drivers/regulator/tps6238x0-regulator.c - kernel/tegra.git - Git at Google

 /*
  * tps6238x0-regulator.c -- TI tps623850/tps623860/tps623870
  *
  * Driver for processor core supply tps623850, tps623860 and tps623870
  *
  * Copyright (c) 2012, NVIDIA Corporation.
  *
  * Author: Laxman Dewangan <ldewangan@nvidia.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  * whether express or implied; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  * 02111-1307, USA
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/tps6238x0-regulator.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/regmap.h>

 /* Register definitions */
 #define REG_VSET0		0
 #define REG_VSET1		1
 #define REG_MODE0		2
 #define REG_MODE1		3
 #define REG_CONTROL		4
 #define REG_EXCEPTION		5
 #define REG_RAMPCTRL		6
 #define REG_IOUT		7
 #define REG_CHIPID		8

 #define TPS6238X0_BASE_VOLTAGE	500000
 #define TPS6238X0_N_VOLTAGES	128
 #define TPS6238X0_MAX_VSET	2
 #define TPS6238X0_VOUT_MASK	0x7F

 /* tps 6238x0 chip information */
 struct tps6238x0_chip {
 	const char *name;
 	struct device *dev;
 	struct regulator_desc desc;
 	struct regulator_dev *rdev;
 	struct regmap *regmap;
 	int vsel_gpio;
 	int change_uv_per_us;
 	bool en_internal_pulldn;
 	bool valid_gpios;
 	int lru_index[TPS6238X0_MAX_VSET];
 	int curr_vset_vsel[TPS6238X0_MAX_VSET];
 	int curr_vset_id;
 };

 /*
  * find_voltage_set_register: Find new voltage configuration register
  * (VSET) id.
  * The finding of the new VSET register will be based on the LRU mechanism.
  * Each VSET register will have different voltage configured . This
  * Function will look if any of the VSET register have requested voltage set
  * or not.
  *     - If it is already there then it will make that register as most
  *       recently used and return as found so that caller need not to set
  *       the VSET register but need to set the proper gpios to select this
  *       VSET register.
  *     - If requested voltage is not found then it will use the least
  *       recently mechanism to get new VSET register for new configuration
  *       and will return not_found so that caller need to set new VSET
  *       register and then gpios (both).
  */
 static bool find_voltage_set_register(struct tps6238x0_chip *tps,
 		int req_vsel, int *vset_reg_id)
 {
 	int i;
 	bool found = false;
 	int new_vset_reg = tps->lru_index[1];
 	int found_index = 1;
 	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
 		if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
 			new_vset_reg = tps->lru_index[i];
 			found_index = i;
 			found = true;
 			goto update_lru_index;
 		}
 	}

 update_lru_index:
 	for (i = found_index; i > 0; i--)
 		tps->lru_index[i] = tps->lru_index[i - 1];

 	tps->lru_index[0] = new_vset_reg;
 	*vset_reg_id = new_vset_reg;
 	return found;
 }

 static int tps6238x0_get_voltage_sel(struct regulator_dev *dev)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);
 	unsigned int data;
 	int ret;

 	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
 	if (ret < 0) {
 		dev_err(tps->dev, "%s: Error in reading register %d\n",
 			__func__, REG_VSET0 + tps->curr_vset_id);
 		return ret;
 	}
 	return data & TPS6238X0_VOUT_MASK;
 }

 static int tps6238x0_set_voltage(struct regulator_dev *dev,
 	     int min_uV, int max_uV, unsigned *selector)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);
 	int vsel;
 	int ret;
 	bool found = false;
 	int new_vset_id = tps->curr_vset_id;

 	if (min_uV >
 		((TPS6238X0_BASE_VOLTAGE + (TPS6238X0_N_VOLTAGES - 1) * 10000)))
 		return -EINVAL;

 	if ((max_uV < min_uV) || (max_uV < TPS6238X0_BASE_VOLTAGE))
 		return -EINVAL;

 	vsel = DIV_ROUND_UP(min_uV - TPS6238X0_BASE_VOLTAGE, 10000);
 	if (selector)
 		*selector = (vsel & TPS6238X0_VOUT_MASK);

