Merge tag 'backlight-for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "Core Frameworks:
   - Add Daniel Thompson as co-maintainer

  Fix-ups:
   - Improve error handling; adp5520_bl
   - Split initial power checks into dedicated function; pwm_bl
   - Check current PWM status; pwm_bl

  Bug Fixes:
   - Fix potential race; lcd
   - Fix module auto-loading; da9052"

* tag 'backlight-for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  MAINTAINERS: Rework entry for Backlight
  backlight: da9052: Fix module autoload
  backlight: pwm_bl: Check the PWM state for initial backlight power state
  backlight: pwm_bl: Move the checks for initial power state to a separate function
  backlight: adp5520: Fix error handling in adp5520_bl_probe()
  backlight: lcd: Fix race condition during register

5 files changed, 58 insertions, 25 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 7515e66945af..83a74a87ddf0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2380,12 +2380,15 @@ S:	Maintained
 F:	drivers/net/wireless/broadcom/b43legacy/
 
 BACKLIGHT CLASS/SUBSYSTEM
-M:	Jingoo Han <jingoohan1@gmail.com>
 M:	Lee Jones <lee.jones@linaro.org>
+M:	Daniel Thompson <daniel.thompson@linaro.org>
+M:	Jingoo Han <jingoohan1@gmail.com>
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight.git
 S:	Maintained
 F:	drivers/video/backlight/
 F:	include/linux/backlight.h
+F:	include/linux/pwm_backlight.h
+F:	Documentation/devicetree/bindings/leds/backlight
 
 BATMAN ADVANCED
 M:	Marek Lindner <mareklindner@neomailbox.ch>
diff --git a/drivers/video/backlight/adp5520_bl.c b/drivers/video/backlight/adp5520_bl.c
index dd88ba1d71ce..35373e2065b2 100644
--- a/drivers/video/backlight/adp5520_bl.c
+++ b/drivers/video/backlight/adp5520_bl.c
@@ -332,10 +332,18 @@ static int adp5520_bl_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, bl);
-	ret |= adp5520_bl_setup(bl);
+	ret = adp5520_bl_setup(bl);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup\n");
+		if (data->pdata->en_ambl_sens)
+			sysfs_remove_group(&bl->dev.kobj,
+					&adp5520_bl_attr_group);
+		return ret;
+	}
+
 	backlight_update_status(bl);
 
-	return ret;
+	return 0;
 }
 
 static int adp5520_bl_remove(struct platform_device *pdev)
diff --git a/drivers/video/backlight/da9052_bl.c b/drivers/video/backlight/da9052_bl.c
index fd2be417aa64..49035c12739a 100644
--- a/drivers/video/backlight/da9052_bl.c
+++ b/drivers/video/backlight/da9052_bl.c
@@ -167,6 +167,7 @@ static const struct platform_device_id da9052_wled_ids[] = {
 	},
 	{ },
 };
+MODULE_DEVICE_TABLE(platform, da9052_wled_ids);
 
 static struct platform_driver da9052_wled_driver = {
 	.probe		= da9052_backlight_probe,
@@ -182,4 +183,3 @@ module_platform_driver(da9052_wled_driver);
 MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 MODULE_DESCRIPTION("Backlight driver for DA9052 PMIC");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:da9052-backlight");
diff --git a/drivers/video/backlight/lcd.c b/drivers/video/backlight/lcd.c
index 7de847df224f..4b40c6a4d441 100644
--- a/drivers/video/backlight/lcd.c
+++ b/drivers/video/backlight/lcd.c
@@ -226,6 +226,8 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 	dev_set_name(&new_ld->dev, "%s", name);
 	dev_set_drvdata(&new_ld->dev, devdata);
 
+	new_ld->ops = ops;
+
 	rc = device_register(&new_ld->dev);
 	if (rc) {
 		put_device(&new_ld->dev);
@@ -238,8 +240,6 @@ struct lcd_device *lcd_device_register(const char *name, struct device *parent,
 		return ERR_PTR(rc);
 	}
 
-	new_ld->ops = ops;
-
 	return new_ld;
 }
 EXPORT_SYMBOL(lcd_device_register);
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 12614006211e..d7efcb632f7d 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -192,6 +192,36 @@ static int pwm_backlight_parse_dt(struct device *dev,
 }
 #endif
 
+static int pwm_backlight_initial_power_state(const struct pwm_bl_data *pb)
+{
+	struct device_node *node = pb->dev->of_node;
+
+	/* Not booted with device tree or no phandle link to the node */
+	if (!node || !node->phandle)
+		return FB_BLANK_UNBLANK;
+
+	/*
+	 * 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 the enable GPIO is disabled, do not enable the backlight */
+	if (pb->enable_gpio && gpiod_get_value(pb->enable_gpio) == 0)
+		return FB_BLANK_POWERDOWN;
+
+	/* The regulator is disabled, do not enable the backlight */
+	if (!regulator_is_enabled(pb->power_supply))
+		return FB_BLANK_POWERDOWN;
+
+	/* The PWM is disabled, keep it like this */
+	if (!pwm_is_enabled(pb->pwm))
+		return FB_BLANK_POWERDOWN;
+
+	return FB_BLANK_UNBLANK;
+}
+
 static int pwm_backlight_probe(struct platform_device *pdev)
 {
 	struct platform_pwm_backlight_data *data = dev_get_platdata(&pdev->dev);
@@ -200,7 +230,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	struct backlight_device *bl;
 	struct device_node *node = pdev->dev.of_node;
 	struct pwm_bl_data *pb;
-	int initial_blank = FB_BLANK_UNBLANK;
 	struct pwm_args pargs;
 	int ret;
 
@@ -267,20 +296,16 @@ 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 (node && node->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);
-	}
+	/*
+	 * If the GPIO is configured as input, 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_IN)
+		gpiod_direction_output(pb->enable_gpio, 1);
 
 	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
 	if (IS_ERR(pb->power_supply)) {
@@ -288,9 +313,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		goto err_alloc;
 	}
 
-	if (node && node->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 && !node) {
 		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
@@ -347,7 +369,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	}
 
 	bl->props.brightness = data->dft_brightness;
-	bl->props.power = initial_blank;
+	bl->props.power = pwm_backlight_initial_power_state(pb);
 	backlight_update_status(bl);
 
 	platform_set_drvdata(pdev, bl);