drivers/regulator/lp8755.c - third_party/linux - Git at Google

 /*
  * LP8755 High Performance Power Management Unit : System Interface Driver
  * (based on rev. 0.26)
  * Copyright 2012 Texas Instruments
  *
  * Author: Daniel(Geon Si) Jeong <daniel.jeong@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/i2c.h>
 #include <linux/err.h>
 #include <linux/irq.h>
 #include <linux/interrupt.h>
 #include <linux/gpio.h>
 #include <linux/regmap.h>
 #include <linux/uaccess.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/platform_data/lp8755.h>

 #define LP8755_REG_BUCK0	0x00
 #define LP8755_REG_BUCK1	0x03
 #define LP8755_REG_BUCK2	0x04
 #define LP8755_REG_BUCK3	0x01
 #define LP8755_REG_BUCK4	0x05
 #define LP8755_REG_BUCK5	0x02
 #define LP8755_REG_MAX		0xFF

 #define LP8755_BUCK_EN_M	BIT(7)
 #define LP8755_BUCK_LINEAR_OUT_MAX	0x76
 #define LP8755_BUCK_VOUT_M	0x7F

 struct lp8755_mphase {
 	int nreg;
 	int buck_num[LP8755_BUCK_MAX];
 };

 struct lp8755_chip {
 	struct device *dev;
 	struct regmap *regmap;
 	struct lp8755_platform_data *pdata;

 	int irq;
 	unsigned int irqmask;

 	int mphase;
 	struct regulator_dev *rdev[LP8755_BUCK_MAX];
 };

 /**
  *lp8755_read : read a single register value from lp8755.
  *@pchip : device to read from
  *@reg   : register to read from
  *@val   : pointer to store read value
  */
 static int lp8755_read(struct lp8755_chip *pchip, unsigned int reg,
 		       unsigned int *val)
 {
 	return regmap_read(pchip->regmap, reg, val);
 }

 /**
  *lp8755_write : write a single register value to lp8755.
  *@pchip : device to write to
  *@reg   : register to write to
  *@val   : value to be written
  */
 static int lp8755_write(struct lp8755_chip *pchip, unsigned int reg,
 			unsigned int val)
 {
 	return regmap_write(pchip->regmap, reg, val);
 }

 /**
  *lp8755_update_bits : set the values of bit fields in lp8755 register.
  *@pchip : device to read from
  *@reg   : register to update
  *@mask  : bitmask to be changed
  *@val   : value for bitmask
  */
 static int lp8755_update_bits(struct lp8755_chip *pchip, unsigned int reg,
 			      unsigned int mask, unsigned int val)
 {
 	return regmap_update_bits(pchip->regmap, reg, mask, val);
 }

 static int lp8755_buck_enable_time(struct regulator_dev *rdev)
 {
 	int ret;
 	unsigned int regval;
 	enum lp8755_bucks id = rdev_get_id(rdev);
 	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

 	ret = lp8755_read(pchip, 0x12 + id, &regval);
 	if (ret < 0) {
 		dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 		return ret;
 	}
 	return (regval & 0xff) * 100;
 }

 static int lp8755_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
 {
 	int ret;
 	unsigned int regbval = 0x0;
 	enum lp8755_bucks id = rdev_get_id(rdev);
 	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

 	switch (mode) {
 	case REGULATOR_MODE_FAST:
 		/* forced pwm mode */
 		regbval = (0x01 << id);
 		break;
 	case REGULATOR_MODE_NORMAL:
 		/* enable automatic pwm/pfm mode */
 		ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x00);
 		if (ret < 0)
 			goto err_i2c;
 		break;
 	case REGULATOR_MODE_IDLE:
 		/* enable automatic pwm/pfm/lppfm mode */
 		ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x20);
 		if (ret < 0)
 			goto err_i2c;

 		ret = lp8755_update_bits(pchip, 0x10, 0x01, 0x01);
 		if (ret < 0)
 			goto err_i2c;
 		break;
 	default:
 		dev_err(pchip->dev, "Not supported buck mode %s\n", __func__);
 		/* forced pwm mode */
 		regbval = (0x01 << id);
 	}

 	ret = lp8755_update_bits(pchip, 0x06, 0x01 << id, regbval);
 	if (ret < 0)
 		goto err_i2c;
 	return ret;
 err_i2c:
 	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 	return ret;
 }

 static unsigned int lp8755_buck_get_mode(struct regulator_dev *rdev)
 {
 	int ret;
 	unsigned int regval;
 	enum lp8755_bucks id = rdev_get_id(rdev);
 	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

 	ret = lp8755_read(pchip, 0x06, &regval);
 	if (ret < 0)
 		goto err_i2c;

