pwm-backlight: Add power supply support
Backlights require a power supply to work properly. This commit adds a
regulator to power up and power down the backlight.
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index cdef4a3..eec6c98 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -21,6 +21,7 @@
#include <linux/err.h>
#include <linux/pwm.h>
#include <linux/pwm_backlight.h>
+#include <linux/regulator/consumer.h>
#include <linux/slab.h>
struct pwm_bl_data {
@@ -30,6 +31,7 @@
unsigned int lth_brightness;
unsigned int *levels;
bool enabled;
+ struct regulator *power_supply;
int enable_gpio;
unsigned long enable_gpio_flags;
int (*notify)(struct device *,
@@ -60,6 +62,10 @@
pwm_config(pb->pwm, duty_cycle, pb->period);
+ err = regulator_enable(pb->power_supply);
+ if (err < 0)
+ dev_err(pb->dev, "failed to enable power supply\n");
+
if (gpio_is_valid(pb->enable_gpio)) {
if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
gpio_set_value(pb->enable_gpio, 0);
@@ -86,6 +92,7 @@
gpio_set_value(pb->enable_gpio, 0);
}
+ regulator_disable(pb->power_supply);
pb->enabled = false;
}
@@ -268,6 +275,12 @@
}
}
+ pb->power_supply = devm_regulator_get(&pdev->dev, "power");
+ if (IS_ERR(pb->power_supply)) {
+ ret = PTR_ERR(pb->power_supply);
+ goto err_gpio;
+ }
+
pb->pwm = devm_pwm_get(&pdev->dev, NULL);
if (IS_ERR(pb->pwm)) {
dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");