lkml.org 
[lkml]   [2020]   [Aug]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] leds: pwm: Allow automatic labels for DT based devices
From
Date
Hi Alexander,

On 8/26/20 11:37 AM, Alexander Dahl wrote:
> From: Alexander Dahl <post@lespocky.de>
>
> 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@lespocky.de>
> ---
>
> 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.
It would be good to switch to yaml by this occassion.

--
Best regards,
Jacek Anaszewski

\
 
 \ /
  Last update: 2020-08-27 23:29    [W:0.073 / U:0.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site