drivers/leds/leds-max77693.c

/*
 * LED Flash class driver for the flash cell of max77693 mfd.
 *
 *	Copyright (C) 2015, Samsung Electronics Co., Ltd.
 *
 *	Authors: Jacek Anaszewski <j.anaszewski@samsung.com>
 *		 Andrzej Hajda <a.hajda@samsung.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#include <linux/led-class-flash.h>
#include <linux/mfd/max77693.h>
#include <linux/mfd/max77693-private.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <media/v4l2-flash-led-class.h>

#define MODE_OFF		0
#define MODE_FLASH(a)		(1 << (a))
#define MODE_TORCH(a)		(1 << (2 + (a)))
#define MODE_FLASH_EXTERNAL(a)	(1 << (4 + (a)))

#define MODE_FLASH_MASK		(MODE_FLASH(FLED1) | MODE_FLASH(FLED2) | \
				 MODE_FLASH_EXTERNAL(FLED1) | \
				 MODE_FLASH_EXTERNAL(FLED2))
#define MODE_TORCH_MASK		(MODE_TORCH(FLED1) | MODE_TORCH(FLED2))

#define FLED1_IOUT		(1 << 0)
#define FLED2_IOUT		(1 << 1)

enum max77693_fled {
	FLED1,
	FLED2,
};

enum max77693_led_mode {
	FLASH,
	TORCH,
};

struct max77693_led_config_data {
	const char *label[2];
	u32 iout_torch_max[2];
	u32 iout_flash_max[2];
	u32 flash_timeout_max[2];
	u32 num_leds;
	u32 boost_mode;
	u32 boost_vout;
	u32 low_vsys;
};

struct max77693_sub_led {
	/* corresponding FLED output identifier */
	int fled_id;
	/* corresponding LED Flash class device */
	struct led_classdev_flash fled_cdev;
	/* assures led-triggers compatibility */
	struct work_struct work_brightness_set;
	/* V4L2 Flash device */
	struct v4l2_flash *v4l2_flash;

	/* brightness cache */
	unsigned int torch_brightness;
	/* flash timeout cache */
	unsigned int flash_timeout;
	/* flash faults that may have occurred */
	u32 flash_faults;
};

struct max77693_led_device {
	/* parent mfd regmap */
	struct regmap *regmap;
	/* platform device data */
	struct platform_device *pdev;
	/* secures access to the device */
	struct mutex lock;

	/* sub led data */
	struct max77693_sub_led sub_leds[2];

	/* maximum torch current values for FLED outputs */
	u32 iout_torch_max[2];
	/* maximum flash current values for FLED outputs */
	u32 iout_flash_max[2];

	/* current flash timeout cache */
	unsigned int current_flash_timeout;
	/* ITORCH register cache */
	u8 torch_iout_reg;
	/* mode of fled outputs */
	unsigned int mode_flags;
	/* recently strobed fled */
	int strobing_sub_led_id;
	/* bitmask of FLED outputs use state (bit 0. - FLED1, bit 1. - FLED2) */
	u8 fled_mask;
	/* FLED modes that can be set */
	u8 allowed_modes;

	/* arrangement of current outputs */
	bool iout_joint;
};

static u8 max77693_led_iout_to_reg(u32 ua)
{
	if (ua < FLASH_IOUT_MIN)
		ua = FLASH_IOUT_MIN;
	return (ua - FLASH_IOUT_MIN) / FLASH_IOUT_STEP;
}

static u8 max77693_flash_timeout_to_reg(u32 us)
{
	return (us - FLASH_TIMEOUT_MIN) / FLASH_TIMEOUT_STEP;
}

static inline struct max77693_sub_led *flcdev_to_sub_led(
					struct led_classdev_flash *fled_cdev)
{
	return container_of(fled_cdev, struct max77693_sub_led, fled_cdev);
}

static inline struct max77693_led_device *sub_led_to_led(
					struct max77693_sub_led *sub_led)
{
	return container_of(sub_led, struct max77693_led_device,
				sub_leds[sub_led->fled_id]);
}

static inline u8 max77693_led_vsys_to_reg(u32 mv)
{
	return ((mv - MAX_FLASH1_VSYS_MIN) / MAX_FLASH1_VSYS_STEP) << 2;
}

static inline u8 max77693_led_vout_to_reg(u32 mv)
{
	return (mv - FLASH_VOUT_MIN) / FLASH_VOUT_STEP + FLASH_VOUT_RMIN;
}

static inline bool max77693_fled_used(struct max77693_led_device *led,
					 int fled_id)
{
	u8 fled_bit = (fled_id == FLED1) ? FLED1_IOUT : FLED2_IOUT;

