Merge tag 'backlight-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "New Drivers:
   - Add support for Monolithic Power Systems MP3309C WLED Step-up Converter

  Fix-ups:
   - Use/convert to new/better APIs/helpers/MACROs instead of
     hand-rolling implementations
   - Device Tree Binding updates
   - Demote non-kerneldoc header comments
   - Improve error handling; return proper error values, simplify, avoid
     duplicates, etc
   - Convert over to the new (kinda) GPIOD API

  Bug Fixes:
   - Fix uninitialised local variable"

* tag 'backlight-next-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: hx8357: Convert to agnostic GPIO API
  backlight: ili922x: Add an error code check in ili922x_write()
  backlight: ili922x: Drop kernel-doc for local macros
  backlight: mp3309c: Fix uninitialized local variable
  backlight: pwm_bl: Use dev_err_probe
  backlight: mp3309c: Add support for MPS MP3309C
  dt-bindings: backlight: mp3309c: Remove two required properties

Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml

@@ -14,8 +14,8 @@ description: |
   programmable switching frequency to optimize efficiency.
   It supports two different dimming modes:
 
-  - analog mode, via I2C commands (default)
-  - PWM controlled mode.
+  - analog mode, via I2C commands, as default mode (32 dimming levels)
+  - PWM controlled mode (optional)
 
   The datasheet is available at:
   https://www.monolithicpower.com/en/mp3309c.html
@@ -50,8 +50,6 @@ properties:
 required:
   - compatible
   - reg
-  - max-brightness
-  - default-brightness
 
 unevaluatedProperties: false
 
@@ -66,8 +64,8 @@ examples:
             compatible = "mps,mp3309c";
             reg = <0x17>;
             pwms = <&pwm1 0 3333333 0>; /* 300 Hz --> (1/f) * 1*10^9 */
-            max-brightness = <100>;
-            default-brightness = <80>;
+            brightness-levels = <0 4 8 16 32 64 128 255>;
+            default-brightness = <6>;
             mps,overvoltage-protection-microvolt = <24000000>;
         };
     };

MAINTAINERS

@@ -14804,6 +14804,13 @@ S:	Maintained
 F:	Documentation/driver-api/tty/moxa-smartio.rst
 F:	drivers/tty/mxser.*
 
+MP3309C BACKLIGHT DRIVER
+M:	Flavio Suligoi <f.suligoi@asem.it>
+L:	dri-devel@lists.freedesktop.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/leds/backlight/mps,mp3309c.yaml
+F:	drivers/video/backlight/mp3309c.c
+
 MR800 AVERMEDIA USB FM RADIO DRIVER
 M:	Alexey Klimov <klimov.linux@gmail.com>
 L:	linux-media@vger.kernel.org

drivers/gpio/gpiolib-of.c

@@ -184,7 +184,7 @@ static void of_gpio_try_fixup_polarity(const struct device_node *np,
 		const char *propname;
 		bool active_high;
 	} gpios[] = {
-#if !IS_ENABLED(CONFIG_LCD_HX8357)
+#if IS_ENABLED(CONFIG_LCD_HX8357)
 		/*
 		 * Himax LCD controllers used incorrectly named
 		 * "gpios-reset" property and also specified wrong
@@ -478,7 +478,7 @@ static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
 		 */
 		const char *compatible;
 	} gpios[] = {
-#if !IS_ENABLED(CONFIG_LCD_HX8357)
+#if IS_ENABLED(CONFIG_LCD_HX8357)
 		/* Himax LCD controllers used "gpios-reset" */
 		{ "reset",	"gpios-reset",	"himax,hx8357" },
 		{ "reset",	"gpios-reset",	"himax,hx8369" },

drivers/video/backlight/Kconfig

@@ -395,6 +395,17 @@ config BACKLIGHT_LP8788
 	help
 	  This supports TI LP8788 backlight driver.
 
+config BACKLIGHT_MP3309C
+	tristate "Backlight Driver for MPS MP3309C"
+	depends on I2C && PWM
+	select REGMAP_I2C
+	help
+	  This supports MPS MP3309C backlight WLED driver in both PWM and
+	  analog/I2C dimming modes.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called mp3309c.
+
 config BACKLIGHT_PANDORA
 	tristate "Backlight driver for Pandora console"
 	depends on TWL4030_CORE

drivers/video/backlight/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_BACKLIGHT_LP855X)		+= lp855x_bl.o
 obj-$(CONFIG_BACKLIGHT_LP8788)		+= lp8788_bl.o
 obj-$(CONFIG_BACKLIGHT_LV5207LP)	+= lv5207lp.o
 obj-$(CONFIG_BACKLIGHT_MAX8925)		+= max8925_bl.o
+obj-$(CONFIG_BACKLIGHT_MP3309C)		+= mp3309c.o
 obj-$(CONFIG_BACKLIGHT_MT6370)		+= mt6370-backlight.o
 obj-$(CONFIG_BACKLIGHT_OMAP1)		+= omap1_bl.o
 obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o

drivers/video/backlight/hx8357.c

@@ -6,11 +6,11 @@
  */
 
 #include <linux/delay.h>
+#include <linux/gpio/consumer.h>
 #include <linux/lcd.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <linux/spi/spi.h>
 
