drivers/regulator/lp8788-buck.c - kernel/msm-4.9 - Gitiles

 /*
  * TI LP8788 MFD - buck regulator driver
  *
  * Copyright 2012 Texas Instruments
  *
  * Author: Milo(Woogyom) Kim <milo.kim@ti.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/module.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/mfd/lp8788.h>
 #include <linux/gpio.h>

 /* register address */
 #define LP8788_EN_BUCK			0x0C
 #define LP8788_BUCK_DVS_SEL		0x1D
 #define LP8788_BUCK1_VOUT0		0x1E
 #define LP8788_BUCK1_VOUT1		0x1F
 #define LP8788_BUCK1_VOUT2		0x20
 #define LP8788_BUCK1_VOUT3		0x21
 #define LP8788_BUCK2_VOUT0		0x22
 #define LP8788_BUCK2_VOUT1		0x23
 #define LP8788_BUCK2_VOUT2		0x24
 #define LP8788_BUCK2_VOUT3		0x25
 #define LP8788_BUCK3_VOUT		0x26
 #define LP8788_BUCK4_VOUT		0x27
 #define LP8788_BUCK1_TIMESTEP		0x28
 #define LP8788_BUCK_PWM			0x2D

 /* mask/shift bits */
 #define LP8788_EN_BUCK1_M		BIT(0)	/* Addr 0Ch */
 #define LP8788_EN_BUCK2_M		BIT(1)
 #define LP8788_EN_BUCK3_M		BIT(2)
 #define LP8788_EN_BUCK4_M		BIT(3)
 #define LP8788_BUCK1_DVS_SEL_M		0x04	/* Addr 1Dh */
 #define LP8788_BUCK1_DVS_M		0x03
 #define LP8788_BUCK1_DVS_S		0
 #define LP8788_BUCK2_DVS_SEL_M		0x40
 #define LP8788_BUCK2_DVS_M		0x30
 #define LP8788_BUCK2_DVS_S		4
 #define LP8788_BUCK1_DVS_I2C		BIT(2)
 #define LP8788_BUCK2_DVS_I2C		BIT(6)
 #define LP8788_BUCK1_DVS_PIN		(0 << 2)
 #define LP8788_BUCK2_DVS_PIN		(0 << 6)
 #define LP8788_VOUT_M			0x1F	/* Addr 1Eh ~ 27h */
 #define LP8788_STARTUP_TIME_M		0xF8	/* Addr 28h ~ 2Bh */
 #define LP8788_STARTUP_TIME_S		3
 #define LP8788_FPWM_BUCK1_M		BIT(0)	/* Addr 2Dh */
 #define LP8788_FPWM_BUCK1_S		0
 #define LP8788_FPWM_BUCK2_M		BIT(1)
 #define LP8788_FPWM_BUCK2_S		1
 #define LP8788_FPWM_BUCK3_M		BIT(2)
 #define LP8788_FPWM_BUCK3_S		2
 #define LP8788_FPWM_BUCK4_M		BIT(3)
 #define LP8788_FPWM_BUCK4_S		3

 #define INVALID_ADDR			0xFF
 #define LP8788_FORCE_PWM		1
 #define LP8788_AUTO_PWM			0
 #define PIN_LOW				0
 #define PIN_HIGH			1
 #define ENABLE_TIME_USEC		32

 #define BUCK_FPWM_MASK(x)		(1 << (x))
 #define BUCK_FPWM_SHIFT(x)		(x)

 enum lp8788_dvs_state {
 	DVS_LOW  = GPIOF_OUT_INIT_LOW,
 	DVS_HIGH = GPIOF_OUT_INIT_HIGH,
 };

 enum lp8788_dvs_mode {
 	REGISTER,
 	EXTPIN,
 };

 enum lp8788_buck_id {
 	BUCK1,
 	BUCK2,
 	BUCK3,
 	BUCK4,
 };

 struct lp8788_buck {
 	struct lp8788 *lp;
 	struct regulator_dev *regulator;
 	void *dvs;
 };

 /* BUCK 1 ~ 4 voltage table */
 static const int lp8788_buck_vtbl[] = {
 	 500000,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
 	1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
 	1550000, 1600000, 1650000, 1700000, 1750000, 1800000, 1850000, 1900000,
 	1950000, 2000000,
 };

 static void lp8788_buck1_set_dvs(struct lp8788_buck *buck)
 {
 	struct lp8788_buck1_dvs *dvs = (struct lp8788_buck1_dvs *)buck->dvs;
 	enum lp8788_dvs_state pinstate;

 	if (!dvs)
 		return;

 	pinstate = dvs->vsel == DVS_SEL_V0 ? DVS_LOW : DVS_HIGH;
 	if (gpio_is_valid(dvs->gpio))
 		gpio_set_value(dvs->gpio, pinstate);
 }