 	/* mode fast means forced pwm mode */
 	if (regval & (0x01 << id))
 		return REGULATOR_MODE_FAST;

 	ret = lp8755_read(pchip, 0x08 + id, &regval);
 	if (ret < 0)
 		goto err_i2c;

 	/* mode idle means automatic pwm/pfm/lppfm mode */
 	if (regval & 0x20)
 		return REGULATOR_MODE_IDLE;

 	/* mode normal means automatic pwm/pfm mode */
 	return REGULATOR_MODE_NORMAL;

 err_i2c:
 	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 	return 0;
 }

 static int lp8755_buck_set_ramp(struct regulator_dev *rdev, int ramp)
 {
 	int ret;
 	unsigned int regval = 0x00;
 	enum lp8755_bucks id = rdev_get_id(rdev);
 	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

 	/* uV/us */
 	switch (ramp) {
 	case 0 ... 230:
 		regval = 0x07;
 		break;
 	case 231 ... 470:
 		regval = 0x06;
 		break;
 	case 471 ... 940:
 		regval = 0x05;
 		break;
 	case 941 ... 1900:
 		regval = 0x04;
 		break;
 	case 1901 ... 3800:
 		regval = 0x03;
 		break;
 	case 3801 ... 7500:
 		regval = 0x02;
 		break;
 	case 7501 ... 15000:
 		regval = 0x01;
 		break;
 	case 15001 ... 30000:
 		regval = 0x00;
 		break;
 	default:
 		dev_err(pchip->dev,
 			"Not supported ramp value %d %s\n", ramp, __func__);
 		return -EINVAL;
 	}

 	ret = lp8755_update_bits(pchip, 0x07 + id, 0x07, regval);
 	if (ret < 0)
 		goto err_i2c;
 	return ret;
 err_i2c:
 	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 	return ret;
 }

 static struct regulator_ops lp8755_buck_ops = {
 	.map_voltage = regulator_map_voltage_linear,
 	.list_voltage = regulator_list_voltage_linear,
 	.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 = lp8755_buck_enable_time,
 	.set_mode = lp8755_buck_set_mode,
 	.get_mode = lp8755_buck_get_mode,
 	.set_ramp_delay = lp8755_buck_set_ramp,
 };

 #define lp8755_rail(_id) "lp8755_buck"#_id
 #define lp8755_buck_init(_id)\
 {\
 	.constraints = {\
 		.name = lp8755_rail(_id),\
 		.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,\
 		.min_uV = 500000,\
 		.max_uV = 1675000,\
 	},\
 }

 static struct regulator_init_data lp8755_reg_default[LP8755_BUCK_MAX] = {
 	[LP8755_BUCK0] = lp8755_buck_init(0),
 	[LP8755_BUCK1] = lp8755_buck_init(1),
 	[LP8755_BUCK2] = lp8755_buck_init(2),
 	[LP8755_BUCK3] = lp8755_buck_init(3),
 	[LP8755_BUCK4] = lp8755_buck_init(4),
 	[LP8755_BUCK5] = lp8755_buck_init(5),
 };

 static const struct lp8755_mphase mphase_buck[MPHASE_CONF_MAX] = {
 	{ 3, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK5 } },
 	{ 6, { LP8755_BUCK0, LP8755_BUCK1, LP8755_BUCK2, LP8755_BUCK3,
 	       LP8755_BUCK4, LP8755_BUCK5 } },
 	{ 5, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK4,
 	       LP8755_BUCK5} },
 	{ 4, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK4, LP8755_BUCK5} },
 	{ 3, { LP8755_BUCK0, LP8755_BUCK4, LP8755_BUCK5} },
 	{ 2, { LP8755_BUCK0, LP8755_BUCK5} },
 	{ 1, { LP8755_BUCK0} },
 	{ 2, { LP8755_BUCK0, LP8755_BUCK3} },
 	{ 4, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK5} },
 };

 static int lp8755_init_data(struct lp8755_chip *pchip)
 {
 	unsigned int regval;
 	int ret, icnt, buck_num;
 	struct lp8755_platform_data *pdata = pchip->pdata;