 	/*
 	 * If gpios are available to select the VSET register then least
 	 * recently used register for new configuration.
 	 */
 	if (tps->valid_gpios)
 		found = find_voltage_set_register(tps, vsel, &new_vset_id);

 	if (!found) {
 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
 				TPS6238X0_VOUT_MASK, vsel);
 		if (ret < 0) {
 			dev_err(tps->dev, "%s: Error in updating register %d\n",
 				 __func__, REG_VSET0 + new_vset_id);
 			return ret;
 		}
 		tps->curr_vset_id = new_vset_id;
 		tps->curr_vset_vsel[new_vset_id] = vsel;
 	}

 	/* Select proper VSET register vio gpios */
 	if (tps->valid_gpios)
 		gpio_set_value_cansleep(tps->vsel_gpio, new_vset_id & 0x1);
 	return 0;
 }

 static int tps6238x0_list_voltage(struct regulator_dev *dev,
 			unsigned selector)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);

 	if ((selector < 0) || (selector >= tps->desc.n_voltages))
 		return -EINVAL;

 	return TPS6238X0_BASE_VOLTAGE + selector * 10000;
 }

 static int tps6238x0_regulator_enable_time(struct regulator_dev *rdev)
 {
 	return 300;
 }

 static int tps6238x0_set_voltage_time_sel(struct regulator_dev *rdev,
 		unsigned int old_selector, unsigned int new_selector)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
 	int old_uV, new_uV;
 	old_uV = tps6238x0_list_voltage(rdev, old_selector);

 	if (old_uV < 0)
 		return old_uV;

 	new_uV = tps6238x0_list_voltage(rdev, new_selector);
 	if (new_uV < 0)
 		return new_uV;

 	return DIV_ROUND_UP(abs(old_uV - new_uV),
 				tps->change_uv_per_us);
 }

 static int tps6238x0_is_enable(struct regulator_dev *rdev)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
 	unsigned int data;
 	int ret;

 	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
 	if (ret < 0) {
 		dev_err(tps->dev, "%s: Error in reading register %d\n",
 			__func__, REG_VSET0 + tps->curr_vset_id);
 		return ret;
 	}
 	return !!(data & BIT(7));
 }

 static int tps6238x0_enable(struct regulator_dev *rdev)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
 	int ret;
 	int i;

 	/* Enable required VSET configuration */
 	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
 		unsigned int en = 0;
 		if (tps->valid_gpios || (i == tps->curr_vset_id))
 			en = BIT(7);

 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
 				BIT(7), en);
 		if (ret < 0) {
 			dev_err(tps->dev, "%s() fails in updating reg %d\n",
 					__func__, REG_VSET0 + i);
 			return ret;
 		}
 	}
 	return ret;
 }

 static int tps6238x0_disable(struct regulator_dev *rdev)
 {
 	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
 	int ret;
 	int i;

 	/* Disable required VSET configuration */
 	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
 				BIT(7), 0);
 		if (ret < 0) {
 			dev_err(tps->dev, "%s() fails in updating reg %d\n",
 					__func__, REG_VSET0 + i);
 			return ret;
 		}
 	}
 	return ret;
 }

 static struct regulator_ops tps6238x0_ops = {
 	.is_enabled		= tps6238x0_is_enable,
 	.enable			= tps6238x0_enable,
 	.disable		= tps6238x0_disable,
 	.enable_time		= tps6238x0_regulator_enable_time,
 	.set_voltage_time_sel	= tps6238x0_set_voltage_time_sel,
 	.get_voltage_sel	= tps6238x0_get_voltage_sel,
 	.set_voltage		= tps6238x0_set_voltage,
 	.list_voltage		= tps6238x0_list_voltage,
 };

 static int tps6238x0_configure(struct tps6238x0_chip *tps,
 		struct tps6238x0_regulator_platform_data *pdata)
 {
 	int ret;
 	int i;

 	/* Initailize internal pull up/down control */
 	if (tps->en_internal_pulldn)
 		ret = regmap_write(tps->regmap, REG_CONTROL, 0xC0);
 	else
 		ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
 	if (ret < 0) {
 		dev_err(tps->dev, "%s() fails in writing reg %d\n",
 			__func__, REG_CONTROL);
 		return ret;
 	}