 static void lp8788_buck2_set_dvs(struct lp8788_buck *buck)
 {
 	struct lp8788_buck2_dvs *dvs = (struct lp8788_buck2_dvs *)buck->dvs;
 	enum lp8788_dvs_state pin1, pin2;

 	if (!dvs)
 		return;

 	switch (dvs->vsel) {
 	case DVS_SEL_V0:
 		pin1 = DVS_LOW;
 		pin2 = DVS_LOW;
 		break;
 	case DVS_SEL_V1:
 		pin1 = DVS_HIGH;
 		pin2 = DVS_LOW;
 		break;
 	case DVS_SEL_V2:
 		pin1 = DVS_LOW;
 		pin2 = DVS_HIGH;
 		break;
 	case DVS_SEL_V3:
 		pin1 = DVS_HIGH;
 		pin2 = DVS_HIGH;
 		break;
 	default:
 		return;
 	}

 	if (gpio_is_valid(dvs->gpio[0]))
 		gpio_set_value(dvs->gpio[0], pin1);

 	if (gpio_is_valid(dvs->gpio[1]))
 		gpio_set_value(dvs->gpio[1], pin2);
 }

 static void lp8788_set_dvs(struct lp8788_buck *buck, enum lp8788_buck_id id)
 {
 	switch (id) {
 	case BUCK1:
 		lp8788_buck1_set_dvs(buck);
 		break;
 	case BUCK2:
 		lp8788_buck2_set_dvs(buck);
 		break;
 	default:
 		break;
 	}
 }

 static enum lp8788_dvs_mode
 lp8788_get_buck_dvs_ctrl_mode(struct lp8788_buck *buck, enum lp8788_buck_id id)
 {
 	u8 val, mask;

 	switch (id) {
 	case BUCK1:
 		mask = LP8788_BUCK1_DVS_SEL_M;
 		break;
 	case BUCK2:
 		mask = LP8788_BUCK2_DVS_SEL_M;
 		break;
 	default:
 		return REGISTER;
 	}

 	lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);

 	return val & mask ? REGISTER : EXTPIN;
 }

 static bool lp8788_is_valid_buck_addr(u8 addr)
 {
 	switch (addr) {
 	case LP8788_BUCK1_VOUT0:
 	case LP8788_BUCK1_VOUT1:
 	case LP8788_BUCK1_VOUT2:
 	case LP8788_BUCK1_VOUT3:
 	case LP8788_BUCK2_VOUT0:
 	case LP8788_BUCK2_VOUT1:
 	case LP8788_BUCK2_VOUT2:
 	case LP8788_BUCK2_VOUT3:
 		return true;
 	default:
 		return false;
 	}
 }

 static u8 lp8788_select_buck_vout_addr(struct lp8788_buck *buck,
 					enum lp8788_buck_id id)
 {
 	enum lp8788_dvs_mode mode = lp8788_get_buck_dvs_ctrl_mode(buck, id);
 	struct lp8788_buck1_dvs *b1_dvs;
 	struct lp8788_buck2_dvs *b2_dvs;
 	u8 val, idx, addr;
 	int pin1, pin2;

 	switch (id) {
 	case BUCK1:
 		if (mode == EXTPIN) {
 			b1_dvs = (struct lp8788_buck1_dvs *)buck->dvs;
 			if (!b1_dvs)
 				goto err;

 			idx = gpio_get_value(b1_dvs->gpio) ? 1 : 0;
 		} else {
 			lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);
 			idx = (val & LP8788_BUCK1_DVS_M) >> LP8788_BUCK1_DVS_S;
 		}
 		addr = LP8788_BUCK1_VOUT0 + idx;
 		break;
 	case BUCK2:
 		if (mode == EXTPIN) {
 			b2_dvs = (struct lp8788_buck2_dvs *)buck->dvs;
 			if (!b2_dvs)
 				goto err;

 			pin1 = gpio_get_value(b2_dvs->gpio[0]);
 			pin2 = gpio_get_value(b2_dvs->gpio[1]);

 			if (pin1 == PIN_LOW && pin2 == PIN_LOW)
 				idx = 0;
 			else if (pin1 == PIN_LOW && pin2 == PIN_HIGH)
 				idx = 2;
 			else if (pin1 == PIN_HIGH && pin2 == PIN_LOW)
 				idx = 1;
 			else
 				idx = 3;
 		} else {
 			lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);
 			idx = (val & LP8788_BUCK2_DVS_M) >> LP8788_BUCK2_DVS_S;
 		}
 		addr = LP8788_BUCK2_VOUT0 + idx;
 		break;
 	default:
 		goto err;
 	}

 	return addr;
 err:
 	return INVALID_ADDR;
 }

 static int lp8788_buck12_set_voltage_sel(struct regulator_dev *rdev,
 					unsigned selector)
 {
 	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
 	enum lp8788_buck_id id = rdev_get_id(rdev);
 	u8 addr;

