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| author | Enric Balletbo i Serra <enric.balletbo@collabora.com> | 2018-03-28 19:03:25 +0200 |
|---|---|---|
| committer | Lee Jones <lee.jones@linaro.org> | 2018-04-30 10:50:44 +0100 |
| commit | 3157694d8c7fed9046dece8b63434cafef21cbf6 (patch) | |
| tree | fad20686e233da7d607d81292a3a9718b6784ff8 | |
| parent | ac7bfb27729fbfe85b93b083cba7898a1c9a9d91 (diff) | |
| download | linux-3157694d8c7fed9046dece8b63434cafef21cbf6.tar.gz linux-3157694d8c7fed9046dece8b63434cafef21cbf6.tar.bz2 linux-3157694d8c7fed9046dece8b63434cafef21cbf6.zip | |
pwm-backlight: Add support for PWM delays proprieties.
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: Pavel Machek <pavel@ucw.cz>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
| -rw-r--r-- | drivers/video/backlight/pwm_bl.c | 19 | ||||
| -rw-r--r-- | include/linux/pwm_backlight.h | 2 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 698ec68bcdc9..8e3f1245f5c5 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); @@ -178,6 +187,14 @@ 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; } @@ -276,6 +293,8 @@ 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 e8afbd71a140..8ea265a022fd 100644 --- a/include/linux/pwm_backlight.h +++ b/include/linux/pwm_backlight.h @@ -14,6 +14,8 @@ 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); |