 	/* Enable required VSET configuration */
 	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
 		unsigned int en = 0;
 		if (tps->valid_gpios || (i == tps->curr_vset_id))
 			en = BIT(7);

 		ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
 				BIT(7), en);
 		if (ret < 0) {
 			dev_err(tps->dev, "%s() fails in updating reg %d\n",
 					__func__, REG_VSET0 + i);
 			return ret;
 		}
 	}

 	/* Enable output discharge path to have faster discharge */
 	ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
 	if (ret < 0)
 		dev_err(tps->dev, "%s() fails in updating reg %d\n",
 			__func__, REG_RAMPCTRL);
 	tps->change_uv_per_us = 312;
 	return ret;
 }

 static const struct regmap_config tps6238x0_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = REG_CHIPID,
 	.num_reg_defaults_raw = REG_CHIPID + 1,
 	.cache_type = REGCACHE_RBTREE,
 };

 static int tps6238x0_probe(struct i2c_client *client,
 				     const struct i2c_device_id *id)
 {
 	struct tps6238x0_regulator_platform_data *pdata;
 	struct regulator_dev *rdev;
 	struct tps6238x0_chip *tps;
 	struct regulator_config config = { };
 	int ret;
 	int i;

 	pdata = client->dev.platform_data;
 	if (!pdata) {
 		dev_err(&client->dev, "%s() Err: Platform data not found\n",
 						__func__);
 		return -EIO;
 	}

 	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
 	if (!tps) {
 		dev_err(&client->dev, "%s() Err: Memory allocation fails\n",
 						__func__);
 		return -ENOMEM;
 	}

 	tps->en_internal_pulldn = pdata->en_internal_pulldn;
 	tps->vsel_gpio = pdata->vsel_gpio;
 	tps->dev = &client->dev;

 	tps->desc.name = id->name;
 	tps->desc.id = 0;
 	tps->desc.n_voltages = TPS6238X0_N_VOLTAGES;
 	tps->desc.ops = &tps6238x0_ops;
 	tps->desc.type = REGULATOR_VOLTAGE;
 	tps->desc.owner = THIS_MODULE;
 	tps->regmap = devm_regmap_init_i2c(client, &tps6238x0_regmap_config);
 	if (IS_ERR(tps->regmap)) {
 		ret = PTR_ERR(tps->regmap);
 		dev_err(&client->dev, "%s() Err: Failed to allocate register"
 			"map: %d\n", __func__, ret);
 		return ret;
 	}
 	i2c_set_clientdata(client, tps);

 	tps->curr_vset_id = (pdata->vsel_def_state & 1);
 	tps->lru_index[0] = tps->curr_vset_id;
 	tps->valid_gpios = false;

 	if (gpio_is_valid(tps->vsel_gpio)) {
 		int gpio_flag;
 		gpio_flag = (tps->curr_vset_id) ?
 				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
 		ret = gpio_request_one(tps->vsel_gpio,
 					gpio_flag, "tps6238x0-vsel0");
 		if (ret) {
 			dev_err(&client->dev,
 				"Err: Could not obtain vsel GPIO %d: %d\n",
 						tps->vsel_gpio, ret);
 			return ret;
 		}
 		tps->valid_gpios = true;

 		/*
 		 * Initialize the lru index with vset_reg id
 		 * The index 0 will be most recently used and
 		 * set with the tps->curr_vset_id */
 		for (i = 0; i < TPS6238X0_MAX_VSET; ++i)
 			tps->lru_index[i] = i;
 		tps->lru_index[0] = tps->curr_vset_id;
 		tps->lru_index[tps->curr_vset_id] = 0;
 	}

 	ret = tps6238x0_configure(tps, pdata);
 	if (ret < 0) {
 		dev_err(tps->dev, "%s() Err: Init fails with = %d\n",
 				__func__, ret);
 		goto err_init;
 	}

 	config.dev = &client->dev;
 	config.init_data = pdata->init_data;
 	config.driver_data = tps;

