- New Drivers

- Add support for Richtek RT4831 Backlight
 
  - New Device Support
    - Add support for Qualcomm PMI8994 WLED Backlight
 
  - Fix-ups
    - Device Tree adaptions; richtek,rt4831-backlight
    - Trivial; spelling, whitespace, etc; Kconfig
    - Use Atomic PWM API; lm3630a_bl
 
  - Bug Fixes
    - Fix Firmware Node Leak in error path; lm3630a_bl
    - Fix erroneous return codes; lm3630a_bl
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Merge tag 'backlight-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "New Drivers:
   - Add support for Richtek RT4831 Backlight

  New Device Support:
   - Add support for Qualcomm PMI8994 WLED Backlight

  Fix-ups:
   - Device Tree adaptions to richtek,rt4831-backlight
   - Trivial spelling, whitespace, etc in Kconfig
   - Use Atomic PWM API in lm3630a_bl

  Bug Fixes:
   - Fix Firmware Node Leak in error path in lm3630a_bl
   - Fix erroneous return codes in lm3630a_bl"

* tag 'backlight-next-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: lm3630a: Convert to atomic PWM API and check for errors
  backlight: lm3630a: Fix return code of .update_status() callback
  backlight: Kconfig whitespace and indentation cleanups
  video: backlight: qcom-wled: Add PMI8994 compatible
  backlight: rt4831: Adds support for Richtek RT4831 backlight
  backlight: rt4831: Adds DT binding document for Richtek RT4831 backlight
  backlight: lm3630a_bl: Put fwnode in error case during ->probe()

drivers/video/backlight/Kconfig

@@ -128,7 +128,7 @@ config LCD_HX8357
 	  If you have a HX-8357 LCD panel, say Y to enable its LCD control
 	  driver.
 
-  config LCD_OTM3225A
+config LCD_OTM3225A
 	tristate "ORISE Technology OTM3225A support"
 	depends on SPI
 	help
@@ -289,6 +289,14 @@ config BACKLIGHT_QCOM_WLED
 	  If you have the Qualcomm PMIC, say Y to enable a driver for the
 	  WLED block. Currently it supports PM8941 and PMI8998.
 
+config BACKLIGHT_RT4831
+	tristate "Richtek RT4831 Backlight Driver"
+	depends on MFD_RT4831
+	help
+	  This enables support for Richtek RT4831 Backlight driver.
+	  It's commonly used to drive the display WLED. There're four channels
+	  inisde, and each channel can provide up to 30mA current.
+
 config BACKLIGHT_SAHARA
 	tristate "Tabletkiosk Sahara Touch-iT Backlight Driver"
 	depends on X86

drivers/video/backlight/Makefile

@@ -49,6 +49,7 @@ obj-$(CONFIG_BACKLIGHT_PANDORA)		+= pandora_bl.o
 obj-$(CONFIG_BACKLIGHT_PCF50633)	+= pcf50633-backlight.o
 obj-$(CONFIG_BACKLIGHT_PWM)		+= pwm_bl.o
 obj-$(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

drivers/video/backlight/lm3630a_bl.c

@@ -52,6 +52,7 @@ struct lm3630a_chip {
 	struct gpio_desc *enable_gpio;
 	struct regmap *regmap;
 	struct pwm_device *pwmd;
+	struct pwm_state pwmd_state;
 };
 
 /* i2c access */
@@ -167,16 +168,19 @@ static int lm3630a_intr_config(struct lm3630a_chip *pchip)
 	return rval;
 }
 
-static void lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
+static int lm3630a_pwm_ctrl(struct lm3630a_chip *pchip, int br, int br_max)
 {
-	unsigned int period = pchip->pdata->pwm_period;
+	int err;
-	unsigned int duty = br * period / br_max;
 
-	pwm_config(pchip->pwmd, duty, period);
+	pchip->pwmd_state.period = pchip->pdata->pwm_period;
-	if (duty)
+
-		pwm_enable(pchip->pwmd);
+	err = pwm_set_relative_duty_cycle(&pchip->pwmd_state, br, br_max);
-	else
+	if (err)
-		pwm_disable(pchip->pwmd);
+		return err;
+
+	pchip->pwmd_state.enabled = pchip->pwmd_state.duty_cycle ? true : false;
+
+	return pwm_apply_state(pchip->pwmd, &pchip->pwmd_state);
 }
 