 #define HX8357_NUM_IM_PINS	3
@@ -83,11 +83,10 @@
 #define HX8369_SET_GAMMA_CURVE_RELATED		0xe0
 
 struct hx8357_data {
-	unsigned		im_pins[HX8357_NUM_IM_PINS];
-	unsigned		reset;
+	struct gpio_descs	*im_pins;
+	struct gpio_desc	*reset;
 	struct spi_device	*spi;
 	int			state;
-	bool			use_im_pins;
 };
 
 static u8 hx8357_seq_power[] = {
@@ -321,11 +320,11 @@ static void hx8357_lcd_reset(struct lcd_device *lcdev)
 	struct hx8357_data *lcd = lcd_get_data(lcdev);
 
 	/* Reset the screen */
-	gpio_set_value(lcd->reset, 1);
+	gpiod_set_value(lcd->reset, 0);
 	usleep_range(10000, 12000);
-	gpio_set_value(lcd->reset, 0);
+	gpiod_set_value(lcd->reset, 1);
 	usleep_range(10000, 12000);
-	gpio_set_value(lcd->reset, 1);
+	gpiod_set_value(lcd->reset, 0);
 
 	/* The controller needs 120ms to recover from reset */
 	msleep(120);
@@ -340,10 +339,10 @@ static int hx8357_lcd_init(struct lcd_device *lcdev)
 	 * Set the interface selection pins to SPI mode, with three
 	 * wires
 	 */
-	if (lcd->use_im_pins) {
-		gpio_set_value_cansleep(lcd->im_pins[0], 1);
-		gpio_set_value_cansleep(lcd->im_pins[1], 0);
-		gpio_set_value_cansleep(lcd->im_pins[2], 1);
+	if (lcd->im_pins) {
+		gpiod_set_value_cansleep(lcd->im_pins->desc[0], 1);
+		gpiod_set_value_cansleep(lcd->im_pins->desc[1], 0);
+		gpiod_set_value_cansleep(lcd->im_pins->desc[2], 1);
 	}
 
 	ret = hx8357_spi_write_array(lcdev, hx8357_seq_power,
@@ -580,6 +579,7 @@ MODULE_DEVICE_TABLE(of, hx8357_dt_ids);
 
 static int hx8357_probe(struct spi_device *spi)
 {
+	struct device *dev = &spi->dev;
 	struct lcd_device *lcdev;
 	struct hx8357_data *lcd;
 	const struct of_device_id *match;
@@ -601,49 +601,19 @@ static int hx8357_probe(struct spi_device *spi)
 	if (!match || !match->data)
 		return -EINVAL;
 
-	lcd->reset = of_get_named_gpio(spi->dev.of_node, "gpios-reset", 0);
-	if (!gpio_is_valid(lcd->reset)) {
-		dev_err(&spi->dev, "Missing dt property: gpios-reset\n");
-		return -EINVAL;
-	}
-
-	ret = devm_gpio_request_one(&spi->dev, lcd->reset,
-				    GPIOF_OUT_INIT_HIGH,
-				    "hx8357-reset");
-	if (ret) {
-		dev_err(&spi->dev,
-			"failed to request gpio %d: %d\n",
-			lcd->reset, ret);
-		return -EINVAL;
-	}
+	lcd->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->reset))
+		return dev_err_probe(dev, PTR_ERR(lcd->reset), "failed to request reset GPIO\n");
+	gpiod_set_consumer_name(lcd->reset, "hx8357-reset");
 
-	if (of_property_present(spi->dev.of_node, "im-gpios")) {
-		lcd->use_im_pins = 1;
+	lcd->im_pins = devm_gpiod_get_array_optional(dev, "im", GPIOD_OUT_LOW);
+	if (IS_ERR(lcd->im_pins))
+		return dev_err_probe(dev, PTR_ERR(lcd->im_pins), "failed to request im GPIOs\n");
+	if (lcd->im_pins->ndescs < HX8357_NUM_IM_PINS)
+		return dev_err_probe(dev, -EINVAL, "not enough im GPIOs\n");
 
