Merge tag 'backlight-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "New Drivers:
   - Add support for Kinetic KTZ8866 Backlight

  Removed Drivers:
   - Toshiba Sharp SL-6000 LCD and Backlight

  Fix-ups:
   - Provide some profiling optimisations with respect to
     pwm_get_state() and pwm_apply_state()
   - Make use of the dev_err_probe() API
   - Provide some Device Tree documentation additions / adaptions
   - Drop fall-back legacy PWM probing support
   - Convert over to new I2C probing API
   - Fix incorrect documentation
   - Make use of backlight_get_brightness() API

  Bug Fixes:
   - Fix disabling backlight on i.MX6 when inverted PWMs are used"

* tag 'backlight-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: ktz8866: Convert to i2c's .probe_new()
  backlight: ktz8866: Add support for Kinetic KTZ8866 backlight
  dt-bindings: leds: backlight: Add Kinetic KTZ8866 backlight
  backlight: pwm_bl: Don't rely on a disabled PWM emiting inactive state
  backlight: pwm_bl: Configure pwm only once per backlight toggle
  backlight: Remove pxa tosa support
  backlight: aat2870: Use backlight helper
  backlight: ipaq_micro: Use backlight helper
  backlight: arcxcnn: Use backlight helper
  backlight: sky81452: Fix sky81452_bl_platform_data kernel-doc
  backlight: pwm_bl: Drop support for legacy PWM probing
  dt-bindings: backlight: qcom-wled: Add PMI8950 compatible
  backlight: ktd253: Switch to use dev_err_probe() helper
  backlight: backlight: Fix doc for backlight_device_get_by_name

Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/backlight/kinetic,ktz8866.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Kinetic Technologies KTZ8866 backlight
+
+maintainers:
+  - Jianhua Lu <lujianhua000@gmail.com>
+
+description: |
+  The Kinetic Technologies KTZ8866 is a high efficiency 6-channels-current-sinks
+  led backlight with dual lcd bias power.
+  https://www.kinet-ic.com/ktz8866/
+
+allOf:
+  - $ref: common.yaml#
+
+properties:
+  compatible:
+    const: kinetic,ktz8866
+
+  vddpos-supply:
+    description: positive boost supply regulator.
+
+  vddneg-supply:
+    description: negative boost supply regulator.
+
+  enable-gpios:
+    description: GPIO to use to enable/disable the backlight (HWEN pin).
+    maxItems: 1
+
+  current-num-sinks:
+    description: number of the LED current sinks' channels.
+    enum: [1, 2, 3, 4, 5, 6]
+
+  kinetic,current-ramp-delay-ms:
+    description: |
+      LED current ramping delay time in milliseconds, note that the
+      case 1 will be mapped to 1μs.
+    enum: [1, 2, 4, 8, 16, 32, 64, 128, 192, 256, 320, 384, 448, 512, 576, 640]
+
+  kinetic,led-enable-ramp-delay-ms:
+    description: |
+      LED on/off ramping delay time in milliseconds, note that the case 0 will be
+      mapped to 512μs because ktz8866 can't ramp faster than it.
+    enum: [0, 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384]
+
+  kinetic,enable-lcd-bias:
+    description: Set if we want to output bias power supply for LCD.
+    type: boolean
+
+required:
+  - compatible
+  - vddpos-supply
+  - vddneg-supply
+  - enable-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    backlight {
+        compatible = "kinetic,ktz8866";
+
+        vddpos-supply = <&bl_vddpos_5p5>;
+        vddneg-supply = <&bl_vddneg_5p5>;
+        enable-gpios = <&tlmm 139 GPIO_ACTIVE_HIGH>;
+        current-num-sinks = <5>;
+        kinetic,current-ramp-delay-ms = <128>;
+        kinetic,led-enable-ramp-delay-ms = <1>;
+        kinetic,enable-lcd-bias;
+    };

Documentation/devicetree/bindings/leds/backlight/qcom-wled.yaml

@@ -19,6 +19,7 @@ properties:
   compatible:
     enum:
       - qcom,pm8941-wled
+      - qcom,pmi8950-wled
       - qcom,pmi8994-wled
       - qcom,pmi8998-wled
       - qcom,pm660l-wled

MAINTAINERS

@@ -11572,6 +11572,12 @@ M:	John Hawley <warthog9@eaglescrag.net>
 S:	Maintained
 F:	tools/testing/ktest
 
+KTZ8866 BACKLIGHT DRIVER
+M:	Jianhua Lu <lujianhua000@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/kinetic,ktz8866.yaml
+F:	drivers/video/backlight/ktz8866.c
+
 L3MDEV
 M:	David Ahern <dsahern@kernel.org>
 L:	netdev@vger.kernel.org

drivers/video/backlight/Kconfig

@@ -90,13 +90,6 @@ config LCD_PLATFORM
 	  This driver provides a platform-device registered LCD power
 	  control interface.
 
