drivers/led/led_lp5562.c - filogic/uboot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2018 Doug Zobel <douglas.zobel@climate.com>
  *
  * Driver for TI lp5562 4 channel LED driver.  There are only 3
  * engines available for the 4 LEDs, so white and blue LEDs share
  * the same engine.  This means that the blink period is shared
  * between them.  Changing the period of blue blink will affect
  * the white period (and vice-versa).  Blue and white On/Off
  * states remain independent (as would PWM brightness if that's
  * ever added to the LED core).
  */

 #include <dm.h>
 #include <errno.h>
 #include <led.h>
 #include <i2c.h>
 #include <asm/gpio.h>
 #include <linux/delay.h>

 #define DEFAULT_CURRENT			100  /* 10 mA */
 #define MIN_BLINK_PERIOD		32   /* ms */
 #define MAX_BLINK_PERIOD		2248 /* ms */

 /* Register Map */
 #define REG_ENABLE			0x00
 #define REG_OP_MODE			0x01
 #define REG_B_PWM			0x02
 #define REG_G_PWM			0x03
 #define REG_R_PWM			0x04
 #define REG_B_CUR			0x05
 #define REG_G_CUR			0x06
 #define REG_R_CUR			0x07
 #define REG_CONFIG			0x08
 #define REG_ENG1_PC			0x09
 #define REG_ENG2_PC			0x0A
 #define REG_ENG3_PC			0x0B
 #define REG_STATUS			0x0C
 #define REG_RESET			0x0D
 #define REG_W_PWM			0x0E
 #define REG_W_CUR			0x0F
 #define REG_ENG1_MEM_BEGIN		0x10
 #define REG_ENG2_MEM_BEGIN		0x30
 #define REG_ENG3_MEM_BEGIN		0x50
 #define REG_LED_MAP			0x70

 /* LED Register Values */
 /* 0x00  ENABLE */
 #define REG_ENABLE_CHIP_ENABLE		(0x1 << 6)
 #define REG_ENABLE_ENG_EXEC_HOLD	0x0
 #define REG_ENABLE_ENG_EXEC_RUN		0x2
 #define REG_ENABLE_ENG_EXEC_MASK	0x3

 /* 0x01  OP MODE */
 #define REG_OP_MODE_DISABLED		0x0
 #define REG_OP_MODE_LOAD_SRAM		0x1
 #define REG_OP_MODE_RUN			0x2
 #define REG_OP_MODE_MASK		0x3

 /* 0x02, 0x03, 0x04, 0x0E  PWM */
 #define REG_PWM_MIN_VALUE		0
 #define REG_PWM_MAX_VALUE		0xFF

 /* 0x08  CONFIG */
 #define REG_CONFIG_EXT_CLK		0x0
 #define REG_CONFIG_INT_CLK		0x1
 #define REG_CONFIG_AUTO_CLK		0x2
 #define REG_CONFIG_CLK_MASK		0x3

 /* 0x0D  RESET */
 #define REG_RESET_RESET			0xFF

 /* 0x70  LED MAP */
 #define REG_LED_MAP_ENG_MASK		0x03
 #define REG_LED_MAP_W_ENG_SHIFT		6
 #define REG_LED_MAP_R_ENG_SHIFT		4
 #define REG_LED_MAP_G_ENG_SHIFT		2
 #define REG_LED_MAP_B_ENG_SHIFT		0

 /* Engine program related */
 #define REG_ENGINE_MEM_SIZE		0x20
 #define LED_PGRM_RAMP_INCREMENT_SHIFT	0
 #define LED_PGRM_RAMP_SIGN_SHIFT	7
 #define LED_PGRM_RAMP_STEP_SHIFT	8
 #define LED_PGRM_RAMP_PRESCALE_SHIFT	14

 struct lp5562_led_wrap_priv {
 	struct gpio_desc enable_gpio;
 };

 struct lp5562_led_priv {
 	u8 reg_pwm;
 	u8 reg_current;
 	u8 map_shift;
 	u8 enginenum;
 };

 /* enum values map to LED_MAP (0x70) values */
 enum lp5562_led_ctl_mode {
 	I2C = 0x0,
 #ifdef CONFIG_LED_BLINK
 	ENGINE1 = 0x1,
 	ENGINE2 = 0x2,
 	ENGINE3 = 0x3
 #endif
 };

 /*
  * Update a register value
  *  dev     - I2C udevice (parent of led)
  *  regnum  - register number to update
  *  value   - value to write to register
  *  mask    - mask of bits that should be changed
  */
 static int lp5562_led_reg_update(struct udevice *dev, int regnum,
 				 u8 value, u8 mask)
 {
 	int ret;

 	if (mask == 0xFF)
 		ret = dm_i2c_reg_write(dev, regnum, value);
 	else
 		ret = dm_i2c_reg_clrset(dev, regnum, mask, value);