 	/* Register the regulators */
 	rdev = regulator_register(&tps->desc, &config);
 	if (IS_ERR(rdev)) {
 		dev_err(tps->dev, "%s() Err: Failed to register %s\n",
 				__func__, id->name);
 		ret = PTR_ERR(rdev);
 		goto err_init;
 	}

 	tps->rdev = rdev;
 	return 0;

 err_init:
 	if (gpio_is_valid(tps->vsel_gpio))
 		gpio_free(tps->vsel_gpio);

 	return ret;
 }

 /**
  * tps6238x0_remove - tps62360 driver i2c remove handler
  * @client: i2c driver client device structure
  *
  * Unregister TPS driver as an i2c client device driver
  */
 static int tps6238x0_remove(struct i2c_client *client)
 {
 	struct tps6238x0_chip *tps = i2c_get_clientdata(client);

 	if (gpio_is_valid(tps->vsel_gpio))
 		gpio_free(tps->vsel_gpio);

 	regulator_unregister(tps->rdev);
 	return 0;
 }

 static const struct i2c_device_id tps6238x0_id[] = {
 	{.name = "tps623850", },
 	{.name = "tps623860", },
 	{.name = "tps623870", },
 	{},
 };

 MODULE_DEVICE_TABLE(i2c, tps6238x0_id);

 static struct i2c_driver tps6238x0_i2c_driver = {
 	.driver = {
 		.name = "tps6238x0",
 		.owner = THIS_MODULE,
 	},
 	.probe = tps6238x0_probe,
 	.remove = tps6238x0_remove,
 	.id_table = tps6238x0_id,
 };

 static int __init tps6238x0_init(void)
 {
 	return i2c_add_driver(&tps6238x0_i2c_driver);
 }
 subsys_initcall(tps6238x0_init);

 static void __exit tps6238x0_cleanup(void)
 {
 	i2c_del_driver(&tps6238x0_i2c_driver);
 }
 module_exit(tps6238x0_cleanup);

 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 MODULE_DESCRIPTION("TPS623850/TPS623860/TPS623870 voltage regulator driver");
 MODULE_LICENSE("GPL v2");
	/*
	* tps6238x0-regulator.c -- TI tps623850/tps623860/tps623870
	*
	* Driver for processor core supply tps623850, tps623860 and tps623870
	*
	* Copyright (c) 2012, NVIDIA Corporation.
	*
	* Author: Laxman Dewangan <ldewangan@nvidia.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
	* whether express or implied; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	* 02111-1307, USA
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/machine.h>
	#include <linux/regulator/tps6238x0-regulator.h>
	#include <linux/gpio.h>
	#include <linux/i2c.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/regmap.h>

	/* Register definitions */
	#define REG_VSET0 0
	#define REG_VSET1 1
	#define REG_MODE0 2
	#define REG_MODE1 3
	#define REG_CONTROL 4
	#define REG_EXCEPTION 5
	#define REG_RAMPCTRL 6
	#define REG_IOUT 7
	#define REG_CHIPID 8

	#define TPS6238X0_BASE_VOLTAGE 500000
	#define TPS6238X0_N_VOLTAGES 128
	#define TPS6238X0_MAX_VSET 2
	#define TPS6238X0_VOUT_MASK 0x7F

	/* tps 6238x0 chip information */
	struct tps6238x0_chip {
	const char *name;
	struct device *dev;
	struct regulator_desc desc;
	struct regulator_dev *rdev;
	struct regmap *regmap;
	int vsel_gpio;
	int change_uv_per_us;
	bool en_internal_pulldn;
	bool valid_gpios;
	int lru_index[TPS6238X0_MAX_VSET];
	int curr_vset_vsel[TPS6238X0_MAX_VSET];
	int curr_vset_id;
	};