-config LCD_TOSA
-	tristate "Sharp SL-6000 LCD Driver"
-	depends on I2C && SPI && MACH_TOSA
-	help
-	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
-	  for its LCD.
-
 config LCD_HP700
 	tristate "HP Jornada 700 series LCD Driver"
 	depends on SA1100_JORNADA720_SSP && !PREEMPTION
@@ -190,6 +183,14 @@ config BACKLIGHT_KTD253
 	  which is a 1-wire GPIO-controlled backlight found in some mobile
 	  phones.
 
+config BACKLIGHT_KTZ8866
+	tristate "Backlight Driver for Kinetic KTZ8866"
+	depends on I2C
+	select REGMAP_I2C
+	help
+		Say Y to enable the backlight driver for the Kinetic KTZ8866
+		found in Xiaomi Mi Pad 5 series.
+
 config BACKLIGHT_LM3533
 	tristate "Backlight Driver for LM3533"
 	depends on MFD_LM3533
@@ -288,13 +289,6 @@ config BACKLIGHT_APPLE
 	  If you have an Intel-based Apple say Y to enable a driver for its
 	  backlight.
 
-config BACKLIGHT_TOSA
-	tristate "Sharp SL-6000 Backlight Driver"
-	depends on I2C && MACH_TOSA && LCD_TOSA
-	help
-	  If you have an Sharp SL-6000 Zaurus say Y to enable a driver
-	  for its backlight
-
 config BACKLIGHT_QCOM_WLED
 	tristate "Qualcomm PMIC WLED Driver"
 	select REGMAP

drivers/video/backlight/Makefile

@@ -15,7 +15,6 @@ obj-$(CONFIG_LCD_LTV350QV)		+= ltv350qv.o
 obj-$(CONFIG_LCD_OTM3225A)		+= otm3225a.o
 obj-$(CONFIG_LCD_PLATFORM)		+= platform_lcd.o
 obj-$(CONFIG_LCD_TDO24M)		+= tdo24m.o
-obj-$(CONFIG_LCD_TOSA)			+= tosa_lcd.o
 obj-$(CONFIG_LCD_VGG2432A4)		+= vgg2432a4.o
 
 obj-$(CONFIG_BACKLIGHT_88PM860X)	+= 88pm860x_bl.o
@@ -36,6 +35,7 @@ obj-$(CONFIG_BACKLIGHT_HP680)		+= hp680_bl.o
 obj-$(CONFIG_BACKLIGHT_HP700)		+= jornada720_bl.o
 obj-$(CONFIG_BACKLIGHT_IPAQ_MICRO)	+= ipaq_micro_bl.o
 obj-$(CONFIG_BACKLIGHT_KTD253)		+= ktd253-backlight.o
+obj-$(CONFIG_BACKLIGHT_KTZ8866)		+= ktz8866.o
 obj-$(CONFIG_BACKLIGHT_LM3533)		+= lm3533_bl.o
 obj-$(CONFIG_BACKLIGHT_LM3630A)		+= lm3630a_bl.o
 obj-$(CONFIG_BACKLIGHT_LM3639)		+= lm3639_bl.o
@@ -53,7 +53,6 @@ obj-$(CONFIG_BACKLIGHT_QCOM_WLED)	+= qcom-wled.o
 obj-$(CONFIG_BACKLIGHT_RT4831)		+= rt4831-backlight.o
 obj-$(CONFIG_BACKLIGHT_SAHARA)		+= kb3886_bl.o
 obj-$(CONFIG_BACKLIGHT_SKY81452)	+= sky81452-backlight.o
-obj-$(CONFIG_BACKLIGHT_TOSA)		+= tosa_bl.o
 obj-$(CONFIG_BACKLIGHT_TPS65217)	+= tps65217_bl.o
 obj-$(CONFIG_BACKLIGHT_WM831X)		+= wm831x_bl.o
 obj-$(CONFIG_BACKLIGHT_ARCXCNN) 	+= arcxcnn_bl.o

drivers/video/backlight/aat2870_bl.c

@@ -59,7 +59,7 @@ static int aat2870_bl_update_status(struct backlight_device *bd)
 	struct aat2870_bl_driver_data *aat2870_bl = bl_get_data(bd);
 	struct aat2870_data *aat2870 =
 			dev_get_drvdata(aat2870_bl->pdev->dev.parent);
-	int brightness = bd->props.brightness;
+	int brightness = backlight_get_brightness(bd);
 	int ret;
 
 	if ((brightness < 0) || (bd->props.max_brightness < brightness)) {
@@ -70,11 +70,6 @@ static int aat2870_bl_update_status(struct backlight_device *bd)
 	dev_dbg(&bd->dev, "brightness=%d, power=%d, state=%d\n",
 		 bd->props.brightness, bd->props.power, bd->props.state);
 
-	if ((bd->props.power != FB_BLANK_UNBLANK) ||
-			(bd->props.state & BL_CORE_FBBLANK) ||
-			(bd->props.state & BL_CORE_SUSPENDED))
-		brightness = 0;
-
 	ret = aat2870->write(aat2870, AAT2870_BLM,
 			     (u8)aat2870_brightness(aat2870_bl, brightness));
 	if (ret < 0)

drivers/video/backlight/arcxcnn_bl.c

@@ -130,12 +130,9 @@ static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness)
 static int arcxcnn_bl_update_status(struct backlight_device *bl)
 {
 	struct arcxcnn *lp = bl_get_data(bl);
-	u32 brightness = bl->props.brightness;
+	u32 brightness = backlight_get_brightness(bl);
 	int ret;
 
