On Fri, Feb 28, 2014 at 1:25 PM, Russell King
<rmk+kernel@xxxxxxxxxxxxxxxx> wrote:
> Some PWM outputs are wired such that the LED they're controlling is
> connected to supply rather than ground. Therefore, the duty cycle
> needs to be inverted to make the LED behave as it should do.
>
> We also provide a way to specify the default brightness when a
> trigger is not specified.
>
> Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
> ---
> Documentation/devicetree/bindings/leds/leds-pwm.txt | 3 +++
> drivers/leds/leds-pwm.c | 15 +++++++++++----
> 2 files changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/leds/leds-pwm.txt b/Documentation/devicetree/bindings/leds/leds-pwm.txt
> index 7297107cf832..ffcb74ab61fd 100644
> --- a/Documentation/devicetree/bindings/leds/leds-pwm.txt
> +++ b/Documentation/devicetree/bindings/leds/leds-pwm.txt
> @@ -13,6 +13,9 @@ node's name represents the name of the corresponding LED.
> For the pwms and pwm-names property please refer to:
> Documentation/devicetree/bindings/pwm/pwm.txt
> - max-brightness : Maximum brightness possible for the LED
> +- default-brightness : (optional) Default brightness for the LED
> +- active-low : (optional) For PWMs where the LED is wired to supply
> + rather than ground.
> - label : (optional)
> see Documentation/devicetree/bindings/leds/common.txt
> - linux,default-trigger : (optional)
Why remove "max-brightness", "label" and "linux,default-trigger" here?
I believe you're still using them in your second patch like
+ front {
+ active-low;
+ default-brightness = <128>;
+ label = "imx6:red:front";
+ max-brightness = <248>;
+ pwms = <&pwm1 0 50000>;
+ };
Others are good to me.
Thierry, could you please review this patchset?
Thanks,
-Bryan
> diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c
> index 605047428b5a..fe2cd849b593 100644
> --- a/drivers/leds/leds-pwm.c
> +++ b/drivers/leds/leds-pwm.c
> @@ -70,6 +70,10 @@ static void led_pwm_set(struct led_classdev *led_cdev,
>
> duty *= brightness;
> do_div(duty, max);
> +
> + if (led_dat->active_low)
> + duty = led_dat->period - duty;
> +
> led_dat->duty = duty;
>
> if (led_dat->can_sleep)
> @@ -93,6 +97,10 @@ static int led_pwm_create_of(struct platform_device *pdev,
> for_each_child_of_node(pdev->dev.of_node, child) {
> struct led_pwm_data *led_dat = &priv->leds[priv->num_leds];
>
> + led_dat->cdev.brightness_set = led_pwm_set;
> + led_dat->cdev.brightness = LED_OFF;
> + led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
> +
> led_dat->cdev.name = of_get_property(child, "label",
> NULL) ? : child->name;
>
> @@ -110,10 +118,9 @@ static int led_pwm_create_of(struct platform_device *pdev,
> "linux,default-trigger", NULL);
> of_property_read_u32(child, "max-brightness",
> &led_dat->cdev.max_brightness);
> -
> - led_dat->cdev.brightness_set = led_pwm_set;
> - led_dat->cdev.brightness = LED_OFF;
> - led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
> + of_property_read_u32(child, "default-brightness",
> + &led_dat->cdev.brightness);
> + led_dat->active_low = of_property_read_bool(child, "active-low");
>
> led_dat->can_sleep = pwm_can_sleep(led_dat->pwm);
> if (led_dat->can_sleep)
> --
> 1.8.3.1
>
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