 	/* read back  muti-phase configuration */
 	ret = lp8755_read(pchip, 0x3D, &regval);
 	if (ret < 0)
 		goto out_i2c_error;
 	pchip->mphase = regval & 0x0F;

 	/* set default data based on multi-phase config */
 	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
 		buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
 		pdata->buck_data[buck_num] = &lp8755_reg_default[buck_num];
 	}
 	return ret;

 out_i2c_error:
 	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 	return ret;
 }

 #define lp8755_buck_desc(_id)\
 {\
 	.name = lp8755_rail(_id),\
 	.id   = LP8755_BUCK##_id,\
 	.ops  = &lp8755_buck_ops,\
 	.n_voltages = LP8755_BUCK_LINEAR_OUT_MAX+1,\
 	.uV_step = 10000,\
 	.min_uV = 500000,\
 	.type = REGULATOR_VOLTAGE,\
 	.owner = THIS_MODULE,\
 	.enable_reg = LP8755_REG_BUCK##_id,\
 	.enable_mask = LP8755_BUCK_EN_M,\
 	.vsel_reg = LP8755_REG_BUCK##_id,\
 	.vsel_mask = LP8755_BUCK_VOUT_M,\
 }

 static struct regulator_desc lp8755_regulators[] = {
 	lp8755_buck_desc(0),
 	lp8755_buck_desc(1),
 	lp8755_buck_desc(2),
 	lp8755_buck_desc(3),
 	lp8755_buck_desc(4),
 	lp8755_buck_desc(5),
 };

 static int lp8755_regulator_init(struct lp8755_chip *pchip)
 {
 	int ret, icnt, buck_num;
 	struct lp8755_platform_data *pdata = pchip->pdata;
 	struct regulator_config rconfig = { };

 	rconfig.regmap = pchip->regmap;
 	rconfig.dev = pchip->dev;
 	rconfig.driver_data = pchip;

 	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
 		buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
 		rconfig.init_data = pdata->buck_data[buck_num];
 		rconfig.of_node = pchip->dev->of_node;
 		pchip->rdev[buck_num] =
 		    devm_regulator_register(pchip->dev,
 				    &lp8755_regulators[buck_num], &rconfig);
 		if (IS_ERR(pchip->rdev[buck_num])) {
 			ret = PTR_ERR(pchip->rdev[buck_num]);
 			pchip->rdev[buck_num] = NULL;
 			dev_err(pchip->dev, "regulator init failed: buck %d\n",
 				buck_num);
 			return ret;
 		}
 	}

 	return 0;
 }

 static irqreturn_t lp8755_irq_handler(int irq, void *data)
 {
 	int ret, icnt;
 	unsigned int flag0, flag1;
 	struct lp8755_chip *pchip = data;

 	/* read flag0 register */
 	ret = lp8755_read(pchip, 0x0D, &flag0);
 	if (ret < 0)
 		goto err_i2c;
 	/* clear flag register to pull up int. pin */
 	ret = lp8755_write(pchip, 0x0D, 0x00);
 	if (ret < 0)
 		goto err_i2c;

 	/* sent power fault detection event to specific regulator */
 	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
 		if ((flag0 & (0x4 << icnt))
 		    && (pchip->irqmask & (0x04 << icnt))
 		    && (pchip->rdev[icnt] != NULL))
 			regulator_notifier_call_chain(pchip->rdev[icnt],
 						      LP8755_EVENT_PWR_FAULT,
 						      NULL);

 	/* read flag1 register */
 	ret = lp8755_read(pchip, 0x0E, &flag1);
 	if (ret < 0)
 		goto err_i2c;
 	/* clear flag register to pull up int. pin */
 	ret = lp8755_write(pchip, 0x0E, 0x00);
 	if (ret < 0)
 		goto err_i2c;

