[v4,3/5] pwm-backlight: add support for PWM delays proprieties.

Message ID 20170721104813.5389-3-enric.balletbo@collabora.com
State New
Headers show

Commit Message

Enric Balletbo i Serra July 21, 2017, 10:48 a.m.
Some panels (i.e. N116BGE-L41), in their power sequence specifications,
request a delay between set the PWM signal and enable the backlight and
between clear the PWM signal and disable the backlight. Add support for
the new post-pwm-on-delay-ms and pwm-off-delay-ms proprieties to meet
the timings.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---
Changes since v3:
 - Use two named members instead of pwm_delay[] (Daniel and Pavel)
 - Use msleep instead of usleep_range. (Pavel)
Changes since v2:
 - Move the pwm/enable sequence to another patch (Thierry Reding)
Changes since v1:
 - As suggested by Daniel Thompson
   - Do not assume power-on delay and power-off delay will be the same
 - Move the check of dt property to the parse dt function.

 drivers/video/backlight/pwm_bl.c | 19 +++++++++++++++++++
 include/linux/pwm_backlight.h    |  2 ++
 2 files changed, 21 insertions(+)

Comments

Pavel Machek July 21, 2017, 11:21 a.m. | #1
On Fri 2017-07-21 12:48:11, Enric Balletbo i Serra wrote:
> Some panels (i.e. N116BGE-L41), in their power sequence specifications,
> request a delay between set the PWM signal and enable the backlight and
> between clear the PWM signal and disable the backlight. Add support for
> the new post-pwm-on-delay-ms and pwm-off-delay-ms proprieties to meet
> the timings.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

For 3-5:

Acked-by: Pavel Machek <pavel@ucw.cz>

I guess you probably meant "properties" and I guess english could be
improved in the comments, but... this is good enough and not worth
more iterations.
Daniel Thompson July 24, 2017, 3:22 p.m. | #2
On 21/07/17 11:48, Enric Balletbo i Serra wrote:
> Some panels (i.e. N116BGE-L41), in their power sequence specifications,
> request a delay between set the PWM signal and enable the backlight and
> between clear the PWM signal and disable the backlight. Add support for
> the new post-pwm-on-delay-ms and pwm-off-delay-ms proprieties to meet
> the timings.
> 
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Acked-by: Daniel Thompson <daniel.thompson@linaro.org>


> ---
> Changes since v3:
>   - Use two named members instead of pwm_delay[] (Daniel and Pavel)
>   - Use msleep instead of usleep_range. (Pavel)
> Changes since v2:
>   - Move the pwm/enable sequence to another patch (Thierry Reding)
> Changes since v1:
>   - As suggested by Daniel Thompson
>     - Do not assume power-on delay and power-off delay will be the same
>   - Move the check of dt property to the parse dt function.
> 
>   drivers/video/backlight/pwm_bl.c | 19 +++++++++++++++++++
>   include/linux/pwm_backlight.h    |  2 ++
>   2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 909a686..6cf6109 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -10,6 +10,7 @@
>    * published by the Free Software Foundation.
>    */
>   
> +#include <linux/delay.h>
>   #include <linux/gpio/consumer.h>
>   #include <linux/gpio.h>
>   #include <linux/module.h>
> @@ -35,6 +36,8 @@ struct pwm_bl_data {
>   	struct gpio_desc	*enable_gpio;
>   	unsigned int		scale;
>   	bool			legacy;
> +	unsigned int		post_pwm_on_delay;
> +	unsigned int		pwm_off_delay;
>   	int			(*notify)(struct device *,
>   					  int brightness);
>   	void			(*notify_after)(struct device *,
> @@ -56,6 +59,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
>   
>   	pwm_enable(pb->pwm);
>   
> +	if (pb->post_pwm_on_delay)
> +		msleep(pb->post_pwm_on_delay);
> +
>   	if (pb->enable_gpio)
>   		gpiod_set_value_cansleep(pb->enable_gpio, 1);
>   
> @@ -70,6 +76,9 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
>   	if (pb->enable_gpio)
>   		gpiod_set_value_cansleep(pb->enable_gpio, 0);
>   
> +	if (pb->pwm_off_delay)
> +		msleep(pb->pwm_off_delay);
> +
>   	pwm_config(pb->pwm, 0, pb->period);
>   	pwm_disable(pb->pwm);
>   
> @@ -175,6 +184,14 @@ static int pwm_backlight_parse_dt(struct device *dev,
>   		data->max_brightness--;
>   	}
>   
> +	/*
> +	 * These values are optional and set as 0 by default, the out values
> +	 * are modified only if a valid u32 value can be decoded.
> +	 */
> +	of_property_read_u32(node, "post-pwm-on-delay-ms",
> +			     &data->post_pwm_on_delay);
> +	of_property_read_u32(node, "pwm-off-delay-ms", &data->pwm_off_delay);
> +
>   	data->enable_gpio = -EINVAL;
>   	return 0;
>   }
> @@ -273,6 +290,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
>   	pb->exit = data->exit;
>   	pb->dev = &pdev->dev;
>   	pb->enabled = false;
> +	pb->post_pwm_on_delay = data->post_pwm_on_delay;
> +	pb->pwm_off_delay = data->pwm_off_delay;
>   
>   	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
>   						  GPIOD_ASIS);
> diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
> index efdd922..62f59c4 100644
> --- a/include/linux/pwm_backlight.h
> +++ b/include/linux/pwm_backlight.h
> @@ -13,6 +13,8 @@ struct platform_pwm_backlight_data {
>   	unsigned int lth_brightness;
>   	unsigned int pwm_period_ns;
>   	unsigned int *levels;
> +	unsigned int post_pwm_on_delay;
> +	unsigned int pwm_off_delay;
>   	/* TODO remove once all users are switched to gpiod_* API */
>   	int enable_gpio;
>   	int (*init)(struct device *dev);
> 

