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-rw-r--r--drivers/video/backlight/gpio_backlight.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c
index e84f3087e29f..18e053e4716c 100644
--- a/drivers/video/backlight/gpio_backlight.c
+++ b/drivers/video/backlight/gpio_backlight.c
@@ -59,13 +59,11 @@ static int gpio_backlight_probe_dt(struct platform_device *pdev,
struct gpio_backlight *gbl)
{
struct device *dev = &pdev->dev;
- enum gpiod_flags flags;
int ret;
gbl->def_value = device_property_read_bool(dev, "default-on");
- flags = gbl->def_value ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
- gbl->gpiod = devm_gpiod_get(dev, NULL, flags);
+ gbl->gpiod = devm_gpiod_get(dev, NULL, GPIOD_ASIS);
if (IS_ERR(gbl->gpiod)) {
ret = PTR_ERR(gbl->gpiod);
@@ -79,6 +77,22 @@ static int gpio_backlight_probe_dt(struct platform_device *pdev,
return 0;
}
+static int gpio_backlight_initial_power_state(struct gpio_backlight *gbl)
+{
+ struct device_node *node = gbl->dev->of_node;
+
+ /* Not booted with device tree or no phandle link to the node */
+ if (!node || !node->phandle)
+ return gbl->def_value ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+
+ /* if the enable GPIO is disabled, do not enable the backlight */
+ if (gpiod_get_value_cansleep(gbl->gpiod) == 0)
+ return FB_BLANK_POWERDOWN;
+
+ return FB_BLANK_UNBLANK;
+}
+
+
static int gpio_backlight_probe(struct platform_device *pdev)
{
struct gpio_backlight_platform_data *pdata =
@@ -136,7 +150,9 @@ static int gpio_backlight_probe(struct platform_device *pdev)
return PTR_ERR(bl);
}
- bl->props.brightness = gbl->def_value;
+ bl->props.power = gpio_backlight_initial_power_state(gbl);
+ bl->props.brightness = 1;
+
backlight_update_status(bl);
platform_set_drvdata(pdev, bl);