 	/* send OCP event to all regualtor devices */
 	if ((flag1 & 0x01) && (pchip->irqmask & 0x01))
 		for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
 			if (pchip->rdev[icnt] != NULL)
 				regulator_notifier_call_chain(pchip->rdev[icnt],
 							      LP8755_EVENT_OCP,
 							      NULL);

 	/* send OVP event to all regualtor devices */
 	if ((flag1 & 0x02) && (pchip->irqmask & 0x02))
 		for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
 			if (pchip->rdev[icnt] != NULL)
 				regulator_notifier_call_chain(pchip->rdev[icnt],
 							      LP8755_EVENT_OVP,
 							      NULL);
 	return IRQ_HANDLED;

 err_i2c:
 	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 	return IRQ_NONE;
 }

 static int lp8755_int_config(struct lp8755_chip *pchip)
 {
 	int ret;
 	unsigned int regval;

 	if (pchip->irq == 0) {
 		dev_warn(pchip->dev, "not use interrupt : %s\n", __func__);
 		return 0;
 	}

 	ret = lp8755_read(pchip, 0x0F, &regval);
 	if (ret < 0) {
 		dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
 		return ret;
 	}

 	pchip->irqmask = regval;
 	return devm_request_threaded_irq(pchip->dev, pchip->irq, NULL,
 					 lp8755_irq_handler,
 					 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
 					 "lp8755-irq", pchip);
 }

 static const struct regmap_config lp8755_regmap = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = LP8755_REG_MAX,
 };

 static int lp8755_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret, icnt;
 	struct lp8755_chip *pchip;
 	struct lp8755_platform_data *pdata = dev_get_platdata(&client->dev);

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_err(&client->dev, "i2c functionality check fail.\n");
 		return -EOPNOTSUPP;
 	}

 	pchip = devm_kzalloc(&client->dev,
 			     sizeof(struct lp8755_chip), GFP_KERNEL);
 	if (!pchip)
 		return -ENOMEM;

 	pchip->dev = &client->dev;
 	pchip->regmap = devm_regmap_init_i2c(client, &lp8755_regmap);
 	if (IS_ERR(pchip->regmap)) {
 		ret = PTR_ERR(pchip->regmap);
 		dev_err(&client->dev, "fail to allocate regmap %d\n", ret);
 		return ret;
 	}
 	i2c_set_clientdata(client, pchip);

 	if (pdata != NULL) {
 		pchip->pdata = pdata;
 		pchip->mphase = pdata->mphase;
 	} else {
 		pchip->pdata = devm_kzalloc(pchip->dev,
 					    sizeof(struct lp8755_platform_data),
 					    GFP_KERNEL);
 		if (!pchip->pdata)
 			return -ENOMEM;
 		ret = lp8755_init_data(pchip);
 		if (ret < 0) {
 			dev_err(&client->dev, "fail to initialize chip\n");
 			return ret;
 		}
 	}

 	ret = lp8755_regulator_init(pchip);
 	if (ret < 0) {
 		dev_err(&client->dev, "fail to initialize regulators\n");
 		goto err;
 	}

 	pchip->irq = client->irq;
 	ret = lp8755_int_config(pchip);
 	if (ret < 0) {
 		dev_err(&client->dev, "fail to irq config\n");
 		goto err;
 	}

 	return ret;

 err:
 	/* output disable */
 	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
 		lp8755_write(pchip, icnt, 0x00);

 	return ret;
 }

 static int lp8755_remove(struct i2c_client *client)
 {
 	int icnt;
 	struct lp8755_chip *pchip = i2c_get_clientdata(client);

 	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
 		lp8755_write(pchip, icnt, 0x00);

 	return 0;
 }

 static const struct i2c_device_id lp8755_id[] = {
 	{LP8755_NAME, 0},
 	{}
 };

 MODULE_DEVICE_TABLE(i2c, lp8755_id);

 static struct i2c_driver lp8755_i2c_driver = {
 	.driver = {
 		   .name = LP8755_NAME,
 		   },
 	.probe = lp8755_probe,
 	.remove = lp8755_remove,
 	.id_table = lp8755_id,
 };

 static int __init lp8755_init(void)
 {
 	return i2c_add_driver(&lp8755_i2c_driver);
 }

 subsys_initcall(lp8755_init);

 static void __exit lp8755_exit(void)
 {
 	i2c_del_driver(&lp8755_i2c_driver);
 }

 module_exit(lp8755_exit);

