Merge tag 'backlight-next-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
"Core Framework:
- Trivial: Code refactoring
- New API backlight_is_blank()
- New API backlight_get_brightness()
- Additional/reworked documentation
- Remove 'extern' labels from prototypes
- Drop backlight_put()
- Staticify of_find_backlight()

Driver Removal:
- Removal of unused OT200 driver
- Removal of unused Generic Backlight driver

Fix-ups
- Bunch of W=1 warning fixes
- Convert to GPIO descriptors; sky81452
- Move platform data handling into driver; sky81452
- Remove superfluous code; lms501kf03
- Many instances of using new APIs"

* tag 'backlight-next-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight: (34 commits)
video: backlight: cr_bllcd: Remove unused variable 'intensity'
backlight: backlight: Make of_find_backlight static
backlight: backlight: Drop backlight_put()
backlight: Use backlight_get_brightness() throughout
backlight: jornada720_bl: Introduce backlight_is_blank()
backlight: gpio_backlight: Simplify update_status()
backlight: cr_bllcd: Introduce gpio-backlight semantics
backlight: as3711_bl: Simplify update_status
backlight: backlight: Introduce backlight_get_brightness()
doc-rst: Wire-up Backlight kernel-doc documentation
backlight: backlight: Add overview and update existing doc
backlight: backlight: Drop extern from prototypes
backlight: generic_bl: Remove this driver as it is unused
backlight: backlight: Document enums in backlight.h
backlight: backlight: Document inline functions in backlight.h
backlight: backlight: Improve backlight_device documentation
backlight: backlight: Improve backlight_properties documentation
backlight: backlight: Improve backlight_ops documentation
backlight: backlight: Add backlight_is_blank()
backlight: backlight: Refactor fb_notifier_callback()
...

Documentation/gpu/backlight.rst

···
+=================
+Backlight support
+=================
+
+.. kernel-doc:: drivers/video/backlight/backlight.c
+   :doc: overview
+
+.. kernel-doc:: include/linux/backlight.h
+   :internal:
+
+.. kernel-doc:: drivers/video/backlight/backlight.c
+   :export:

Documentation/gpu/index.rst

···
    drm-uapi
    drm-client
    drivers
+   backlight
    vga-switcheroo
    vgaarbiter
    todo

drivers/mfd/sky81452.c

···
 	memset(cells, 0, sizeof(cells));
 	cells[0].name = "sky81452-backlight";
 	cells[0].of_compatible = "skyworks,sky81452-backlight";
-	cells[0].platform_data = pdata->bl_pdata;
-	cells[0].pdata_size = sizeof(*pdata->bl_pdata);
 	cells[1].name = "sky81452-regulator";
 	cells[1].platform_data = pdata->regulator_init_data;
 	cells[1].pdata_size = sizeof(*pdata->regulator_init_data);

drivers/video/backlight/88pm860x_bl.c

···
 
 static int pm860x_backlight_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.state & BL_CORE_SUSPENDED)
-		brightness = 0;
-
-	return pm860x_backlight_set(bl, brightness);
+	return pm860x_backlight_set(bl, backlight_get_brightness(bl));
 }
 
 static int pm860x_backlight_get_brightness(struct backlight_device *bl)

drivers/video/backlight/Kconfig

···
 	  To compile this driver as a module, choose M here: the module will
 	  be called ep93xx_bl.
 
-config BACKLIGHT_GENERIC
-	tristate "Generic (aka Sharp Corgi) Backlight Driver"
-	default y
-	help
-	  Say y to enable the generic platform backlight driver previously
-	  known as the Corgi backlight driver. If you have a Sharp Zaurus
-	  SL-C7xx, SL-Cxx00 or SL-6000x say y.
-
 config BACKLIGHT_IPAQ_MICRO
 	tristate "iPAQ microcontroller backlight driver"
 	depends on MFD_IPAQ_MICRO
···
 	depends on MFD_LP8788 && PWM
 	help
 	  This supports TI LP8788 backlight driver.
-
-config BACKLIGHT_OT200
-	tristate "Backlight driver for ot200 visualisation device"
-	depends on CS5535_MFGPT && GPIO_CS5535
-	help
-	  To compile this driver as a module, choose M here: the module will be
-	  called ot200_bl.
 
 config BACKLIGHT_PANDORA
 	tristate "Backlight driver for Pandora console"

drivers/video/backlight/Makefile

···
 obj-$(CONFIG_BACKLIGHT_DA903X)		+= da903x_bl.o
 obj-$(CONFIG_BACKLIGHT_DA9052)		+= da9052_bl.o
 obj-$(CONFIG_BACKLIGHT_EP93XX)		+= ep93xx_bl.o
-obj-$(CONFIG_BACKLIGHT_GENERIC)		+= generic_bl.o
 obj-$(CONFIG_BACKLIGHT_GPIO)		+= gpio_backlight.o
 obj-$(CONFIG_BACKLIGHT_HP680)		+= hp680_bl.o
 obj-$(CONFIG_BACKLIGHT_HP700)		+= jornada720_bl.o
···
 obj-$(CONFIG_BACKLIGHT_LV5207LP)	+= lv5207lp.o
 obj-$(CONFIG_BACKLIGHT_MAX8925)		+= max8925_bl.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
-obj-$(CONFIG_BACKLIGHT_OT200)		+= ot200_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
 obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o

drivers/video/backlight/adp5520_bl.c

···
 
 static int adp5520_bl_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	return adp5520_bl_set(bl, brightness);
+	return adp5520_bl_set(bl, backlight_get_brightness(bl));
 }
 
 static int adp5520_bl_get_brightness(struct backlight_device *bl)

drivers/video/backlight/adp8860_bl.c

···
 
 static int adp8860_bl_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	return adp8860_bl_set(bl, brightness);
+	return adp8860_bl_set(bl, backlight_get_brightness(bl));
 }
 
 static int adp8860_bl_get_brightness(struct backlight_device *bl)

drivers/video/backlight/adp8870_bl.c

···
 
 static int adp8870_bl_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	return adp8870_bl_set(bl, brightness);
+	return adp8870_bl_set(bl, backlight_get_brightness(bl));
 }
 
 static int adp8870_bl_get_brightness(struct backlight_device *bl)

drivers/video/backlight/as3711_bl.c

···
 	struct as3711_bl_data *data = bl_get_data(bl);
 	struct as3711_bl_supply *supply = to_supply(data);
 	struct as3711 *as3711 = supply->as3711;
-	int brightness = bl->props.brightness;
+	int brightness;
 	int ret = 0;
 
-	dev_dbg(&bl->dev, "%s(): brightness %u, pwr %x, blank %x, state %x\n",
-		__func__, bl->props.brightness, bl->props.power,
-		bl->props.fb_blank, bl->props.state);
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		brightness = 0;
+	brightness = backlight_get_brightness(bl);
 
 	if (data->type == AS3711_BL_SU1) {
 		ret = as3711_set_brightness_v(as3711, brightness,

drivers/video/backlight/backlight.c

···
 #include <asm/backlight.h>
 #endif
 
+/**
+ * DOC: overview
+ *
+ * The backlight core supports implementing backlight drivers.
+ *
+ * A backlight driver registers a driver using
+ * devm_backlight_device_register(). The properties of the backlight
+ * driver such as type and max_brightness must be specified.
+ * When the core detect changes in for example brightness or power state
+ * the update_status() operation is called. The backlight driver shall
+ * implement this operation and use it to adjust backlight.
+ *
+ * Several sysfs attributes are provided by the backlight core::
+ *
+ * - brightness         R/W, set the requested brightness level
+ * - actual_brightness  RO, the brightness level used by the HW
+ * - max_brightness     RO, the maximum  brightness level supported
+ *
+ * See Documentation/ABI/stable/sysfs-class-backlight for the full list.
+ *
+ * The backlight can be adjusted using the sysfs interface, and
+ * the backlight driver may also support adjusting backlight using
+ * a hot-key or some other platform or firmware specific way.
+ *
+ * The driver must implement the get_brightness() operation if
+ * the HW do not support all the levels that can be specified in
+ * brightness, thus providing user-space access to the actual level
+ * via the actual_brightness attribute.
+ *
+ * When the backlight changes this is reported to user-space using
+ * an uevent connected to the actual_brightness attribute.
+ * When brightness is set by platform specific means, for example
+ * a hot-key to adjust backlight, the driver must notify the backlight
+ * core that brightness has changed using backlight_force_update().
+ *
+ * The backlight driver core receives notifications from fbdev and
+ * if the event is FB_EVENT_BLANK and if the value of blank, from the
+ * FBIOBLANK ioctrl, results in a change in the backlight state the
+ * update_status() operation is called.
+ */
+
 static struct list_head backlight_dev_list;
 static struct mutex backlight_dev_list_mutex;
 static struct blocking_notifier_head backlight_notifier;
···
 
