2023-07-03 14:28:52

by Astrid Rost

Subject: [PATCH v3 2/2] led: led-class: Read max-brightness from devicetree

Normally, the maximum brightness is determined by the hardware, and this
property is not required. This property is used to set a software limit.
It could happen that an LED is made so bright that it gets damaged or
causes damage due to restrictions in a specific system, such as mounting
conditions.
Note that this flag is mainly used for PWM-LEDs, where it is not possible
to map brightness to current. Drivers for other controllers should use
led-max-microamp.

Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Astrid Rost <[email protected]>
---
drivers/leds/led-class.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 9255bc11f99d..ce652abf9336 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -457,6 +457,10 @@ int led_classdev_register_ext(struct device *parent,
if (fwnode_property_present(init_data->fwnode,
"retain-state-shutdown"))
led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+
+ fwnode_property_read_u32(init_data->fwnode,
+ "max-brightness",
+ &led_cdev->max_brightness);
}
} else {
proposed_name = led_cdev->name;
--
2.30.2

2023-07-03 21:58:20

by Jacek Anaszewski

Subject: Re: [PATCH v3 2/2] led: led-class: Read max-brightness from devicetree

Hi Astrid,

Thanks for the update.

On 7/3/23 15:03, Astrid Rost wrote:
> Normally, the maximum brightness is determined by the hardware, and this
> property is not required. This property is used to set a software limit.
> It could happen that an LED is made so bright that it gets damaged or
> causes damage due to restrictions in a specific system, such as mounting
> conditions.
> Note that this flag is mainly used for PWM-LEDs, where it is not possible
> to map brightness to current. Drivers for other controllers should use
> led-max-microamp.
>
> Reviewed-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Astrid Rost <[email protected]>
> ---
> drivers/leds/led-class.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 9255bc11f99d..ce652abf9336 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -457,6 +457,10 @@ int led_classdev_register_ext(struct device *parent,
> if (fwnode_property_present(init_data->fwnode,
> "retain-state-shutdown"))
> led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
> +
> + fwnode_property_read_u32(init_data->fwnode,
> + "max-brightness",
> + &led_cdev->max_brightness);
> }
> } else {
> proposed_name = led_cdev->name;

For the whole set:

Acked-by: Jacek Anaszewski <[email protected]>

--
Best regards,
Jacek Anaszewski

2023-07-13 13:49:03

by Lee Jones

Subject: Re: [PATCH v3 2/2] led: led-class: Read max-brightness from devicetree

On Mon, 03 Jul 2023, Astrid Rost wrote:

> Normally, the maximum brightness is determined by the hardware, and this
> property is not required. This property is used to set a software limit.
> It could happen that an LED is made so bright that it gets damaged or
> causes damage due to restrictions in a specific system, such as mounting
> conditions.
> Note that this flag is mainly used for PWM-LEDs, where it is not possible
> to map brightness to current. Drivers for other controllers should use
> led-max-microamp.
>
> Reviewed-by: Andy Shevchenko <[email protected]>
> Signed-off-by: Astrid Rost <[email protected]>
> ---
> drivers/leds/led-class.c | 4 ++++
> 1 file changed, 4 insertions(+)

Applied, thanks

--
Lee Jones [李琼斯]