From 3157694d8c7fed9046dece8b63434cafef21cbf6 Mon Sep 17 00:00:00 2001 From: Enric Balletbo i Serra Date: Wed, 28 Mar 2018 19:03:25 +0200 Subject: 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 Acked-by: Pavel Machek Acked-by: Daniel Thompson Acked-by: Jingoo Han Acked-by: Thierry Reding Signed-off-by: Lee Jones --- drivers/video/backlight/pwm_bl.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'drivers') 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 #include #include #include @@ -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); -- cgit v1.2.3