 	/*
 	 * Data sheet says "Delay between consecutive I2C writes to
 	 * ENABLE register (00h) need to be longer than 488 us
 	 * (typical)." and "Delay between consecutive I2C writes to
 	 * OP_MODE register need to be longer than 153 us (typ)."
 	 *
 	 * The linux driver does usleep_range(500, 600) and
 	 * usleep_range(200, 300), respectively.
 	 */
 	switch (regnum) {
 	case REG_ENABLE:
 		udelay(600);
 		break;
 	case REG_OP_MODE:
 		udelay(300);
 		break;
 	}

 	return ret;
 }

 #ifdef CONFIG_LED_BLINK
 /*
  * Program the lp5562 engine
  *  dev     - I2C udevice (parent of led)
  *  program - array of commands
  *  size    - number of commands in program array (1-16)
  *  engine  - engine number (1-3)
  */
 static int lp5562_led_program_engine(struct udevice *dev, u16 *program,
 				     u8 size, u8 engine)
 {
 	int ret, cmd;
 	u8 engine_reg = REG_ENG1_MEM_BEGIN +
 			     ((engine - 1) * REG_ENGINE_MEM_SIZE);
 	u8 shift = (3 - engine) * 2;
 	__be16 prog_be[16];

 	if (size < 1 || size > 16 || engine < 1 || engine > 3)
 		return -EINVAL;

 	for (cmd = 0; cmd < size; cmd++)
 		prog_be[cmd] = cpu_to_be16(program[cmd]);

 	/* set engine mode to 'disabled' */
 	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
 				    REG_OP_MODE_DISABLED << shift,
 				    REG_OP_MODE_MASK << shift);
 	if (ret != 0)
 		goto done;

 	/* set exec mode to 'hold' */
 	ret = lp5562_led_reg_update(dev, REG_ENABLE,
 				    REG_ENABLE_ENG_EXEC_HOLD << shift,
 				    REG_ENABLE_ENG_EXEC_MASK << shift);
 	if (ret != 0)
 		goto done;

 	/* set engine mode to 'load SRAM' */
 	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
 				    REG_OP_MODE_LOAD_SRAM << shift,
 				    REG_OP_MODE_MASK << shift);
 	if (ret != 0)
 		goto done;

 	/* send the re-ordered program sequence */
 	ret = dm_i2c_write(dev, engine_reg, (uchar *)prog_be, sizeof(u16) * size);
 	if (ret != 0)
 		goto done;

 	/* set engine mode to 'run' */
 	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
 				    REG_OP_MODE_RUN << shift,
 				    REG_OP_MODE_MASK << shift);
 	if (ret != 0)
 		goto done;

 	/* set engine exec to 'run' */
 	ret = lp5562_led_reg_update(dev, REG_ENABLE,
 				    REG_ENABLE_ENG_EXEC_RUN << shift,
 				    REG_ENABLE_ENG_EXEC_MASK << shift);

 done:
 	return ret;
 }

 /*
  * Get the LED's current control mode (I2C or ENGINE[1-3])
  *  dev       - led udevice (child udevice)
  */
 static enum lp5562_led_ctl_mode lp5562_led_get_control_mode(struct udevice *dev)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);
 	u8 data;
 	enum lp5562_led_ctl_mode mode = I2C;

 	if (dm_i2c_read(dev_get_parent(dev), REG_LED_MAP, &data, 1) == 0)
 		mode = (data & (REG_LED_MAP_ENG_MASK << priv->map_shift))
 			>> priv->map_shift;

 	return mode;
 }
 #endif

 /*
  * Set the LED's control mode to I2C or ENGINE[1-3]
  *  dev       - led udevice (child udevice)
  *  mode      - mode to change to
  */
 static int lp5562_led_set_control_mode(struct udevice *dev,
 				       enum lp5562_led_ctl_mode mode)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);

 	return (lp5562_led_reg_update(dev_get_parent(dev), REG_LED_MAP,
 				      mode << priv->map_shift,
 				      REG_LED_MAP_ENG_MASK << priv->map_shift));
 }

 /*
  * Return the LED's PWM value;  If LED is in BLINK state, then it is
  * under engine control mode which doesn't use this PWM value.
  *  dev       - led udevice (child udevice)
  */
 static int lp5562_led_get_pwm(struct udevice *dev)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);
 	u8 data;

 	if (dm_i2c_read(dev_get_parent(dev), priv->reg_pwm, &data, 1) != 0)
 		return -EINVAL;

 	return data;
 }

 /*
  * Set the LED's PWM value and configure it to use this (I2C mode).
  *  dev       - led udevice (child udevice)
  *  value     - PWM value (0 - 255)
  */
 static int lp5562_led_set_pwm(struct udevice *dev, u8 value)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);

 	if (lp5562_led_reg_update(dev_get_parent(dev), priv->reg_pwm,
 				  value, 0xff) != 0)
 		return -EINVAL;

