label, don't
> >> override that. This is necessary for an upcoming driver for ti,lp5562,
> >> where the DT binding unfortunately says to use "chan-name" and not
> >> "label".
> >>
> >> Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
> >> ---
> >>   drivers/led/led-uclass.c | 4 +++-
> >>   1 file changed, 3 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/led/led-uclass.c b/drivers/led/led-uclass.c
> >> index 5a5d07b9a7..0232fa84de 100644
> >> --- a/drivers/led/led-uclass.c
> >> +++ b/drivers/led/led-uclass.c
> >> @@ -71,7 +71,9 @@ static int led_post_bind(struct udevice *dev)
> >>       struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
> >>       const char *default_state;
> >>   -    uc_plat->label = dev_read_string(dev, "label");
> >> +    if (!uc_plat->label)
> >> +        uc_plat->label = dev_read_string(dev, "label");
> >> +
> >
> > One thing I have to wonder about is, why does this controller have label
> > property in the top-level node , what is that used for ?
> >
> > (see Linux Documentation/devicetree/bindings/leds/leds-lp55xx.yaml)
> >
> > Reviewed-by: Marek Vasut <marex at denx.de>
>
> Reading the linux driver, it seems that the top-level label, if any, is
> used as part of the naming for individual channels if they don't have
> individual chan-name properties:
>
>
>         if (pdata->led_config[chan].name) {
>                 led->cdev.name = pdata->led_config[chan].name;
>         } else {
>                 snprintf(name, sizeof(name), "%s:channel%d",
>                         pdata->label ? : chip->cl->name, chan);
>                 led->cdev.name = name;
>         }
>
> but I think the rationale in d1188adb2dabc is a bit weak, since the only
> example also does have individual chan-name properties.
>
> [Complete aside: At first I thought it was related to the multi-color
> LED work that has been ongoing for many many years (I think there was an
> LWN article at some point), where this could be exposed as a single
> multi-color LED, as opposed to the "traditional" three/four individual
> LEDs. In the former case, there would only be one sysfs entry, but with
> attributes exposing the multicolor functionality. I must admit I don't
> know the status of that work, when something reaches v31,
> http://archive.lwn.net:8080/linux-kernel/20200722071055.GA8984@amd/t/ ,
> it's hard to know if it ever lands, or if pieces of it has landed.]
>
> Rasmus
>

I have an almost similar patch sent out today as I have not seen yours
before. The end results
is the same as mine
https://patchwork.ozlabs.org/project/uboot/patch/20231023082117.39290-1-christian.gmeiner@gmail.com/

Reviewed-by: Christian Gmeiner <christian.gmeiner at gmail.com>

-- 
greets
--
Christian Gmeiner, MSc

https://christian-gmeiner.info/privacypolicy