 	if (buck->dvs)
 		lp8788_set_dvs(buck, id);

 	addr = lp8788_select_buck_vout_addr(buck, id);
 	if (!lp8788_is_valid_buck_addr(addr))
 		return -EINVAL;

 	return lp8788_update_bits(buck->lp, addr, LP8788_VOUT_M, selector);
 }

 static int lp8788_buck12_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
 	enum lp8788_buck_id id = rdev_get_id(rdev);
 	int ret;
 	u8 val, addr;

 	addr = lp8788_select_buck_vout_addr(buck, id);
 	if (!lp8788_is_valid_buck_addr(addr))
 		return -EINVAL;

 	ret = lp8788_read_byte(buck->lp, addr, &val);
 	if (ret)
 		return ret;

 	return val & LP8788_VOUT_M;
 }

 static int lp8788_buck_enable_time(struct regulator_dev *rdev)
 {
 	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
 	enum lp8788_buck_id id = rdev_get_id(rdev);
 	u8 val, addr = LP8788_BUCK1_TIMESTEP + id;

 	if (lp8788_read_byte(buck->lp, addr, &val))
 		return -EINVAL;

 	val = (val & LP8788_STARTUP_TIME_M) >> LP8788_STARTUP_TIME_S;

 	return ENABLE_TIME_USEC * val;
 }

 static int lp8788_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
 {
 	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
 	enum lp8788_buck_id id = rdev_get_id(rdev);
 	u8 mask, val;

 	mask = BUCK_FPWM_MASK(id);
 	switch (mode) {
 	case REGULATOR_MODE_FAST:
 		val = LP8788_FORCE_PWM << BUCK_FPWM_SHIFT(id);
 		break;
 	case REGULATOR_MODE_NORMAL:
 		val = LP8788_AUTO_PWM << BUCK_FPWM_SHIFT(id);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return lp8788_update_bits(buck->lp, LP8788_BUCK_PWM, mask, val);
 }

 static unsigned int lp8788_buck_get_mode(struct regulator_dev *rdev)
 {
 	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
 	enum lp8788_buck_id id = rdev_get_id(rdev);
 	u8 val;
 	int ret;

 	ret = lp8788_read_byte(buck->lp, LP8788_BUCK_PWM, &val);
 	if (ret)
 		return ret;

 	return val & BUCK_FPWM_MASK(id) ?
 				REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
 }

 static struct regulator_ops lp8788_buck12_ops = {
 	.list_voltage = regulator_list_voltage_table,
 	.map_voltage = regulator_map_voltage_ascend,
 	.set_voltage_sel = lp8788_buck12_set_voltage_sel,
 	.get_voltage_sel = lp8788_buck12_get_voltage_sel,
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 	.enable_time = lp8788_buck_enable_time,
 	.set_mode = lp8788_buck_set_mode,
 	.get_mode = lp8788_buck_get_mode,
 };

 static struct regulator_ops lp8788_buck34_ops = {
 	.list_voltage = regulator_list_voltage_table,
 	.map_voltage = regulator_map_voltage_ascend,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 	.enable_time = lp8788_buck_enable_time,
 	.set_mode = lp8788_buck_set_mode,
 	.get_mode = lp8788_buck_get_mode,
 };

 static struct regulator_desc lp8788_buck_desc[] = {
 	{
 		.name = "buck1",
 		.id = BUCK1,
 		.ops = &lp8788_buck12_ops,
 		.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
 		.volt_table = lp8788_buck_vtbl,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_reg = LP8788_EN_BUCK,
 		.enable_mask = LP8788_EN_BUCK1_M,
 	},
 	{
 		.name = "buck2",
 		.id = BUCK2,
 		.ops = &lp8788_buck12_ops,
 		.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
 		.volt_table = lp8788_buck_vtbl,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.enable_reg = LP8788_EN_BUCK,
 		.enable_mask = LP8788_EN_BUCK2_M,
 	},
 	{
 		.name = "buck3",
 		.id = BUCK3,
 		.ops = &lp8788_buck34_ops,
 		.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
 		.volt_table = lp8788_buck_vtbl,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.vsel_reg = LP8788_BUCK3_VOUT,
 		.vsel_mask = LP8788_VOUT_M,
 		.enable_reg = LP8788_EN_BUCK,
 		.enable_mask = LP8788_EN_BUCK3_M,
 	},
 	{
 		.name = "buck4",
 		.id = BUCK4,
 		.ops = &lp8788_buck34_ops,
 		.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
 		.volt_table = lp8788_buck_vtbl,
 		.type = REGULATOR_VOLTAGE,
 		.owner = THIS_MODULE,
 		.vsel_reg = LP8788_BUCK4_VOUT,
 		.vsel_mask = LP8788_VOUT_M,
 		.enable_reg = LP8788_EN_BUCK,
 		.enable_mask = LP8788_EN_BUCK4_M,
 	},
 };

