leds: rt4505: Add support for Richtek RT4505 flash LED controller

Add support for RT4505 flash LED controller. It can support up to 1.5A
flash current with hardware timeout and low input voltage protection.
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

drivers/leds/flash/Kconfig

@@ -2,6 +2,17 @@
 
 if LEDS_CLASS_FLASH
 
+config LEDS_RT4505
+	tristate "LED support for RT4505 flashlight controller"
+	depends on I2C && OF
+	depends on V4L2_FLASH_LED_CLASS || !V4L2_FLASH_LED_CLASS
+	select REGMAP_I2C
+	help
+	  This option enables support for the RT4505 flash LED controller.
+	  RT4505 includes torch and flash functions with programmable current.
+	  And it's commonly used to compensate the illuminance for the camera
+	  inside the mobile product like as phones or tablets.
+
 config LEDS_RT8515
 	tristate "LED support for Richtek RT8515 flash/torch LED"
 	depends on GPIOLIB

drivers/leds/flash/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
+obj-$(CONFIG_LEDS_RT4505)	+= leds-rt4505.o
 obj-$(CONFIG_LEDS_RT8515)	+= leds-rt8515.o

drivers/leds/flash/leds-rt4505.c

+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/led-class-flash.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <media/v4l2-flash-led-class.h>
+
+#define RT4505_REG_RESET	0x0
+#define RT4505_REG_CONFIG	0x8
+#define RT4505_REG_ILED		0x9
+#define RT4505_REG_ENABLE	0xA
+#define RT4505_REG_FLAGS	0xB
+
+#define RT4505_RESET_MASK	BIT(7)
+#define RT4505_FLASHTO_MASK	GENMASK(2, 0)
+#define RT4505_ITORCH_MASK	GENMASK(7, 5)
+#define RT4505_ITORCH_SHIFT	5
+#define RT4505_IFLASH_MASK	GENMASK(4, 0)
+#define RT4505_ENABLE_MASK	GENMASK(5, 0)
+#define RT4505_TORCH_SET	(BIT(0) | BIT(4))
+#define RT4505_FLASH_SET	(BIT(0) | BIT(1) | BIT(2) | BIT(4))
+#define RT4505_EXT_FLASH_SET	(BIT(0) | BIT(1) | BIT(4) | BIT(5))
+#define RT4505_FLASH_GET	(BIT(0) | BIT(1) | BIT(4))
+#define RT4505_OVP_MASK		BIT(3)
+#define RT4505_SHORT_MASK	BIT(2)
+#define RT4505_OTP_MASK		BIT(1)
+#define RT4505_TIMEOUT_MASK	BIT(0)
+
+#define RT4505_ITORCH_MINUA	46000
+#define RT4505_ITORCH_MAXUA	375000
+#define RT4505_ITORCH_STPUA	47000
+#define RT4505_IFLASH_MINUA	93750
+#define RT4505_IFLASH_MAXUA	1500000
+#define RT4505_IFLASH_STPUA	93750
+#define RT4505_FLASHTO_MINUS	100000
+#define RT4505_FLASHTO_MAXUS	800000
+#define RT4505_FLASHTO_STPUS	100000
+
+struct rt4505_priv {
+	struct device *dev;
+	struct regmap *regmap;
+	struct mutex lock;
+	struct led_classdev_flash flash;
+	struct v4l2_flash *v4l2_flash;
+};
+
+static int rt4505_torch_brightness_set(struct led_classdev *lcdev,
+				       enum led_brightness level)
+{
+	struct rt4505_priv *priv =
+		container_of(lcdev, struct rt4505_priv, flash.led_cdev);
+	u32 val = 0;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	if (level != LED_OFF) {
+		ret = regmap_update_bits(priv->regmap,
+					 RT4505_REG_ILED, RT4505_ITORCH_MASK,
+					 (level - 1) << RT4505_ITORCH_SHIFT);
+		if (ret)
+			goto unlock;
+
+		val = RT4505_TORCH_SET;
+	}
+
+	ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+				 RT4505_ENABLE_MASK, val);
