Re: [PATCH 2/2] leds: pwm: Add optional DT property default-brightness

From: Lee Jones
Date: Thu Oct 31 2024 - 10:33:04 EST


On Tue, 15 Oct 2024, George Stark wrote:

> When probing if default LED state is on then default brightness will be
> applied instead of max brightness.
>
> Signed-off-by: George Stark <gnstark@xxxxxxxxxxxxxxxxx>
> ---
> drivers/leds/leds-pwm.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> index 7961dca0db2f..514fc8ca3e80 100644
> --- a/drivers/leds/leds-pwm.c
> +++ b/drivers/leds/leds-pwm.c
> @@ -65,7 +65,8 @@ static int led_pwm_set(struct led_classdev *led_cdev,
>
> __attribute__((nonnull))
> static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
> - struct led_pwm *led, struct fwnode_handle *fwnode)
> + struct led_pwm *led, struct fwnode_handle *fwnode,
> + unsigned int default_brightness)
> {
> struct led_pwm_data *led_data = &priv->leds[priv->num_leds];
> struct led_init_data init_data = { .fwnode = fwnode };
> @@ -104,7 +105,7 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
> /* set brightness */
> switch (led->default_state) {
> case LEDS_DEFSTATE_ON:
> - led_data->cdev.brightness = led->max_brightness;
> + led_data->cdev.brightness = default_brightness;
> break;
> case LEDS_DEFSTATE_KEEP:
> {
> @@ -141,6 +142,7 @@ static int led_pwm_add(struct device *dev, struct led_pwm_priv *priv,
> static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv)
> {
> struct led_pwm led;
> + unsigned int default_brightness;
> int ret;
>
> device_for_each_child_node_scoped(dev, fwnode) {
> @@ -160,7 +162,12 @@ static int led_pwm_create_fwnode(struct device *dev, struct led_pwm_priv *priv)
>
> led.default_state = led_init_default_state_get(fwnode);
>
> - ret = led_pwm_add(dev, priv, &led, fwnode);
> + ret = fwnode_property_read_u32(fwnode, "default-brightness",
> + &default_brightness);
> + if (ret < 0 || default_brightness > led.max_brightness)
> + default_brightness = led.max_brightness;
> +
> + ret = led_pwm_add(dev, priv, &led, fwnode, default_brightness);

This creates a lot more hopping around than is necessary.

Since led_pwm_add() already has access to the fwnode, why not look up
the property in there instead, thus massively simplifying things.


> if (ret)
> return ret;
> }
> --
> 2.25.1
>

--
Lee Jones [李琼斯]