-	if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
-		brightness = 0;
-
 	ret = arcxcnn_set_brightness(lp, brightness);
 	if (ret)
 		return ret;

drivers/video/backlight/backlight.c

@@ -501,7 +501,7 @@ EXPORT_SYMBOL(backlight_device_get_by_type);
  *
  * This function looks up a backlight device by its name. It obtains a reference
  * on the backlight device and it is the caller's responsibility to drop the
- * reference by calling backlight_put().
+ * reference by calling put_device().
  *
  * Returns:
  * A pointer to the backlight device if found, otherwise NULL.

drivers/video/backlight/ipaq_micro_bl.c

@@ -16,17 +16,12 @@
 static int micro_bl_update_status(struct backlight_device *bd)
 {
 	struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
-	int intensity = bd->props.brightness;
+	int intensity = backlight_get_brightness(bd);
 	struct ipaq_micro_msg msg = {
 		.id = MSG_BACKLIGHT,
 		.tx_len = 3,
 	};
 
-	if (bd->props.power != FB_BLANK_UNBLANK)
-		intensity = 0;
-	if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
-		intensity = 0;
-
 	/*
 	 * Message format:
 	 * Byte 0: backlight instance (usually 1)

drivers/video/backlight/ktd253-backlight.c

@@ -173,12 +173,9 @@ static int ktd253_backlight_probe(struct platform_device *pdev)
 	}
 
 	ktd253->gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
-	if (IS_ERR(ktd253->gpiod)) {
-		ret = PTR_ERR(ktd253->gpiod);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "gpio line missing or invalid.\n");
-		return ret;
-	}
+	if (IS_ERR(ktd253->gpiod))
+		return dev_err_probe(dev, PTR_ERR(ktd253->gpiod),
+				     "gpio line missing or invalid.\n");
 	gpiod_set_consumer_name(ktd253->gpiod, dev_name(dev));
 	/* Bring backlight to a known off state */
 	msleep(KTD253_T_OFF_MS);

