linux/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 void rt4505_remove(struct i2c_client *client)
{
	struct rt4505_priv *priv = i2c_get_clientdata(client);

	v4l2_flash_release(priv->v4l2_flash);
}

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 = rt4505_probe,
	.remove = rt4505_remove,
	.shutdown = rt4505_shutdown,
};
module_i2c_driver(rt4505_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("Richtek RT4505 LED driver");
MODULE_LICENSE("GPL v2");