-		for (i = 0; i < HX8357_NUM_IM_PINS; i++) {
-			lcd->im_pins[i] = of_get_named_gpio(spi->dev.of_node,
-							    "im-gpios", i);
-			if (lcd->im_pins[i] == -EPROBE_DEFER) {
-				dev_info(&spi->dev, "GPIO requested is not here yet, deferring the probe\n");
-				return -EPROBE_DEFER;
-			}
-			if (!gpio_is_valid(lcd->im_pins[i])) {
-				dev_err(&spi->dev, "Missing dt property: im-gpios\n");
-				return -EINVAL;
-			}
-
-			ret = devm_gpio_request_one(&spi->dev, lcd->im_pins[i],
-						    GPIOF_OUT_INIT_LOW,
-						    "im_pins");
-			if (ret) {
-				dev_err(&spi->dev, "failed to request gpio %d: %d\n",
-					lcd->im_pins[i], ret);
-				return -EINVAL;
-			}
-		}
-	} else {
-		lcd->use_im_pins = 0;
-	}
+	for (i = 0; i < HX8357_NUM_IM_PINS; i++)
+		gpiod_set_consumer_name(lcd->im_pins->desc[i], "im_pins");
 
 	lcdev = devm_lcd_device_register(&spi->dev, "mxsfb", &spi->dev, lcd,
 					&hx8357_ops);

drivers/video/backlight/ili922x.c

@@ -81,7 +81,7 @@
 #define START_RW_WRITE		0
 #define START_RW_READ		1
 
-/**
+/*
  * START_BYTE(id, rs, rw)
  *
  * Set the start byte according to the required operation.
@@ -100,7 +100,7 @@
 #define START_BYTE(id, rs, rw)	\
 	(0x70 | (((id) & 0x01) << 2) | (((rs) & 0x01) << 1) | ((rw) & 0x01))
 
-/**
+/*
  * CHECK_FREQ_REG(spi_device s, spi_transfer x) - Check the frequency
  *	for the SPI transfer. According to the datasheet, the controller
  *	accept higher frequency for the GRAM transfer, but it requires
@@ -269,6 +269,10 @@ static int ili922x_write(struct spi_device *spi, u8 reg, u16 value)
 	spi_message_add_tail(&xfer_regindex, &msg);
 
 	ret = spi_sync(spi, &msg);
+	if (ret < 0) {
+		dev_err(&spi->dev, "Error sending SPI message 0x%x", ret);
+		return ret;
+	}
 
 	spi_message_init(&msg);
 	tbuf[0] = set_tx_byte(START_BYTE(ili922x_id, START_RS_REG,

drivers/video/backlight/pwm_bl.c

@@ -461,10 +461,9 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 
 	if (!data) {
 		ret = pwm_backlight_parse_dt(&pdev->dev, &defdata);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "failed to find platform data\n");
-			return ret;
-		}
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret,
+					     "failed to find platform data\n");
 
 		data = &defdata;
 	}
@@ -493,24 +492,27 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
 						  GPIOD_ASIS);
 	if (IS_ERR(pb->enable_gpio)) {
-		ret = PTR_ERR(pb->enable_gpio);
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(pb->enable_gpio),
+				    "failed to acquire enable GPIO\n");
 		goto err_alloc;
 	}
 
 	pb->power_supply = devm_regulator_get_optional(&pdev->dev, "power");
 	if (IS_ERR(pb->power_supply)) {
 		ret = PTR_ERR(pb->power_supply);
-		if (ret == -ENODEV)
+		if (ret == -ENODEV) {
 			pb->power_supply = NULL;
-		else
+		} else {
+			dev_err_probe(&pdev->dev, ret,
+				      "failed to acquire power regulator\n");
 			goto err_alloc;
 		}
+	}
 
 	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
 	if (IS_ERR(pb->pwm)) {
-		ret = PTR_ERR(pb->pwm);
-		if (ret != -EPROBE_DEFER)
-			dev_err(&pdev->dev, "unable to request PWM\n");
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(pb->pwm),
+				    "unable to request PWM\n");
 		goto err_alloc;
 	}
 
@@ -530,8 +532,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 
 	ret = pwm_apply_might_sleep(pb->pwm, &state);
 	if (ret) {
-		dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n",
-			ret);
+		dev_err_probe(&pdev->dev, ret,
+			      "failed to apply initial PWM state");
 		goto err_alloc;
 	}
 
@@ -568,7 +570,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		ret = pwm_backlight_brightness_default(&pdev->dev, data,
 						       state.period);
 		if (ret < 0) {
-			dev_err(&pdev->dev,
+			dev_err_probe(&pdev->dev, ret,
 				      "failed to setup default brightness table\n");
 			goto err_alloc;
 		}
@@ -597,8 +599,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	bl = backlight_device_register(dev_name(&pdev->dev), &pdev->dev, pb,
 				       &pwm_backlight_ops, &props);
 	if (IS_ERR(bl)) {
-		dev_err(&pdev->dev, "failed to register backlight\n");
-		ret = PTR_ERR(bl);
+		ret = dev_err_probe(&pdev->dev, PTR_ERR(bl),
+				    "failed to register backlight\n");
 		goto err_alloc;
 	}