1 files changed, 22 insertions, 1 deletions

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index ae3c6b6fd5db..3daf9cc9bc31 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -199,6 +199,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	struct backlight_properties props;
 	struct backlight_device *bl;
 	struct pwm_bl_data *pb;
+	phandle phandle = pdev->dev.of_node->phandle;
+	int initial_blank = FB_BLANK_UNBLANK;
 	int ret;
 
 	if (!data) {
@@ -242,7 +244,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	pb->enabled = false;
 
 	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
-						  GPIOD_OUT_HIGH);
+						  GPIOD_ASIS);
 	if (IS_ERR(pb->enable_gpio)) {
 		ret = PTR_ERR(pb->enable_gpio);
 		goto err_alloc;
@@ -264,12 +266,30 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		pb->enable_gpio = gpio_to_desc(data->enable_gpio);
 	}
 
+	if (pb->enable_gpio) {
+		/*
+		 * If the driver is probed from the device tree and there is a
+		 * phandle link pointing to the backlight node, it is safe to
+		 * assume that another driver will enable the backlight at the
+		 * appropriate time. Therefore, if it is disabled, keep it so.
+		 */
+		if (phandle &&
+		    gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT &&
+		    gpiod_get_value(pb->enable_gpio) == 0)
+			initial_blank = FB_BLANK_POWERDOWN;
+		else
+			gpiod_direction_output(pb->enable_gpio, 1);
+	}
+
 	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
 	if (IS_ERR(pb->power_supply)) {
 		ret = PTR_ERR(pb->power_supply);
 		goto err_alloc;
 	}
 
+	if (phandle && !regulator_is_enabled(pb->power_supply))
+		initial_blank = FB_BLANK_POWERDOWN;
+
 	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
 	if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER
 	    && !pdev->dev.of_node) {
@@ -320,6 +340,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	}
 
 	bl->props.brightness = data->dft_brightness;
+	bl->props.power = initial_blank;
 	backlight_update_status(bl);
 
 	platform_set_drvdata(pdev, bl);