Merge tag 'backlight-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
"Additions:
- Add support for Awinic AW99706 backlight driver

Fixes:
- Add GPIOLIB dependency to backlight ktd2801 driver
- Add devlink to LED Backlight's supplier LEDs to enforce correct
removal order and prevent NULL pointer dereferences
- Fix kernel-doc warnings in lp855x.h

Removals:
- Do not include <linux/fb.h> in backlight.h
- Fix unused function warnings from suspend/resume ops in aw99706.c
by switching to DEFINE_SIMPLE_DEV_PM_OPS and using pm_ptr()

Bindings:
- Add Awinic AW99706 backlight binding to MAINTAINERS
- Add Awinic AW99706 backlight binding documentation"

* tag 'backlight-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
backlight: aw99706: Fix unused function warnings from suspend/resume ops
backlight: lp855x: Fix lp855x.h kernel-doc warnings
dt-bindings: leds: backlight: Add Awinic AW99706 backlight
backlight: aw99706: Add support for Awinic AW99706 backlight
backlight: led-bl: Add devlink to supplier LEDs
backlight: ktd2801: Depend on GPIOLIB
backlight: Do not include <linux/fb.h> in header file

Documentation/devicetree/bindings/leds/backlight/awinic,aw99706.yaml

···
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/awinic,aw99706.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Awinic AW99706 6-channel WLED Backlight Driver
+
+maintainers:
+  - Junjie Cao <[e-mail]>
+
+allOf:
+  - $ref: common.yaml#
+
+properties:
+  compatible:
+    const: awinic,aw99706
+
+  reg:
+    maxItems: 1
+
+  enable-gpios:
+    description: GPIO to use to enable/disable the backlight (HWEN pin).
+    maxItems: 1
+
+  awinic,dim-mode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: >
+      Select dimming mode of the device.
+        0 = Bypass mode.
+        1 = DC mode.
+        2 = MIX mode(PWM at low brightness and DC at high brightness).
+        3 = MIX-26k mode(MIX mode with different PWM frequency).
+    enum: [ 0, 1, 2, 3 ]
+    default: 1
+
+  awinic,sw-freq-hz:
+    description: Boost switching frequency in Hz.
+    enum: [ 300000, 400000, 500000, 600000, 660000, 750000, 850000, 1000000,
+            1200000, 1330000, 1500000, 1700000 ]
+    default: 750000
+
+  awinic,sw-ilmt-microamp:
+    description: Switching current limitation in uA.
+    enum: [ 1500000, 2000000, 2500000, 3000000 ]
+    default: 3000000
+
+  awinic,iled-max-microamp:
+    description: Maximum LED current setting in uA.
+    minimum: 5000
+    maximum: 50000
+    multipleOf: 500
+    default: 20000
+
+  awinic,uvlo-thres-microvolt:
+    description: UVLO(Under Voltage Lock Out) in uV.
+    enum: [ 2200000, 5000000 ]
+    default: 2200000
+
+  awinic,ramp-ctl:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: >
+      Select ramp control and filter of the device.
+        0 = Fade in/fade out.
+        1 = Light filter.
+        2 = Medium filter.
+        3 = Heavy filter.
+    enum: [ 0, 1, 2, 3 ]
+    default: 2
+
+required:
+  - compatible
+  - reg
+  - enable-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        backlight@76 {
+            compatible = "awinic,aw99706";
+            reg = <0x76>;
+            enable-gpios = <&tlmm 88 GPIO_ACTIVE_HIGH>;
+            default-brightness = <2047>;
+            max-brightness = <4095>;
+            awinic,dim-mode = <1>;
+            awinic,sw-freq-hz = <750000>;
+            awinic,sw-ilmt-microamp = <3000000>;
+            awinic,uvlo-thres-microvolt = <2200000>;
+            awinic,iled-max-microamp = <20000>;
+            awinic,ramp-ctl = <2>;
+        };
+    };
+
+...