 	/* set LED to I2C register mode */
 	return lp5562_led_set_control_mode(dev, I2C);
 }

 /*
  * Return the led's current state
  *  dev     - led udevice (child udevice)
  *
  */
 static enum led_state_t lp5562_led_get_state(struct udevice *dev)
 {
 	enum led_state_t state = LEDST_ON;

 	if (lp5562_led_get_pwm(dev) == REG_PWM_MIN_VALUE)
 		state = LEDST_OFF;

 #ifdef CONFIG_LED_BLINK
 	if (lp5562_led_get_control_mode(dev) != I2C)
 		state = LEDST_BLINK;
 #endif

 	return state;
 }

 /*
  * Set the led state
  *  dev     - led udevice (child udevice)
  *  state   - State to set the LED to
  */
 static int lp5562_led_set_state(struct udevice *dev, enum led_state_t state)
 {
 #ifdef CONFIG_LED_BLINK
 	struct lp5562_led_priv *priv = dev_get_priv(dev);
 #endif

 	switch (state) {
 	case LEDST_OFF:
 		return lp5562_led_set_pwm(dev, REG_PWM_MIN_VALUE);
 	case LEDST_ON:
 		return lp5562_led_set_pwm(dev, REG_PWM_MAX_VALUE);
 #ifdef CONFIG_LED_BLINK
 	case LEDST_BLINK:
 		return lp5562_led_set_control_mode(dev, priv->enginenum);
 #endif
 	case LEDST_TOGGLE:
 		if (lp5562_led_get_state(dev) == LEDST_OFF)
 			return lp5562_led_set_state(dev, LEDST_ON);
 		else
 			return lp5562_led_set_state(dev, LEDST_OFF);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 #ifdef CONFIG_LED_BLINK
 /*
  * Set the blink period of an LED; note blue and white share the same
  * engine so changing the period of one affects the other.
  *  dev       - led udevice (child udevice)
  *  period_ms - blink period in ms
  */
 static int lp5562_led_set_period(struct udevice *dev, int period_ms)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);
 	u8 opcode = 0;
 	u16 program[7];
 	u16 wait_time;

 	/* Blink is implemented as an engine program.  Simple on/off
 	 * for short periods, or fade in/fade out for longer periods:
 	 *
 	 *  if (period_ms < 500):
 	 *    set PWM to 100%
 	 *    pause for period / 2
 	 *    set PWM to 0%
 	 *    pause for period / 2
 	 *    goto start
 	 *
 	 *  else
 	 *    raise PWM 0% -> 50% in 62.7 ms
 	 *    raise PWM 50% -> 100% in 62.7 ms
 	 *    pause for (period - 4 * 62.7) / 2
 	 *    lower PWM 100% -> 50% in 62.7 ms
 	 *    lower PWM 50% -> 0% in 62.7 ms
 	 *    pause for (period - 4 * 62.7) / 2
 	 *    goto start
 	 */

 	if (period_ms < MIN_BLINK_PERIOD)
 		period_ms = MIN_BLINK_PERIOD;
 	else if (period_ms > MAX_BLINK_PERIOD)
 		period_ms = MAX_BLINK_PERIOD;

 	if (period_ms < 500) {
 		/* Simple on/off blink */
 		wait_time = period_ms / 2;

 		/* 1st command is full brightness */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			REG_PWM_MAX_VALUE;

 		/* 2nd command is wait (period / 2) using 15.6ms steps */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) |
 			(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 3rd command is 0% brightness */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT);

 		/* 4th command is wait (period / 2) using 15.6ms steps */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) |
 			(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 5th command: repeat */
 		program[opcode++] = 0x00;
 	} else {
 		/* fade-in / fade-out blink */
 		wait_time = ((period_ms - 251) / 2);

 		/* ramp up time is 256 * 0.49ms (125.4ms) done in 2 steps */
 		/* 1st command is ramp up 1/2 way */
 		program[opcode++] =
 			(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(1 << LED_PGRM_RAMP_STEP_SHIFT) |
 			(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 2nd command is ramp up rest of the way */
 		program[opcode++] =
 			(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(1 << LED_PGRM_RAMP_STEP_SHIFT) |
 			(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 3rd: wait ((period - 2 * ramp_time) / 2) (15.6ms steps) */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) |
 			(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* ramp down is same as ramp up with sign bit set */
 		/* 4th command is ramp down 1/2 way */
 		program[opcode++] =
 			(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(1 << LED_PGRM_RAMP_STEP_SHIFT) |
 			(1 << LED_PGRM_RAMP_SIGN_SHIFT) |
 			(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 5th command is ramp down rest of the way */
 		program[opcode++] =
 			(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(1 << LED_PGRM_RAMP_STEP_SHIFT) |
 			(1 << LED_PGRM_RAMP_SIGN_SHIFT) |
 			(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 6th: wait ((period - 2 * ramp_time) / 2) (15.6ms steps) */
 		program[opcode++] =
 			(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) |
 			(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) |
 			(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

