[v1] leds: pwm: Add default-brightness property

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

Posted by George Stark 1 year, 3 months ago

When probing if default LED state is on then default brightness will be
applied instead of max brightness.

Signed-off-by: George Stark <gnstark@salutedevices.com>
---
 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);
 		if (ret)
 			return ret;
 	}
-- 
2.25.1

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

Posted by Lee Jones 1 year, 3 months ago

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@salutedevices.com>
> ---
>  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]

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

Posted by George Stark 1 year, 3 months ago

Hello Lee

Thanks for the review!

On 10/31/24 17:32, Lee Jones wrote:
> 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@salutedevices.com>
>> ---
>>   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.

I looked up the new property here to be near to
led_init_default_state_get (both props are from the same group) and
led_pwm_add is big enough already. And you're absolutely right that the
patch can be optimized. Please take a look at the v2

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

-- 
Best regards
George