MAINTAINERS

···
 F:	Documentation/devicetree/bindings/iio/adc/avia-hx711.yaml
 F:	drivers/iio/adc/hx711.c
 
+AWINIC AW99706 WLED BACKLIGHT DRIVER
+M:	Junjie Cao <[e-mail]>
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/awinic,aw99706.yaml
+F:	drivers/video/backlight/aw99706.c
+
 AX.25 NETWORK LAYER
 L:	[e-mail]
 S:	Orphan

drivers/video/backlight/Kconfig

···
 	  If in doubt, it's safe to enable this option; it doesn't kick
 	  in unless the board's description says it's wired that way.
 
+config BACKLIGHT_AW99706
+	tristate "Backlight Driver for Awinic AW99706"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you have a LCD backlight connected to the WLED output of AW99706
+	  WLED output, say Y here to enable this driver.
+
 config BACKLIGHT_EP93XX
 	tristate "Cirrus EP93xx Backlight Driver"
 	depends on FB_EP93XX
···
 
 config BACKLIGHT_KTD2801
 	tristate "Backlight Driver for Kinetic KTD2801"
+	depends on GPIOLIB || COMPILE_TEST
 	select LEDS_EXPRESSWIRE
 	help
 	  Say Y to enable the backlight driver for the Kinetic KTD2801 1-wire

drivers/video/backlight/Makefile

···
 obj-$(CONFIG_BACKLIGHT_APPLE)		+= apple_bl.o
 obj-$(CONFIG_BACKLIGHT_APPLE_DWI)	+= apple_dwi_bl.o
 obj-$(CONFIG_BACKLIGHT_AS3711)		+= as3711_bl.o
+obj-$(CONFIG_BACKLIGHT_AW99706)		+= aw99706.o
 obj-$(CONFIG_BACKLIGHT_BD6107)		+= bd6107.o
 obj-$(CONFIG_BACKLIGHT_CLASS_DEVICE)	+= backlight.o
 obj-$(CONFIG_BACKLIGHT_DA903X)		+= da903x_bl.o