 		/* 7th command: repeat */
 		program[opcode++] = 0x00;
 	}

 	return lp5562_led_program_engine(dev_get_parent(dev), program,
 					 opcode, priv->enginenum);
 }
 #endif

 static const struct led_ops lp5562_led_ops = {
 	.get_state = lp5562_led_get_state,
 	.set_state = lp5562_led_set_state,
 #ifdef CONFIG_LED_BLINK
 	.set_period = lp5562_led_set_period,
 #endif
 };

 static int lp5562_led_probe(struct udevice *dev)
 {
 	struct lp5562_led_priv *priv = dev_get_priv(dev);
 	u8 current;
 	int ret = 0;

 	/* Child LED nodes */
 	switch (dev_read_addr(dev)) {
 	case 0:
 		priv->reg_current = REG_R_CUR;
 		priv->reg_pwm = REG_R_PWM;
 		priv->map_shift = REG_LED_MAP_R_ENG_SHIFT;
 		priv->enginenum = 1;
 		break;
 	case 1:
 		priv->reg_current = REG_G_CUR;
 		priv->reg_pwm = REG_G_PWM;
 		priv->map_shift = REG_LED_MAP_G_ENG_SHIFT;
 		priv->enginenum = 2;
 		break;
 	case 2:
 		priv->reg_current = REG_B_CUR;
 		priv->reg_pwm = REG_B_PWM;
 		priv->map_shift = REG_LED_MAP_B_ENG_SHIFT;
 		priv->enginenum = 3; /* shared with white */
 		break;
 	case 3:
 		priv->reg_current = REG_W_CUR;
 		priv->map_shift = REG_LED_MAP_W_ENG_SHIFT;
 		priv->enginenum = 3; /* shared with blue */
 		break;
 	default:
 		return -EINVAL;
 	}

 	current = dev_read_u8_default(dev, "max-cur", DEFAULT_CURRENT);

 	ret = lp5562_led_reg_update(dev_get_parent(dev), priv->reg_current,
 				    current, 0xff);

 	return ret;
 }

 static int lp5562_led_bind(struct udevice *dev)
 {
 	struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);

 	/*
 	 * For the child nodes, parse a "chan-name" property, since
 	 * the DT bindings for this device use that instead of
 	 * "label".
 	 */
 	uc_plat->label = dev_read_string(dev, "chan-name");

 	return 0;
 }

 U_BOOT_DRIVER(lp5562_led) = {
 	.name = "lp5562-led",
 	.id = UCLASS_LED,
 	.bind = lp5562_led_bind,
 	.probe = lp5562_led_probe,
 	.priv_auto = sizeof(struct lp5562_led_priv),
 	.ops = &lp5562_led_ops,
 };

 static int lp5562_led_wrap_probe(struct udevice *dev)
 {
 	struct lp5562_led_wrap_priv *priv = dev_get_priv(dev);
 	u8 clock_mode;
 	int ret;

 	/* Enable gpio if needed */
 	if (gpio_request_by_name(dev, "enabled-gpios", 0,
 				 &priv->enable_gpio, GPIOD_IS_OUT) == 0) {
 		dm_gpio_set_value(&priv->enable_gpio, 1);
 		udelay(1000);
 	}

 	/* Ensure all registers have default values. */
 	ret = lp5562_led_reg_update(dev, REG_RESET, REG_RESET_RESET, 0xff);
 	if (ret)
 		return ret;
 	udelay(10000);

 	/* Enable the chip */
 	ret = lp5562_led_reg_update(dev, REG_ENABLE, REG_ENABLE_CHIP_ENABLE, 0xff);
 	if (ret)
 		return ret;

 	/*
 	 * The DT bindings say 0=auto, 1=internal, 2=external, while
 	 * the register[0:1] values are 0=external, 1=internal,
 	 * 2=auto.
 	 */
 	clock_mode = dev_read_u8_default(dev, "clock-mode", 0);
 	ret = lp5562_led_reg_update(dev, REG_CONFIG, 2 - clock_mode, REG_CONFIG_CLK_MASK);

 	return ret;
 }

 static int lp5562_led_wrap_bind(struct udevice *dev)
 {
 	return led_bind_generic(dev, "lp5562-led");
 }

 static const struct udevice_id lp5562_led_ids[] = {
 	{ .compatible = "ti,lp5562" },
 	{ /* sentinel */ }
 };