 #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
 			   defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
-/* This callback gets called when something important happens inside a
- * framebuffer driver. We're looking if that important event is blanking,
- * and if it is and necessary, we're switching backlight power as well ...
+/*
+ * fb_notifier_callback
+ *
+ * This callback gets called when something important happens inside a
+ * framebuffer driver. The backlight core only cares about FB_BLANK_UNBLANK
+ * which is reported to the driver using backlight_update_status()
+ * as a state change.
+ *
+ * There may be several fbdev's connected to the backlight device,
+ * in which case they are kept track of. A state change is only reported
+ * if there is a change in backlight for the specified fbdev.
  */
 static int fb_notifier_callback(struct notifier_block *self,
 				unsigned long event, void *data)
···
 
 	bd = container_of(self, struct backlight_device, fb_notif);
 	mutex_lock(&bd->ops_lock);
-	if (bd->ops)
-		if (!bd->ops->check_fb ||
-		    bd->ops->check_fb(bd, evdata->info)) {
-			fb_blank = *(int *)evdata->data;
-			if (fb_blank == FB_BLANK_UNBLANK &&
-			    !bd->fb_bl_on[node]) {
-				bd->fb_bl_on[node] = true;
-				if (!bd->use_count++) {
-					bd->props.state &= ~BL_CORE_FBBLANK;
-					bd->props.fb_blank = FB_BLANK_UNBLANK;
-					backlight_update_status(bd);
-				}
-			} else if (fb_blank != FB_BLANK_UNBLANK &&
-				   bd->fb_bl_on[node]) {
-				bd->fb_bl_on[node] = false;
-				if (!(--bd->use_count)) {
-					bd->props.state |= BL_CORE_FBBLANK;
-					bd->props.fb_blank = fb_blank;
-					backlight_update_status(bd);
-				}
-			}
+
+	if (!bd->ops)
+		goto out;
+	if (bd->ops->check_fb && !bd->ops->check_fb(bd, evdata->info))
+		goto out;
+
+	fb_blank = *(int *)evdata->data;
+	if (fb_blank == FB_BLANK_UNBLANK && !bd->fb_bl_on[node]) {
+		bd->fb_bl_on[node] = true;
+		if (!bd->use_count++) {
+			bd->props.state &= ~BL_CORE_FBBLANK;
+			bd->props.fb_blank = FB_BLANK_UNBLANK;
+			backlight_update_status(bd);
 		}
+	} else if (fb_blank != FB_BLANK_UNBLANK && bd->fb_bl_on[node]) {
+		bd->fb_bl_on[node] = false;
+		if (!(--bd->use_count)) {
+			bd->props.state |= BL_CORE_FBBLANK;
+			bd->props.fb_blank = fb_blank;
+			backlight_update_status(bd);
+		}
+	}
+out:
 	mutex_unlock(&bd->ops_lock);
 	return 0;
 }
···
  * backlight_force_update - tell the backlight subsystem that hardware state
  *   has changed
  * @bd: the backlight device to update
+ * @reason: reason for update
  *
  * Updates the internal state of the backlight in response to a hardware event,
- * and generate a uevent to notify userspace
+ * and generates an uevent to notify userspace. A backlight driver shall call
+ * backlight_force_update() when the backlight is changed using, for example,
+ * a hot-key. The updated brightness is read using get_brightness() and the
+ * brightness value is reported using an uevent.
  */
 void backlight_force_update(struct backlight_device *bd,
 			    enum backlight_update_reason reason)
···
 }
 EXPORT_SYMBOL(backlight_force_update);
 
-/**
- * backlight_device_register - create and register a new object of
- *   backlight_device class.
- * @name: the name of the new object(must be the same as the name of the
- *   respective framebuffer device).
- * @parent: a pointer to the parent device
- * @devdata: an optional pointer to be stored for private driver use. The
- *   methods may retrieve it by using bl_get_data(bd).
- * @ops: the backlight operations structure.
- *
- * Creates and registers new backlight device. Returns either an
- * ERR_PTR() or a pointer to the newly allocated device.
- */
+/* deprecated - use devm_backlight_device_register() */
 struct backlight_device *backlight_device_register(const char *name,
 	struct device *parent, void *devdata, const struct backlight_ops *ops,
 	const struct backlight_properties *props)
···
 }
 EXPORT_SYMBOL(backlight_device_register);
 
+/** backlight_device_get_by_type - find first backlight device of a type
+ * @type: the type of backlight device
+ *
+ * Look up the first backlight device of the specified type
+ *
+ * RETURNS:
+ *
+ * Pointer to backlight device if any was found. Otherwise NULL.
+ */
 struct backlight_device *backlight_device_get_by_type(enum backlight_type type)
 {
 	bool found = false;
···
 }
 EXPORT_SYMBOL(backlight_device_get_by_name);
 
-/**
- * backlight_device_unregister - unregisters a backlight device object.
- * @bd: the backlight device object to be unregistered and freed.
- *
- * Unregisters a previously registered via backlight_device_register object.
- */
+/* deprecated - use devm_backlight_device_unregister() */
 void backlight_device_unregister(struct backlight_device *bd)
 {
 	if (!bd)
···
  * backlight_register_notifier - get notified of backlight (un)registration
  * @nb: notifier block with the notifier to call on backlight (un)registration
  *
- * @return 0 on success, otherwise a negative error code
- *
  * Register a notifier to get notified when backlight devices get registered
  * or unregistered.
+ *
+ * RETURNS:
+ *
+ * 0 on success, otherwise a negative error code
  */
 int backlight_register_notifier(struct notifier_block *nb)
 {
···
  * backlight_unregister_notifier - unregister a backlight notifier
  * @nb: notifier block to unregister
  *
- * @return 0 on success, otherwise a negative error code
- *
  * Register a notifier to get notified when backlight devices get registered
  * or unregistered.
+ *
+ * RETURNS:
+ *
+ * 0 on success, otherwise a negative error code
  */
 int backlight_unregister_notifier(struct notifier_block *nb)
 {
···
 EXPORT_SYMBOL(backlight_unregister_notifier);
 
 /**
- * devm_backlight_device_register - resource managed backlight_device_register()
+ * devm_backlight_device_register - register a new backlight device
  * @dev: the device to register
  * @name: the name of the device
- * @parent: a pointer to the parent device
+ * @parent: a pointer to the parent device (often the same as @dev)
  * @devdata: an optional pointer to be stored for private driver use
  * @ops: the backlight operations structure
  * @props: the backlight properties
  *
- * @return a struct backlight on success, or an ERR_PTR on error
+ * Creates and registers new backlight device. When a backlight device
+ * is registered the configuration must be specified in the @props
+ * parameter. See description of &backlight_properties.
  *
- * Managed backlight_device_register(). The backlight_device returned
- * from this function are automatically freed on driver detach.
- * See backlight_device_register() for more information.
+ * RETURNS:
+ *
+ * struct backlight on success, or an ERR_PTR on error
  */
 struct backlight_device *devm_backlight_device_register(struct device *dev,
 	const char *name, struct device *parent, void *devdata,
···
 EXPORT_SYMBOL(devm_backlight_device_register);
 