 static int lp8788_dvs_gpio_request(struct platform_device *pdev,
 				struct lp8788_buck *buck,
 				enum lp8788_buck_id id)
 {
 	struct lp8788_platform_data *pdata = buck->lp->pdata;
 	char *b1_name = "LP8788_B1_DVS";
 	char *b2_name[] = { "LP8788_B2_DVS1", "LP8788_B2_DVS2" };
 	int i, gpio, ret;

 	switch (id) {
 	case BUCK1:
 		gpio = pdata->buck1_dvs->gpio;
 		ret = devm_gpio_request_one(&pdev->dev, gpio, DVS_LOW,
 					    b1_name);
 		if (ret)
 			return ret;

 		buck->dvs = pdata->buck1_dvs;
 		break;
 	case BUCK2:
 		for (i = 0; i < LP8788_NUM_BUCK2_DVS; i++) {
 			gpio = pdata->buck2_dvs->gpio[i];
 			ret = devm_gpio_request_one(&pdev->dev, gpio,
 						    DVS_LOW, b2_name[i]);
 			if (ret)
 				return ret;
 		}
 		buck->dvs = pdata->buck2_dvs;
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 static int lp8788_init_dvs(struct platform_device *pdev,
 			struct lp8788_buck *buck, enum lp8788_buck_id id)
 {
 	struct lp8788_platform_data *pdata = buck->lp->pdata;
 	u8 mask[] = { LP8788_BUCK1_DVS_SEL_M, LP8788_BUCK2_DVS_SEL_M };
 	u8 val[]  = { LP8788_BUCK1_DVS_PIN, LP8788_BUCK2_DVS_PIN };
 	u8 default_dvs_mode[] = { LP8788_BUCK1_DVS_I2C, LP8788_BUCK2_DVS_I2C };

 	/* no dvs for buck3, 4 */
 	if (id > BUCK2)
 		return 0;

 	/* no dvs platform data, then dvs will be selected by I2C registers */
 	if (!pdata)
 		goto set_default_dvs_mode;

 	if ((id == BUCK1 && !pdata->buck1_dvs) ||
 		(id == BUCK2 && !pdata->buck2_dvs))
 		goto set_default_dvs_mode;

 	if (lp8788_dvs_gpio_request(pdev, buck, id))
 		goto set_default_dvs_mode;

 	return lp8788_update_bits(buck->lp, LP8788_BUCK_DVS_SEL, mask[id],
 				val[id]);

 set_default_dvs_mode:
 	return lp8788_update_bits(buck->lp, LP8788_BUCK_DVS_SEL, mask[id],
 				  default_dvs_mode[id]);
 }

 static int lp8788_buck_probe(struct platform_device *pdev)
 {
 	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
 	int id = pdev->id;
 	struct lp8788_buck *buck;
 	struct regulator_config cfg = { };
 	struct regulator_dev *rdev;
 	int ret;

 	if (id >= LP8788_NUM_BUCKS)
 		return -EINVAL;

 	buck = devm_kzalloc(&pdev->dev, sizeof(struct lp8788_buck), GFP_KERNEL);
 	if (!buck)
 		return -ENOMEM;

 	buck->lp = lp;

 	ret = lp8788_init_dvs(pdev, buck, id);
 	if (ret)
 		return ret;

 	cfg.dev = pdev->dev.parent;
 	cfg.init_data = lp->pdata ? lp->pdata->buck_data[id] : NULL;
 	cfg.driver_data = buck;
 	cfg.regmap = lp->regmap;

 	rdev = regulator_register(&lp8788_buck_desc[id], &cfg);
 	if (IS_ERR(rdev)) {
 		ret = PTR_ERR(rdev);
 		dev_err(&pdev->dev, "BUCK%d regulator register err = %d\n",
 				id + 1, ret);
 		return ret;
 	}

 	buck->regulator = rdev;
 	platform_set_drvdata(pdev, buck);

 	return 0;
 }

 static int lp8788_buck_remove(struct platform_device *pdev)
 {
 	struct lp8788_buck *buck = platform_get_drvdata(pdev);

 	platform_set_drvdata(pdev, NULL);
 	regulator_unregister(buck->regulator);

 	return 0;
 }

 static struct platform_driver lp8788_buck_driver = {
 	.probe = lp8788_buck_probe,
 	.remove = lp8788_buck_remove,
 	.driver = {
 		.name = LP8788_DEV_BUCK,
 		.owner = THIS_MODULE,
 	},
 };

 static int __init lp8788_buck_init(void)
 {
 	return platform_driver_register(&lp8788_buck_driver);
 }
 subsys_initcall(lp8788_buck_init);

 static void __exit lp8788_buck_exit(void)
 {
 	platform_driver_unregister(&lp8788_buck_driver);
 }
 module_exit(lp8788_buck_exit);