	return led->fled_mask & fled_bit;
}

static int max77693_set_mode_reg(struct max77693_led_device *led, u8 mode)
{
	struct regmap *rmap = led->regmap;
	int ret, v = 0, i;

	for (i = FLED1; i <= FLED2; ++i) {
		if (mode & MODE_TORCH(i))
			v |= FLASH_EN_ON << TORCH_EN_SHIFT(i);

		if (mode & MODE_FLASH(i)) {
			v |= FLASH_EN_ON << FLASH_EN_SHIFT(i);
		} else if (mode & MODE_FLASH_EXTERNAL(i)) {
			v |= FLASH_EN_FLASH << FLASH_EN_SHIFT(i);
			/*
			 * Enable hw triggering also for torch mode, as some
			 * camera sensors use torch led to fathom ambient light
			 * conditions before strobing the flash.
			 */
			v |= FLASH_EN_TORCH << TORCH_EN_SHIFT(i);
		}
	}

	/* Reset the register only prior setting flash modes */
	if (mode & ~(MODE_TORCH(FLED1) | MODE_TORCH(FLED2))) {
		ret = regmap_write(rmap, MAX77693_LED_REG_FLASH_EN, 0);
		if (ret < 0)
			return ret;
	}

	return regmap_write(rmap, MAX77693_LED_REG_FLASH_EN, v);
}

static int max77693_add_mode(struct max77693_led_device *led, u8 mode)
{
	u8 new_mode_flags;
	int i, ret;

	if (led->iout_joint)
		/* Span the mode on FLED2 for joint iouts case */
		mode |= (mode << 1);

	/*
	 * FLASH_EXTERNAL mode activates FLASHEN and TORCHEN pins in the device.
	 * Corresponding register bit fields interfere with SW triggered modes,
	 * thus clear them to ensure proper device configuration.
	 */
	for (i = FLED1; i <= FLED2; ++i)
		if (mode & MODE_FLASH_EXTERNAL(i))
			led->mode_flags &= (~MODE_TORCH(i) & ~MODE_FLASH(i));

	new_mode_flags = mode | led->mode_flags;
	new_mode_flags &= led->allowed_modes;

	if (new_mode_flags ^ led->mode_flags)
		led->mode_flags = new_mode_flags;
	else
		return 0;

	ret = max77693_set_mode_reg(led, led->mode_flags);
	if (ret < 0)
		return ret;

	/*
	 * Clear flash mode flag after setting the mode to avoid spurious flash
	 * strobing on each subsequent torch mode setting.
	 */
	if (mode & MODE_FLASH_MASK)
		led->mode_flags &= ~mode;

	return ret;
}

static int max77693_clear_mode(struct max77693_led_device *led,
				u8 mode)
{
	if (led->iout_joint)
		/* Clear mode also on FLED2 for joint iouts case */
		mode |= (mode << 1);

	led->mode_flags &= ~mode;

	return max77693_set_mode_reg(led, led->mode_flags);
}

static void max77693_add_allowed_modes(struct max77693_led_device *led,
				int fled_id, enum max77693_led_mode mode)
{
	if (mode == FLASH)
		led->allowed_modes |= (MODE_FLASH(fled_id) |
				       MODE_FLASH_EXTERNAL(fled_id));
	else
		led->allowed_modes |= MODE_TORCH(fled_id);
}

static void max77693_distribute_currents(struct max77693_led_device *led,
				int fled_id, enum max77693_led_mode mode,
				u32 micro_amp, u32 iout_max[2], u32 iout[2])
{
	if (!led->iout_joint) {
		iout[fled_id] = micro_amp;
		max77693_add_allowed_modes(led, fled_id, mode);
		return;
	}

	iout[FLED1] = min(micro_amp, iout_max[FLED1]);
	iout[FLED2] = micro_amp - iout[FLED1];

	if (mode == FLASH)
		led->allowed_modes &= ~MODE_FLASH_MASK;
	else
		led->allowed_modes &= ~MODE_TORCH_MASK;

	max77693_add_allowed_modes(led, FLED1, mode);

	if (iout[FLED2])
		max77693_add_allowed_modes(led, FLED2, mode);
}

static int max77693_set_torch_current(struct max77693_led_device *led,
				int fled_id, u32 micro_amp)
{
	struct regmap *rmap = led->regmap;
	u8 iout1_reg = 0, iout2_reg = 0;
	u32 iout[2];

	max77693_distribute_currents(led, fled_id, TORCH, micro_amp,
					led->iout_torch_max, iout);