 /**
- * devm_backlight_device_unregister - resource managed backlight_device_unregister()
+ * devm_backlight_device_unregister - unregister backlight device
  * @dev: the device to unregister
  * @bd: the backlight device to unregister
  *
- * Deallocated a backlight allocated with devm_backlight_device_register().
+ * Deallocates a backlight allocated with devm_backlight_device_register().
  * Normally this function will not need to be called and the resource management
- * code will ensure that the resource is freed.
+ * code will ensure that the resources are freed.
  */
 void devm_backlight_device_unregister(struct device *dev,
 				struct backlight_device *bd)
···
 EXPORT_SYMBOL(of_find_backlight_by_node);
 #endif
 
-/**
- * of_find_backlight - Get backlight device
- * @dev: Device
- *
- * This function looks for a property named 'backlight' on the DT node
- * connected to @dev and looks up the backlight device.
- *
- * Call backlight_put() to drop the reference on the backlight device.
- *
- * Returns:
- * A pointer to the backlight device if found.
- * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
- * device is found.
- * NULL if there's no backlight property.
- */
-struct backlight_device *of_find_backlight(struct device *dev)
+static struct backlight_device *of_find_backlight(struct device *dev)
 {
 	struct backlight_device *bd = NULL;
 	struct device_node *np;
···
 
 	return bd;
 }
-EXPORT_SYMBOL(of_find_backlight);
 
 static void devm_backlight_release(void *data)
 {
-	backlight_put(data);
+	struct backlight_device *bd = data;
+
+	if (bd)
+		put_device(&bd->dev);
 }
 
 /**
- * devm_of_find_backlight - Resource-managed of_find_backlight()
- * @dev: Device
+ * devm_of_find_backlight - find backlight for a device
+ * @dev: the device
  *
- * Device managed version of of_find_backlight().
- * The reference on the backlight device is automatically
+ * This function looks for a property named 'backlight' on the DT node
+ * connected to @dev and looks up the backlight device. The lookup is
+ * device managed so the reference to the backlight device is automatically
  * dropped on driver detach.
+ *
+ * RETURNS:
+ *
+ * A pointer to the backlight device if found.
+ * Error pointer -EPROBE_DEFER if the DT property is set, but no backlight
+ * device is found. NULL if there's no backlight property.
  */
 struct backlight_device *devm_of_find_backlight(struct device *dev)
 {
···
 		return bd;
 	ret = devm_add_action(dev, devm_backlight_release, bd);
 	if (ret) {
-		backlight_put(bd);
+		put_device(&bd->dev);
 		return ERR_PTR(ret);
 	}
 	return bd;

drivers/video/backlight/bd6107.c

···
 static int bd6107_backlight_update_status(struct backlight_device *backlight)
 {
 	struct bd6107 *bd = bl_get_data(backlight);
-	int brightness = backlight->props.brightness;
-
-	if (backlight->props.power != FB_BLANK_UNBLANK ||
-	    backlight->props.fb_blank != FB_BLANK_UNBLANK ||
-	    backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		brightness = 0;
+	int brightness = backlight_get_brightness(backlight);
 
 	if (brightness) {
 		bd6107_write(bd, BD6107_PORTSEL, BD6107_PORTSEL_LEDM(2) |

drivers/video/backlight/corgi_lcd.c

···
 static int corgi_bl_update_status(struct backlight_device *bd)
 {
 	struct corgi_lcd *lcd = bl_get_data(bd);
-	int intensity = bd->props.brightness;
-
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-
-	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
-		intensity = 0;
+	int intensity = backlight_get_brightness(bd);
 
 	if (corgibl_flags & CORGIBL_SUSPENDED)
 		intensity = 0;

drivers/video/backlight/cr_bllcd.c

···
 
 static int cr_backlight_set_intensity(struct backlight_device *bd)
 {
-	int intensity = bd->props.brightness;
 	u32 addr = gpio_bar + CRVML_PANEL_PORT;
 	u32 cur = inl(addr);
 
-	if (bd->props.power == FB_BLANK_UNBLANK)
-		intensity = FB_BLANK_UNBLANK;
-	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
-		intensity = FB_BLANK_UNBLANK;
-	if (bd->props.power == FB_BLANK_POWERDOWN)
-		intensity = FB_BLANK_POWERDOWN;
-	if (bd->props.fb_blank == FB_BLANK_POWERDOWN)
-		intensity = FB_BLANK_POWERDOWN;
-
-	if (intensity == FB_BLANK_UNBLANK) { /* FULL ON */
-		cur &= ~CRVML_BACKLIGHT_OFF;
-		outl(cur, addr);
-	} else if (intensity == FB_BLANK_POWERDOWN) { /* OFF */
+	if (backlight_get_brightness(bd) == 0) {
+		/* OFF */
 		cur |= CRVML_BACKLIGHT_OFF;
 		outl(cur, addr);
-	} /* anything else, don't bother */
+	} else {
+		/* FULL ON */
+		cur &= ~CRVML_BACKLIGHT_OFF;
+		outl(cur, addr);
+	}
 
 	return 0;
 }
···
 	u8 intensity;
 
 	if (cur & CRVML_BACKLIGHT_OFF)
-		intensity = FB_BLANK_POWERDOWN;
+		intensity = 0;
 	else
-		intensity = FB_BLANK_UNBLANK;
+		intensity = 1;
 
 	return intensity;
 }

drivers/video/backlight/da903x_bl.c

···
 
 static int da903x_backlight_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.state & BL_CORE_SUSPENDED)
-		brightness = 0;
-
-	return da903x_backlight_set(bl, brightness);
+	return da903x_backlight_set(bl, backlight_get_brightness(bl));
 }
 
 static int da903x_backlight_get_brightness(struct backlight_device *bl)

drivers/video/backlight/ep93xx_bl.c

···
 
 static int ep93xxbl_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	return ep93xxbl_set(bl, brightness);
+	return ep93xxbl_set(bl, backlight_get_brightness(bl));
 }
 
 static int ep93xxbl_get_brightness(struct backlight_device *bl)