 U_BOOT_DRIVER(lp5562_led_wrap) = {
 	.name = "lp5562-led-wrap",
 	.id = UCLASS_NOP,
 	.of_match = lp5562_led_ids,
 	.bind = lp5562_led_wrap_bind,
 	.probe = lp5562_led_wrap_probe,
 	.priv_auto = sizeof(struct lp5562_led_wrap_priv),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* Copyright (C) 2018 Doug Zobel <douglas.zobel@climate.com>
	*
	* Driver for TI lp5562 4 channel LED driver. There are only 3
	* engines available for the 4 LEDs, so white and blue LEDs share
	* the same engine. This means that the blink period is shared
	* between them. Changing the period of blue blink will affect
	* the white period (and vice-versa). Blue and white On/Off
	* states remain independent (as would PWM brightness if that's
	* ever added to the LED core).
	*/

	#include <dm.h>
	#include <errno.h>
	#include <led.h>
	#include <i2c.h>
	#include <asm/gpio.h>
	#include <linux/delay.h>

	#define DEFAULT_CURRENT 100 /* 10 mA */
	#define MIN_BLINK_PERIOD 32 /* ms */
	#define MAX_BLINK_PERIOD 2248 /* ms */

	/* Register Map */
	#define REG_ENABLE 0x00
	#define REG_OP_MODE 0x01
	#define REG_B_PWM 0x02
	#define REG_G_PWM 0x03
	#define REG_R_PWM 0x04
	#define REG_B_CUR 0x05
	#define REG_G_CUR 0x06
	#define REG_R_CUR 0x07
	#define REG_CONFIG 0x08
	#define REG_ENG1_PC 0x09
	#define REG_ENG2_PC 0x0A
	#define REG_ENG3_PC 0x0B
	#define REG_STATUS 0x0C
	#define REG_RESET 0x0D
	#define REG_W_PWM 0x0E
	#define REG_W_CUR 0x0F
	#define REG_ENG1_MEM_BEGIN 0x10
	#define REG_ENG2_MEM_BEGIN 0x30
	#define REG_ENG3_MEM_BEGIN 0x50
	#define REG_LED_MAP 0x70

	/* LED Register Values */
	/* 0x00 ENABLE */
	#define REG_ENABLE_CHIP_ENABLE (0x1 << 6)
	#define REG_ENABLE_ENG_EXEC_HOLD 0x0
	#define REG_ENABLE_ENG_EXEC_RUN 0x2
	#define REG_ENABLE_ENG_EXEC_MASK 0x3

	/* 0x01 OP MODE */
	#define REG_OP_MODE_DISABLED 0x0
	#define REG_OP_MODE_LOAD_SRAM 0x1
	#define REG_OP_MODE_RUN 0x2
	#define REG_OP_MODE_MASK 0x3

	/* 0x02, 0x03, 0x04, 0x0E PWM */
	#define REG_PWM_MIN_VALUE 0
	#define REG_PWM_MAX_VALUE 0xFF

	/* 0x08 CONFIG */
	#define REG_CONFIG_EXT_CLK 0x0
	#define REG_CONFIG_INT_CLK 0x1
	#define REG_CONFIG_AUTO_CLK 0x2
	#define REG_CONFIG_CLK_MASK 0x3

	/* 0x0D RESET */
	#define REG_RESET_RESET 0xFF

	/* 0x70 LED MAP */
	#define REG_LED_MAP_ENG_MASK 0x03
	#define REG_LED_MAP_W_ENG_SHIFT 6
	#define REG_LED_MAP_R_ENG_SHIFT 4
	#define REG_LED_MAP_G_ENG_SHIFT 2
	#define REG_LED_MAP_B_ENG_SHIFT 0

	/* Engine program related */
	#define REG_ENGINE_MEM_SIZE 0x20
	#define LED_PGRM_RAMP_INCREMENT_SHIFT 0
	#define LED_PGRM_RAMP_SIGN_SHIFT 7
	#define LED_PGRM_RAMP_STEP_SHIFT 8
	#define LED_PGRM_RAMP_PRESCALE_SHIFT 14

	struct lp5562_led_wrap_priv {
	struct gpio_desc enable_gpio;
	};

	struct lp5562_led_priv {
	u8 reg_pwm;
	u8 reg_current;
	u8 map_shift;
	u8 enginenum;
	};

	/* enum values map to LED_MAP (0x70) values */
	enum lp5562_led_ctl_mode {
	I2C = 0x0,
	#ifdef CONFIG_LED_BLINK
	ENGINE1 = 0x1,
	ENGINE2 = 0x2,
	ENGINE3 = 0x3
	#endif
	};