	if (fled_id == FLED1 || led->iout_joint) {
		iout1_reg = max77693_led_iout_to_reg(iout[FLED1]);
		led->torch_iout_reg &= TORCH_IOUT_MASK(TORCH_IOUT2_SHIFT);
	}
	if (fled_id == FLED2 || led->iout_joint) {
		iout2_reg = max77693_led_iout_to_reg(iout[FLED2]);
		led->torch_iout_reg &= TORCH_IOUT_MASK(TORCH_IOUT1_SHIFT);
	}

	led->torch_iout_reg |= ((iout1_reg << TORCH_IOUT1_SHIFT) |
				(iout2_reg << TORCH_IOUT2_SHIFT));

	return regmap_write(rmap, MAX77693_LED_REG_ITORCH,
						led->torch_iout_reg);
}

static int max77693_set_flash_current(struct max77693_led_device *led,
					int fled_id,
					u32 micro_amp)
{
	struct regmap *rmap = led->regmap;
	u8 iout1_reg, iout2_reg;
	u32 iout[2];
	int ret = -EINVAL;

	max77693_distribute_currents(led, fled_id, FLASH, micro_amp,
					led->iout_flash_max, iout);

	if (fled_id == FLED1 || led->iout_joint) {
		iout1_reg = max77693_led_iout_to_reg(iout[FLED1]);
		ret = regmap_write(rmap, MAX77693_LED_REG_IFLASH1,
							iout1_reg);
		if (ret < 0)
			return ret;
	}
	if (fled_id == FLED2 || led->iout_joint) {
		iout2_reg = max77693_led_iout_to_reg(iout[FLED2]);
		ret = regmap_write(rmap, MAX77693_LED_REG_IFLASH2,
							iout2_reg);
	}

	return ret;
}

static int max77693_set_timeout(struct max77693_led_device *led, u32 microsec)
{
	struct regmap *rmap = led->regmap;
	u8 v;
	int ret;

	v = max77693_flash_timeout_to_reg(microsec) | FLASH_TMR_LEVEL;

	ret = regmap_write(rmap, MAX77693_LED_REG_FLASH_TIMER, v);
	if (ret < 0)
		return ret;

	led->current_flash_timeout = microsec;

	return 0;
}

static int max77693_get_strobe_status(struct max77693_led_device *led,
					bool *state)
{
	struct regmap *rmap = led->regmap;
	unsigned int v;
	int ret;

	ret = regmap_read(rmap, MAX77693_LED_REG_FLASH_STATUS, &v);
	if (ret < 0)
		return ret;

	*state = v & FLASH_STATUS_FLASH_ON;

	return ret;
}

static int max77693_get_flash_faults(struct max77693_sub_led *sub_led)
{
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	struct regmap *rmap = led->regmap;
	unsigned int v;
	u8 fault_open_mask, fault_short_mask;
	int ret;

	sub_led->flash_faults = 0;

	if (led->iout_joint) {
		fault_open_mask = FLASH_INT_FLED1_OPEN | FLASH_INT_FLED2_OPEN;
		fault_short_mask = FLASH_INT_FLED1_SHORT |
							FLASH_INT_FLED2_SHORT;
	} else {
		fault_open_mask = (sub_led->fled_id == FLED1) ?
						FLASH_INT_FLED1_OPEN :
						FLASH_INT_FLED2_OPEN;
		fault_short_mask = (sub_led->fled_id == FLED1) ?
						FLASH_INT_FLED1_SHORT :
						FLASH_INT_FLED2_SHORT;
	}

	ret = regmap_read(rmap, MAX77693_LED_REG_FLASH_INT, &v);
	if (ret < 0)
		return ret;

	if (v & fault_open_mask)
		sub_led->flash_faults |= LED_FAULT_OVER_VOLTAGE;
	if (v & fault_short_mask)
		sub_led->flash_faults |= LED_FAULT_SHORT_CIRCUIT;
	if (v & FLASH_INT_OVER_CURRENT)
		sub_led->flash_faults |= LED_FAULT_OVER_CURRENT;

	return 0;
}

static int max77693_setup(struct max77693_led_device *led,
			 struct max77693_led_config_data *led_cfg)
{
	struct regmap *rmap = led->regmap;
	int i, first_led, last_led, ret;
	u32 max_flash_curr[2];
	u8 v;