 MODULE_DESCRIPTION("TI LP8788 BUCK Driver");
 MODULE_AUTHOR("Milo Kim");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:lp8788-buck");
	/*
	* TI LP8788 MFD - buck regulator driver
	*
	* Copyright 2012 Texas Instruments
	*
	* Author: Milo(Woogyom) Kim <milo.kim@ti.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/module.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/driver.h>
	#include <linux/mfd/lp8788.h>
	#include <linux/gpio.h>

	/* register address */
	#define LP8788_EN_BUCK 0x0C
	#define LP8788_BUCK_DVS_SEL 0x1D
	#define LP8788_BUCK1_VOUT0 0x1E
	#define LP8788_BUCK1_VOUT1 0x1F
	#define LP8788_BUCK1_VOUT2 0x20
	#define LP8788_BUCK1_VOUT3 0x21
	#define LP8788_BUCK2_VOUT0 0x22
	#define LP8788_BUCK2_VOUT1 0x23
	#define LP8788_BUCK2_VOUT2 0x24
	#define LP8788_BUCK2_VOUT3 0x25
	#define LP8788_BUCK3_VOUT 0x26
	#define LP8788_BUCK4_VOUT 0x27
	#define LP8788_BUCK1_TIMESTEP 0x28
	#define LP8788_BUCK_PWM 0x2D

	/* mask/shift bits */
	#define LP8788_EN_BUCK1_M BIT(0) /* Addr 0Ch */
	#define LP8788_EN_BUCK2_M BIT(1)
	#define LP8788_EN_BUCK3_M BIT(2)
	#define LP8788_EN_BUCK4_M BIT(3)
	#define LP8788_BUCK1_DVS_SEL_M 0x04 /* Addr 1Dh */
	#define LP8788_BUCK1_DVS_M 0x03
	#define LP8788_BUCK1_DVS_S 0
	#define LP8788_BUCK2_DVS_SEL_M 0x40
	#define LP8788_BUCK2_DVS_M 0x30
	#define LP8788_BUCK2_DVS_S 4
	#define LP8788_BUCK1_DVS_I2C BIT(2)
	#define LP8788_BUCK2_DVS_I2C BIT(6)
	#define LP8788_BUCK1_DVS_PIN (0 << 2)
	#define LP8788_BUCK2_DVS_PIN (0 << 6)
	#define LP8788_VOUT_M 0x1F /* Addr 1Eh ~ 27h */
	#define LP8788_STARTUP_TIME_M 0xF8 /* Addr 28h ~ 2Bh */
	#define LP8788_STARTUP_TIME_S 3
	#define LP8788_FPWM_BUCK1_M BIT(0) /* Addr 2Dh */
	#define LP8788_FPWM_BUCK1_S 0
	#define LP8788_FPWM_BUCK2_M BIT(1)
	#define LP8788_FPWM_BUCK2_S 1
	#define LP8788_FPWM_BUCK3_M BIT(2)
	#define LP8788_FPWM_BUCK3_S 2
	#define LP8788_FPWM_BUCK4_M BIT(3)
	#define LP8788_FPWM_BUCK4_S 3

	#define INVALID_ADDR 0xFF
	#define LP8788_FORCE_PWM 1
	#define LP8788_AUTO_PWM 0
	#define PIN_LOW 0
	#define PIN_HIGH 1
	#define ENABLE_TIME_USEC 32

	#define BUCK_FPWM_MASK(x) (1 << (x))
	#define BUCK_FPWM_SHIFT(x) (x)

	enum lp8788_dvs_state {
	DVS_LOW = GPIOF_OUT_INIT_LOW,
	DVS_HIGH = GPIOF_OUT_INIT_HIGH,
	};

	enum lp8788_dvs_mode {
	REGISTER,
	EXTPIN,
	};

	enum lp8788_buck_id {
	BUCK1,
	BUCK2,
	BUCK3,
	BUCK4,
	};

	struct lp8788_buck {
	struct lp8788 *lp;
	struct regulator_dev *regulator;
	void *dvs;
	};