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static enum led_brightness rt4505_torch_brightness_get(
+						struct led_classdev *lcdev)
+{
+	struct rt4505_priv *priv =
+		container_of(lcdev, struct rt4505_priv, flash.led_cdev);
+	u32 val;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	ret = regmap_read(priv->regmap, RT4505_REG_ENABLE, &val);
+	if (ret) {
+		dev_err(lcdev->dev, "Failed to get LED enable\n");
+		ret = LED_OFF;
+		goto unlock;
+	}
+
+	if ((val & RT4505_ENABLE_MASK) != RT4505_TORCH_SET) {
+		ret = LED_OFF;
+		goto unlock;
+	}
+
+	ret = regmap_read(priv->regmap, RT4505_REG_ILED, &val);
+	if (ret) {
+		dev_err(lcdev->dev, "Failed to get LED brightness\n");
+		ret = LED_OFF;
+		goto unlock;
+	}
+
+	ret = ((val & RT4505_ITORCH_MASK) >> RT4505_ITORCH_SHIFT) + 1;
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static int rt4505_flash_brightness_set(struct led_classdev_flash *fled_cdev,
+				       u32 brightness)
+{
+	struct rt4505_priv *priv =
+		container_of(fled_cdev, struct rt4505_priv, flash);
+	struct led_flash_setting *s = &fled_cdev->brightness;
+	u32 val = (brightness - s->min) / s->step;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, RT4505_REG_ILED,
+				 RT4505_IFLASH_MASK, val);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int rt4505_flash_strobe_set(struct led_classdev_flash *fled_cdev,
+				   bool state)
+{
+	struct rt4505_priv *priv =
+		container_of(fled_cdev, struct rt4505_priv, flash);
+	u32 val = state ? RT4505_FLASH_SET : 0;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+				 RT4505_ENABLE_MASK, val);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int rt4505_flash_strobe_get(struct led_classdev_flash *fled_cdev,
+				   bool *state)
+{
+	struct rt4505_priv *priv =
+		container_of(fled_cdev, struct rt4505_priv, flash);
+	u32 val;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	ret = regmap_read(priv->regmap, RT4505_REG_ENABLE, &val);
+	if (ret)
+		goto unlock;
+
+	*state = (val & RT4505_FLASH_GET) == RT4505_FLASH_GET;
+
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static int rt4505_flash_timeout_set(struct led_classdev_flash *fled_cdev,
+				    u32 timeout)
+{
+	struct rt4505_priv *priv =
+		container_of(fled_cdev, struct rt4505_priv, flash);
+	struct led_flash_setting *s = &fled_cdev->timeout;
+	u32 val = (timeout - s->min) / s->step;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, RT4505_REG_CONFIG,
+				 RT4505_FLASHTO_MASK, val);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int rt4505_fault_get(struct led_classdev_flash *fled_cdev, u32 *fault)
+{
+	struct rt4505_priv *priv =
+		container_of(fled_cdev, struct rt4505_priv, flash);
+	u32 val, led_faults = 0;
+	int ret;
+
+	ret = regmap_read(priv->regmap, RT4505_REG_FLAGS, &val);
+	if (ret)
+		return ret;
+
+	if (val & RT4505_OVP_MASK)
+		led_faults |= LED_FAULT_OVER_VOLTAGE;
+
+	if (val & RT4505_SHORT_MASK)
+		led_faults |= LED_FAULT_SHORT_CIRCUIT;
+
+	if (val & RT4505_OTP_MASK)
+		led_faults |= LED_FAULT_OVER_TEMPERATURE;
+
+	if (val & RT4505_TIMEOUT_MASK)
+		led_faults |= LED_FAULT_TIMEOUT;
+
+	*fault = led_faults;
+	return 0;