drivers/video/backlight/ktz8866.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Backlight driver for the Kinetic KTZ8866
+ *
+ * Copyright (C) 2022, 2023 Jianhua Lu <lujianhua000@gmail.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+#define DEFAULT_BRIGHTNESS 1500
+#define MAX_BRIGHTNESS 2047
+#define REG_MAX 0x15
+
+/* reg */
+#define DEVICE_ID 0x01
+#define BL_CFG1 0x02
+#define BL_CFG2 0x03
+#define BL_BRT_LSB 0x04
+#define BL_BRT_MSB 0x05
+#define BL_EN 0x08
+#define LCD_BIAS_CFG1 0x09
+#define LCD_BIAS_CFG2 0x0A
+#define LCD_BIAS_CFG3 0x0B
+#define LCD_BOOST_CFG 0x0C
+#define OUTP_CFG 0x0D
+#define OUTN_CFG 0x0E
+#define FLAG 0x0F
+#define BL_OPTION1 0x10
+#define BL_OPTION2 0x11
+#define PWM2DIG_LSBs 0x12
+#define PWM2DIG_MSBs 0x13
+#define BL_DIMMING 0x14
+#define PWM_RAMP_TIME 0x15
+
+/* definition */
+#define BL_EN_BIT BIT(6)
+#define LCD_BIAS_EN 0x9F
+#define PWM_HYST 0x5
+
+struct ktz8866 {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	bool led_on;
+	struct gpio_desc *enable_gpio;
+};
+
+static const struct regmap_config ktz8866_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_MAX,
+};
+
+static int ktz8866_write(struct ktz8866 *ktz, unsigned int reg,
+			 unsigned int val)
+{
+	return regmap_write(ktz->regmap, reg, val);
+}
+
+static int ktz8866_update_bits(struct ktz8866 *ktz, unsigned int reg,
+			       unsigned int mask, unsigned int val)
+{
+	return regmap_update_bits(ktz->regmap, reg, mask, val);
+}
+
+static int ktz8866_backlight_update_status(struct backlight_device *backlight_dev)
+{
+	struct ktz8866 *ktz = bl_get_data(backlight_dev);
+	unsigned int brightness = backlight_get_brightness(backlight_dev);
+
+	if (!ktz->led_on && brightness > 0) {
+		ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, BL_EN_BIT);
+		ktz->led_on = true;
+	} else if (brightness == 0) {
+		ktz8866_update_bits(ktz, BL_EN, BL_EN_BIT, 0);
+		ktz->led_on = false;
+	}
+
+	/* Set brightness */
+	ktz8866_write(ktz, BL_BRT_LSB, brightness & 0x7);
+	ktz8866_write(ktz, BL_BRT_MSB, (brightness >> 3) & 0xFF);
+
+	return 0;
+}
+
+static const struct backlight_ops ktz8866_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = ktz8866_backlight_update_status,
+};
+
+static void ktz8866_init(struct ktz8866 *ktz)
+{
+	unsigned int val = 0;
+
+	if (of_property_read_u32(ktz->client->dev.of_node, "current-num-sinks", &val))
+		ktz8866_write(ktz, BL_EN, BIT(val) - 1);
+	else
+		/* Enable all 6 current sinks if the number of current sinks isn't specified. */
+		ktz8866_write(ktz, BL_EN, BIT(6) - 1);
+
+	if (of_property_read_u32(ktz->client->dev.of_node, "kinetic,current-ramp-delay-ms", &val)) {
+		if (val <= 128)
+			ktz8866_write(ktz, BL_CFG2, BIT(7) | (ilog2(val) << 3) | PWM_HYST);
+		else
+			ktz8866_write(ktz, BL_CFG2, BIT(7) | ((5 + val / 64) << 3) | PWM_HYST);
+	}
+
+	if (of_property_read_u32(ktz->client->dev.of_node, "kinetic,led-enable-ramp-delay-ms", &val)) {
+		if (val == 0)
+			ktz8866_write(ktz, BL_DIMMING, 0);
+		else {
+			unsigned int ramp_off_time = ilog2(val) + 1;
+			unsigned int ramp_on_time = ramp_off_time << 4;
+			ktz8866_write(ktz, BL_DIMMING, ramp_on_time | ramp_off_time);
+		}
+	}
+
+	if (of_property_read_bool(ktz->client->dev.of_node, "kinetic,enable-lcd-bias"))
+		ktz8866_write(ktz, LCD_BIAS_CFG1, LCD_BIAS_EN);
+}
+
+static int ktz8866_probe(struct i2c_client *client)
+{
+	struct backlight_device *backlight_dev;
+	struct backlight_properties props;
+	struct ktz8866 *ktz;
+	int ret = 0;
+
+	ktz = devm_kzalloc(&client->dev, sizeof(*ktz), GFP_KERNEL);
+	if (!ktz)
+		return -ENOMEM;
+
+	ktz->client = client;
+	ktz->regmap = devm_regmap_init_i2c(client, &ktz8866_regmap_config);
+	if (IS_ERR(ktz->regmap))
+		return dev_err_probe(&client->dev, PTR_ERR(ktz->regmap), "failed to init regmap\n");
+
+	ret = devm_regulator_get_enable(&client->dev, "vddpos");
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "get regulator vddpos failed\n");
+	ret = devm_regulator_get_enable(&client->dev, "vddneg");
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "get regulator vddneg failed\n");
+
+	ktz->enable_gpio = devm_gpiod_get_optional(&client->dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(ktz->enable_gpio))
+		return PTR_ERR(ktz->enable_gpio);
+
+	memset(&props, 0, sizeof(props));
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = MAX_BRIGHTNESS;
+	props.brightness = DEFAULT_BRIGHTNESS;
+	props.scale = BACKLIGHT_SCALE_LINEAR;
+
+	backlight_dev = devm_backlight_device_register(&client->dev, "ktz8866-backlight",
+					&client->dev, ktz, &ktz8866_backlight_ops, &props);
+	if (IS_ERR(backlight_dev))
+		return dev_err_probe(&client->dev, PTR_ERR(backlight_dev),
+				"failed to register backlight device\n");
+
+	ktz8866_init(ktz);
+
+	i2c_set_clientdata(client, backlight_dev);
+	backlight_update_status(backlight_dev);
+
+	return 0;
+}
+
+static void ktz8866_remove(struct i2c_client *client)
+{
+	struct backlight_device *backlight_dev = i2c_get_clientdata(client);
+	backlight_dev->props.brightness = 0;
+	backlight_update_status(backlight_dev);
+}
+
+static const struct i2c_device_id ktz8866_ids[] = {
+	{ "ktz8866", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, ktz8866_ids);
+
+static const struct of_device_id ktz8866_match_table[] = {
+	{
+		.compatible = "kinetic,ktz8866",
+	},
+	{},
+};
+
+static struct i2c_driver ktz8866_driver = {
+	.driver = {
+		.name = "ktz8866",
+		.of_match_table = ktz8866_match_table,
+	},
+	.probe_new = ktz8866_probe,
+	.remove = ktz8866_remove,
+	.id_table = ktz8866_ids,
+};
+
+module_i2c_driver(ktz8866_driver);
+
+MODULE_DESCRIPTION("Kinetic KTZ8866 Backlight Driver");
+MODULE_AUTHOR("Jianhua Lu <lujianhua000@gmail.com>");
+MODULE_LICENSE("GPL");

drivers/video/backlight/pwm_bl.c

@@ -28,7 +28,6 @@ struct pwm_bl_data {
 	struct regulator	*power_supply;
 	struct gpio_desc	*enable_gpio;
 	unsigned int		scale;
-	bool			legacy;
 	unsigned int		post_pwm_on_delay;
 	unsigned int		pwm_off_delay;
 	int			(*notify)(struct device *,
@@ -41,19 +40,16 @@ struct pwm_bl_data {
 
 static void pwm_backlight_power_on(struct pwm_bl_data *pb)
 {
-	struct pwm_state state;
 	int err;
 
