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path: root/drivers/video/backlight/pwm_bl.c
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Diffstat (limited to 'drivers/video/backlight/pwm_bl.c')
-rw-r--r--drivers/video/backlight/pwm_bl.c34
1 files changed, 27 insertions, 7 deletions
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 1c2289ddd555..44ac5bde4e9d 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 *,
@@ -54,10 +57,14 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
if (err < 0)
dev_err(pb->dev, "failed to enable power supply\n");
+ 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);
- pwm_enable(pb->pwm);
pb->enabled = true;
}
@@ -66,12 +73,15 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
if (!pb->enabled)
return;
- pwm_config(pb->pwm, 0, pb->period);
- pwm_disable(pb->pwm);
-
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);
+
regulator_disable(pb->power_supply);
pb->enabled = false;
}
@@ -177,6 +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;
}
@@ -275,6 +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);
@@ -301,14 +321,14 @@ static int pwm_backlight_probe(struct platform_device *pdev)
/*
* If the GPIO is not known to be already configured as output, that
- * is, if gpiod_get_direction returns either GPIOF_DIR_IN or -EINVAL,
- * change the direction to output and set the GPIO as active.
+ * is, if gpiod_get_direction returns either 1 or -EINVAL, change the
+ * direction to output and set the GPIO as active.
* Do not force the GPIO to active when it was already output as it
* could cause backlight flickering or we would enable the backlight too
* early. Leave the decision of the initial backlight state for later.
*/
if (pb->enable_gpio &&
- gpiod_get_direction(pb->enable_gpio) != GPIOF_DIR_OUT)
+ gpiod_get_direction(pb->enable_gpio) != 0)
gpiod_direction_output(pb->enable_gpio, 1);
pb->power_supply = devm_regulator_get(&pdev->dev, "power");