	/* BUCK 1 ~ 4 voltage table */
	static const int lp8788_buck_vtbl[] = {
	500000, 800000, 850000, 900000, 950000, 1000000, 1050000, 1100000,
	1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
	1550000, 1600000, 1650000, 1700000, 1750000, 1800000, 1850000, 1900000,
	1950000, 2000000,
	};

	static void lp8788_buck1_set_dvs(struct lp8788_buck *buck)
	{
	struct lp8788_buck1_dvs dvs = (struct lp8788_buck1_dvs )buck->dvs;
	enum lp8788_dvs_state pinstate;

	if (!dvs)
	return;

	pinstate = dvs->vsel == DVS_SEL_V0 ? DVS_LOW : DVS_HIGH;
	if (gpio_is_valid(dvs->gpio))
	gpio_set_value(dvs->gpio, pinstate);
	}

	static void lp8788_buck2_set_dvs(struct lp8788_buck *buck)
	{
	struct lp8788_buck2_dvs dvs = (struct lp8788_buck2_dvs )buck->dvs;
	enum lp8788_dvs_state pin1, pin2;

	if (!dvs)
	return;

	switch (dvs->vsel) {
	case DVS_SEL_V0:
	pin1 = DVS_LOW;
	pin2 = DVS_LOW;
	break;
	case DVS_SEL_V1:
	pin1 = DVS_HIGH;
	pin2 = DVS_LOW;
	break;
	case DVS_SEL_V2:
	pin1 = DVS_LOW;
	pin2 = DVS_HIGH;
	break;
	case DVS_SEL_V3:
	pin1 = DVS_HIGH;
	pin2 = DVS_HIGH;
	break;
	default:
	return;
	}

	if (gpio_is_valid(dvs->gpio[0]))
	gpio_set_value(dvs->gpio[0], pin1);

	if (gpio_is_valid(dvs->gpio[1]))
	gpio_set_value(dvs->gpio[1], pin2);
	}

	static void lp8788_set_dvs(struct lp8788_buck *buck, enum lp8788_buck_id id)
	{
	switch (id) {
	case BUCK1:
	lp8788_buck1_set_dvs(buck);
	break;
	case BUCK2:
	lp8788_buck2_set_dvs(buck);
	break;
	default:
	break;
	}
	}

	static enum lp8788_dvs_mode
	lp8788_get_buck_dvs_ctrl_mode(struct lp8788_buck *buck, enum lp8788_buck_id id)
	{
	u8 val, mask;

	switch (id) {
	case BUCK1:
	mask = LP8788_BUCK1_DVS_SEL_M;
	break;
	case BUCK2:
	mask = LP8788_BUCK2_DVS_SEL_M;
	break;
	default:
	return REGISTER;
	}

	lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);

	return val & mask ? REGISTER : EXTPIN;
	}

	static bool lp8788_is_valid_buck_addr(u8 addr)
	{
	switch (addr) {
	case LP8788_BUCK1_VOUT0:
	case LP8788_BUCK1_VOUT1:
	case LP8788_BUCK1_VOUT2:
	case LP8788_BUCK1_VOUT3:
	case LP8788_BUCK2_VOUT0:
	case LP8788_BUCK2_VOUT1:
	case LP8788_BUCK2_VOUT2:
	case LP8788_BUCK2_VOUT3:
	return true;
	default:
	return false;
	}
	}

	static u8 lp8788_select_buck_vout_addr(struct lp8788_buck *buck,
	enum lp8788_buck_id id)
	{
	enum lp8788_dvs_mode mode = lp8788_get_buck_dvs_ctrl_mode(buck, id);
	struct lp8788_buck1_dvs *b1_dvs;
	struct lp8788_buck2_dvs *b2_dvs;
	u8 val, idx, addr;
	int pin1, pin2;

	switch (id) {
	case BUCK1:
	if (mode == EXTPIN) {
	b1_dvs = (struct lp8788_buck1_dvs *)buck->dvs;
	if (!b1_dvs)
	goto err;

	idx = gpio_get_value(b1_dvs->gpio) ? 1 : 0;
	} else {
	lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);
	idx = (val & LP8788_BUCK1_DVS_M) >> LP8788_BUCK1_DVS_S;
	}
	addr = LP8788_BUCK1_VOUT0 + idx;
	break;
	case BUCK2:
	if (mode == EXTPIN) {
	b2_dvs = (struct lp8788_buck2_dvs *)buck->dvs;
	if (!b2_dvs)
	goto err;

	pin1 = gpio_get_value(b2_dvs->gpio[0]);
	pin2 = gpio_get_value(b2_dvs->gpio[1]);

	if (pin1 == PIN_LOW && pin2 == PIN_LOW)
	idx = 0;
	else if (pin1 == PIN_LOW && pin2 == PIN_HIGH)
	idx = 2;
	else if (pin1 == PIN_HIGH && pin2 == PIN_LOW)
	idx = 1;
	else
	idx = 3;
	} else {
	lp8788_read_byte(buck->lp, LP8788_BUCK_DVS_SEL, &val);
	idx = (val & LP8788_BUCK2_DVS_M) >> LP8788_BUCK2_DVS_S;
	}
	addr = LP8788_BUCK2_VOUT0 + idx;
	break;
	default:
	goto err;
	}

	return addr;
	err:
	return INVALID_ADDR;
	}

	static int lp8788_buck12_set_voltage_sel(struct regulator_dev *rdev,
	unsigned selector)
	{
	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
	enum lp8788_buck_id id = rdev_get_id(rdev);
	u8 addr;