-	pwm_get_state(pb->pwm, &state);
 	if (pb->enabled)
 		return;
 
-	err = regulator_enable(pb->power_supply);
-	if (err < 0)
-		dev_err(pb->dev, "failed to enable power supply\n");
-
-	state.enabled = true;
-	pwm_apply_state(pb->pwm, &state);
+	if (pb->power_supply) {
+		err = regulator_enable(pb->power_supply);
+		if (err < 0)
+			dev_err(pb->dev, "failed to enable power supply\n");
+	}
 
 	if (pb->post_pwm_on_delay)
 		msleep(pb->post_pwm_on_delay);
@@ -66,9 +62,6 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb)
 
 static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 {
-	struct pwm_state state;
-
-	pwm_get_state(pb->pwm, &state);
 	if (!pb->enabled)
 		return;
 
@@ -78,28 +71,22 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 	if (pb->pwm_off_delay)
 		msleep(pb->pwm_off_delay);
 
-	state.enabled = false;
-	state.duty_cycle = 0;
-	pwm_apply_state(pb->pwm, &state);
-
-	regulator_disable(pb->power_supply);
+	if (pb->power_supply)
+		regulator_disable(pb->power_supply);
 	pb->enabled = false;
 }
 
-static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness)
+static int compute_duty_cycle(struct pwm_bl_data *pb, int brightness, struct pwm_state *state)
 {
 	unsigned int lth = pb->lth_brightness;
-	struct pwm_state state;
 	u64 duty_cycle;
 
-	pwm_get_state(pb->pwm, &state);
-
 	if (pb->levels)
 		duty_cycle = pb->levels[brightness];
 	else
 		duty_cycle = brightness;
 
-	duty_cycle *= state.period - lth;
+	duty_cycle *= state->period - lth;
 	do_div(duty_cycle, pb->scale);
 
 	return duty_cycle + lth;
@@ -116,11 +103,26 @@ static int pwm_backlight_update_status(struct backlight_device *bl)
 
 	if (brightness > 0) {
 		pwm_get_state(pb->pwm, &state);
-		state.duty_cycle = compute_duty_cycle(pb, brightness);
+		state.duty_cycle = compute_duty_cycle(pb, brightness, &state);
+		state.enabled = true;
 		pwm_apply_state(pb->pwm, &state);
+
 		pwm_backlight_power_on(pb);
 	} else {
 		pwm_backlight_power_off(pb);
+
+		pwm_get_state(pb->pwm, &state);
+		state.duty_cycle = 0;
+		/*
+		 * We cannot assume a disabled PWM to drive its output to the
+		 * inactive state. If we have an enable GPIO and/or a regulator
+		 * we assume that this isn't relevant and we can disable the PWM
+		 * to save power. If however there is neither an enable GPIO nor
+		 * a regulator keep the PWM on be sure to get a constant
+		 * inactive output.
+		 */
+		state.enabled = !pb->power_supply && !pb->enable_gpio;
+		pwm_apply_state(pb->pwm, &state);
 	}
 
 	if (pb->notify_after)
@@ -417,7 +419,7 @@ static int pwm_backlight_initial_power_state(const struct pwm_bl_data *pb)
 	if (pb->enable_gpio && gpiod_get_value_cansleep(pb->enable_gpio) == 0)
 		active = false;
 
-	if (!regulator_is_enabled(pb->power_supply))
+	if (pb->power_supply && !regulator_is_enabled(pb->power_supply))
 		active = false;
 
 	if (!pwm_is_enabled(pb->pwm))
@@ -455,7 +457,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	struct platform_pwm_backlight_data defdata;
 	struct backlight_properties props;
 	struct backlight_device *bl;
-	struct device_node *node = pdev->dev.of_node;
 	struct pwm_bl_data *pb;
 	struct pwm_state state;
 	unsigned int i;
@@ -499,19 +500,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		goto err_alloc;
 	}
 
-	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
+	pb->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
 	if (IS_ERR(pb->power_supply)) {
 		ret = PTR_ERR(pb->power_supply);
-		goto err_alloc;
+		if (ret == -ENODEV)
+			pb->power_supply = NULL;
+		else
+			goto err_alloc;
 	}
 
 	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");
-		pb->legacy = true;
-		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
-	}
-
 	if (IS_ERR(pb->pwm)) {
 		ret = PTR_ERR(pb->pwm);
 		if (ret != -EPROBE_DEFER)
@@ -604,8 +602,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	if (IS_ERR(bl)) {
 		dev_err(&pdev->dev, "failed to register backlight\n");
 		ret = PTR_ERR(bl);
-		if (pb->legacy)
-			pwm_free(pb->pwm);
 		goto err_alloc;
 	}
 