drivers/video/backlight/aw99706.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * aw99706 - Backlight driver for the AWINIC AW99706
+ *
+ * Copyright (C) 2025 Junjie Cao <[e-mail]>
+ * Copyright (C) 2025 Pengyu Luo <[e-mail]>
+ *
+ * Based on vendor driver:
+ * Copyright (c) 2023 AWINIC Technology CO., LTD
+ */
+
+#include <linux/backlight.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define AW99706_MAX_BRT_LVL		4095
+#define AW99706_REG_MAX			0x1F
+#define AW99706_ID			0x07
+
+/* registers list */
+#define AW99706_CFG0_REG			0x00
+#define AW99706_DIM_MODE_MASK			GENMASK(1, 0)
+
+#define AW99706_CFG1_REG			0x01
+#define AW99706_SW_FREQ_MASK			GENMASK(3, 0)
+#define AW99706_SW_ILMT_MASK			GENMASK(5, 4)
+
+#define AW99706_CFG2_REG			0x02
+#define AW99706_ILED_MAX_MASK			GENMASK(6, 0)
+#define AW99706_UVLOSEL_MASK			BIT(7)
+
+#define AW99706_CFG3_REG			0x03
+#define AW99706_CFG4_REG			0x04
+#define AW99706_BRT_MSB_MASK			GENMASK(3, 0)
+
+#define AW99706_CFG5_REG			0x05
+#define AW99706_BRT_LSB_MASK			GENMASK(7, 0)
+
+#define AW99706_CFG6_REG			0x06
+#define AW99706_RAMP_CTL_MASK			GENMASK(7, 6)
+
+#define AW99706_CFG7_REG			0x07
+#define AW99706_CFG8_REG			0x08
+#define AW99706_CFG9_REG			0x09
+#define AW99706_CFGA_REG			0x0A
+#define AW99706_CFGB_REG			0x0B
+#define AW99706_CFGC_REG			0x0C
+#define AW99706_CFGD_REG			0x0D
+#define AW99706_FLAG_REG			0x10
+#define AW99706_BACKLIGHT_EN_MASK		BIT(7)
+
+#define AW99706_CHIPID_REG			0x11
+#define AW99706_LED_OPEN_FLAG_REG		0x12
+#define AW99706_LED_SHORT_FLAG_REG		0x13
+#define AW99706_MTPLDOSEL_REG			0x1E
+#define AW99706_MTPRUN_REG			0x1F
+
+#define RESV	0
+
+/* Boost switching frequency table, in Hz */
+static const u32 aw99706_sw_freq_tbl[] = {
+	RESV, RESV, RESV, RESV, 300000, 400000, 500000, 600000,
+	660000, 750000, 850000, 1000000, 1200000, 1330000, 1500000, 1700000
+};
+
+/* Switching current limitation table, in uA */
+static const u32 aw99706_sw_ilmt_tbl[] = {
+	1500000, 2000000, 2500000, 3000000
+};
+
+/* ULVO threshold table, in uV */
+static const u32 aw99706_ulvo_thres_tbl[] = {
+	2200000, 5000000
+};
+
+struct aw99706_dt_prop {
+	const char * const name;
+	int (*lookup)(const struct aw99706_dt_prop *prop, u32 dt_val, u8 *val);
+	const u32 * const lookup_tbl;
+	u8 tbl_size;
+	u8 reg;
+	u8 mask;
+	u32 def_val;
+};
+
+static int aw99706_dt_property_lookup(const struct aw99706_dt_prop *prop,
+				      u32 dt_val, u8 *val)
+{
+	int i;
+
+	if (!prop->lookup_tbl) {
+		*val = dt_val;
+		return 0;
+	}
+
+	for (i = 0; i < prop->tbl_size; i++)
+		if (prop->lookup_tbl[i] == dt_val)
+			break;
+
+	*val = i;
+
+	return i == prop->tbl_size ? -1 : 0;
+}
+
+#define MIN_ILED_MAX	5000
+#define MAX_ILED_MAX	50000
+#define STEP_ILED_MAX	500
+
+static int
+aw99706_dt_property_iled_max_convert(const struct aw99706_dt_prop *prop,
+				     u32 dt_val, u8 *val)
+{
+	if (dt_val > MAX_ILED_MAX || dt_val < MIN_ILED_MAX)
+		return -1;
+
+	*val = (dt_val - MIN_ILED_MAX) / STEP_ILED_MAX;
+
+	return (dt_val - MIN_ILED_MAX) % STEP_ILED_MAX;
+}
+
+static const struct aw99706_dt_prop aw99706_dt_props[] = {
+	{
+		"awinic,dim-mode", aw99706_dt_property_lookup,
+		NULL, 0,
+		AW99706_CFG0_REG, AW99706_DIM_MODE_MASK, 1,
+	},
+	{
+		"awinic,sw-freq", aw99706_dt_property_lookup,
+		aw99706_sw_freq_tbl, ARRAY_SIZE(aw99706_sw_freq_tbl),
+		AW99706_CFG1_REG, AW99706_SW_FREQ_MASK, 750000,
+	},
+	{
+		"awinic,sw-ilmt", aw99706_dt_property_lookup,
+		aw99706_sw_ilmt_tbl, ARRAY_SIZE(aw99706_sw_ilmt_tbl),
+		AW99706_CFG1_REG, AW99706_SW_ILMT_MASK, 3000000,
+	},
+	{
+		"awinic,iled-max", aw99706_dt_property_iled_max_convert,
+		NULL, 0,
+		AW99706_CFG2_REG, AW99706_ILED_MAX_MASK, 20000,
+
+	},
+	{
+		"awinic,uvlo-thres", aw99706_dt_property_lookup,
+		aw99706_ulvo_thres_tbl, ARRAY_SIZE(aw99706_ulvo_thres_tbl),
+		AW99706_CFG2_REG, AW99706_UVLOSEL_MASK, 2200000,
+	},
+	{
+		"awinic,ramp-ctl", aw99706_dt_property_lookup,
+		NULL, 0,
+		AW99706_CFG6_REG, AW99706_RAMP_CTL_MASK, 2,
+	}
+};
+
+struct reg_init_data {
+	u8 reg;
+	u8 mask;
+	u8 val;
+};
+
+struct aw99706_device {