 MODULE_DESCRIPTION("Texas Instruments lp8755 driver");
 MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* LP8755 High Performance Power Management Unit : System Interface Driver
	* (based on rev. 0.26)
	* Copyright 2012 Texas Instruments
	*
	* Author: Daniel(Geon Si) Jeong <daniel.jeong@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/i2c.h>
	#include <linux/err.h>
	#include <linux/irq.h>
	#include <linux/interrupt.h>
	#include <linux/gpio.h>
	#include <linux/regmap.h>
	#include <linux/uaccess.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/machine.h>
	#include <linux/platform_data/lp8755.h>

	#define LP8755_REG_BUCK0 0x00
	#define LP8755_REG_BUCK1 0x03
	#define LP8755_REG_BUCK2 0x04
	#define LP8755_REG_BUCK3 0x01
	#define LP8755_REG_BUCK4 0x05
	#define LP8755_REG_BUCK5 0x02
	#define LP8755_REG_MAX 0xFF

	#define LP8755_BUCK_EN_M BIT(7)
	#define LP8755_BUCK_LINEAR_OUT_MAX 0x76
	#define LP8755_BUCK_VOUT_M 0x7F

	struct lp8755_mphase {
	int nreg;
	int buck_num[LP8755_BUCK_MAX];
	};

	struct lp8755_chip {
	struct device *dev;
	struct regmap *regmap;
	struct lp8755_platform_data *pdata;

	int irq;
	unsigned int irqmask;

	int mphase;
	struct regulator_dev *rdev[LP8755_BUCK_MAX];
	};

	/**
	*lp8755_read : read a single register value from lp8755.
	*@pchip : device to read from
	*@reg : register to read from
	*@val : pointer to store read value
	*/
	static int lp8755_read(struct lp8755_chip *pchip, unsigned int reg,
	unsigned int *val)
	{
	return regmap_read(pchip->regmap, reg, val);
	}

	/**
	*lp8755_write : write a single register value to lp8755.
	*@pchip : device to write to
	*@reg : register to write to
	*@val : value to be written
	*/
	static int lp8755_write(struct lp8755_chip *pchip, unsigned int reg,
	unsigned int val)
	{
	return regmap_write(pchip->regmap, reg, val);
	}

	/**
	*lp8755_update_bits : set the values of bit fields in lp8755 register.
	*@pchip : device to read from
	*@reg : register to update
	*@mask : bitmask to be changed
	*@val : value for bitmask
	*/
	static int lp8755_update_bits(struct lp8755_chip *pchip, unsigned int reg,
	unsigned int mask, unsigned int val)
	{
	return regmap_update_bits(pchip->regmap, reg, mask, val);
	}

	static int lp8755_buck_enable_time(struct regulator_dev *rdev)
	{
	int ret;
	unsigned int regval;
	enum lp8755_bucks id = rdev_get_id(rdev);
	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

	ret = lp8755_read(pchip, 0x12 + id, &regval);
	if (ret < 0) {
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return ret;
	}
	return (regval & 0xff) * 100;
	}

	static int lp8755_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
	{
	int ret;
	unsigned int regbval = 0x0;
	enum lp8755_bucks id = rdev_get_id(rdev);
	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

	switch (mode) {
	case REGULATOR_MODE_FAST:
	/* forced pwm mode */
	regbval = (0x01 << id);
	break;
	case REGULATOR_MODE_NORMAL:
	/* enable automatic pwm/pfm mode */
	ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x00);
	if (ret < 0)
	goto err_i2c;
	break;
	case REGULATOR_MODE_IDLE:
	/* enable automatic pwm/pfm/lppfm mode */
	ret = lp8755_update_bits(pchip, 0x08 + id, 0x20, 0x20);
	if (ret < 0)
	goto err_i2c;