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Jingoo Han July 26, 2017, 5:01 p.m. | #3
On Monday, July 24, 2017 11:22 AM, Daniel Thompson wrote:
> On 21/07/17 11:48, Enric Balletbo i Serra wrote:
> > Some panels (i.e. N116BGE-L41), in their power sequence specifications,
> > request a delay between set the PWM signal and enable the backlight and
> > between clear the PWM signal and disable the backlight. Add support for
> > the new post-pwm-on-delay-ms and pwm-off-delay-ms proprieties to meet
> > the timings.
> >
> > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> 
> Acked-by: Daniel Thompson <daniel.thompson@linaro.org>

Acked-by: Jingoo Han <jingoohan1@gmail.com>

Best regards,
Jingoo Han

> 
> 
> > ---
> > Changes since v3:
> >   - Use two named members instead of pwm_delay[] (Daniel and Pavel)
> >   - Use msleep instead of usleep_range. (Pavel)
> > Changes since v2:
> >   - Move the pwm/enable sequence to another patch (Thierry Reding)
> > Changes since v1:
> >   - As suggested by Daniel Thompson
> >     - Do not assume power-on delay and power-off delay will be the same
> >   - Move the check of dt property to the parse dt function.
> >
> >   drivers/video/backlight/pwm_bl.c | 19 +++++++++++++++++++
> >   include/linux/pwm_backlight.h    |  2 ++
> >   2 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/video/backlight/pwm_bl.c
> b/drivers/video/backlight/pwm_bl.c
> > index 909a686..6cf6109 100644
> > --- a/drivers/video/backlight/pwm_bl.c
> > +++ b/drivers/video/backlight/pwm_bl.c
> > @@ -10,6 +10,7 @@
> >    * published by the Free Software Foundation.
> >    */
> >
> > +#include <linux/delay.h>
> >   #include <linux/gpio/consumer.h>
> >   #include <linux/gpio.h>
> >   #include <linux/module.h>
> > @@ -35,6 +36,8 @@ struct pwm_bl_data {
> >   	struct gpio_desc	*enable_gpio;
> >   	unsigned int		scale;
> >   	bool			legacy;
> > +	unsigned int		post_pwm_on_delay;
> > +	unsigned int		pwm_off_delay;
> >   	int			(*notify)(struct device *,
> >   					  int brightness);
> >   	void			(*notify_after)(struct device *,
> > @@ -56,6 +59,9 @@ static void pwm_backlight_power_on(struct pwm_bl_data
> *pb, int brightness)
> >
> >   	pwm_enable(pb->pwm);
> >
> > +	if (pb->post_pwm_on_delay)
> > +		msleep(pb->post_pwm_on_delay);
> > +
> >   	if (pb->enable_gpio)
> >   		gpiod_set_value_cansleep(pb->enable_gpio, 1);
> >
> > @@ -70,6 +76,9 @@ static void pwm_backlight_power_off(struct pwm_bl_data
> *pb)
> >   	if (pb->enable_gpio)
> >   		gpiod_set_value_cansleep(pb->enable_gpio, 0);
> >
> > +	if (pb->pwm_off_delay)
> > +		msleep(pb->pwm_off_delay);
> > +
> >   	pwm_config(pb->pwm, 0, pb->period);
> >   	pwm_disable(pb->pwm);
> >
> > @@ -175,6 +184,14 @@ static int pwm_backlight_parse_dt(struct device
> *dev,
> >   		data->max_brightness--;
> >   	}
> >
> > +	/*
> > +	 * These values are optional and set as 0 by default, the out
> values
> > +	 * are modified only if a valid u32 value can be decoded.
> > +	 */
> > +	of_property_read_u32(node, "post-pwm-on-delay-ms",
> > +			     &data->post_pwm_on_delay);
> > +	of_property_read_u32(node, "pwm-off-delay-ms", &data-
> >pwm_off_delay);
> > +
> >   	data->enable_gpio = -EINVAL;
> >   	return 0;
> >   }
> > @@ -273,6 +290,8 @@ static int pwm_backlight_probe(struct
> platform_device *pdev)
> >   	pb->exit = data->exit;
> >   	pb->dev = &pdev->dev;
> >   	pb->enabled = false;
> > +	pb->post_pwm_on_delay = data->post_pwm_on_delay;
> > +	pb->pwm_off_delay = data->pwm_off_delay;
> >
> >   	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
> >   						  GPIOD_ASIS);
> > diff --git a/include/linux/pwm_backlight.h
> b/include/linux/pwm_backlight.h
> > index efdd922..62f59c4 100644
> > --- a/include/linux/pwm_backlight.h
> > +++ b/include/linux/pwm_backlight.h
> > @@ -13,6 +13,8 @@ struct platform_pwm_backlight_data {
> >   	unsigned int lth_brightness;
> >   	unsigned int pwm_period_ns;
> >   	unsigned int *levels;
> > +	unsigned int post_pwm_on_delay;
> > +	unsigned int pwm_off_delay;
> >   	/* TODO remove once all users are switched to gpiod_* API */
> >   	int enable_gpio;
> >   	int (*init)(struct device *dev);
> >


