Hello Jacek,
Am Donnerstag, 27. August 2020, 23:28:45 CEST schrieb Jacek Anaszewski:
> On 8/26/20 11:37 AM, Alexander Dahl wrote:
> > From: Alexander Dahl <post@xxxxxxxxxxx>
> >
> > If LEDs are configured through device tree and the property 'label' is
> > omitted, the label is supposed to be generated from the properties
> > 'function' and 'color' if present. While this works fine for e.g. the
> > 'leds-gpio' driver, it did not for 'leds-pwm'.
> >
> > The reason is, you get this label naming magic only if you add a LED
> > device through 'devm_led_classdev_register_ext()' and pass a pointer to
> > the current device tree node. The approach to fix this was adopted from
> > the 'leds-gpio' driver.
> >
> > For the following node from dts the LED appeared as 'led5' in sysfs
> > before and as 'red:debug' after this change.
> >
> > pwm_leds {
> >
> > compatible = "pwm-leds";
> >
> > led5 {
> >
> > function = LED_FUNCTION_DEBUG;
> > color = <LED_COLOR_ID_RED>;
> > pwms = <&pwm0 2 10000000 0>;
> > max-brightness = <127>;
> >
> > linux,default-trigger = "heartbeat";
> > panic-indicator;
> >
> > };
> >
> > };
> >
> > Signed-off-by: Alexander Dahl <post@xxxxxxxxxxx>
> > ---
> >
> > Notes:
> > v1: based on v5.9-rc2, backport on v5.4.59 also works
> >
> > drivers/leds/leds-pwm.c | 9 ++++++++-
> > 1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> > index ef7b91bd2064..a27a1d75a3e9 100644
> > --- a/drivers/leds/leds-pwm.c
> > +++ b/drivers/leds/leds-pwm.c
> > @@ -65,6 +65,7 @@ static int led_pwm_add(struct device *dev, struct
> > led_pwm_priv *priv,>
> > struct led_pwm *led, struct fwnode_handle *fwnode)
> >
> > {
> >
> > struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
> >
> > + struct led_init_data init_data = {};
> >
> > int ret;
> >
> > led_data->active_low = led->active_low;
> >
> > @@ -90,7 +91,13 @@ static int led_pwm_add(struct device *dev, struct
> > led_pwm_priv *priv,>
> > pwm_init_state(led_data->pwm, &led_data->pwmstate);
> >
> > - ret = devm_led_classdev_register(dev, &led_data->cdev);
> > + if (fwnode) {
> > + init_data.fwnode = fwnode;
> > + ret = devm_led_classdev_register_ext(dev, &led_data->cdev,
> > + &init_data);
> > + } else {
> > + ret = devm_led_classdev_register(dev, &led_data->cdev);
> > + }
> >
> > if (ret) {
> >
> > dev_err(dev, "failed to register PWM led for %s: %d\n",
> >
> > led->name, ret);
>
> This part looks good, but corresponding update of
> Documentation/devicetree/bindings/leds/leds-pwm.txt is needed as well.
I'm not sure, what needs updating. The properties 'function' and 'color' are
already documented in Documentation/devicetree/bindings/leds/common.yaml … the
only thing I can think of here is updating the examples? That would be nice,
as would be updating to yaml, but I don't see the strong relation, yet.
> It would be good to switch to yaml by this occassion.
Is there some guidance on that in general?
Greets
Alex