drivers/video/backlight/generic_bl.c

···
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  Generic Backlight Driver
- *
- *  Copyright (c) 2004-2008 Richard Purdie
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <linux/mutex.h>
-#include <linux/fb.h>
-#include <linux/backlight.h>
-
-static int genericbl_intensity;
-static struct backlight_device *generic_backlight_device;
-static struct generic_bl_info *bl_machinfo;
-
-static int genericbl_send_intensity(struct backlight_device *bd)
-{
-	int intensity = bd->props.brightness;
-
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-	if (bd->props.state & BL_CORE_FBBLANK)
-		intensity = 0;
-	if (bd->props.state & BL_CORE_SUSPENDED)
-		intensity = 0;
-
-	bl_machinfo->set_bl_intensity(intensity);
-
-	genericbl_intensity = intensity;
-
-	if (bl_machinfo->kick_battery)
-		bl_machinfo->kick_battery();
-
-	return 0;
-}
-
-static int genericbl_get_intensity(struct backlight_device *bd)
-{
-	return genericbl_intensity;
-}
-
-static const struct backlight_ops genericbl_ops = {
-	.options = BL_CORE_SUSPENDRESUME,
-	.get_brightness = genericbl_get_intensity,
-	.update_status  = genericbl_send_intensity,
-};
-
-static int genericbl_probe(struct platform_device *pdev)
-{
-	struct backlight_properties props;
-	struct generic_bl_info *machinfo = dev_get_platdata(&pdev->dev);
-	const char *name = "generic-bl";
-	struct backlight_device *bd;
-
-	bl_machinfo = machinfo;
-	if (!machinfo->limit_mask)
-		machinfo->limit_mask = -1;
-
-	if (machinfo->name)
-		name = machinfo->name;
-
-	memset(&props, 0, sizeof(struct backlight_properties));
-	props.type = BACKLIGHT_RAW;
-	props.max_brightness = machinfo->max_intensity;
-	bd = devm_backlight_device_register(&pdev->dev, name, &pdev->dev,
-					NULL, &genericbl_ops, &props);
-	if (IS_ERR(bd))
-		return PTR_ERR(bd);
-
-	platform_set_drvdata(pdev, bd);
-
-	bd->props.power = FB_BLANK_UNBLANK;
-	bd->props.brightness = machinfo->default_intensity;
-	backlight_update_status(bd);
-
-	generic_backlight_device = bd;
-
-	dev_info(&pdev->dev, "Generic Backlight Driver Initialized.\n");
-	return 0;
-}
-
-static int genericbl_remove(struct platform_device *pdev)
-{
-	struct backlight_device *bd = platform_get_drvdata(pdev);
-
-	bd->props.power = 0;
-	bd->props.brightness = 0;
-	backlight_update_status(bd);
-
-	dev_info(&pdev->dev, "Generic Backlight Driver Unloaded\n");
-	return 0;
-}
-
-static struct platform_driver genericbl_driver = {
-	.probe		= genericbl_probe,
-	.remove		= genericbl_remove,
-	.driver		= {
-		.name	= "generic-bl",
-	},
-};
-
-module_platform_driver(genericbl_driver);
-
-MODULE_AUTHOR("Richard Purdie <[e-mail]>");
-MODULE_DESCRIPTION("Generic Backlight Driver");
-MODULE_LICENSE("GPL");

drivers/video/backlight/gpio_backlight.c

···
 	struct gpio_desc *gpiod;
 };
 
-static int gpio_backlight_get_next_brightness(struct backlight_device *bl)
-{
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		brightness = 0;
-
-	return brightness;
-}
-
 static int gpio_backlight_update_status(struct backlight_device *bl)
 {
 	struct gpio_backlight *gbl = bl_get_data(bl);
-	int brightness = gpio_backlight_get_next_brightness(bl);
 
-	gpiod_set_value_cansleep(gbl->gpiod, brightness);
+	gpiod_set_value_cansleep(gbl->gpiod, backlight_get_brightness(bl));
 
 	return 0;
 }
···
 
 	bl->props.brightness = 1;
 
-	init_brightness = gpio_backlight_get_next_brightness(bl);
+	init_brightness = backlight_get_brightness(bl);
 	ret = gpiod_direction_output(gbl->gpiod, init_brightness);
 	if (ret) {
 		dev_err(dev, "failed to set initial brightness\n");

drivers/video/backlight/hp680_bl.c

···
 {
 	unsigned long flags;
 	u16 v;
-	int intensity = bd->props.brightness;
+	int intensity = backlight_get_brightness(bd);
 
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
-		intensity = 0;
 	if (hp680bl_suspended)
 		intensity = 0;
 

drivers/video/backlight/ili922x.c

···
  *	lower frequency when the registers are read/written.
  *	The macro sets the frequency in the spi_transfer structure if
  *	the frequency exceeds the maximum value.
+ * @s: pointer to an SPI device
+ * @x: pointer to the read/write buffer pair
  */
 #define CHECK_FREQ_REG(s, x)	\
 	do {			\
···
 
 #define set_tx_byte(b)		(tx_invert ? ~(b) : b)
 
-/**
+/*
  * ili922x_id - id as set by manufacturer
  */
 static int ili922x_id = 1;
···
 static int tx_invert;
 module_param(tx_invert, int, 0);
 
-/**
+/*
  * driver's private structure
  */
 struct ili922x {
···
 #ifdef DEBUG
 /**
  * ili922x_reg_dump - dump all registers
+ *
+ * @spi: pointer to an SPI device
  */
 static void ili922x_reg_dump(struct spi_device *spi)
 {

drivers/video/backlight/jornada720_bl.c

···
 	jornada_ssp_start();
 
 	/* If backlight is off then really turn it off */
-	if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
+	if (backlight_is_blank(bd)) {
 		ret = jornada_ssp_byte(BRIGHTNESSOFF);
 		if (ret != TXDUMMY) {
 			dev_info(&bd->dev, "brightness off timeout\n");

drivers/video/backlight/kb3886_bl.c

···
 
 static int kb3886bl_send_intensity(struct backlight_device *bd)
 {
-	int intensity = bd->props.brightness;
+	int intensity = backlight_get_brightness(bd);
 
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
-		intensity = 0;
 	if (kb3886bl_flags & KB3886BL_SUSPENDED)
 		intensity = 0;
 

drivers/video/backlight/lcd.c

···
  * lcd_device_register - register a new object of lcd_device class.
  * @name: the name of the new object(must be the same as the name of the
  *   respective framebuffer device).
+ * @parent: pointer to the parent's struct device .
  * @devdata: an optional pointer to be stored in the device. The
  *   methods may retrieve it by using lcd_get_data(ld).
  * @ops: the lcd operations structure.

drivers/video/backlight/led_bl.c

···
 static int led_bl_update_status(struct backlight_device *bl)
 {
 	struct led_bl_data *priv = bl_get_data(bl);
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & BL_CORE_FBBLANK)
-		brightness = 0;
+	int brightness = backlight_get_brightness(bl);
 
 	if (brightness > 0)
 		led_bl_set_brightness(priv, brightness);

drivers/video/backlight/lm3533_bl.c

···
 static int lm3533_bl_update_status(struct backlight_device *bd)
 {
 	struct lm3533_bl *bl = bl_get_data(bd);
-	int brightness = bd->props.brightness;
 
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	return lm3533_ctrlbank_set_brightness(&bl->cb, (u8)brightness);
+	return lm3533_ctrlbank_set_brightness(&bl->cb, backlight_get_brightness(bd));
 }
 
 static int lm3533_bl_get_brightness(struct backlight_device *bd)
···
 static umode_t lm3533_bl_attr_is_visible(struct kobject *kobj,
 					     struct attribute *attr, int n)
 {
-	struct device *dev = container_of(kobj, struct device, kobj);
+	struct device *dev = kobj_to_dev(kobj);
 	struct lm3533_bl *bl = dev_get_drvdata(dev);
 	umode_t mode = attr->mode;
 

drivers/video/backlight/lm3630a_bl.c

···
 		return ret;
 
 	for (i = 0; i < num_sources; i++) {
-		if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
+		if (sources[i] != LM3630A_SINK_0 && sources[i] != LM3630A_SINK_1)
 			return -EINVAL;
 
 		ret |= BIT(sources[i]);
···
 	if (ret)
 		return ret;
 
-	if (bank < LM3630A_BANK_0 || bank > LM3630A_BANK_1)
+	if (bank != LM3630A_BANK_0 && bank != LM3630A_BANK_1)
 		return -EINVAL;
 
 	led_sources = lm3630a_parse_led_sources(node, BIT(bank));

drivers/video/backlight/lms501kf03.c

···
 #include <linux/backlight.h>
 #include <linux/delay.h>
 #include <linux/fb.h>
-#include <linux/gpio.h>
 #include <linux/lcd.h>
 #include <linux/module.h>
 #include <linux/spi/spi.h>
···
 	0x6a, 0x73, 0x7a, 0x82, 0x8a, 0x91, 0x98, 0xa1, 0xa8, 0xb0,
 	0xb7, 0xc1, 0xc9, 0xcf, 0xd9, 0xe3, 0xea, 0xf4, 0xff, 0x00,
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-};
-
-static const unsigned char seq_up_dn[] = {
-	0x36, 0x10,
-};
-
-static const unsigned char seq_sleep_in[] = {
-	0x10,
 };
 
 static const unsigned char seq_sleep_out[] = {

drivers/video/backlight/locomolcd.c

···
 
 static int locomolcd_set_intensity(struct backlight_device *bd)
 {
-	int intensity = bd->props.brightness;
+	int intensity = backlight_get_brightness(bd);
 