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Patch

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 909a686..6cf6109 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -10,6 +10,7 @@ 
  * published by the Free Software Foundation.
  */
 
+#include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio.h>
 #include <linux/module.h>
@@ -35,6 +36,8 @@  struct pwm_bl_data {
 	struct gpio_desc	*enable_gpio;
 	unsigned int		scale;
 	bool			legacy;
+	unsigned int		post_pwm_on_delay;
+	unsigned int		pwm_off_delay;
 	int			(*notify)(struct device *,
 					  int brightness);
 	void			(*notify_after)(struct device *,
@@ -56,6 +59,9 @@  static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
 
 	pwm_enable(pb->pwm);
 
+	if (pb->post_pwm_on_delay)
+		msleep(pb->post_pwm_on_delay);
+
 	if (pb->enable_gpio)
 		gpiod_set_value_cansleep(pb->enable_gpio, 1);
 
@@ -70,6 +76,9 @@  static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 	if (pb->enable_gpio)
 		gpiod_set_value_cansleep(pb->enable_gpio, 0);
 
+	if (pb->pwm_off_delay)
+		msleep(pb->pwm_off_delay);
+
 	pwm_config(pb->pwm, 0, pb->period);
 	pwm_disable(pb->pwm);
 
@@ -175,6 +184,14 @@  static int pwm_backlight_parse_dt(struct device *dev,
 		data->max_brightness--;
 	}
 
+	/*
+	 * These values are optional and set as 0 by default, the out values
+	 * are modified only if a valid u32 value can be decoded.
+	 */
+	of_property_read_u32(node, "post-pwm-on-delay-ms",
+			     &data->post_pwm_on_delay);
+	of_property_read_u32(node, "pwm-off-delay-ms", &data->pwm_off_delay);
+
 	data->enable_gpio = -EINVAL;
 	return 0;
 }
@@ -273,6 +290,8 @@  static int pwm_backlight_probe(struct platform_device *pdev)
 	pb->exit = data->exit;
 	pb->dev = &pdev->dev;
 	pb->enabled = false;
+	pb->post_pwm_on_delay = data->post_pwm_on_delay;
+	pb->pwm_off_delay = data->pwm_off_delay;
 
 	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
 						  GPIOD_ASIS);
diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
index efdd922..62f59c4 100644
--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h
@@ -13,6 +13,8 @@  struct platform_pwm_backlight_data {
 	unsigned int lth_brightness;
 	unsigned int pwm_period_ns;
 	unsigned int *levels;
+	unsigned int post_pwm_on_delay;
+	unsigned int pwm_off_delay;
 	/* TODO remove once all users are switched to gpiod_* API */
 	int enable_gpio;
 	int (*init)(struct device *dev);