+	struct i2c_client *client;
+	struct device *dev;
+	struct regmap *regmap;
+	struct backlight_device *bl_dev;
+	struct gpio_desc *hwen_gpio;
+	struct reg_init_data init_tbl[ARRAY_SIZE(aw99706_dt_props)];
+	bool bl_enable;
+};
+
+enum reg_access {
+	REG_NONE_ACCESS	= 0,
+	REG_RD_ACCESS	= 1,
+	REG_WR_ACCESS	= 2,
+};
+
+static const u8 aw99706_regs[AW99706_REG_MAX + 1] = {
+	[AW99706_CFG0_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG1_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG2_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG3_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG4_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG5_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG6_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG7_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG8_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFG9_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFGA_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFGB_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFGC_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_CFGD_REG]		= REG_RD_ACCESS | REG_WR_ACCESS,
+	[AW99706_FLAG_REG]		= REG_RD_ACCESS,
+	[AW99706_CHIPID_REG]		= REG_RD_ACCESS,
+	[AW99706_LED_OPEN_FLAG_REG]	= REG_RD_ACCESS,
+	[AW99706_LED_SHORT_FLAG_REG]	= REG_RD_ACCESS,
+
+	/*
+	 * Write bit is dropped here, writing BIT(0) to MTPLDOSEL will unlock
+	 * Multi-time Programmable (MTP).
+	 */
+	[AW99706_MTPLDOSEL_REG]		= REG_RD_ACCESS,
+	[AW99706_MTPRUN_REG]		= REG_NONE_ACCESS,
+};
+
+static bool aw99706_readable_reg(struct device *dev, unsigned int reg)
+{
+	return aw99706_regs[reg] & REG_RD_ACCESS;
+}
+
+static bool aw99706_writeable_reg(struct device *dev, unsigned int reg)
+{
+	return aw99706_regs[reg] & REG_WR_ACCESS;
+}
+
+static inline int aw99706_i2c_read(struct aw99706_device *aw, u8 reg,
+				   unsigned int *val)
+{
+	return regmap_read(aw->regmap, reg, val);
+}
+
+static inline int aw99706_i2c_write(struct aw99706_device *aw, u8 reg, u8 val)
+{
+	return regmap_write(aw->regmap, reg, val);
+}
+
+static inline int aw99706_i2c_update_bits(struct aw99706_device *aw, u8 reg,
+					  u8 mask, u8 val)
+{
+	return regmap_update_bits(aw->regmap, reg, mask, val);
+}
+
+static void aw99706_dt_parse(struct aw99706_device *aw,
+			     struct backlight_properties *bl_props)
+{
+	const struct aw99706_dt_prop *prop;
+	u32 dt_val;
+	int ret, i;
+	u8 val;
+
+	for (i = 0; i < ARRAY_SIZE(aw99706_dt_props); i++) {
+		prop = &aw99706_dt_props[i];
+		ret = device_property_read_u32(aw->dev, prop->name, &dt_val);
+		if (ret < 0)
+			dt_val = prop->def_val;
+
+		if (prop->lookup(prop, dt_val, &val)) {
+			dev_warn(aw->dev, "invalid value %d for property %s, using default value %d\n",
+				 dt_val, prop->name, prop->def_val);
+
+			prop->lookup(prop, prop->def_val, &val);
+		}
+
+		aw->init_tbl[i].reg = prop->reg;
+		aw->init_tbl[i].mask = prop->mask;
+		aw->init_tbl[i].val = val << __ffs(prop->mask);
+	}
+
+	bl_props->brightness = AW99706_MAX_BRT_LVL >> 1;
+	bl_props->max_brightness = AW99706_MAX_BRT_LVL;
+	device_property_read_u32(aw->dev, "default-brightness",
+				 &bl_props->brightness);
+	device_property_read_u32(aw->dev, "max-brightness",
+				 &bl_props->max_brightness);
+
+	if (bl_props->max_brightness > AW99706_MAX_BRT_LVL)
+		bl_props->max_brightness = AW99706_MAX_BRT_LVL;
+
+	if (bl_props->brightness > bl_props->max_brightness)
+		bl_props->brightness = bl_props->max_brightness;
+}
+
+static int aw99706_hw_init(struct aw99706_device *aw)
+{
+	int ret, i;
+
+	gpiod_set_value_cansleep(aw->hwen_gpio, 1);
+
+	for (i = 0; i < ARRAY_SIZE(aw->init_tbl); i++) {
+		ret = aw99706_i2c_update_bits(aw, aw->init_tbl[i].reg,
+					      aw->init_tbl[i].mask,
+					      aw->init_tbl[i].val);
+		if (ret < 0) {
+			dev_err(aw->dev, "Failed to write init data %d\n", ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int aw99706_bl_enable(struct aw99706_device *aw, bool en)
+{
+	int ret;
+	u8 val;
+
+	val = FIELD_PREP(AW99706_BACKLIGHT_EN_MASK, en);
+	ret = aw99706_i2c_update_bits(aw, AW99706_CFGD_REG,