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-	if (bd->props.fb_blank != FB_BLANK_UNBLANK)
-		intensity = 0;
 	if (locomolcd_flags & LOCOMOLCD_SUSPENDED)
 		intensity = 0;
 

drivers/video/backlight/lv5207lp.c

···
 static int lv5207lp_backlight_update_status(struct backlight_device *backlight)
 {
 	struct lv5207lp *lv = bl_get_data(backlight);
-	int brightness = backlight->props.brightness;
-
-	if (backlight->props.power != FB_BLANK_UNBLANK ||
-	    backlight->props.fb_blank != FB_BLANK_UNBLANK ||
-	    backlight->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		brightness = 0;
+	int brightness = backlight_get_brightness(backlight);
 
 	if (brightness) {
 		lv5207lp_write(lv, LV5207LP_CTRL1,

drivers/video/backlight/max8925_bl.c

···
 
 static int max8925_backlight_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.state & BL_CORE_SUSPENDED)
-		brightness = 0;
-
-	return max8925_backlight_set(bl, brightness);
+	return max8925_backlight_set(bl, backlight_get_brightness(bl));
 }
 
 static int max8925_backlight_get_brightness(struct backlight_device *bl)

drivers/video/backlight/ot200_bl.c

···
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2012 Bachmann electronic GmbH
- *	Christian Gmeiner <[e-mail]>
- *
- * Backlight driver for ot200 visualisation device from
- * Bachmann electronic GmbH.
- */
-
-#include <linux/module.h>
-#include <linux/fb.h>
-#include <linux/backlight.h>
-#include <linux/gpio.h>
-#include <linux/platform_device.h>
-#include <linux/cs5535.h>
-
-static struct cs5535_mfgpt_timer *pwm_timer;
-
-/* this array defines the mapping of brightness in % to pwm frequency */
-static const u8 dim_table[101] = {0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
-				  2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4,
-				  4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9,
-				  10, 10, 11, 11, 12, 12, 13, 14, 15, 15, 16,
-				  17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 28,
-				  30, 31, 33, 35, 37, 39, 41, 43, 45, 47, 50,
-				  53, 55, 58, 61, 65, 68, 72, 75, 79, 84, 88,
-				  93, 97, 103, 108, 114, 120, 126, 133, 140,
-				  147, 155, 163};
-
-struct ot200_backlight_data {
-	int current_brightness;
-};
-
-#define GPIO_DIMM	27
-#define SCALE		1
-#define CMP1MODE	0x2	/* compare on GE; output high on compare
-				 * greater than or equal */
-#define PWM_SETUP	(SCALE | CMP1MODE << 6 | MFGPT_SETUP_CNTEN)
-#define MAX_COMP2	163
-
-static int ot200_backlight_update_status(struct backlight_device *bl)
-{
-	struct ot200_backlight_data *data = bl_get_data(bl);
-	int brightness = bl->props.brightness;
-
-	if (bl->props.state & BL_CORE_FBBLANK)
-		brightness = 0;
-
-	/* enable or disable PWM timer */
-	if (brightness == 0)
-		cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, 0);
-	else if (data->current_brightness == 0) {
-		cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0);
-		cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP,
-			MFGPT_SETUP_CNTEN);
-	}
-
-	/* apply new brightness value */
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1,
-		MAX_COMP2 - dim_table[brightness]);
-	data->current_brightness = brightness;
-
-	return 0;
-}
-
-static int ot200_backlight_get_brightness(struct backlight_device *bl)
-{
-	struct ot200_backlight_data *data = bl_get_data(bl);
-	return data->current_brightness;
-}
-
-static const struct backlight_ops ot200_backlight_ops = {
-	.update_status	= ot200_backlight_update_status,
-	.get_brightness	= ot200_backlight_get_brightness,
-};
-
-static int ot200_backlight_probe(struct platform_device *pdev)
-{
-	struct backlight_device *bl;
-	struct ot200_backlight_data *data;
-	struct backlight_properties props;
-	int retval = 0;
-
-	/* request gpio */
-	if (devm_gpio_request(&pdev->dev, GPIO_DIMM,
-				"ot200 backlight dimmer") < 0) {
-		dev_err(&pdev->dev, "failed to request GPIO %d\n", GPIO_DIMM);
-		return -ENODEV;
-	}
-
-	/* request timer */
-	pwm_timer = cs5535_mfgpt_alloc_timer(7, MFGPT_DOMAIN_ANY);
-	if (!pwm_timer) {
-		dev_err(&pdev->dev, "MFGPT 7 not available\n");
-		return -ENODEV;
-	}
-
-	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
-	if (!data) {
-		retval = -ENOMEM;
-		goto error_devm_kzalloc;
-	}
-
-	/* setup gpio */
-	cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_ENABLE);
-	cs5535_gpio_set(GPIO_DIMM, GPIO_OUTPUT_AUX1);
-
-	/* setup timer */
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1, 0);
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP2, MAX_COMP2);
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, PWM_SETUP);
-
-	data->current_brightness = 100;
-	props.max_brightness = 100;
-	props.brightness = 100;
-	props.type = BACKLIGHT_RAW;
-
-	bl = devm_backlight_device_register(&pdev->dev, dev_name(&pdev->dev),
-					&pdev->dev, data, &ot200_backlight_ops,
-					&props);
-	if (IS_ERR(bl)) {
-		dev_err(&pdev->dev, "failed to register backlight\n");
-		retval = PTR_ERR(bl);
-		goto error_devm_kzalloc;
-	}
-
-	platform_set_drvdata(pdev, bl);
-
-	return 0;
-
-error_devm_kzalloc:
-	cs5535_mfgpt_free_timer(pwm_timer);
-	return retval;
-}
-
-static int ot200_backlight_remove(struct platform_device *pdev)
-{
-	/* on module unload set brightness to 100% */
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_COUNTER, 0);
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_SETUP, MFGPT_SETUP_CNTEN);
-	cs5535_mfgpt_write(pwm_timer, MFGPT_REG_CMP1,
-		MAX_COMP2 - dim_table[100]);
-
-	cs5535_mfgpt_free_timer(pwm_timer);
-
-	return 0;
-}
-
-static struct platform_driver ot200_backlight_driver = {
-	.driver		= {
-		.name	= "ot200-backlight",
-	},
-	.probe		= ot200_backlight_probe,
-	.remove		= ot200_backlight_remove,
-};
-
-module_platform_driver(ot200_backlight_driver);
-
-MODULE_DESCRIPTION("backlight driver for ot200 visualisation device");
-MODULE_AUTHOR("Christian Gmeiner <[e-mail]>");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:ot200-backlight");

drivers/video/backlight/pwm_bl.c

···
 static int pwm_backlight_update_status(struct backlight_device *bl)
 {
 	struct pwm_bl_data *pb = bl_get_data(bl);
-	int brightness = bl->props.brightness;
+	int brightness = backlight_get_brightness(bl);
 	struct pwm_state state;
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & BL_CORE_FBBLANK)
-		brightness = 0;
 
 	if (pb->notify)
 		brightness = pb->notify(pb->dev, brightness);

drivers/video/backlight/qcom-wled.c

···
 static int wled_update_status(struct backlight_device *bl)
 {
 	struct wled *wled = bl_get_data(bl);
-	u16 brightness = bl->props.brightness;
+	u16 brightness = backlight_get_brightness(bl);
 	int rc = 0;
-
-	if (bl->props.power != FB_BLANK_UNBLANK ||
-	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
-	    bl->props.state & BL_CORE_FBBLANK)
-		brightness = 0;
 
 	mutex_lock(&wled->lock);
 	if (brightness) {
···
 static const struct wled_var_cfg wled4_string_i_limit_cfg = {
 	.values = wled4_string_i_limit_values,
 	.size = ARRAY_SIZE(wled4_string_i_limit_values),
-};
-
-static const struct wled_var_cfg wled3_string_cfg = {
-	.size = 8,
-};
-
-static const struct wled_var_cfg wled4_string_cfg = {
-	.size = 16,
 };
 
 static const struct wled_var_cfg wled5_mod_sel_cfg = {

drivers/video/backlight/sky81452-backlight.c

···
 
 #include <linux/backlight.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
-#include <linux/platform_data/sky81452-backlight.h>
 #include <linux/slab.h>
 