	/*
	* find_voltage_set_register: Find new voltage configuration register
	* (VSET) id.
	* The finding of the new VSET register will be based on the LRU mechanism.
	* Each VSET register will have different voltage configured . This
	* Function will look if any of the VSET register have requested voltage set
	* or not.
	* - If it is already there then it will make that register as most
	* recently used and return as found so that caller need not to set
	* the VSET register but need to set the proper gpios to select this
	* VSET register.
	* - If requested voltage is not found then it will use the least
	* recently mechanism to get new VSET register for new configuration
	* and will return not_found so that caller need to set new VSET
	* register and then gpios (both).
	*/
	static bool find_voltage_set_register(struct tps6238x0_chip *tps,
	int req_vsel, int *vset_reg_id)
	{
	int i;
	bool found = false;
	int new_vset_reg = tps->lru_index[1];
	int found_index = 1;
	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
	if (tps->curr_vset_vsel[tps->lru_index[i]] == req_vsel) {
	new_vset_reg = tps->lru_index[i];
	found_index = i;
	found = true;
	goto update_lru_index;
	}
	}

	update_lru_index:
	for (i = found_index; i > 0; i--)
	tps->lru_index[i] = tps->lru_index[i - 1];

	tps->lru_index[0] = new_vset_reg;
	*vset_reg_id = new_vset_reg;
	return found;
	}

	static int tps6238x0_get_voltage_sel(struct regulator_dev *dev)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);
	unsigned int data;
	int ret;

	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
	if (ret < 0) {
	dev_err(tps->dev, "%s: Error in reading register %d\n",
	__func__, REG_VSET0 + tps->curr_vset_id);
	return ret;
	}
	return data & TPS6238X0_VOUT_MASK;
	}

	static int tps6238x0_set_voltage(struct regulator_dev *dev,
	int min_uV, int max_uV, unsigned *selector)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);
	int vsel;
	int ret;
	bool found = false;
	int new_vset_id = tps->curr_vset_id;

	if (min_uV >
	((TPS6238X0_BASE_VOLTAGE + (TPS6238X0_N_VOLTAGES - 1) * 10000)))
	return -EINVAL;

	if ((max_uV < min_uV) \|\| (max_uV < TPS6238X0_BASE_VOLTAGE))
	return -EINVAL;

	vsel = DIV_ROUND_UP(min_uV - TPS6238X0_BASE_VOLTAGE, 10000);
	if (selector)
	*selector = (vsel & TPS6238X0_VOUT_MASK);

	/*
	* If gpios are available to select the VSET register then least
	* recently used register for new configuration.
	*/
	if (tps->valid_gpios)
	found = find_voltage_set_register(tps, vsel, &new_vset_id);

	if (!found) {
	ret = regmap_update_bits(tps->regmap, REG_VSET0 + new_vset_id,
	TPS6238X0_VOUT_MASK, vsel);
	if (ret < 0) {
	dev_err(tps->dev, "%s: Error in updating register %d\n",
	__func__, REG_VSET0 + new_vset_id);
	return ret;
	}
	tps->curr_vset_id = new_vset_id;
	tps->curr_vset_vsel[new_vset_id] = vsel;
	}

	/* Select proper VSET register vio gpios */
	if (tps->valid_gpios)
	gpio_set_value_cansleep(tps->vsel_gpio, new_vset_id & 0x1);
	return 0;
	}

	static int tps6238x0_list_voltage(struct regulator_dev *dev,
	unsigned selector)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(dev);

	if ((selector < 0) \|\| (selector >= tps->desc.n_voltages))
	return -EINVAL;

	return TPS6238X0_BASE_VOLTAGE + selector * 10000;
	}

	static int tps6238x0_regulator_enable_time(struct regulator_dev *rdev)
	{
	return 300;
	}

	static int tps6238x0_set_voltage_time_sel(struct regulator_dev *rdev,
	unsigned int old_selector, unsigned int new_selector)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
	int old_uV, new_uV;
	old_uV = tps6238x0_list_voltage(rdev, old_selector);

	if (old_uV < 0)
	return old_uV;

	new_uV = tps6238x0_list_voltage(rdev, new_selector);
	if (new_uV < 0)
	return new_uV;

	return DIV_ROUND_UP(abs(old_uV - new_uV),
	tps->change_uv_per_us);
	}

	static int tps6238x0_is_enable(struct regulator_dev *rdev)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
	unsigned int data;
	int ret;

	ret = regmap_read(tps->regmap, REG_VSET0 + tps->curr_vset_id, &data);
	if (ret < 0) {
	dev_err(tps->dev, "%s: Error in reading register %d\n",
	__func__, REG_VSET0 + tps->curr_vset_id);
	return ret;
	}
	return !!(data & BIT(7));
	}

	static int tps6238x0_enable(struct regulator_dev *rdev)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
	int ret;
	int i;