	ret = lp8755_update_bits(pchip, 0x10, 0x01, 0x01);
	if (ret < 0)
	goto err_i2c;
	break;
	default:
	dev_err(pchip->dev, "Not supported buck mode %s\n", __func__);
	/* forced pwm mode */
	regbval = (0x01 << id);
	}

	ret = lp8755_update_bits(pchip, 0x06, 0x01 << id, regbval);
	if (ret < 0)
	goto err_i2c;
	return ret;
	err_i2c:
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return ret;
	}

	static unsigned int lp8755_buck_get_mode(struct regulator_dev *rdev)
	{
	int ret;
	unsigned int regval;
	enum lp8755_bucks id = rdev_get_id(rdev);
	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

	ret = lp8755_read(pchip, 0x06, &regval);
	if (ret < 0)
	goto err_i2c;

	/* mode fast means forced pwm mode */
	if (regval & (0x01 << id))
	return REGULATOR_MODE_FAST;

	ret = lp8755_read(pchip, 0x08 + id, &regval);
	if (ret < 0)
	goto err_i2c;

	/* mode idle means automatic pwm/pfm/lppfm mode */
	if (regval & 0x20)
	return REGULATOR_MODE_IDLE;

	/* mode normal means automatic pwm/pfm mode */
	return REGULATOR_MODE_NORMAL;

	err_i2c:
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return 0;
	}

	static int lp8755_buck_set_ramp(struct regulator_dev *rdev, int ramp)
	{
	int ret;
	unsigned int regval = 0x00;
	enum lp8755_bucks id = rdev_get_id(rdev);
	struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

	/* uV/us */
	switch (ramp) {
	case 0 ... 230:
	regval = 0x07;
	break;
	case 231 ... 470:
	regval = 0x06;
	break;
	case 471 ... 940:
	regval = 0x05;
	break;
	case 941 ... 1900:
	regval = 0x04;
	break;
	case 1901 ... 3800:
	regval = 0x03;
	break;
	case 3801 ... 7500:
	regval = 0x02;
	break;
	case 7501 ... 15000:
	regval = 0x01;
	break;
	case 15001 ... 30000:
	regval = 0x00;
	break;
	default:
	dev_err(pchip->dev,
	"Not supported ramp value %d %s\n", ramp, __func__);
	return -EINVAL;
	}

	ret = lp8755_update_bits(pchip, 0x07 + id, 0x07, regval);
	if (ret < 0)
	goto err_i2c;
	return ret;
	err_i2c:
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return ret;
	}

	static struct regulator_ops lp8755_buck_ops = {
	.map_voltage = regulator_map_voltage_linear,
	.list_voltage = regulator_list_voltage_linear,
	.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 = lp8755_buck_enable_time,
	.set_mode = lp8755_buck_set_mode,
	.get_mode = lp8755_buck_get_mode,
	.set_ramp_delay = lp8755_buck_set_ramp,
	};

	#define lp8755_rail(_id) "lp8755_buck"#_id
	#define lp8755_buck_init(_id)\
	{\
	.constraints = {\
	.name = lp8755_rail(_id),\
	.valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,\
	.min_uV = 500000,\
	.max_uV = 1675000,\
	},\
	}

	static struct regulator_init_data lp8755_reg_default[LP8755_BUCK_MAX] = {
	[LP8755_BUCK0] = lp8755_buck_init(0),
	[LP8755_BUCK1] = lp8755_buck_init(1),
	[LP8755_BUCK2] = lp8755_buck_init(2),
	[LP8755_BUCK3] = lp8755_buck_init(3),
	[LP8755_BUCK4] = lp8755_buck_init(4),
	[LP8755_BUCK5] = lp8755_buck_init(5),
	};

	static const struct lp8755_mphase mphase_buck[MPHASE_CONF_MAX] = {
	{ 3, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK5 } },
	{ 6, { LP8755_BUCK0, LP8755_BUCK1, LP8755_BUCK2, LP8755_BUCK3,
	LP8755_BUCK4, LP8755_BUCK5 } },
	{ 5, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK4,
	LP8755_BUCK5} },
	{ 4, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK4, LP8755_BUCK5} },
	{ 3, { LP8755_BUCK0, LP8755_BUCK4, LP8755_BUCK5} },
	{ 2, { LP8755_BUCK0, LP8755_BUCK5} },
	{ 1, { LP8755_BUCK0} },
	{ 2, { LP8755_BUCK0, LP8755_BUCK3} },
	{ 4, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK5} },
	};

	static int lp8755_init_data(struct lp8755_chip *pchip)
	{
	unsigned int regval;
	int ret, icnt, buck_num;
	struct lp8755_platform_data *pdata = pchip->pdata;