 /* registers */
···
 
 #define SKY81452_DEFAULT_NAME "lcd-backlight"
 #define SKY81452_MAX_BRIGHTNESS	(SKY81452_CS + 1)
+
+/**
+ * struct sky81452_platform_data
+ * @name:	backlight driver name.
+ *		If it is not defined, default name is lcd-backlight.
+ * @gpiod_enable:GPIO descriptor which control EN pin
+ * @enable:	Enable mask for current sink channel 1, 2, 3, 4, 5 and 6.
+ * @ignore_pwm:	true if DPWMI should be ignored.
+ * @dpwm_mode:	true is DPWM dimming mode, otherwise Analog dimming mode.
+ * @phase_shift:true is phase shift mode.
+ * @short_detection_threshold:	It should be one of 4, 5, 6 and 7V.
+ * @boost_current_limit:	It should be one of 2300, 2750mA.
+ */
+struct sky81452_bl_platform_data {
+	const char *name;
+	struct gpio_desc *gpiod_enable;
+	unsigned int enable;
+	bool ignore_pwm;
+	bool dpwm_mode;
+	bool phase_shift;
+	unsigned int short_detection_threshold;
+	unsigned int boost_current_limit;
+};
 
 #define CTZ(b) __builtin_ctz(b)
 
···
 	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
 	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
 	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
-	pdata->gpio_enable = of_get_gpio(np, 0);
+	pdata->gpiod_enable = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
 
 	ret = of_property_count_u32_elems(np, "led-sources");
 	if (ret < 0) {
···
 {
 	struct device *dev = &pdev->dev;
 	struct regmap *regmap = dev_get_drvdata(dev->parent);
-	struct sky81452_bl_platform_data *pdata = dev_get_platdata(dev);
+	struct sky81452_bl_platform_data *pdata;
 	struct backlight_device *bd;
 	struct backlight_properties props;
 	const char *name;
 	int ret;
 
-	if (!pdata) {
-		pdata = sky81452_bl_parse_dt(dev);
-		if (IS_ERR(pdata))
-			return PTR_ERR(pdata);
-	}
-
-	if (gpio_is_valid(pdata->gpio_enable)) {
-		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
-					GPIOF_OUT_INIT_HIGH, "sky81452-en");
-		if (ret < 0) {
-			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
-			return ret;
-		}
-	}
+	pdata = sky81452_bl_parse_dt(dev);
+	if (IS_ERR(pdata))
+		return PTR_ERR(pdata);
 
 	ret = sky81452_bl_init_device(regmap, pdata);
 	if (ret < 0) {
···
 	bd->props.brightness = 0;
 	backlight_update_status(bd);
 
-	if (gpio_is_valid(pdata->gpio_enable))
-		gpio_set_value_cansleep(pdata->gpio_enable, 0);
+	if (pdata->gpiod_enable)
+		gpiod_set_value_cansleep(pdata->gpiod_enable, 0);
 
 	return 0;
 }

drivers/video/backlight/tps65217_bl.c

···
 {
 	struct tps65217_bl *tps65217_bl = bl_get_data(bl);
 	int rc;
-	int brightness = bl->props.brightness;
-
-	if (bl->props.state & BL_CORE_SUSPENDED)
-		brightness = 0;
-
-	if ((bl->props.power != FB_BLANK_UNBLANK) ||
-		(bl->props.fb_blank != FB_BLANK_UNBLANK))
-		/* framebuffer in low power mode or blanking active */
-		brightness = 0;
+	int brightness = backlight_get_brightness(bl);
 
 	if (brightness > 0) {
 		rc = tps65217_reg_write(tps65217_bl->tps,

drivers/video/backlight/wm831x_bl.c

···
 
 static int wm831x_backlight_update_status(struct backlight_device *bl)
 {
-	int brightness = bl->props.brightness;
-
-	if (bl->props.power != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.fb_blank != FB_BLANK_UNBLANK)
-		brightness = 0;
-
-	if (bl->props.state & BL_CORE_SUSPENDED)
-		brightness = 0;
-
-	return wm831x_backlight_set(bl, brightness);
+	return wm831x_backlight_set(bl, backlight_get_brightness(bl));
 }
 
 static int wm831x_backlight_get_brightness(struct backlight_device *bl)

include/linux/backlight.h

···
 #include <linux/mutex.h>
 #include <linux/notifier.h>
 
-/* Notes on locking:
+/**
+ * enum backlight_update_reason - what method was used to update backlight
  *
- * backlight_device->ops_lock is an internal backlight lock protecting the
- * ops pointer and no code outside the core should need to touch it.
- *
- * Access to update_status() is serialised by the update_lock mutex since
- * most drivers seem to need this and historically get it wrong.
- *
- * Most drivers don't need locking on their get_brightness() method.
- * If yours does, you need to implement it in the driver. You can use the
- * update_lock mutex if appropriate.
- *
- * Any other use of the locks below is probably wrong.
+ * A driver indicates the method (reason) used for updating the backlight
+ * when calling backlight_force_update().
  */
-
 enum backlight_update_reason {
+	/**
+	 * @BACKLIGHT_UPDATE_HOTKEY: The backlight was updated using a hot-key.
+	 */
 	BACKLIGHT_UPDATE_HOTKEY,
+
+	/**
+	 * @BACKLIGHT_UPDATE_SYSFS: The backlight was updated using sysfs.
+	 */
 	BACKLIGHT_UPDATE_SYSFS,
 };
 
+/**
+ * enum backlight_type - the type of backlight control
+ *
+ * The type of interface used to control the backlight.
+ */
 enum backlight_type {
+	/**
+	 * @BACKLIGHT_RAW:
+	 *
+	 * The backlight is controlled using hardware registers.
+	 */
 	BACKLIGHT_RAW = 1,
+
+	/**
+	 * @BACKLIGHT_PLATFORM:
+	 *
+	 * The backlight is controlled using a platform-specific interface.
+	 */
 	BACKLIGHT_PLATFORM,
+
+	/**
+	 * @BACKLIGHT_FIRMWARE:
+	 *
+	 * The backlight is controlled using a standard firmware interface.
+	 */
 	BACKLIGHT_FIRMWARE,
+
+	/**
+	 * @BACKLIGHT_TYPE_MAX: Number of entries.
+	 */
 	BACKLIGHT_TYPE_MAX,
 };
 
+/**
+ * enum backlight_notification - the type of notification
+ *
+ * The notifications that is used for notification sent to the receiver
+ * that registered notifications using backlight_register_notifier().
+ */
 enum backlight_notification {
+	/**
+	 * @BACKLIGHT_REGISTERED: The backlight device is registered.
+	 */
 	BACKLIGHT_REGISTERED,
+
+	/**
+	 * @BACKLIGHT_UNREGISTERED: The backlight revice is unregistered.
+	 */
 	BACKLIGHT_UNREGISTERED,
 };
 
+/** enum backlight_scale - the type of scale used for brightness values
+ *
+ * The type of scale used for brightness values.
+ */
 enum backlight_scale {
+	/**
+	 * @BACKLIGHT_SCALE_UNKNOWN: The scale is unknown.
+	 */
 	BACKLIGHT_SCALE_UNKNOWN = 0,
+
+	/**
+	 * @BACKLIGHT_SCALE_LINEAR: The scale is linear.
+	 *
+	 * The linear scale will increase brightness the same for each step.
+	 */
 	BACKLIGHT_SCALE_LINEAR,
+
+	/**
+	 * @BACKLIGHT_SCALE_NON_LINEAR: The scale is not linear.
+	 *
+	 * This is often used when the brightness values tries to adjust to
+	 * the relative perception of the eye demanding a non-linear scale.
+	 */
 	BACKLIGHT_SCALE_NON_LINEAR,
 };
 
 struct backlight_device;
 struct fb_info;
 