	/*
	 * Initialize only flash current. Torch current doesn't
	 * require initialization as ITORCH register is written with
	 * new value each time brightness_set op is called.
	 */
	if (led->iout_joint) {
		first_led = FLED1;
		last_led = FLED1;
		max_flash_curr[FLED1] = led_cfg->iout_flash_max[FLED1] +
					led_cfg->iout_flash_max[FLED2];
	} else {
		first_led = max77693_fled_used(led, FLED1) ? FLED1 : FLED2;
		last_led = max77693_fled_used(led, FLED2) ? FLED2 : FLED1;
		max_flash_curr[FLED1] = led_cfg->iout_flash_max[FLED1];
		max_flash_curr[FLED2] = led_cfg->iout_flash_max[FLED2];
	}

	for (i = first_led; i <= last_led; ++i) {
		ret = max77693_set_flash_current(led, i,
					max_flash_curr[i]);
		if (ret < 0)
			return ret;
	}

	v = TORCH_TMR_NO_TIMER | MAX77693_LED_TRIG_TYPE_LEVEL;
	ret = regmap_write(rmap, MAX77693_LED_REG_ITORCHTIMER, v);
	if (ret < 0)
		return ret;

	if (led_cfg->low_vsys > 0)
		v = max77693_led_vsys_to_reg(led_cfg->low_vsys) |
						MAX_FLASH1_MAX_FL_EN;
	else
		v = 0;

	ret = regmap_write(rmap, MAX77693_LED_REG_MAX_FLASH1, v);
	if (ret < 0)
		return ret;
	ret = regmap_write(rmap, MAX77693_LED_REG_MAX_FLASH2, 0);
	if (ret < 0)
		return ret;

	if (led_cfg->boost_mode == MAX77693_LED_BOOST_FIXED)
		v = FLASH_BOOST_FIXED;
	else
		v = led_cfg->boost_mode | led_cfg->boost_mode << 1;

	if (max77693_fled_used(led, FLED1) && max77693_fled_used(led, FLED2))
		v |= FLASH_BOOST_LEDNUM_2;

	ret = regmap_write(rmap, MAX77693_LED_REG_VOUT_CNTL, v);
	if (ret < 0)
		return ret;

	v = max77693_led_vout_to_reg(led_cfg->boost_vout);
	ret = regmap_write(rmap, MAX77693_LED_REG_VOUT_FLASH1, v);
	if (ret < 0)
		return ret;

	return max77693_set_mode_reg(led, MODE_OFF);
}

static int __max77693_led_brightness_set(struct max77693_led_device *led,
					int fled_id, enum led_brightness value)
{
	int ret;

	mutex_lock(&led->lock);

	if (value == 0) {
		ret = max77693_clear_mode(led, MODE_TORCH(fled_id));
		if (ret < 0)
			dev_dbg(&led->pdev->dev,
				"Failed to clear torch mode (%d)\n",
				ret);
		goto unlock;
	}

	ret = max77693_set_torch_current(led, fled_id, value * TORCH_IOUT_STEP);
	if (ret < 0) {
		dev_dbg(&led->pdev->dev,
			"Failed to set torch current (%d)\n",
			ret);
		goto unlock;
	}

	ret = max77693_add_mode(led, MODE_TORCH(fled_id));
	if (ret < 0)
		dev_dbg(&led->pdev->dev,
			"Failed to set torch mode (%d)\n",
			ret);
unlock:
	mutex_unlock(&led->lock);
	return ret;
}

static void max77693_led_brightness_set_work(
					struct work_struct *work)
{
	struct max77693_sub_led *sub_led =
			container_of(work, struct max77693_sub_led,
					work_brightness_set);
	struct max77693_led_device *led = sub_led_to_led(sub_led);

	__max77693_led_brightness_set(led, sub_led->fled_id,
				sub_led->torch_brightness);
}

/* LED subsystem callbacks */

static int max77693_led_brightness_set_sync(
				struct led_classdev *led_cdev,
				enum led_brightness value)
{
	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);

	return __max77693_led_brightness_set(led, sub_led->fled_id, value);
}

static void max77693_led_brightness_set(
				struct led_classdev *led_cdev,
				enum led_brightness value)
{
	struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);

	sub_led->torch_brightness = value;
	schedule_work(&sub_led->work_brightness_set);
}

static int max77693_led_flash_brightness_set(
				struct led_classdev_flash *fled_cdev,
				u32 brightness)
{
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int ret;

	mutex_lock(&led->lock);
	ret = max77693_set_flash_current(led, sub_led->fled_id, brightness);
	mutex_unlock(&led->lock);

	return ret;
}

static int max77693_led_flash_strobe_set(
				struct led_classdev_flash *fled_cdev,
				bool state)
{
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int fled_id = sub_led->fled_id;
	int ret;