	/*
	* Update a register value
	* dev - I2C udevice (parent of led)
	* regnum - register number to update
	* value - value to write to register
	* mask - mask of bits that should be changed
	*/
	static int lp5562_led_reg_update(struct udevice *dev, int regnum,
	u8 value, u8 mask)
	{
	int ret;

	if (mask == 0xFF)
	ret = dm_i2c_reg_write(dev, regnum, value);
	else
	ret = dm_i2c_reg_clrset(dev, regnum, mask, value);

	/*
	* Data sheet says "Delay between consecutive I2C writes to
	* ENABLE register (00h) need to be longer than 488 us
	* (typical)." and "Delay between consecutive I2C writes to
	* OP_MODE register need to be longer than 153 us (typ)."
	*
	* The linux driver does usleep_range(500, 600) and
	* usleep_range(200, 300), respectively.
	*/
	switch (regnum) {
	case REG_ENABLE:
	udelay(600);
	break;
	case REG_OP_MODE:
	udelay(300);
	break;
	}

	return ret;
	}

	#ifdef CONFIG_LED_BLINK
	/*
	* Program the lp5562 engine
	* dev - I2C udevice (parent of led)
	* program - array of commands
	* size - number of commands in program array (1-16)
	* engine - engine number (1-3)
	*/
	static int lp5562_led_program_engine(struct udevice dev, u16 program,
	u8 size, u8 engine)
	{
	int ret, cmd;
	u8 engine_reg = REG_ENG1_MEM_BEGIN +
	((engine - 1) * REG_ENGINE_MEM_SIZE);
	u8 shift = (3 - engine) * 2;
	__be16 prog_be[16];

	if (size < 1 \|\| size > 16 \|\| engine < 1 \|\| engine > 3)
	return -EINVAL;

	for (cmd = 0; cmd < size; cmd++)
	prog_be[cmd] = cpu_to_be16(program[cmd]);

	/* set engine mode to 'disabled' */
	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
	REG_OP_MODE_DISABLED << shift,
	REG_OP_MODE_MASK << shift);
	if (ret != 0)
	goto done;

	/* set exec mode to 'hold' */
	ret = lp5562_led_reg_update(dev, REG_ENABLE,
	REG_ENABLE_ENG_EXEC_HOLD << shift,
	REG_ENABLE_ENG_EXEC_MASK << shift);
	if (ret != 0)
	goto done;

	/* set engine mode to 'load SRAM' */
	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
	REG_OP_MODE_LOAD_SRAM << shift,
	REG_OP_MODE_MASK << shift);
	if (ret != 0)
	goto done;

	/* send the re-ordered program sequence */
	ret = dm_i2c_write(dev, engine_reg, (uchar )prog_be, sizeof(u16) size);
	if (ret != 0)
	goto done;

	/* set engine mode to 'run' */
	ret = lp5562_led_reg_update(dev, REG_OP_MODE,
	REG_OP_MODE_RUN << shift,
	REG_OP_MODE_MASK << shift);
	if (ret != 0)
	goto done;

	/* set engine exec to 'run' */
	ret = lp5562_led_reg_update(dev, REG_ENABLE,
	REG_ENABLE_ENG_EXEC_RUN << shift,
	REG_ENABLE_ENG_EXEC_MASK << shift);

	done:
	return ret;
	}

	/*
	* Get the LED's current control mode (I2C or ENGINE[1-3])
	* dev - led udevice (child udevice)
	*/
	static enum lp5562_led_ctl_mode lp5562_led_get_control_mode(struct udevice *dev)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);
	u8 data;
	enum lp5562_led_ctl_mode mode = I2C;

	if (dm_i2c_read(dev_get_parent(dev), REG_LED_MAP, &data, 1) == 0)
	mode = (data & (REG_LED_MAP_ENG_MASK << priv->map_shift))
	>> priv->map_shift;

	return mode;
	}
	#endif

	/*
	* Set the LED's control mode to I2C or ENGINE[1-3]
	* dev - led udevice (child udevice)
	* mode - mode to change to
	*/
	static int lp5562_led_set_control_mode(struct udevice *dev,
	enum lp5562_led_ctl_mode mode)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);

	return (lp5562_led_reg_update(dev_get_parent(dev), REG_LED_MAP,
	mode << priv->map_shift,
	REG_LED_MAP_ENG_MASK << priv->map_shift));
	}

	/*
	* Return the LED's PWM value; If LED is in BLINK state, then it is
	* under engine control mode which doesn't use this PWM value.
	* dev - led udevice (child udevice)
	*/
	static int lp5562_led_get_pwm(struct udevice *dev)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);
	u8 data;

	if (dm_i2c_read(dev_get_parent(dev), priv->reg_pwm, &data, 1) != 0)
	return -EINVAL;

	return data;
	}

	/*
	* Set the LED's PWM value and configure it to use this (I2C mode).
	* dev - led udevice (child udevice)
	* value - PWM value (0 - 255)
	*/
	static int lp5562_led_set_pwm(struct udevice *dev, u8 value)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);

	if (lp5562_led_reg_update(dev_get_parent(dev), priv->reg_pwm,
	value, 0xff) != 0)
	return -EINVAL;