+/**
+ * struct backlight_ops - backlight operations
+ *
+ * The backlight operations are specified when the backlight device is registered.
+ */
 struct backlight_ops {
+	/**
+	 * @options: Configure how operations are called from the core.
+	 *
+	 * The options parameter is used to adjust the behaviour of the core.
+	 * Set BL_CORE_SUSPENDRESUME to get the update_status() operation called
+	 * upon suspend and resume.
+	 */
 	unsigned int options;
 
 #define BL_CORE_SUSPENDRESUME	(1 << 0)
 
-	/* Notify the backlight driver some property has changed */
+	/**
+	 * @update_status: Operation called when properties have changed.
+	 *
+	 * Notify the backlight driver some property has changed.
+	 * The update_status operation is protected by the update_lock.
+	 *
+	 * The backlight driver is expected to use backlight_is_blank()
+	 * to check if the display is blanked and set brightness accordingly.
+	 * update_status() is called when any of the properties has changed.
+	 *
+	 * RETURNS:
+	 *
+	 * 0 on success, negative error code if any failure occurred.
+	 */
 	int (*update_status)(struct backlight_device *);
-	/* Return the current backlight brightness (accounting for power,
-	   fb_blank etc.) */
+
+	/**
+	 * @get_brightness: Return the current backlight brightness.
+	 *
+	 * The driver may implement this as a readback from the HW.
+	 * This operation is optional and if not present then the current
+	 * brightness property value is used.
+	 *
+	 * RETURNS:
+	 *
+	 * A brightness value which is 0 or a positive number.
+	 * On failure a negative error code is returned.
+	 */
 	int (*get_brightness)(struct backlight_device *);
-	/* Check if given framebuffer device is the one bound to this backlight;
-	   return 0 if not, !=0 if it is. If NULL, backlight always matches the fb. */
-	int (*check_fb)(struct backlight_device *, struct fb_info *);
+
+	/**
+	 * @check_fb: Check the framebuffer device.
+	 *
+	 * Check if given framebuffer device is the one bound to this backlight.
+	 * This operation is optional and if not implemented it is assumed that the
+	 * fbdev is always the one bound to the backlight.
+	 *
+	 * RETURNS:
+	 *
+	 * If info is NULL or the info matches the fbdev bound to the backlight return true.
+	 * If info does not match the fbdev bound to the backlight return false.
+	 */
+	int (*check_fb)(struct backlight_device *bd, struct fb_info *info);
 };
 
-/* This structure defines all the properties of a backlight */
+/**
+ * struct backlight_properties - backlight properties
+ *
+ * This structure defines all the properties of a backlight.
+ */
 struct backlight_properties {
-	/* Current User requested brightness (0 - max_brightness) */
+	/**
+	 * @brightness: The current brightness requested by the user.
+	 *
+	 * The backlight core makes sure the range is (0 to max_brightness)
+	 * when the brightness is set via the sysfs attribute:
+	 * /sys/class/backlight/<backlight>/brightness.
+	 *
+	 * This value can be set in the backlight_properties passed
+	 * to devm_backlight_device_register() to set a default brightness
+	 * value.
+	 */
 	int brightness;
-	/* Maximal value for brightness (read-only) */
+
+	/**
+	 * @max_brightness: The maximum brightness value.
+	 *
+	 * This value must be set in the backlight_properties passed to
+	 * devm_backlight_device_register() and shall not be modified by the
+	 * driver after registration.
+	 */
 	int max_brightness;
-	/* Current FB Power mode (0: full on, 1..3: power saving
-	   modes; 4: full off), see FB_BLANK_XXX */
+
+	/**
+	 * @power: The current power mode.
+	 *
+	 * User space can configure the power mode using the sysfs
+	 * attribute: /sys/class/backlight/<backlight>/bl_power
+	 * When the power property is updated update_status() is called.
+	 *
+	 * The possible values are: (0: full on, 1 to 3: power saving
+	 * modes; 4: full off), see FB_BLANK_XXX.
+	 *
+	 * When the backlight device is enabled @power is set
+	 * to FB_BLANK_UNBLANK. When the backlight device is disabled
+	 * @power is set to FB_BLANK_POWERDOWN.
+	 */
 	int power;
-	/* FB Blanking active? (values as for power) */
-	/* Due to be removed, please use (state & BL_CORE_FBBLANK) */
+
+	/**
+	 * @fb_blank: The power state from the FBIOBLANK ioctl.
+	 *
+	 * When the FBIOBLANK ioctl is called @fb_blank is set to the
+	 * blank parameter and the update_status() operation is called.
+	 *
+	 * When the backlight device is enabled @fb_blank is set
+	 * to FB_BLANK_UNBLANK. When the backlight device is disabled
+	 * @fb_blank is set to FB_BLANK_POWERDOWN.
+	 *
+	 * Backlight drivers should avoid using this property. It has been
+	 * replaced by state & BL_CORE_FBLANK (although most drivers should
+	 * use backlight_is_blank() as the preferred means to get the blank
+	 * state).
+	 *
+	 * fb_blank is deprecated and will be removed.
+	 */
 	int fb_blank;
-	/* Backlight type */
+
+	/**
+	 * @type: The type of backlight supported.
+	 *
+	 * The backlight type allows userspace to make appropriate
+	 * policy decisions based on the backlight type.
+	 *
+	 * This value must be set in the backlight_properties
+	 * passed to devm_backlight_device_register().
+	 */
 	enum backlight_type type;
-	/* Flags used to signal drivers of state changes */
+
+	/**
+	 * @state: The state of the backlight core.
+	 *
+	 * The state is a bitmask. BL_CORE_FBBLANK is set when the display
+	 * is expected to be blank. BL_CORE_SUSPENDED is set when the
+	 * driver is suspended.
+	 *
+	 * backlight drivers are expected to use backlight_is_blank()
+	 * in their update_status() operation rather than reading the
+	 * state property.
+	 *
+	 * The state is maintained by the core and drivers may not modify it.
+	 */
 	unsigned int state;
-	/* Type of the brightness scale (linear, non-linear, ...) */
-	enum backlight_scale scale;
 
 #define BL_CORE_SUSPENDED	(1 << 0)	/* backlight is suspended */
 #define BL_CORE_FBBLANK		(1 << 1)	/* backlight is under an fb blank event */
 
+	/**
+	 * @scale: The type of the brightness scale.
+	 */
+	enum backlight_scale scale;
 };
 
+/**
+ * struct backlight_device - backlight device data
+ *
+ * This structure holds all data required by a backlight device.
+ */
 struct backlight_device {
-	/* Backlight properties */
+	/**
+	 * @props: Backlight properties
+	 */
 	struct backlight_properties props;
 
-	/* Serialise access to update_status method */
+	/**
+	 * @update_lock: The lock used when calling the update_status() operation.
+	 *
+	 * update_lock is an internal backlight lock that serialise access
+	 * to the update_status() operation. The backlight core holds the update_lock
+	 * when calling the update_status() operation. The update_lock shall not
+	 * be used by backlight drivers.
+	 */
 	struct mutex update_lock;
 