+				      AW99706_BACKLIGHT_EN_MASK, val);
+	if (ret)
+		dev_err(aw->dev, "Failed to enable backlight!\n");
+
+	return ret;
+}
+
+static int aw99706_update_brightness(struct aw99706_device *aw, u32 brt_lvl)
+{
+	bool bl_enable_now = !!brt_lvl;
+	int ret;
+
+	ret = aw99706_i2c_write(aw, AW99706_CFG4_REG,
+				(brt_lvl >> 8) & AW99706_BRT_MSB_MASK);
+	if (ret < 0)
+		return ret;
+
+	ret = aw99706_i2c_write(aw, AW99706_CFG5_REG,
+				brt_lvl & AW99706_BRT_LSB_MASK);
+	if (ret < 0)
+		return ret;
+
+	if (aw->bl_enable != bl_enable_now) {
+		ret = aw99706_bl_enable(aw, bl_enable_now);
+		if (!ret)
+			aw->bl_enable = bl_enable_now;
+	}
+
+	return ret;
+}
+
+static int aw99706_bl_update_status(struct backlight_device *bl)
+{
+	struct aw99706_device *aw = bl_get_data(bl);
+
+	return aw99706_update_brightness(aw, bl->props.brightness);
+}
+
+static const struct backlight_ops aw99706_bl_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = aw99706_bl_update_status,
+};
+
+static const struct regmap_config aw99706_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = AW99706_REG_MAX,
+	.writeable_reg = aw99706_writeable_reg,
+	.readable_reg = aw99706_readable_reg,
+};
+
+static int aw99706_chip_id_read(struct aw99706_device *aw)
+{
+	int ret;
+	unsigned int val;
+
+	ret = aw99706_i2c_read(aw, AW99706_CHIPID_REG, &val);
+	if (ret < 0)
+		return ret;
+
+	return val;
+}
+
+static int aw99706_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct aw99706_device *aw;
+	struct backlight_device *bl_dev;
+	struct backlight_properties props = {};
+	int ret = 0;
+
+	aw = devm_kzalloc(dev, sizeof(*aw), GFP_KERNEL);
+	if (!aw)
+		return -ENOMEM;
+
+	aw->client = client;
+	aw->dev = dev;
+	i2c_set_clientdata(client, aw);
+
+	aw->regmap = devm_regmap_init_i2c(client, &aw99706_regmap_config);
+	if (IS_ERR(aw->regmap))
+		return dev_err_probe(dev, PTR_ERR(aw->regmap),
+				     "Failed to init regmap\n");
+
+	ret = aw99706_chip_id_read(aw);
+	if (ret != AW99706_ID)
+		return dev_err_probe(dev, -ENODEV,
+				     "Unknown chip id 0x%02x\n", ret);
+
+	aw99706_dt_parse(aw, &props);
+
+	aw->hwen_gpio = devm_gpiod_get(aw->dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(aw->hwen_gpio))
+		return dev_err_probe(dev, PTR_ERR(aw->hwen_gpio),
+				     "Failed to get enable gpio\n");
+
+	ret = aw99706_hw_init(aw);
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "Failed to initialize the chip\n");
+
+	props.type = BACKLIGHT_RAW;
+	props.scale = BACKLIGHT_SCALE_LINEAR;
+
+	bl_dev = devm_backlight_device_register(dev, "aw99706-backlight", dev,
+						aw, &aw99706_bl_ops, &props);
+	if (IS_ERR(bl_dev))
+		return dev_err_probe(dev, PTR_ERR(bl_dev),
+				     "Failed to register backlight!\n");
+
+	aw->bl_dev = bl_dev;
+
+	return 0;
+}
+
+static void aw99706_remove(struct i2c_client *client)
+{
+	struct aw99706_device *aw = i2c_get_clientdata(client);
+
+	aw99706_update_brightness(aw, 0);
+
+	msleep(50);
+
+	gpiod_set_value_cansleep(aw->hwen_gpio, 0);
+}
+
+static int aw99706_suspend(struct device *dev)
+{
+	struct aw99706_device *aw = dev_get_drvdata(dev);
+
+	return aw99706_update_brightness(aw, 0);
+}
+
+static int aw99706_resume(struct device *dev)
+{
+	struct aw99706_device *aw = dev_get_drvdata(dev);
+
+	return aw99706_hw_init(aw);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(aw99706_pm_ops, aw99706_suspend, aw99706_resume);
+
+static const struct i2c_device_id aw99706_ids[] = {
+	{ "aw99706" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, aw99706_ids);
+
+static const struct of_device_id aw99706_match_table[] = {
+	{ .compatible = "awinic,aw99706", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aw99706_match_table);
+
+static struct i2c_driver aw99706_i2c_driver = {
+	.probe = aw99706_probe,
+	.remove = aw99706_remove,
+	.id_table = aw99706_ids,
+	.driver = {
+		.name = "aw99706",
+		.of_match_table = aw99706_match_table,
+		.pm = pm_ptr(&aw99706_pm_ops),
+	},
+};
+
+module_i2c_driver(aw99706_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BackLight driver for aw99706");