	/* set LED to I2C register mode */
	return lp5562_led_set_control_mode(dev, I2C);
	}

	/*
	* Return the led's current state
	* dev - led udevice (child udevice)
	*
	*/
	static enum led_state_t lp5562_led_get_state(struct udevice *dev)
	{
	enum led_state_t state = LEDST_ON;

	if (lp5562_led_get_pwm(dev) == REG_PWM_MIN_VALUE)
	state = LEDST_OFF;

	#ifdef CONFIG_LED_BLINK
	if (lp5562_led_get_control_mode(dev) != I2C)
	state = LEDST_BLINK;
	#endif

	return state;
	}

	/*
	* Set the led state
	* dev - led udevice (child udevice)
	* state - State to set the LED to
	*/
	static int lp5562_led_set_state(struct udevice *dev, enum led_state_t state)
	{
	#ifdef CONFIG_LED_BLINK
	struct lp5562_led_priv *priv = dev_get_priv(dev);
	#endif

	switch (state) {
	case LEDST_OFF:
	return lp5562_led_set_pwm(dev, REG_PWM_MIN_VALUE);
	case LEDST_ON:
	return lp5562_led_set_pwm(dev, REG_PWM_MAX_VALUE);
	#ifdef CONFIG_LED_BLINK
	case LEDST_BLINK:
	return lp5562_led_set_control_mode(dev, priv->enginenum);
	#endif
	case LEDST_TOGGLE:
	if (lp5562_led_get_state(dev) == LEDST_OFF)
	return lp5562_led_set_state(dev, LEDST_ON);
	else
	return lp5562_led_set_state(dev, LEDST_OFF);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	#ifdef CONFIG_LED_BLINK
	/*
	* Set the blink period of an LED; note blue and white share the same
	* engine so changing the period of one affects the other.
	* dev - led udevice (child udevice)
	* period_ms - blink period in ms
	*/
	static int lp5562_led_set_period(struct udevice *dev, int period_ms)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);
	u8 opcode = 0;
	u16 program[7];
	u16 wait_time;

	/* Blink is implemented as an engine program. Simple on/off
	* for short periods, or fade in/fade out for longer periods:
	*
	* if (period_ms < 500):
	* set PWM to 100%
	* pause for period / 2
	* set PWM to 0%
	* pause for period / 2
	* goto start
	*
	* else
	* raise PWM 0% -> 50% in 62.7 ms
	* raise PWM 50% -> 100% in 62.7 ms
	* pause for (period - 4 * 62.7) / 2
	* lower PWM 100% -> 50% in 62.7 ms
	* lower PWM 50% -> 0% in 62.7 ms
	* pause for (period - 4 * 62.7) / 2
	* goto start
	*/

	if (period_ms < MIN_BLINK_PERIOD)
	period_ms = MIN_BLINK_PERIOD;
	else if (period_ms > MAX_BLINK_PERIOD)
	period_ms = MAX_BLINK_PERIOD;

	if (period_ms < 500) {
	/* Simple on/off blink */
	wait_time = period_ms / 2;

	/* 1st command is full brightness */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	REG_PWM_MAX_VALUE;

	/* 2nd command is wait (period / 2) using 15.6ms steps */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) \|
	(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 3rd command is 0% brightness */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT);

	/* 4th command is wait (period / 2) using 15.6ms steps */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) \|
	(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 5th command: repeat */
	program[opcode++] = 0x00;
	} else {
	/* fade-in / fade-out blink */
	wait_time = ((period_ms - 251) / 2);

	/* ramp up time is 256 * 0.49ms (125.4ms) done in 2 steps */
	/* 1st command is ramp up 1/2 way */
	program[opcode++] =
	(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(1 << LED_PGRM_RAMP_STEP_SHIFT) \|
	(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 2nd command is ramp up rest of the way */
	program[opcode++] =
	(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(1 << LED_PGRM_RAMP_STEP_SHIFT) \|
	(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 3rd: wait ((period - 2 * ramp_time) / 2) (15.6ms steps) */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) \|
	(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* ramp down is same as ramp up with sign bit set */
	/* 4th command is ramp down 1/2 way */
	program[opcode++] =
	(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(1 << LED_PGRM_RAMP_STEP_SHIFT) \|
	(1 << LED_PGRM_RAMP_SIGN_SHIFT) \|
	(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 5th command is ramp down rest of the way */
	program[opcode++] =
	(0 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(1 << LED_PGRM_RAMP_STEP_SHIFT) \|
	(1 << LED_PGRM_RAMP_SIGN_SHIFT) \|
	(127 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 6th: wait ((period - 2 * ramp_time) / 2) (15.6ms steps) */
	program[opcode++] =
	(1 << LED_PGRM_RAMP_PRESCALE_SHIFT) \|
	(((wait_time * 10) / 156) << LED_PGRM_RAMP_STEP_SHIFT) \|
	(0 << LED_PGRM_RAMP_INCREMENT_SHIFT);