@@ -639,8 +635,6 @@ static int pwm_backlight_remove(struct platform_device *pdev)
 
 	if (pb->exit)
 		pb->exit(&pdev->dev);
-	if (pb->legacy)
-		pwm_free(pb->pwm);
 
 	return 0;
 }

drivers/video/backlight/sky81452-backlight.c

@@ -41,7 +41,7 @@
 #define SKY81452_MAX_BRIGHTNESS	(SKY81452_CS + 1)
 
 /**
- * struct sky81452_platform_data
+ * struct sky81452_bl_platform_data - backlight platform data
  * @name:	backlight driver name.
  *		If it is not defined, default name is lcd-backlight.
  * @gpiod_enable:GPIO descriptor which control EN pin

drivers/video/backlight/tosa_bl.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  LCD / Backlight control code for Sharp SL-6000x (tosa)
- *
- *  Copyright (c) 2005		Dirk Opfer
- *  Copyright (c) 2007,2008	Dmitry Baryshkov
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/spi/spi.h>
-#include <linux/i2c.h>
-#include <linux/gpio/consumer.h>
-#include <linux/fb.h>
-#include <linux/backlight.h>
-#include <linux/slab.h>
-
-#include <asm/mach/sharpsl_param.h>
-
-#include "tosa_bl.h"
-
-#define COMADJ_DEFAULT	97
-
-#define DAC_CH1		0
-#define DAC_CH2		1
-
-struct tosa_bl_data {
-	struct i2c_client *i2c;
-	struct backlight_device *bl;
-	struct gpio_desc *gpio;
-
-	int comadj;
-};
-
-static void tosa_bl_set_backlight(struct tosa_bl_data *data, int brightness)
-{
-	struct spi_device *spi = dev_get_platdata(&data->i2c->dev);
-
-	i2c_smbus_write_byte_data(data->i2c, DAC_CH1, data->comadj);
-
-	/* SetBacklightDuty */
-	i2c_smbus_write_byte_data(data->i2c, DAC_CH2, (u8)(brightness & 0xff));
-
-	/* SetBacklightVR */
-	gpiod_set_value(data->gpio, brightness & 0x100);
-
-	tosa_bl_enable(spi, brightness);
-}
-
-static int tosa_bl_update_status(struct backlight_device *dev)
-{
-	struct backlight_properties *props = &dev->props;
-	struct tosa_bl_data *data = bl_get_data(dev);
-	int power = max(props->power, props->fb_blank);
-	int brightness = props->brightness;
-
-	if (power)
-		brightness = 0;
-
-	tosa_bl_set_backlight(data, brightness);
-
-	return 0;
-}
-
-static int tosa_bl_get_brightness(struct backlight_device *dev)
-{
-	struct backlight_properties *props = &dev->props;
-
-	return props->brightness;
-}
-
-static const struct backlight_ops bl_ops = {
-	.get_brightness		= tosa_bl_get_brightness,
-	.update_status		= tosa_bl_update_status,
-};
-
-static int tosa_bl_probe(struct i2c_client *client)
-{
-	struct backlight_properties props;
-	struct tosa_bl_data *data;
-	int ret = 0;
-
-	data = devm_kzalloc(&client->dev, sizeof(struct tosa_bl_data),
-				GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	data->comadj = sharpsl_param.comadj == -1 ? COMADJ_DEFAULT : sharpsl_param.comadj;
-	data->gpio = devm_gpiod_get(&client->dev, "backlight", GPIOD_OUT_LOW);
-	ret = PTR_ERR_OR_ZERO(data->gpio);
-	if (ret) {
-		dev_dbg(&data->bl->dev, "Unable to request gpio!\n");
-		return ret;
-	}
-
-	i2c_set_clientdata(client, data);
-	data->i2c = client;
-
-	memset(&props, 0, sizeof(struct backlight_properties));
-	props.type = BACKLIGHT_RAW;
-	props.max_brightness = 512 - 1;
-	data->bl = devm_backlight_device_register(&client->dev, "tosa-bl",
-						&client->dev, data, &bl_ops,
-						&props);
-	if (IS_ERR(data->bl)) {
-		ret = PTR_ERR(data->bl);
-		goto err_reg;
-	}
-
-	data->bl->props.brightness = 69;
-	data->bl->props.power = FB_BLANK_UNBLANK;
-
-	backlight_update_status(data->bl);
-
-	return 0;
-
-err_reg:
-	data->bl = NULL;
-	return ret;
-}
-
-static void tosa_bl_remove(struct i2c_client *client)
-{
-	struct tosa_bl_data *data = i2c_get_clientdata(client);
-
-	data->bl = NULL;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int tosa_bl_suspend(struct device *dev)
-{
-	struct tosa_bl_data *data = dev_get_drvdata(dev);
-
-	tosa_bl_set_backlight(data, 0);
-
-	return 0;
-}
-
-static int tosa_bl_resume(struct device *dev)
-{
-	struct tosa_bl_data *data = dev_get_drvdata(dev);
-
-	backlight_update_status(data->bl);
-	return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(tosa_bl_pm_ops, tosa_bl_suspend, tosa_bl_resume);
-
-static const struct i2c_device_id tosa_bl_id[] = {
-	{ "tosa-bl", 0 },
-	{ },
-};
-MODULE_DEVICE_TABLE(i2c, tosa_bl_id);
-
-static struct i2c_driver tosa_bl_driver = {
-	.driver = {
-		.name		= "tosa-bl",
-		.pm		= &tosa_bl_pm_ops,
-	},
-	.probe_new	= tosa_bl_probe,
-	.remove		= tosa_bl_remove,
-	.id_table	= tosa_bl_id,
-};
-
-module_i2c_driver(tosa_bl_driver);
-
-MODULE_AUTHOR("Dmitry Baryshkov");
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
-