+}
+
+static const struct led_flash_ops rt4505_flash_ops = {
+	.flash_brightness_set = rt4505_flash_brightness_set,
+	.strobe_set = rt4505_flash_strobe_set,
+	.strobe_get = rt4505_flash_strobe_get,
+	.timeout_set = rt4505_flash_timeout_set,
+	.fault_get = rt4505_fault_get,
+};
+
+static bool rt4505_is_accessible_reg(struct device *dev, unsigned int reg)
+{
+	if (reg == RT4505_REG_RESET ||
+		(reg >= RT4505_REG_CONFIG && reg <= RT4505_REG_FLAGS))
+		return true;
+	return false;
+}
+
+static const struct regmap_config rt4505_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = RT4505_REG_FLAGS,
+
+	.readable_reg = rt4505_is_accessible_reg,
+	.writeable_reg = rt4505_is_accessible_reg,
+};
+
+#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
+static int rt4505_flash_external_strobe_set(struct v4l2_flash *v4l2_flash,
+					    bool enable)
+{
+	struct led_classdev_flash *flash = v4l2_flash->fled_cdev;
+	struct rt4505_priv *priv =
+		container_of(flash, struct rt4505_priv, flash);
+	u32 val = enable ? RT4505_EXT_FLASH_SET : 0;
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = regmap_update_bits(priv->regmap, RT4505_REG_ENABLE,
+				 RT4505_ENABLE_MASK, val);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static const struct v4l2_flash_ops v4l2_flash_ops = {
+	.external_strobe_set = rt4505_flash_external_strobe_set,
+};
+
+static void rt4505_init_v4l2_config(struct rt4505_priv *priv,
+				    struct v4l2_flash_config *config)
+{
+	struct led_classdev_flash *flash = &priv->flash;
+	struct led_classdev *lcdev = &flash->led_cdev;
+	struct led_flash_setting *s;
+
+	strscpy(config->dev_name, lcdev->dev->kobj.name,
+		sizeof(config->dev_name));
+
+	s = &config->intensity;
+	s->min = RT4505_ITORCH_MINUA;
+	s->step = RT4505_ITORCH_STPUA;
+	s->max = s->val = s->min + (lcdev->max_brightness - 1) * s->step;
+
+	config->flash_faults = LED_FAULT_OVER_VOLTAGE |
+			       LED_FAULT_SHORT_CIRCUIT |
+			       LED_FAULT_LED_OVER_TEMPERATURE |
+			       LED_FAULT_TIMEOUT;
+	config->has_external_strobe = 1;
+}
+#else
+static const struct v4l2_flash_ops v4l2_flash_ops;
+static void rt4505_init_v4l2_config(struct rt4505_priv *priv,
+				    struct v4l2_flash_config *config)
+{
+}
+#endif
+
+static void rt4505_init_flash_properties(struct rt4505_priv *priv,
+					 struct fwnode_handle *child)
+{
+	struct led_classdev_flash *flash = &priv->flash;
+	struct led_classdev *lcdev = &flash->led_cdev;
+	struct led_flash_setting *s;
+	u32 val;
+	int ret;
+
+	ret = fwnode_property_read_u32(child, "led-max-microamp", &val);
+	if (ret) {
+		dev_warn(priv->dev, "led-max-microamp DT property missing\n");
+		val = RT4505_ITORCH_MINUA;
+	} else
+		val = clamp_val(val, RT4505_ITORCH_MINUA, RT4505_ITORCH_MAXUA);
+
+	lcdev->max_brightness =
+		(val - RT4505_ITORCH_MINUA) / RT4505_ITORCH_STPUA + 1;
+	lcdev->brightness_set_blocking = rt4505_torch_brightness_set;
+	lcdev->brightness_get = rt4505_torch_brightness_get;
+	lcdev->flags |= LED_DEV_CAP_FLASH;
+
+	ret = fwnode_property_read_u32(child, "flash-max-microamp", &val);
+	if (ret) {