	/* Enable required VSET configuration */
	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
	unsigned int en = 0;
	if (tps->valid_gpios \|\| (i == tps->curr_vset_id))
	en = BIT(7);

	ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
	BIT(7), en);
	if (ret < 0) {
	dev_err(tps->dev, "%s() fails in updating reg %d\n",
	__func__, REG_VSET0 + i);
	return ret;
	}
	}
	return ret;
	}

	static int tps6238x0_disable(struct regulator_dev *rdev)
	{
	struct tps6238x0_chip *tps = rdev_get_drvdata(rdev);
	int ret;
	int i;

	/* Disable required VSET configuration */
	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
	ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
	BIT(7), 0);
	if (ret < 0) {
	dev_err(tps->dev, "%s() fails in updating reg %d\n",
	__func__, REG_VSET0 + i);
	return ret;
	}
	}
	return ret;
	}

	static struct regulator_ops tps6238x0_ops = {
	.is_enabled = tps6238x0_is_enable,
	.enable = tps6238x0_enable,
	.disable = tps6238x0_disable,
	.enable_time = tps6238x0_regulator_enable_time,
	.set_voltage_time_sel = tps6238x0_set_voltage_time_sel,
	.get_voltage_sel = tps6238x0_get_voltage_sel,
	.set_voltage = tps6238x0_set_voltage,
	.list_voltage = tps6238x0_list_voltage,
	};

	static int tps6238x0_configure(struct tps6238x0_chip *tps,
	struct tps6238x0_regulator_platform_data *pdata)
	{
	int ret;
	int i;

	/* Initailize internal pull up/down control */
	if (tps->en_internal_pulldn)
	ret = regmap_write(tps->regmap, REG_CONTROL, 0xC0);
	else
	ret = regmap_write(tps->regmap, REG_CONTROL, 0x0);
	if (ret < 0) {
	dev_err(tps->dev, "%s() fails in writing reg %d\n",
	__func__, REG_CONTROL);
	return ret;
	}

	/* Enable required VSET configuration */
	for (i = 0; i < TPS6238X0_MAX_VSET; ++i) {
	unsigned int en = 0;
	if (tps->valid_gpios \|\| (i == tps->curr_vset_id))
	en = BIT(7);

	ret = regmap_update_bits(tps->regmap, REG_VSET0 + i,
	BIT(7), en);
	if (ret < 0) {
	dev_err(tps->dev, "%s() fails in updating reg %d\n",
	__func__, REG_VSET0 + i);
	return ret;
	}
	}

	/* Enable output discharge path to have faster discharge */
	ret = regmap_update_bits(tps->regmap, REG_RAMPCTRL, BIT(2), BIT(2));
	if (ret < 0)
	dev_err(tps->dev, "%s() fails in updating reg %d\n",
	__func__, REG_RAMPCTRL);
	tps->change_uv_per_us = 312;
	return ret;
	}

	static const struct regmap_config tps6238x0_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = REG_CHIPID,
	.num_reg_defaults_raw = REG_CHIPID + 1,
	.cache_type = REGCACHE_RBTREE,
	};

	static int tps6238x0_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct tps6238x0_regulator_platform_data *pdata;
	struct regulator_dev *rdev;
	struct tps6238x0_chip *tps;
	struct regulator_config config = { };
	int ret;
	int i;

	pdata = client->dev.platform_data;
	if (!pdata) {
	dev_err(&client->dev, "%s() Err: Platform data not found\n",
	__func__);
	return -EIO;
	}

	tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
	if (!tps) {
	dev_err(&client->dev, "%s() Err: Memory allocation fails\n",
	__func__);
	return -ENOMEM;
	}

	tps->en_internal_pulldn = pdata->en_internal_pulldn;
	tps->vsel_gpio = pdata->vsel_gpio;
	tps->dev = &client->dev;