drivers/video/backlight/tosa_bl.h

-/* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef _TOSA_BL_H
-#define _TOSA_BL_H
-
-struct spi_device;
-extern int tosa_bl_enable(struct spi_device *spi, int enable);
-
-#endif

drivers/video/backlight/tosa_lcd.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  LCD / Backlight control code for Sharp SL-6000x (tosa)
- *
- *  Copyright (c) 2005		Dirk Opfer
- *  Copyright (c) 2007,2008	Dmitry Baryshkov
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/spi/spi.h>
-#include <linux/i2c.h>
-#include <linux/slab.h>
-#include <linux/gpio/consumer.h>
-#include <linux/delay.h>
-#include <linux/lcd.h>
-#include <linux/fb.h>
-
-#include <asm/mach/sharpsl_param.h>
-
-#include "tosa_bl.h"
-
-#define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
-
-#define TG_REG0_VQV	0x0001
-#define TG_REG0_COLOR	0x0002
-#define TG_REG0_UD	0x0004
-#define TG_REG0_LR	0x0008
-
-/*
- * Timing Generator
- */
-#define TG_PNLCTL 	0x00
-#define TG_TPOSCTL 	0x01
-#define TG_DUTYCTL 	0x02
-#define TG_GPOSR 	0x03
-#define TG_GPODR1 	0x04
-#define TG_GPODR2 	0x05
-#define TG_PINICTL 	0x06
-#define TG_HPOSCTL 	0x07
-
-
-#define	DAC_BASE	0x4e
-
-struct tosa_lcd_data {
-	struct spi_device *spi;
-	struct lcd_device *lcd;
-	struct i2c_client *i2c;
-	struct gpio_desc *gpiod_tg;
-
-	int lcd_power;
-	bool is_vga;
-};
-
-static int tosa_tg_send(struct spi_device *spi, int adrs, uint8_t data)
-{
-	u8 buf[1];
-	struct spi_message msg;
-	struct spi_transfer xfer = {
-		.len		= 1,
-		.cs_change	= 0,
-		.tx_buf		= buf,
-	};
-
-	buf[0] = ((adrs & 0x07) << 5) | (data & 0x1f);
-	spi_message_init(&msg);
-	spi_message_add_tail(&xfer, &msg);
-
-	return spi_sync(spi, &msg);
-}
-
-int tosa_bl_enable(struct spi_device *spi, int enable)
-{
-	/* bl_enable GP04=1 otherwise GP04=0*/
-	return tosa_tg_send(spi, TG_GPODR2, enable ? 0x01 : 0x00);
-}
-EXPORT_SYMBOL(tosa_bl_enable);
-
-static void tosa_lcd_tg_init(struct tosa_lcd_data *data)
-{
-	/* TG on */
-	gpiod_set_value(data->gpiod_tg, 0);
-
-	mdelay(60);
-
-	/* delayed 0clk TCTL signal for VGA */
-	tosa_tg_send(data->spi, TG_TPOSCTL, 0x00);
-	/* GPOS0=powercontrol, GPOS1=GPIO, GPOS2=TCTL */
-	tosa_tg_send(data->spi, TG_GPOSR, 0x02);
-}
-
-static void tosa_lcd_tg_on(struct tosa_lcd_data *data)
-{
-	struct spi_device *spi = data->spi;
-	int value = TG_REG0_COLOR | TG_REG0_UD | TG_REG0_LR;
-
-	if (data->is_vga)
-		value |= TG_REG0_VQV;
-
-	tosa_tg_send(spi, TG_PNLCTL, value);
-
-	/* TG LCD pannel power up */
-	tosa_tg_send(spi, TG_PINICTL, 0x4);
-	mdelay(50);
-
-	/* TG LCD GVSS */
-	tosa_tg_send(spi, TG_PINICTL, 0x0);
-
-	if (IS_ERR_OR_NULL(data->i2c)) {
-		/*
-		 * after the pannel is powered up the first time,
-		 * we can access the i2c bus so probe for the DAC
-		 */
-		struct i2c_adapter *adap = i2c_get_adapter(0);
-		struct i2c_board_info info = {
-			.dev_name = "tosa-bl",
-			.type	= "tosa-bl",
-			.addr	= DAC_BASE,
-			.platform_data = data->spi,
-		};
-		data->i2c = i2c_new_client_device(adap, &info);
-	}
-}
-
-static void tosa_lcd_tg_off(struct tosa_lcd_data *data)
-{
-	struct spi_device *spi = data->spi;
-
-	/* TG LCD VHSA off */
-	tosa_tg_send(spi, TG_PINICTL, 0x4);
-	mdelay(50);
-
-	/* TG LCD signal off */
-	tosa_tg_send(spi, TG_PINICTL, 0x6);
-	mdelay(50);
-
-	/* TG Off */