	/* 7th command: repeat */
	program[opcode++] = 0x00;
	}

	return lp5562_led_program_engine(dev_get_parent(dev), program,
	opcode, priv->enginenum);
	}
	#endif

	static const struct led_ops lp5562_led_ops = {
	.get_state = lp5562_led_get_state,
	.set_state = lp5562_led_set_state,
	#ifdef CONFIG_LED_BLINK
	.set_period = lp5562_led_set_period,
	#endif
	};

	static int lp5562_led_probe(struct udevice *dev)
	{
	struct lp5562_led_priv *priv = dev_get_priv(dev);
	u8 current;
	int ret = 0;

	/* Child LED nodes */
	switch (dev_read_addr(dev)) {
	case 0:
	priv->reg_current = REG_R_CUR;
	priv->reg_pwm = REG_R_PWM;
	priv->map_shift = REG_LED_MAP_R_ENG_SHIFT;
	priv->enginenum = 1;
	break;
	case 1:
	priv->reg_current = REG_G_CUR;
	priv->reg_pwm = REG_G_PWM;
	priv->map_shift = REG_LED_MAP_G_ENG_SHIFT;
	priv->enginenum = 2;
	break;
	case 2:
	priv->reg_current = REG_B_CUR;
	priv->reg_pwm = REG_B_PWM;
	priv->map_shift = REG_LED_MAP_B_ENG_SHIFT;
	priv->enginenum = 3; /* shared with white */
	break;
	case 3:
	priv->reg_current = REG_W_CUR;
	priv->map_shift = REG_LED_MAP_W_ENG_SHIFT;
	priv->enginenum = 3; /* shared with blue */
	break;
	default:
	return -EINVAL;
	}

	current = dev_read_u8_default(dev, "max-cur", DEFAULT_CURRENT);

	ret = lp5562_led_reg_update(dev_get_parent(dev), priv->reg_current,
	current, 0xff);

	return ret;
	}

	static int lp5562_led_bind(struct udevice *dev)
	{
	struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);

	/*
	* For the child nodes, parse a "chan-name" property, since
	* the DT bindings for this device use that instead of
	* "label".
	*/
	uc_plat->label = dev_read_string(dev, "chan-name");

	return 0;
	}

	U_BOOT_DRIVER(lp5562_led) = {
	.name = "lp5562-led",
	.id = UCLASS_LED,
	.bind = lp5562_led_bind,
	.probe = lp5562_led_probe,
	.priv_auto = sizeof(struct lp5562_led_priv),
	.ops = &lp5562_led_ops,
	};

	static int lp5562_led_wrap_probe(struct udevice *dev)
	{
	struct lp5562_led_wrap_priv *priv = dev_get_priv(dev);
	u8 clock_mode;
	int ret;

	/* Enable gpio if needed */
	if (gpio_request_by_name(dev, "enabled-gpios", 0,
	&priv->enable_gpio, GPIOD_IS_OUT) == 0) {
	dm_gpio_set_value(&priv->enable_gpio, 1);
	udelay(1000);
	}

	/* Ensure all registers have default values. */
	ret = lp5562_led_reg_update(dev, REG_RESET, REG_RESET_RESET, 0xff);
	if (ret)
	return ret;
	udelay(10000);

	/* Enable the chip */
	ret = lp5562_led_reg_update(dev, REG_ENABLE, REG_ENABLE_CHIP_ENABLE, 0xff);
	if (ret)
	return ret;

	/*
	* The DT bindings say 0=auto, 1=internal, 2=external, while
	* the register[0:1] values are 0=external, 1=internal,
	* 2=auto.
	*/
	clock_mode = dev_read_u8_default(dev, "clock-mode", 0);
	ret = lp5562_led_reg_update(dev, REG_CONFIG, 2 - clock_mode, REG_CONFIG_CLK_MASK);

	return ret;
	}

	static int lp5562_led_wrap_bind(struct udevice *dev)
	{
	return led_bind_generic(dev, "lp5562-led");
	}

	static const struct udevice_id lp5562_led_ids[] = {
	{ .compatible = "ti,lp5562" },
	{ /* sentinel */ }
	};

	U_BOOT_DRIVER(lp5562_led_wrap) = {
	.name = "lp5562-led-wrap",
	.id = UCLASS_NOP,
	.of_match = lp5562_led_ids,
	.bind = lp5562_led_wrap_bind,
	.probe = lp5562_led_wrap_probe,
	.priv_auto = sizeof(struct lp5562_led_wrap_priv),
	};