	tps->desc.name = id->name;
	tps->desc.id = 0;
	tps->desc.n_voltages = TPS6238X0_N_VOLTAGES;
	tps->desc.ops = &tps6238x0_ops;
	tps->desc.type = REGULATOR_VOLTAGE;
	tps->desc.owner = THIS_MODULE;
	tps->regmap = devm_regmap_init_i2c(client, &tps6238x0_regmap_config);
	if (IS_ERR(tps->regmap)) {
	ret = PTR_ERR(tps->regmap);
	dev_err(&client->dev, "%s() Err: Failed to allocate register"
	"map: %d\n", __func__, ret);
	return ret;
	}
	i2c_set_clientdata(client, tps);

	tps->curr_vset_id = (pdata->vsel_def_state & 1);
	tps->lru_index[0] = tps->curr_vset_id;
	tps->valid_gpios = false;

	if (gpio_is_valid(tps->vsel_gpio)) {
	int gpio_flag;
	gpio_flag = (tps->curr_vset_id) ?
	GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
	ret = gpio_request_one(tps->vsel_gpio,
	gpio_flag, "tps6238x0-vsel0");
	if (ret) {
	dev_err(&client->dev,
	"Err: Could not obtain vsel GPIO %d: %d\n",
	tps->vsel_gpio, ret);
	return ret;
	}
	tps->valid_gpios = true;

	/*
	* Initialize the lru index with vset_reg id
	* The index 0 will be most recently used and
	* set with the tps->curr_vset_id */
	for (i = 0; i < TPS6238X0_MAX_VSET; ++i)
	tps->lru_index[i] = i;
	tps->lru_index[0] = tps->curr_vset_id;
	tps->lru_index[tps->curr_vset_id] = 0;
	}

	ret = tps6238x0_configure(tps, pdata);
	if (ret < 0) {
	dev_err(tps->dev, "%s() Err: Init fails with = %d\n",
	__func__, ret);
	goto err_init;
	}

	config.dev = &client->dev;
	config.init_data = pdata->init_data;
	config.driver_data = tps;

	/* Register the regulators */
	rdev = regulator_register(&tps->desc, &config);
	if (IS_ERR(rdev)) {
	dev_err(tps->dev, "%s() Err: Failed to register %s\n",
	__func__, id->name);
	ret = PTR_ERR(rdev);
	goto err_init;
	}

	tps->rdev = rdev;
	return 0;

	err_init:
	if (gpio_is_valid(tps->vsel_gpio))
	gpio_free(tps->vsel_gpio);

	return ret;
	}

	/**
	* tps6238x0_remove - tps62360 driver i2c remove handler
	* @client: i2c driver client device structure
	*
	* Unregister TPS driver as an i2c client device driver
	*/
	static int tps6238x0_remove(struct i2c_client *client)
	{
	struct tps6238x0_chip *tps = i2c_get_clientdata(client);

	if (gpio_is_valid(tps->vsel_gpio))
	gpio_free(tps->vsel_gpio);

	regulator_unregister(tps->rdev);
	return 0;
	}

	static const struct i2c_device_id tps6238x0_id[] = {
	{.name = "tps623850", },
	{.name = "tps623860", },
	{.name = "tps623870", },
	{},
	};

	MODULE_DEVICE_TABLE(i2c, tps6238x0_id);

	static struct i2c_driver tps6238x0_i2c_driver = {
	.driver = {
	.name = "tps6238x0",
	.owner = THIS_MODULE,
	},
	.probe = tps6238x0_probe,
	.remove = tps6238x0_remove,
	.id_table = tps6238x0_id,
	};

	static int __init tps6238x0_init(void)
	{
	return i2c_add_driver(&tps6238x0_i2c_driver);
	}
	subsys_initcall(tps6238x0_init);

	static void __exit tps6238x0_cleanup(void)
	{
	i2c_del_driver(&tps6238x0_i2c_driver);
	}
	module_exit(tps6238x0_cleanup);

	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
	MODULE_DESCRIPTION("TPS623850/TPS623860/TPS623870 voltage regulator driver");
	MODULE_LICENSE("GPL v2");