	mutex_lock(&led->lock);

	if (!state) {
		ret = max77693_clear_mode(led, MODE_FLASH(fled_id));
		goto unlock;
	}

	if (sub_led->flash_timeout != led->current_flash_timeout) {
		ret = max77693_set_timeout(led, sub_led->flash_timeout);
		if (ret < 0)
			goto unlock;
	}

	led->strobing_sub_led_id = fled_id;

	ret = max77693_add_mode(led, MODE_FLASH(fled_id));
	if (ret < 0)
		goto unlock;

	ret = max77693_get_flash_faults(sub_led);

unlock:
	mutex_unlock(&led->lock);
	return ret;
}

static int max77693_led_flash_fault_get(
				struct led_classdev_flash *fled_cdev,
				u32 *fault)
{
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);

	*fault = sub_led->flash_faults;

	return 0;
}

static int max77693_led_flash_strobe_get(
				struct led_classdev_flash *fled_cdev,
				bool *state)
{
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int ret;

	if (!state)
		return -EINVAL;

	mutex_lock(&led->lock);

	ret = max77693_get_strobe_status(led, state);

	*state = !!(*state && (led->strobing_sub_led_id == sub_led->fled_id));

	mutex_unlock(&led->lock);

	return ret;
}

static int max77693_led_flash_timeout_set(
				struct led_classdev_flash *fled_cdev,
				u32 timeout)
{
	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);

	mutex_lock(&led->lock);
	sub_led->flash_timeout = timeout;
	mutex_unlock(&led->lock);

	return 0;
}

static int max77693_led_parse_dt(struct max77693_led_device *led,
				struct max77693_led_config_data *cfg,
				struct device_node **sub_nodes)
{
	struct device *dev = &led->pdev->dev;
	struct max77693_sub_led *sub_leds = led->sub_leds;
	struct device_node *node = dev->of_node, *child_node;
	struct property *prop;
	u32 led_sources[2];
	int i, ret, fled_id;

	of_property_read_u32(node, "maxim,boost-mode", &cfg->boost_mode);
	of_property_read_u32(node, "maxim,boost-mvout", &cfg->boost_vout);
	of_property_read_u32(node, "maxim,mvsys-min", &cfg->low_vsys);

	for_each_available_child_of_node(node, child_node) {
		prop = of_find_property(child_node, "led-sources", NULL);
		if (prop) {
			const __be32 *srcs = NULL;

			for (i = 0; i < ARRAY_SIZE(led_sources); ++i) {
				srcs = of_prop_next_u32(prop, srcs,
							&led_sources[i]);
				if (!srcs)
					break;
			}
		} else {
			dev_err(dev,
				"led-sources DT property missing\n");
			of_node_put(child_node);
			return -EINVAL;
		}

		if (i == 2) {
			fled_id = FLED1;
			led->fled_mask = FLED1_IOUT | FLED2_IOUT;
		} else if (led_sources[0] == FLED1) {
			fled_id = FLED1;
			led->fled_mask |= FLED1_IOUT;
		} else if (led_sources[0] == FLED2) {
			fled_id = FLED2;
			led->fled_mask |= FLED2_IOUT;
		} else {
			dev_err(dev,
				"Wrong led-sources DT property value.\n");
			of_node_put(child_node);
			return -EINVAL;
		}

		if (sub_nodes[fled_id]) {
			dev_err(dev,
				"Conflicting \"led-sources\" DT properties\n");
			return -EINVAL;
		}

		sub_nodes[fled_id] = child_node;
		sub_leds[fled_id].fled_id = fled_id;

		cfg->label[fled_id] =
			of_get_property(child_node, "label", NULL) ? :
						child_node->name;

		ret = of_property_read_u32(child_node, "led-max-microamp",
					&cfg->iout_torch_max[fled_id]);
		if (ret < 0) {
			cfg->iout_torch_max[fled_id] = TORCH_IOUT_MIN;
			dev_warn(dev, "led-max-microamp DT property missing\n");
		}

		ret = of_property_read_u32(child_node, "flash-max-microamp",
					&cfg->iout_flash_max[fled_id]);
		if (ret < 0) {
			cfg->iout_flash_max[fled_id] = FLASH_IOUT_MIN;
			dev_warn(dev,
				 "flash-max-microamp DT property missing\n");
		}

		ret = of_property_read_u32(child_node, "flash-max-timeout-us",
					&cfg->flash_timeout_max[fled_id]);
		if (ret < 0) {
			cfg->flash_timeout_max[fled_id] = FLASH_TIMEOUT_MIN;
			dev_warn(dev,
				 "flash-max-timeout-us DT property missing\n");
		}