	if (buck->dvs)
	lp8788_set_dvs(buck, id);

	addr = lp8788_select_buck_vout_addr(buck, id);
	if (!lp8788_is_valid_buck_addr(addr))
	return -EINVAL;

	return lp8788_update_bits(buck->lp, addr, LP8788_VOUT_M, selector);
	}

	static int lp8788_buck12_get_voltage_sel(struct regulator_dev *rdev)
	{
	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
	enum lp8788_buck_id id = rdev_get_id(rdev);
	int ret;
	u8 val, addr;

	addr = lp8788_select_buck_vout_addr(buck, id);
	if (!lp8788_is_valid_buck_addr(addr))
	return -EINVAL;

	ret = lp8788_read_byte(buck->lp, addr, &val);
	if (ret)
	return ret;

	return val & LP8788_VOUT_M;
	}

	static int lp8788_buck_enable_time(struct regulator_dev *rdev)
	{
	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
	enum lp8788_buck_id id = rdev_get_id(rdev);
	u8 val, addr = LP8788_BUCK1_TIMESTEP + id;

	if (lp8788_read_byte(buck->lp, addr, &val))
	return -EINVAL;

	val = (val & LP8788_STARTUP_TIME_M) >> LP8788_STARTUP_TIME_S;

	return ENABLE_TIME_USEC * val;
	}

	static int lp8788_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
	{
	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
	enum lp8788_buck_id id = rdev_get_id(rdev);
	u8 mask, val;

	mask = BUCK_FPWM_MASK(id);
	switch (mode) {
	case REGULATOR_MODE_FAST:
	val = LP8788_FORCE_PWM << BUCK_FPWM_SHIFT(id);
	break;
	case REGULATOR_MODE_NORMAL:
	val = LP8788_AUTO_PWM << BUCK_FPWM_SHIFT(id);
	break;
	default:
	return -EINVAL;
	}

	return lp8788_update_bits(buck->lp, LP8788_BUCK_PWM, mask, val);
	}

	static unsigned int lp8788_buck_get_mode(struct regulator_dev *rdev)
	{
	struct lp8788_buck *buck = rdev_get_drvdata(rdev);
	enum lp8788_buck_id id = rdev_get_id(rdev);
	u8 val;
	int ret;

	ret = lp8788_read_byte(buck->lp, LP8788_BUCK_PWM, &val);
	if (ret)
	return ret;

	return val & BUCK_FPWM_MASK(id) ?
	REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
	}

	static struct regulator_ops lp8788_buck12_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_ascend,
	.set_voltage_sel = lp8788_buck12_set_voltage_sel,
	.get_voltage_sel = lp8788_buck12_get_voltage_sel,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.enable_time = lp8788_buck_enable_time,
	.set_mode = lp8788_buck_set_mode,
	.get_mode = lp8788_buck_get_mode,
	};

	static struct regulator_ops lp8788_buck34_ops = {
	.list_voltage = regulator_list_voltage_table,
	.map_voltage = regulator_map_voltage_ascend,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.enable_time = lp8788_buck_enable_time,
	.set_mode = lp8788_buck_set_mode,
	.get_mode = lp8788_buck_get_mode,
	};

	static struct regulator_desc lp8788_buck_desc[] = {
	{
	.name = "buck1",
	.id = BUCK1,
	.ops = &lp8788_buck12_ops,
	.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
	.volt_table = lp8788_buck_vtbl,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_reg = LP8788_EN_BUCK,
	.enable_mask = LP8788_EN_BUCK1_M,
	},
	{
	.name = "buck2",
	.id = BUCK2,
	.ops = &lp8788_buck12_ops,
	.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
	.volt_table = lp8788_buck_vtbl,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.enable_reg = LP8788_EN_BUCK,
	.enable_mask = LP8788_EN_BUCK2_M,
	},
	{
	.name = "buck3",
	.id = BUCK3,
	.ops = &lp8788_buck34_ops,
	.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
	.volt_table = lp8788_buck_vtbl,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.vsel_reg = LP8788_BUCK3_VOUT,
	.vsel_mask = LP8788_VOUT_M,
	.enable_reg = LP8788_EN_BUCK,
	.enable_mask = LP8788_EN_BUCK3_M,
	},
	{
	.name = "buck4",
	.id = BUCK4,
	.ops = &lp8788_buck34_ops,
	.n_voltages = ARRAY_SIZE(lp8788_buck_vtbl),
	.volt_table = lp8788_buck_vtbl,
	.type = REGULATOR_VOLTAGE,
	.owner = THIS_MODULE,
	.vsel_reg = LP8788_BUCK4_VOUT,
	.vsel_mask = LP8788_VOUT_M,
	.enable_reg = LP8788_EN_BUCK,
	.enable_mask = LP8788_EN_BUCK4_M,
	},
	};