 /* update and get brightness */
@@ -187,11 +191,9 @@ static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0) {
+	if ((pwm_ctrl & LM3630A_PWM_BANK_A) != 0)
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
 					bl->props.max_brightness);
-		return bl->props.brightness;
-	}
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -210,8 +212,8 @@ static int lm3630a_bank_a_update_status(struct backlight_device *bl)
 	return 0;
 
 out_i2c_err:
-	dev_err(pchip->dev, "i2c failed to access\n");
+	dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
-	return bl->props.brightness;
+	return ret;
 }
 
 static int lm3630a_bank_a_get_brightness(struct backlight_device *bl)
@@ -264,11 +266,9 @@ static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 	enum lm3630a_pwm_ctrl pwm_ctrl = pchip->pdata->pwm_ctrl;
 
 	/* pwm control */
-	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0) {
+	if ((pwm_ctrl & LM3630A_PWM_BANK_B) != 0)
-		lm3630a_pwm_ctrl(pchip, bl->props.brightness,
+		return lm3630a_pwm_ctrl(pchip, bl->props.brightness,
 					bl->props.max_brightness);
-		return bl->props.brightness;
-	}
 
 	/* disable sleep */
 	ret = lm3630a_update(pchip, REG_CTRL, 0x80, 0x00);
@@ -287,8 +287,8 @@ static int lm3630a_bank_b_update_status(struct backlight_device *bl)
 	return 0;
 
 out_i2c_err:
-	dev_err(pchip->dev, "i2c failed to access REG_CTRL\n");
+	dev_err(pchip->dev, "i2c failed to access (%pe)\n", ERR_PTR(ret));
-	return bl->props.brightness;
+	return ret;
 }
 
 static int lm3630a_bank_b_get_brightness(struct backlight_device *bl)
@@ -482,9 +482,11 @@ static int lm3630a_parse_node(struct lm3630a_chip *pchip,
 
 	device_for_each_child_node(pchip->dev, node) {
 		ret = lm3630a_parse_bank(pdata, node, &seen_led_sources);
-		if (ret)
+		if (ret) {
+			fwnode_handle_put(node);
 			return ret;
 		}
+	}
 
 	return ret;
 }
@@ -563,11 +565,7 @@ static int lm3630a_probe(struct i2c_client *client,
 			return PTR_ERR(pchip->pwmd);
 		}
 
-		/*
+		pwm_init_state(pchip->pwmd, &pchip->pwmd_state);
-		 * FIXME: pwm_apply_args() should be removed when switching to
-		 * the atomic PWM API.
-		 */
-		pwm_apply_args(pchip->pwmd);
 	}
 
 	/* interrupt enable  : irq 0 is not allowed */

drivers/video/backlight/qcom-wled.c

@@ -1717,6 +1717,7 @@ static int wled_remove(struct platform_device *pdev)
 
 static const struct of_device_id wled_match_table[] = {
 	{ .compatible = "qcom,pm8941-wled", .data = (void *)3 },
+	{ .compatible = "qcom,pmi8994-wled", .data = (void *)4 },
 	{ .compatible = "qcom,pmi8998-wled", .data = (void *)4 },
 	{ .compatible = "qcom,pm660l-wled", .data = (void *)4 },
 	{ .compatible = "qcom,pm8150l-wled", .data = (void *)5 },