		if (++cfg->num_leds == 2 ||
		    (max77693_fled_used(led, FLED1) &&
		     max77693_fled_used(led, FLED2))) {
			of_node_put(child_node);
			break;
		}
	}

	if (cfg->num_leds == 0) {
		dev_err(dev, "No DT child node found for connected LED(s).\n");
		return -EINVAL;
	}

	return 0;
}

static void clamp_align(u32 *v, u32 min, u32 max, u32 step)
{
	*v = clamp_val(*v, min, max);
	if (step > 1)
		*v = (*v - min) / step * step + min;
}

static void max77693_align_iout_current(struct max77693_led_device *led,
					u32 *iout, u32 min, u32 max, u32 step)
{
	int i;

	if (led->iout_joint) {
		if (iout[FLED1] > min) {
			iout[FLED1] /= 2;
			iout[FLED2] = iout[FLED1];
		} else {
			iout[FLED1] = min;
			iout[FLED2] = 0;
			return;
		}
	}

	for (i = FLED1; i <= FLED2; ++i)
		if (max77693_fled_used(led, i))
			clamp_align(&iout[i], min, max, step);
		else
			iout[i] = 0;
}

static void max77693_led_validate_configuration(struct max77693_led_device *led,
					struct max77693_led_config_data *cfg)
{
	u32 flash_iout_max = cfg->boost_mode ? FLASH_IOUT_MAX_2LEDS :
					       FLASH_IOUT_MAX_1LED;
	int i;

	if (cfg->num_leds == 1 &&
	    max77693_fled_used(led, FLED1) && max77693_fled_used(led, FLED2))
		led->iout_joint = true;

	cfg->boost_mode = clamp_val(cfg->boost_mode, MAX77693_LED_BOOST_NONE,
			    MAX77693_LED_BOOST_FIXED);

	/* Boost must be enabled if both current outputs are used */
	if ((cfg->boost_mode == MAX77693_LED_BOOST_NONE) && led->iout_joint)
		cfg->boost_mode = MAX77693_LED_BOOST_FIXED;

	max77693_align_iout_current(led, cfg->iout_torch_max,
			TORCH_IOUT_MIN, TORCH_IOUT_MAX, TORCH_IOUT_STEP);

	max77693_align_iout_current(led, cfg->iout_flash_max,
			FLASH_IOUT_MIN, flash_iout_max, FLASH_IOUT_STEP);

	for (i = 0; i < ARRAY_SIZE(cfg->flash_timeout_max); ++i)
		clamp_align(&cfg->flash_timeout_max[i], FLASH_TIMEOUT_MIN,
				FLASH_TIMEOUT_MAX, FLASH_TIMEOUT_STEP);

	clamp_align(&cfg->boost_vout, FLASH_VOUT_MIN, FLASH_VOUT_MAX,
							FLASH_VOUT_STEP);

	if (cfg->low_vsys)
		clamp_align(&cfg->low_vsys, MAX_FLASH1_VSYS_MIN,
				MAX_FLASH1_VSYS_MAX, MAX_FLASH1_VSYS_STEP);
}

static int max77693_led_get_configuration(struct max77693_led_device *led,
				struct max77693_led_config_data *cfg,
				struct device_node **sub_nodes)
{
	int ret;

	ret = max77693_led_parse_dt(led, cfg, sub_nodes);
	if (ret < 0)
		return ret;

	max77693_led_validate_configuration(led, cfg);

	memcpy(led->iout_torch_max, cfg->iout_torch_max,
				sizeof(led->iout_torch_max));
	memcpy(led->iout_flash_max, cfg->iout_flash_max,
				sizeof(led->iout_flash_max));

	return 0;
}

static const struct led_flash_ops flash_ops = {
	.flash_brightness_set	= max77693_led_flash_brightness_set,
	.strobe_set		= max77693_led_flash_strobe_set,
	.strobe_get		= max77693_led_flash_strobe_get,
	.timeout_set		= max77693_led_flash_timeout_set,
	.fault_get		= max77693_led_flash_fault_get,
};

static void max77693_init_flash_settings(struct max77693_sub_led *sub_led,
				 struct max77693_led_config_data *led_cfg)
{
	struct led_classdev_flash *fled_cdev = &sub_led->fled_cdev;
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int fled_id = sub_led->fled_id;
	struct led_flash_setting *setting;