	/* read back muti-phase configuration */
	ret = lp8755_read(pchip, 0x3D, &regval);
	if (ret < 0)
	goto out_i2c_error;
	pchip->mphase = regval & 0x0F;

	/* set default data based on multi-phase config */
	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
	buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
	pdata->buck_data[buck_num] = &lp8755_reg_default[buck_num];
	}
	return ret;

	out_i2c_error:
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return ret;
	}

	#define lp8755_buck_desc(_id)\
	{\
	.name = lp8755_rail(_id),\
	.id = LP8755_BUCK##_id,\
	.ops = &lp8755_buck_ops,\
	.n_voltages = LP8755_BUCK_LINEAR_OUT_MAX+1,\
	.uV_step = 10000,\
	.min_uV = 500000,\
	.type = REGULATOR_VOLTAGE,\
	.owner = THIS_MODULE,\
	.enable_reg = LP8755_REG_BUCK##_id,\
	.enable_mask = LP8755_BUCK_EN_M,\
	.vsel_reg = LP8755_REG_BUCK##_id,\
	.vsel_mask = LP8755_BUCK_VOUT_M,\
	}

	static struct regulator_desc lp8755_regulators[] = {
	lp8755_buck_desc(0),
	lp8755_buck_desc(1),
	lp8755_buck_desc(2),
	lp8755_buck_desc(3),
	lp8755_buck_desc(4),
	lp8755_buck_desc(5),
	};

	static int lp8755_regulator_init(struct lp8755_chip *pchip)
	{
	int ret, icnt, buck_num;
	struct lp8755_platform_data *pdata = pchip->pdata;
	struct regulator_config rconfig = { };

	rconfig.regmap = pchip->regmap;
	rconfig.dev = pchip->dev;
	rconfig.driver_data = pchip;

	for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
	buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
	rconfig.init_data = pdata->buck_data[buck_num];
	rconfig.of_node = pchip->dev->of_node;
	pchip->rdev[buck_num] =
	devm_regulator_register(pchip->dev,
	&lp8755_regulators[buck_num], &rconfig);
	if (IS_ERR(pchip->rdev[buck_num])) {
	ret = PTR_ERR(pchip->rdev[buck_num]);
	pchip->rdev[buck_num] = NULL;
	dev_err(pchip->dev, "regulator init failed: buck %d\n",
	buck_num);
	return ret;
	}
	}

	return 0;
	}

	static irqreturn_t lp8755_irq_handler(int irq, void *data)
	{
	int ret, icnt;
	unsigned int flag0, flag1;
	struct lp8755_chip *pchip = data;

	/* read flag0 register */
	ret = lp8755_read(pchip, 0x0D, &flag0);
	if (ret < 0)
	goto err_i2c;
	/* clear flag register to pull up int. pin */
	ret = lp8755_write(pchip, 0x0D, 0x00);
	if (ret < 0)
	goto err_i2c;

	/* sent power fault detection event to specific regulator */
	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
	if ((flag0 & (0x4 << icnt))
	&& (pchip->irqmask & (0x04 << icnt))
	&& (pchip->rdev[icnt] != NULL))
	regulator_notifier_call_chain(pchip->rdev[icnt],
	LP8755_EVENT_PWR_FAULT,
	NULL);

	/* read flag1 register */
	ret = lp8755_read(pchip, 0x0E, &flag1);
	if (ret < 0)
	goto err_i2c;
	/* clear flag register to pull up int. pin */
	ret = lp8755_write(pchip, 0x0E, 0x00);
	if (ret < 0)
	goto err_i2c;

	/* send OCP event to all regualtor devices */
	if ((flag1 & 0x01) && (pchip->irqmask & 0x01))
	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
	if (pchip->rdev[icnt] != NULL)
	regulator_notifier_call_chain(pchip->rdev[icnt],
	LP8755_EVENT_OCP,
	NULL);