drivers/video/backlight/rt4831-backlight.c

@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <dt-bindings/leds/rt4831-backlight.h>
+#include <linux/backlight.h>
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define RT4831_REG_BLCFG	0x02
+#define RT4831_REG_BLDIML	0x04
+#define RT4831_REG_ENABLE	0x08
+
+#define RT4831_BLMAX_BRIGHTNESS	2048
+
+#define RT4831_BLOVP_MASK	GENMASK(7, 5)
+#define RT4831_BLOVP_SHIFT	5
+#define RT4831_BLPWMEN_MASK	BIT(0)
+#define RT4831_BLEN_MASK	BIT(4)
+#define RT4831_BLCH_MASK	GENMASK(3, 0)
+#define RT4831_BLDIML_MASK	GENMASK(2, 0)
+#define RT4831_BLDIMH_MASK	GENMASK(10, 3)
+#define RT4831_BLDIMH_SHIFT	3
+
+struct rt4831_priv {
+	struct device *dev;
+	struct regmap *regmap;
+	struct backlight_device *bl;
+};
+
+static int rt4831_bl_update_status(struct backlight_device *bl_dev)
+{
+	struct rt4831_priv *priv = bl_get_data(bl_dev);
+	int brightness = backlight_get_brightness(bl_dev);
+	unsigned int enable = brightness ? RT4831_BLEN_MASK : 0;
+	u8 v[2];
+	int ret;
+
+	if (brightness) {
+		v[0] = (brightness - 1) & RT4831_BLDIML_MASK;
+		v[1] = ((brightness - 1) & RT4831_BLDIMH_MASK) >> RT4831_BLDIMH_SHIFT;
+
+		ret = regmap_raw_write(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v));
+		if (ret)
+			return ret;
+	}
+
+	return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLEN_MASK, enable);
+
+}
+
+static int rt4831_bl_get_brightness(struct backlight_device *bl_dev)
+{
+	struct rt4831_priv *priv = bl_get_data(bl_dev);
+	unsigned int val;
+	u8 v[2];
+	int ret;
+
+	ret = regmap_read(priv->regmap, RT4831_REG_ENABLE, &val);
+	if (ret)
+		return ret;
+
+	if (!(val & RT4831_BLEN_MASK))
+		return 0;
+
+	ret = regmap_raw_read(priv->regmap, RT4831_REG_BLDIML, v, sizeof(v));
+	if (ret)
+		return ret;
+
+	ret = (v[1] << RT4831_BLDIMH_SHIFT) + (v[0] & RT4831_BLDIML_MASK) + 1;
+
+	return ret;
+}
+
+static const struct backlight_ops rt4831_bl_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = rt4831_bl_update_status,
+	.get_brightness = rt4831_bl_get_brightness,
+};
+
+static int rt4831_parse_backlight_properties(struct rt4831_priv *priv,
+					     struct backlight_properties *bl_props)
+{
+	struct device *dev = priv->dev;
+	u8 propval;
+	u32 brightness;
+	unsigned int val = 0;
+	int ret;
+
+	/* common properties */
+	ret = device_property_read_u32(dev, "max-brightness", &brightness);
+	if (ret)
+		brightness = RT4831_BLMAX_BRIGHTNESS;
+
+	bl_props->max_brightness = min_t(u32, brightness, RT4831_BLMAX_BRIGHTNESS);
+
+	ret = device_property_read_u32(dev, "default-brightness", &brightness);
+	if (ret)
+		brightness = bl_props->max_brightness;
+
+	bl_props->brightness = min_t(u32, brightness, bl_props->max_brightness);
+
+	/* vendor properties */
+	if (device_property_read_bool(dev, "richtek,pwm-enable"))
+		val = RT4831_BLPWMEN_MASK;
+
+	ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLPWMEN_MASK, val);
+	if (ret)
+		return ret;
+
+	ret = device_property_read_u8(dev, "richtek,bled-ovp-sel", &propval);
+	if (ret)
+		propval = RT4831_BLOVPLVL_21V;
+
+	propval = min_t(u8, propval, RT4831_BLOVPLVL_29V);
+	ret = regmap_update_bits(priv->regmap, RT4831_REG_BLCFG, RT4831_BLOVP_MASK,
+				 propval << RT4831_BLOVP_SHIFT);
+	if (ret)
+		return ret;
+
+	ret = device_property_read_u8(dev, "richtek,channel-use", &propval);
+	if (ret) {
+		dev_err(dev, "richtek,channel-use DT property missing\n");
+		return ret;
+	}
+
+	if (!(propval & RT4831_BLCH_MASK)) {
+		dev_err(dev, "No channel specified\n");
+		return -EINVAL;
+	}
+
+	return regmap_update_bits(priv->regmap, RT4831_REG_ENABLE, RT4831_BLCH_MASK, propval);
+}
+
+static int rt4831_bl_probe(struct platform_device *pdev)
+{
+	struct rt4831_priv *priv;
+	struct backlight_properties bl_props = { .type = BACKLIGHT_RAW,
+						 .scale = BACKLIGHT_SCALE_LINEAR };
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+
+	priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!priv->regmap) {
+		dev_err(&pdev->dev, "Failed to init regmap\n");
+		return -ENODEV;
+	}
+
+	ret = rt4831_parse_backlight_properties(priv, &bl_props);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to parse backlight properties\n");
+		return ret;
+	}
+
+	priv->bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev, priv,
+						  &rt4831_bl_ops, &bl_props);
+	if (IS_ERR(priv->bl)) {
+		dev_err(&pdev->dev, "Failed to register backlight\n");
+		return PTR_ERR(priv->bl);
+	}
+
+	backlight_update_status(priv->bl);
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static int rt4831_bl_remove(struct platform_device *pdev)
+{
+	struct rt4831_priv *priv = platform_get_drvdata(pdev);
+	struct backlight_device *bl_dev = priv->bl;
+
+	bl_dev->props.brightness = 0;
+	backlight_update_status(priv->bl);
+
+	return 0;
+}
+
+static const struct of_device_id __maybe_unused rt4831_bl_of_match[] = {
+	{ .compatible = "richtek,rt4831-backlight", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt4831_bl_of_match);
+
+static struct platform_driver rt4831_bl_driver = {
+	.driver = {
+		.name = "rt4831-backlight",
+		.of_match_table = rt4831_bl_of_match,
+	},
+	.probe = rt4831_bl_probe,
+	.remove = rt4831_bl_remove,
+};
+module_platform_driver(rt4831_bl_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_LICENSE("GPL v2");