	/* Init flash intensity setting */
	setting = &fled_cdev->brightness;
	setting->min = FLASH_IOUT_MIN;
	setting->max = led->iout_joint ?
		led_cfg->iout_flash_max[FLED1] +
		led_cfg->iout_flash_max[FLED2] :
		led_cfg->iout_flash_max[fled_id];
	setting->step = FLASH_IOUT_STEP;
	setting->val = setting->max;

	/* Init flash timeout setting */
	setting = &fled_cdev->timeout;
	setting->min = FLASH_TIMEOUT_MIN;
	setting->max = led_cfg->flash_timeout_max[fled_id];
	setting->step = FLASH_TIMEOUT_STEP;
	setting->val = setting->max;
}

#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)

static int max77693_led_external_strobe_set(
				struct v4l2_flash *v4l2_flash,
				bool enable)
{
	struct max77693_sub_led *sub_led =
				flcdev_to_sub_led(v4l2_flash->fled_cdev);
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int fled_id = sub_led->fled_id;
	int ret;

	mutex_lock(&led->lock);

	if (enable)
		ret = max77693_add_mode(led, MODE_FLASH_EXTERNAL(fled_id));
	else
		ret = max77693_clear_mode(led, MODE_FLASH_EXTERNAL(fled_id));

	mutex_unlock(&led->lock);

	return ret;
}

static void max77693_init_v4l2_flash_config(struct max77693_sub_led *sub_led,
				struct max77693_led_config_data *led_cfg,
				struct v4l2_flash_config *v4l2_sd_cfg)
{
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	struct device *dev = &led->pdev->dev;
	struct max77693_dev *iodev = dev_get_drvdata(dev->parent);
	struct i2c_client *i2c = iodev->i2c;
	struct led_flash_setting *s;

	snprintf(v4l2_sd_cfg->dev_name, sizeof(v4l2_sd_cfg->dev_name),
		 "%s %d-%04x", sub_led->fled_cdev.led_cdev.name,
		 i2c_adapter_id(i2c->adapter), i2c->addr);

	s = &v4l2_sd_cfg->torch_intensity;
	s->min = TORCH_IOUT_MIN;
	s->max = sub_led->fled_cdev.led_cdev.max_brightness * TORCH_IOUT_STEP;
	s->step = TORCH_IOUT_STEP;
	s->val = s->max;

	/* Init flash faults config */
	v4l2_sd_cfg->flash_faults = LED_FAULT_OVER_VOLTAGE |
				LED_FAULT_SHORT_CIRCUIT |
				LED_FAULT_OVER_CURRENT;

	v4l2_sd_cfg->has_external_strobe = true;
}

static const struct v4l2_flash_ops v4l2_flash_ops = {
	.external_strobe_set = max77693_led_external_strobe_set,
};
#else
static inline void max77693_init_v4l2_flash_config(
				struct max77693_sub_led *sub_led,
				struct max77693_led_config_data *led_cfg,
				struct v4l2_flash_config *v4l2_sd_cfg)
{
}
static const struct v4l2_flash_ops v4l2_flash_ops;
#endif

static void max77693_init_fled_cdev(struct max77693_sub_led *sub_led,
				struct max77693_led_config_data *led_cfg)
{
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	int fled_id = sub_led->fled_id;
	struct led_classdev_flash *fled_cdev;
	struct led_classdev *led_cdev;

	/* Initialize LED Flash class device */
	fled_cdev = &sub_led->fled_cdev;
	fled_cdev->ops = &flash_ops;
	led_cdev = &fled_cdev->led_cdev;

	led_cdev->name = led_cfg->label[fled_id];

	led_cdev->brightness_set = max77693_led_brightness_set;
	led_cdev->brightness_set_sync = max77693_led_brightness_set_sync;
	led_cdev->max_brightness = (led->iout_joint ?
					led_cfg->iout_torch_max[FLED1] +
					led_cfg->iout_torch_max[FLED2] :
					led_cfg->iout_torch_max[fled_id]) /
				   TORCH_IOUT_STEP;
	led_cdev->flags |= LED_DEV_CAP_FLASH;
	INIT_WORK(&sub_led->work_brightness_set,
			max77693_led_brightness_set_work);

	max77693_init_flash_settings(sub_led, led_cfg);

	/* Init flash timeout cache */
	sub_led->flash_timeout = fled_cdev->timeout.val;
}

static int max77693_register_led(struct max77693_sub_led *sub_led,
				 struct max77693_led_config_data *led_cfg,
				 struct device_node *sub_node)
{
	struct max77693_led_device *led = sub_led_to_led(sub_led);
	struct led_classdev_flash *fled_cdev = &sub_led->fled_cdev;
	struct device *dev = &led->pdev->dev;
	struct v4l2_flash_config v4l2_sd_cfg = {};
	int ret;