	/* send OVP event to all regualtor devices */
	if ((flag1 & 0x02) && (pchip->irqmask & 0x02))
	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
	if (pchip->rdev[icnt] != NULL)
	regulator_notifier_call_chain(pchip->rdev[icnt],
	LP8755_EVENT_OVP,
	NULL);
	return IRQ_HANDLED;

	err_i2c:
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return IRQ_NONE;
	}

	static int lp8755_int_config(struct lp8755_chip *pchip)
	{
	int ret;
	unsigned int regval;

	if (pchip->irq == 0) {
	dev_warn(pchip->dev, "not use interrupt : %s\n", __func__);
	return 0;
	}

	ret = lp8755_read(pchip, 0x0F, &regval);
	if (ret < 0) {
	dev_err(pchip->dev, "i2c acceess error %s\n", __func__);
	return ret;
	}

	pchip->irqmask = regval;
	return devm_request_threaded_irq(pchip->dev, pchip->irq, NULL,
	lp8755_irq_handler,
	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	"lp8755-irq", pchip);
	}

	static const struct regmap_config lp8755_regmap = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = LP8755_REG_MAX,
	};

	static int lp8755_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret, icnt;
	struct lp8755_chip *pchip;
	struct lp8755_platform_data *pdata = dev_get_platdata(&client->dev);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	dev_err(&client->dev, "i2c functionality check fail.\n");
	return -EOPNOTSUPP;
	}

	pchip = devm_kzalloc(&client->dev,
	sizeof(struct lp8755_chip), GFP_KERNEL);
	if (!pchip)
	return -ENOMEM;

	pchip->dev = &client->dev;
	pchip->regmap = devm_regmap_init_i2c(client, &lp8755_regmap);
	if (IS_ERR(pchip->regmap)) {
	ret = PTR_ERR(pchip->regmap);
	dev_err(&client->dev, "fail to allocate regmap %d\n", ret);
	return ret;
	}
	i2c_set_clientdata(client, pchip);

	if (pdata != NULL) {
	pchip->pdata = pdata;
	pchip->mphase = pdata->mphase;
	} else {
	pchip->pdata = devm_kzalloc(pchip->dev,
	sizeof(struct lp8755_platform_data),
	GFP_KERNEL);
	if (!pchip->pdata)
	return -ENOMEM;
	ret = lp8755_init_data(pchip);
	if (ret < 0) {
	dev_err(&client->dev, "fail to initialize chip\n");
	return ret;
	}
	}

	ret = lp8755_regulator_init(pchip);
	if (ret < 0) {
	dev_err(&client->dev, "fail to initialize regulators\n");
	goto err;
	}

	pchip->irq = client->irq;
	ret = lp8755_int_config(pchip);
	if (ret < 0) {
	dev_err(&client->dev, "fail to irq config\n");
	goto err;
	}

	return ret;

	err:
	/* output disable */
	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
	lp8755_write(pchip, icnt, 0x00);

	return ret;
	}

	static int lp8755_remove(struct i2c_client *client)
	{
	int icnt;
	struct lp8755_chip *pchip = i2c_get_clientdata(client);

	for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
	lp8755_write(pchip, icnt, 0x00);

	return 0;
	}

	static const struct i2c_device_id lp8755_id[] = {
	{LP8755_NAME, 0},
	{}
	};

	MODULE_DEVICE_TABLE(i2c, lp8755_id);

	static struct i2c_driver lp8755_i2c_driver = {
	.driver = {
	.name = LP8755_NAME,
	},
	.probe = lp8755_probe,
	.remove = lp8755_remove,
	.id_table = lp8755_id,
	};

	static int __init lp8755_init(void)
	{
	return i2c_add_driver(&lp8755_i2c_driver);
	}

	subsys_initcall(lp8755_init);

	static void __exit lp8755_exit(void)
	{
	i2c_del_driver(&lp8755_i2c_driver);
	}

	module_exit(lp8755_exit);

	MODULE_DESCRIPTION("Texas Instruments lp8755 driver");
	MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
	MODULE_LICENSE("GPL v2");