+		dev_warn(priv->dev, "flash-max-microamp DT property missing\n");
+		val = RT4505_IFLASH_MINUA;
+	} else
+		val = clamp_val(val, RT4505_IFLASH_MINUA, RT4505_IFLASH_MAXUA);
+
+	s = &flash->brightness;
+	s->min = RT4505_IFLASH_MINUA;
+	s->step = RT4505_IFLASH_STPUA;
+	s->max = s->val = val;
+
+	ret = fwnode_property_read_u32(child, "flash-max-timeout-us", &val);
+	if (ret) {
+		dev_warn(priv->dev,
+			 "flash-max-timeout-us DT property missing\n");
+		val = RT4505_FLASHTO_MINUS;
+	} else
+		val = clamp_val(val, RT4505_FLASHTO_MINUS,
+				RT4505_FLASHTO_MAXUS);
+
+	s = &flash->timeout;
+	s->min = RT4505_FLASHTO_MINUS;
+	s->step = RT4505_FLASHTO_STPUS;
+	s->max = s->val = val;
+
+	flash->ops = &rt4505_flash_ops;
+}
+
+static int rt4505_probe(struct i2c_client *client)
+{
+	struct rt4505_priv *priv;
+	struct fwnode_handle *child;
+	struct led_init_data init_data = {};
+	struct v4l2_flash_config v4l2_config = {};
+	int ret;
+
+	priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &client->dev;
+	mutex_init(&priv->lock);
+
+	priv->regmap = devm_regmap_init_i2c(client, &rt4505_regmap_config);
+	if (IS_ERR(priv->regmap)) {
+		dev_err(priv->dev, "Failed to allocate register map\n");
+		return PTR_ERR(priv->regmap);
+	}
+
+	ret = regmap_write(priv->regmap, RT4505_REG_RESET, RT4505_RESET_MASK);
+	if (ret) {
+		dev_err(priv->dev, "Failed to reset registers\n");
+		return ret;
+	}
+
+	child = fwnode_get_next_available_child_node(client->dev.fwnode, NULL);
+	if (!child) {
+		dev_err(priv->dev, "Failed to get child node\n");
+		return -EINVAL;
+	}
+	init_data.fwnode = child;
+
+	rt4505_init_flash_properties(priv, child);
+	ret = devm_led_classdev_flash_register_ext(priv->dev, &priv->flash,
+						   &init_data);
+	if (ret) {
+		dev_err(priv->dev, "Failed to register flash\n");
+		return ret;
+	}
+
+	rt4505_init_v4l2_config(priv, &v4l2_config);
+	priv->v4l2_flash = v4l2_flash_init(priv->dev, init_data.fwnode,
+					   &priv->flash, &v4l2_flash_ops,
+					   &v4l2_config);
+	if (IS_ERR(priv->v4l2_flash)) {
+		dev_err(priv->dev, "Failed to register v4l2 flash\n");
+		return PTR_ERR(priv->v4l2_flash);
+	}
+
+	i2c_set_clientdata(client, priv);
+	return 0;
+}
+
+static int rt4505_remove(struct i2c_client *client)
+{
+	struct rt4505_priv *priv = i2c_get_clientdata(client);
+
+	v4l2_flash_release(priv->v4l2_flash);
+	return 0;
+}
+
+static void rt4505_shutdown(struct i2c_client *client)
+{
+	struct rt4505_priv *priv = i2c_get_clientdata(client);
+
+	/* Reset registers to make sure all off before shutdown */
+	regmap_write(priv->regmap, RT4505_REG_RESET, RT4505_RESET_MASK);
+}
+
+static const struct of_device_id __maybe_unused rt4505_leds_match[] = {
+	{ .compatible = "richtek,rt4505", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, rt4505_leds_match);
+
+static struct i2c_driver rt4505_driver = {
+	.driver = {
+		.name = "rt4505",
+		.of_match_table = of_match_ptr(rt4505_leds_match),
+	},
+	.probe_new = rt4505_probe,
+	.remove = rt4505_remove,
+	.shutdown = rt4505_shutdown,
+};
+module_i2c_driver(rt4505_driver);
+
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_LICENSE("GPL v2");