-	/* This protects the 'ops' field. If 'ops' is NULL, the driver that
-	   registered this device has been unloaded, and if class_get_devdata()
-	   points to something in the body of that driver, it is also invalid. */
+	/**
+	 * @ops_lock: The lock used around everything related to backlight_ops.
+	 *
+	 * ops_lock is an internal backlight lock that protects the ops pointer
+	 * and is used around all accesses to ops and when the operations are
+	 * invoked. The ops_lock shall not be used by backlight drivers.
+	 */
 	struct mutex ops_lock;
+
+	/**
+	 * @ops: Pointer to the backlight operations.
+	 *
+	 * If ops is NULL, the driver that registered this device has been unloaded,
+	 * and if class_get_devdata() points to something in the body of that driver,
+	 * it is also invalid.
+	 */
 	const struct backlight_ops *ops;
 
-	/* The framebuffer notifier block */
+	/**
+	 * @fb_notif: The framebuffer notifier block
+	 */
 	struct notifier_block fb_notif;
 
-	/* list entry of all registered backlight devices */
+	/**
+	 * @entry: List entry of all registered backlight devices
+	 */
 	struct list_head entry;
 
+	/**
+	 * @dev: Parent device.
+	 */
 	struct device dev;
 
-	/* Multiple framebuffers may share one backlight device */
+	/**
+	 * @fb_bl_on: The state of individual fbdev's.
+	 *
+	 * Multiple fbdev's may share one backlight device. The fb_bl_on
+	 * records the state of the individual fbdev.
+	 */
 	bool fb_bl_on[FB_MAX];
 
+	/**
+	 * @use_count: The number of uses of fb_bl_on.
+	 */
 	int use_count;
 };
 
+/**
+ * backlight_update_status - force an update of the backlight device status
+ * @bd: the backlight device
+ */
 static inline int backlight_update_status(struct backlight_device *bd)
 {
 	int ret = -ENOENT;
···
 }
 
 /**
- * backlight_put - Drop backlight reference
- * @bd: the backlight device to put
+ * backlight_is_blank - Return true if display is expected to be blank
+ * @bd: the backlight device
+ *
+ * Display is expected to be blank if any of these is true::
+ *
+ *   1) if power in not UNBLANK
+ *   2) if fb_blank is not UNBLANK
+ *   3) if state indicate BLANK or SUSPENDED
+ *
+ * Returns true if display is expected to be blank, false otherwise.
  */
-static inline void backlight_put(struct backlight_device *bd)
+static inline bool backlight_is_blank(const struct backlight_device *bd)
 {
-	if (bd)
-		put_device(&bd->dev);
+	return bd->props.power != FB_BLANK_UNBLANK ||
+	       bd->props.fb_blank != FB_BLANK_UNBLANK ||
+	       bd->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK);
 }
 
-extern struct backlight_device *backlight_device_register(const char *name,
-	struct device *dev, void *devdata, const struct backlight_ops *ops,
-	const struct backlight_properties *props);
-extern struct backlight_device *devm_backlight_device_register(
-	struct device *dev, const char *name, struct device *parent,
-	void *devdata, const struct backlight_ops *ops,
-	const struct backlight_properties *props);
-extern void backlight_device_unregister(struct backlight_device *bd);
-extern void devm_backlight_device_unregister(struct device *dev,
-					struct backlight_device *bd);
-extern void backlight_force_update(struct backlight_device *bd,
-				   enum backlight_update_reason reason);
-extern int backlight_register_notifier(struct notifier_block *nb);
-extern int backlight_unregister_notifier(struct notifier_block *nb);
-extern struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
+/**
+ * backlight_get_brightness - Returns the current brightness value
+ * @bd: the backlight device
+ *
+ * Returns the current brightness value, taking in consideration the current
+ * state. If backlight_is_blank() returns true then return 0 as brightness
+ * otherwise return the current brightness property value.
+ *
+ * Backlight drivers are expected to use this function in their update_status()
+ * operation to get the brightness value.
+ */
+static inline int backlight_get_brightness(const struct backlight_device *bd)
+{
+	if (backlight_is_blank(bd))
+		return 0;
+	else
+		return bd->props.brightness;
+}
+
+struct backlight_device *
+backlight_device_register(const char *name, struct device *dev, void *devdata,
+			  const struct backlight_ops *ops,
+			  const struct backlight_properties *props);
+struct backlight_device *
+devm_backlight_device_register(struct device *dev, const char *name,
+			       struct device *parent, void *devdata,
+			       const struct backlight_ops *ops,
+			       const struct backlight_properties *props);
+void backlight_device_unregister(struct backlight_device *bd);
+void devm_backlight_device_unregister(struct device *dev,
+				      struct backlight_device *bd);
+void backlight_force_update(struct backlight_device *bd,
+			    enum backlight_update_reason reason);
+int backlight_register_notifier(struct notifier_block *nb);
+int backlight_unregister_notifier(struct notifier_block *nb);
 struct backlight_device *backlight_device_get_by_name(const char *name);
-extern int backlight_device_set_brightness(struct backlight_device *bd, unsigned long brightness);
+struct backlight_device *backlight_device_get_by_type(enum backlight_type type);
+int backlight_device_set_brightness(struct backlight_device *bd,
+				    unsigned long brightness);
 
 #define to_backlight_device(obj) container_of(obj, struct backlight_device, dev)
 
+/**
+ * bl_get_data - access devdata
+ * @bl_dev: pointer to backlight device
+ *
+ * When a backlight device is registered the driver has the possibility
+ * to supply a void * devdata. bl_get_data() return a pointer to the
+ * devdata.
+ *
+ * RETURNS:
+ *
+ * pointer to devdata stored while registering the backlight device.
+ */
 static inline void * bl_get_data(struct backlight_device *bl_dev)
 {
 	return dev_get_drvdata(&bl_dev->dev);
 }
-
-struct generic_bl_info {
-	const char *name;
-	int max_intensity;
-	int default_intensity;
-	int limit_mask;
-	void (*set_bl_intensity)(int intensity);
-	void (*kick_battery)(void);
-};
 
 #ifdef CONFIG_OF
 struct backlight_device *of_find_backlight_by_node(struct device_node *node);
···
 #endif
 
 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
-struct backlight_device *of_find_backlight(struct device *dev);
 struct backlight_device *devm_of_find_backlight(struct device *dev);
 #else
-static inline struct backlight_device *of_find_backlight(struct device *dev)
-{
-	return NULL;
-}
-
 static inline struct backlight_device *
 devm_of_find_backlight(struct device *dev)
 {

include/linux/mfd/sky81452.h

···
 #ifndef _SKY81452_H
 #define _SKY81452_H
 
-#include <linux/platform_data/sky81452-backlight.h>
 #include <linux/regulator/machine.h>
 
 struct sky81452_platform_data {
-	struct sky81452_bl_platform_data *bl_pdata;
 	struct regulator_init_data *regulator_init_data;
 };
 

include/linux/platform_data/sky81452-backlight.h

···
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * sky81452.h	SKY81452 backlight driver
- *
- * Copyright 2014 Skyworks Solutions Inc.
- * Author : Gyungoh Yoo <[e-mail]>
- */
-
-#ifndef _SKY81452_BACKLIGHT_H
-#define _SKY81452_BACKLIGHT_H
-
-/**
- * struct sky81452_platform_data
- * @name:	backlight driver name.
-		If it is not defined, default name is lcd-backlight.
- * @gpio_enable:GPIO number which control EN pin
- * @enable:	Enable mask for current sink channel 1, 2, 3, 4, 5 and 6.
- * @ignore_pwm:	true if DPWMI should be ignored.
- * @dpwm_mode:	true is DPWM dimming mode, otherwise Analog dimming mode.
- * @phase_shift:true is phase shift mode.
- * @short_detecion_threshold:	It should be one of 4, 5, 6 and 7V.
- * @boost_current_limit:	It should be one of 2300, 2750mA.
- */
-struct sky81452_bl_platform_data {
-	const char *name;
-	int gpio_enable;
-	unsigned int enable;
-	bool ignore_pwm;
-	bool dpwm_mode;
-	bool phase_shift;
-	unsigned int short_detection_threshold;
-	unsigned int boost_current_limit;
-};
-
-#endif