	static int lp8788_dvs_gpio_request(struct platform_device *pdev,
	struct lp8788_buck *buck,
	enum lp8788_buck_id id)
	{
	struct lp8788_platform_data *pdata = buck->lp->pdata;
	char *b1_name = "LP8788_B1_DVS";
	char *b2_name[] = { "LP8788_B2_DVS1", "LP8788_B2_DVS2" };
	int i, gpio, ret;

	switch (id) {
	case BUCK1:
	gpio = pdata->buck1_dvs->gpio;
	ret = devm_gpio_request_one(&pdev->dev, gpio, DVS_LOW,
	b1_name);
	if (ret)
	return ret;

	buck->dvs = pdata->buck1_dvs;
	break;
	case BUCK2:
	for (i = 0; i < LP8788_NUM_BUCK2_DVS; i++) {
	gpio = pdata->buck2_dvs->gpio[i];
	ret = devm_gpio_request_one(&pdev->dev, gpio,
	DVS_LOW, b2_name[i]);
	if (ret)
	return ret;
	}
	buck->dvs = pdata->buck2_dvs;
	break;
	default:
	break;
	}

	return 0;
	}

	static int lp8788_init_dvs(struct platform_device *pdev,
	struct lp8788_buck *buck, enum lp8788_buck_id id)
	{
	struct lp8788_platform_data *pdata = buck->lp->pdata;
	u8 mask[] = { LP8788_BUCK1_DVS_SEL_M, LP8788_BUCK2_DVS_SEL_M };
	u8 val[] = { LP8788_BUCK1_DVS_PIN, LP8788_BUCK2_DVS_PIN };
	u8 default_dvs_mode[] = { LP8788_BUCK1_DVS_I2C, LP8788_BUCK2_DVS_I2C };

	/* no dvs for buck3, 4 */
	if (id > BUCK2)
	return 0;

	/* no dvs platform data, then dvs will be selected by I2C registers */
	if (!pdata)
	goto set_default_dvs_mode;

	if ((id == BUCK1 && !pdata->buck1_dvs) \|\|
	(id == BUCK2 && !pdata->buck2_dvs))
	goto set_default_dvs_mode;

	if (lp8788_dvs_gpio_request(pdev, buck, id))
	goto set_default_dvs_mode;

	return lp8788_update_bits(buck->lp, LP8788_BUCK_DVS_SEL, mask[id],
	val[id]);

	set_default_dvs_mode:
	return lp8788_update_bits(buck->lp, LP8788_BUCK_DVS_SEL, mask[id],
	default_dvs_mode[id]);
	}

	static int lp8788_buck_probe(struct platform_device *pdev)
	{
	struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
	int id = pdev->id;
	struct lp8788_buck *buck;
	struct regulator_config cfg = { };
	struct regulator_dev *rdev;
	int ret;

	if (id >= LP8788_NUM_BUCKS)
	return -EINVAL;

	buck = devm_kzalloc(&pdev->dev, sizeof(struct lp8788_buck), GFP_KERNEL);
	if (!buck)
	return -ENOMEM;

	buck->lp = lp;

	ret = lp8788_init_dvs(pdev, buck, id);
	if (ret)
	return ret;

	cfg.dev = pdev->dev.parent;
	cfg.init_data = lp->pdata ? lp->pdata->buck_data[id] : NULL;
	cfg.driver_data = buck;
	cfg.regmap = lp->regmap;

	rdev = regulator_register(&lp8788_buck_desc[id], &cfg);
	if (IS_ERR(rdev)) {
	ret = PTR_ERR(rdev);
	dev_err(&pdev->dev, "BUCK%d regulator register err = %d\n",
	id + 1, ret);
	return ret;
	}

	buck->regulator = rdev;
	platform_set_drvdata(pdev, buck);

	return 0;
	}

	static int lp8788_buck_remove(struct platform_device *pdev)
	{
	struct lp8788_buck *buck = platform_get_drvdata(pdev);

	platform_set_drvdata(pdev, NULL);
	regulator_unregister(buck->regulator);

	return 0;
	}

	static struct platform_driver lp8788_buck_driver = {
	.probe = lp8788_buck_probe,
	.remove = lp8788_buck_remove,
	.driver = {
	.name = LP8788_DEV_BUCK,
	.owner = THIS_MODULE,
	},
	};

	static int __init lp8788_buck_init(void)
	{
	return platform_driver_register(&lp8788_buck_driver);
	}
	subsys_initcall(lp8788_buck_init);

	static void __exit lp8788_buck_exit(void)
	{
	platform_driver_unregister(&lp8788_buck_driver);
	}
	module_exit(lp8788_buck_exit);

	MODULE_DESCRIPTION("TI LP8788 BUCK Driver");
	MODULE_AUTHOR("Milo Kim");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:lp8788-buck");