	/* Register in the LED subsystem */
	ret = led_classdev_flash_register(dev, fled_cdev);
	if (ret < 0)
		return ret;

	max77693_init_v4l2_flash_config(sub_led, led_cfg, &v4l2_sd_cfg);

	/* Register in the V4L2 subsystem. */
	sub_led->v4l2_flash = v4l2_flash_init(dev, sub_node, fled_cdev, NULL,
					      &v4l2_flash_ops, &v4l2_sd_cfg);
	if (IS_ERR(sub_led->v4l2_flash)) {
		ret = PTR_ERR(sub_led->v4l2_flash);
		goto err_v4l2_flash_init;
	}

	return 0;

err_v4l2_flash_init:
	led_classdev_flash_unregister(fled_cdev);
	return ret;
}

static int max77693_led_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct max77693_dev *iodev = dev_get_drvdata(dev->parent);
	struct max77693_led_device *led;
	struct max77693_sub_led *sub_leds;
	struct device_node *sub_nodes[2] = {};
	struct max77693_led_config_data led_cfg = {};
	int init_fled_cdev[2], i, ret;

	led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);
	if (!led)
		return -ENOMEM;

	led->pdev = pdev;
	led->regmap = iodev->regmap;
	led->allowed_modes = MODE_FLASH_MASK;
	sub_leds = led->sub_leds;

	platform_set_drvdata(pdev, led);
	ret = max77693_led_get_configuration(led, &led_cfg, sub_nodes);
	if (ret < 0)
		return ret;

	ret = max77693_setup(led, &led_cfg);
	if (ret < 0)
		return ret;

	mutex_init(&led->lock);

	init_fled_cdev[FLED1] =
			led->iout_joint || max77693_fled_used(led, FLED1);
	init_fled_cdev[FLED2] =
			!led->iout_joint && max77693_fled_used(led, FLED2);

	for (i = FLED1; i <= FLED2; ++i) {
		if (!init_fled_cdev[i])
			continue;

		/* Initialize LED Flash class device */
		max77693_init_fled_cdev(&sub_leds[i], &led_cfg);

		/*
		 * Register LED Flash class device and corresponding
		 * V4L2 Flash device.
		 */
		ret = max77693_register_led(&sub_leds[i], &led_cfg,
						sub_nodes[i]);
		if (ret < 0) {
			/*
			 * At this moment FLED1 might have been already
			 * registered and it needs to be released.
			 */
			if (i == FLED2)
				goto err_register_led2;
			else
				goto err_register_led1;
		}
	}

	return 0;

err_register_led2:
	/* It is possible than only FLED2 was to be registered */
	if (!init_fled_cdev[FLED1])
		goto err_register_led1;
	v4l2_flash_release(sub_leds[FLED1].v4l2_flash);
	led_classdev_flash_unregister(&sub_leds[FLED1].fled_cdev);
err_register_led1:
	mutex_destroy(&led->lock);

	return ret;
}

static int max77693_led_remove(struct platform_device *pdev)
{
	struct max77693_led_device *led = platform_get_drvdata(pdev);
	struct max77693_sub_led *sub_leds = led->sub_leds;

	if (led->iout_joint || max77693_fled_used(led, FLED1)) {
		v4l2_flash_release(sub_leds[FLED1].v4l2_flash);
		led_classdev_flash_unregister(&sub_leds[FLED1].fled_cdev);
		cancel_work_sync(&sub_leds[FLED1].work_brightness_set);
	}

	if (!led->iout_joint && max77693_fled_used(led, FLED2)) {
		v4l2_flash_release(sub_leds[FLED2].v4l2_flash);
		led_classdev_flash_unregister(&sub_leds[FLED2].fled_cdev);
		cancel_work_sync(&sub_leds[FLED2].work_brightness_set);
	}

	mutex_destroy(&led->lock);

	return 0;
}

static const struct of_device_id max77693_led_dt_match[] = {
	{ .compatible = "maxim,max77693-led" },
	{},
};

static struct platform_driver max77693_led_driver = {
	.probe		= max77693_led_probe,
	.remove		= max77693_led_remove,
	.driver		= {
		.name	= "max77693-led",
		.of_match_table = max77693_led_dt_match,
	},
};

module_platform_driver(max77693_led_driver);

MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
MODULE_AUTHOR("Andrzej Hajda <a.hajda@samsung.com>");
MODULE_DESCRIPTION("Maxim MAX77693 led flash driver");
MODULE_LICENSE("GPL v2");