-	gpiod_set_value(data->gpiod_tg, 1);
-	mdelay(100);
-}
-
-int tosa_lcd_set_power(struct lcd_device *lcd, int power)
-{
-	struct tosa_lcd_data *data = lcd_get_data(lcd);
-
-	if (POWER_IS_ON(power) && !POWER_IS_ON(data->lcd_power))
-		tosa_lcd_tg_on(data);
-
-	if (!POWER_IS_ON(power) && POWER_IS_ON(data->lcd_power))
-		tosa_lcd_tg_off(data);
-
-	data->lcd_power = power;
-	return 0;
-}
-
-static int tosa_lcd_get_power(struct lcd_device *lcd)
-{
-	struct tosa_lcd_data *data = lcd_get_data(lcd);
-
-	return data->lcd_power;
-}
-
-static int tosa_lcd_set_mode(struct lcd_device *lcd, struct fb_videomode *mode)
-{
-	struct tosa_lcd_data *data = lcd_get_data(lcd);
-
-	if (mode->xres == 320 || mode->yres == 320)
-		data->is_vga = false;
-	else
-		data->is_vga = true;
-
-	if (POWER_IS_ON(data->lcd_power))
-		tosa_lcd_tg_on(data);
-
-	return 0;
-}
-
-static struct lcd_ops tosa_lcd_ops = {
-	.set_power = tosa_lcd_set_power,
-	.get_power = tosa_lcd_get_power,
-	.set_mode = tosa_lcd_set_mode,
-};
-
-static int tosa_lcd_probe(struct spi_device *spi)
-{
-	int ret;
-	struct tosa_lcd_data *data;
-
-	data = devm_kzalloc(&spi->dev, sizeof(struct tosa_lcd_data),
-				GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
-
-	data->is_vga = true; /* default to VGA mode */
-
-	/*
-	 * bits_per_word cannot be configured in platform data
-	 */
-	spi->bits_per_word = 8;
-
-	ret = spi_setup(spi);
-	if (ret < 0)
-		return ret;
-
-	data->spi = spi;
-	spi_set_drvdata(spi, data);
-
-	data->gpiod_tg = devm_gpiod_get(&spi->dev, "tg #pwr", GPIOD_OUT_LOW);
-	if (IS_ERR(data->gpiod_tg))
-		return PTR_ERR(data->gpiod_tg);
-
-	mdelay(60);
-
-	tosa_lcd_tg_init(data);
-
-	tosa_lcd_tg_on(data);
-
-	data->lcd = devm_lcd_device_register(&spi->dev, "tosa-lcd", &spi->dev,
-					data, &tosa_lcd_ops);
-
-	if (IS_ERR(data->lcd)) {
-		ret = PTR_ERR(data->lcd);
-		data->lcd = NULL;
-		goto err_register;
-	}
-
-	return 0;
-
-err_register:
-	tosa_lcd_tg_off(data);
-	return ret;
-}
-
-static void tosa_lcd_remove(struct spi_device *spi)
-{
-	struct tosa_lcd_data *data = spi_get_drvdata(spi);
-
-	i2c_unregister_device(data->i2c);
-
-	tosa_lcd_tg_off(data);
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int tosa_lcd_suspend(struct device *dev)
-{
-	struct tosa_lcd_data *data = dev_get_drvdata(dev);
-
-	tosa_lcd_tg_off(data);
-
-	return 0;
-}
-
-static int tosa_lcd_resume(struct device *dev)
-{
-	struct tosa_lcd_data *data = dev_get_drvdata(dev);
-
-	tosa_lcd_tg_init(data);
-	if (POWER_IS_ON(data->lcd_power))
-		tosa_lcd_tg_on(data);
-	else
-		tosa_lcd_tg_off(data);
-
-	return 0;
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(tosa_lcd_pm_ops, tosa_lcd_suspend, tosa_lcd_resume);
-
-static struct spi_driver tosa_lcd_driver = {
-	.driver = {
-		.name		= "tosa-lcd",
-		.pm		= &tosa_lcd_pm_ops,
-	},
-	.probe		= tosa_lcd_probe,
-	.remove		= tosa_lcd_remove,
-};
-
-module_spi_driver(tosa_lcd_driver);
-
-MODULE_AUTHOR("Dmitry Baryshkov");
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("LCD/Backlight control for Sharp SL-6000 PDA");
-MODULE_ALIAS("spi:tosa-lcd");

include/linux/pwm_backlight.h

@@ -8,7 +8,6 @@
 #include <linux/backlight.h>
 
 struct platform_pwm_backlight_data {
-	int pwm_id;
 	unsigned int max_brightness;
 	unsigned int dft_brightness;
 	unsigned int lth_brightness;