drivers/video/backlight/led_bl.c

···
 	}
 
 	for (i = 0; i < priv->nb_leds; i++) {
+		struct device_link *link;
+
+		link = device_link_add(&pdev->dev, priv->leds[i]->dev->parent,
+				       DL_FLAG_AUTOREMOVE_CONSUMER);
+		if (!link) {
+			dev_err(&pdev->dev, "Failed to add devlink (consumer %s, supplier %s)\n",
+				dev_name(&pdev->dev), dev_name(priv->leds[i]->dev->parent));
+			backlight_device_unregister(priv->bl_dev);
+			return -EINVAL;
+		}
+	}
+
+	for (i = 0; i < priv->nb_leds; i++) {
 		mutex_lock(&priv->leds[i]->led_access);
 		led_sysfs_disable(priv->leds[i]);
 		mutex_unlock(&priv->leds[i]->led_access);

include/linux/backlight.h

···
 #define _LINUX_BACKLIGHT_H
 
 #include <linux/device.h>
-#include <linux/fb.h>
 #include <linux/mutex.h>
 #include <linux/types.h>
 

include/linux/platform_data/lp855x.h

···
 };
 
 /**
- * struct lp855x_platform_data
+ * struct lp855x_platform_data - lp855 platform-specific data
  * @name : Backlight driver name. If it is not defined, default name is set.
  * @device_control : value of DEVICE CONTROL register
  * @initial_brightness : initial value of backlight brightness
  * @period_ns : platform specific pwm period value. unit is nano.
-		Only valid when mode is PWM_BASED.
+ *		Only valid when mode is PWM_BASED.
  * @size_program : total size of lp855x_rom_data
  * @rom_data : list of new eeprom/eprom registers
  */