[mirror_ubuntu-zesty-kernel.git] / drivers / regulator / max8973-regulator.c

/*
 * max8973-regulator.c -- Maxim max8973
 *
 * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
 *
 * 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/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/max8973-regulator.h>
#include <linux/regulator/of_regulator.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/regmap.h>

/* Register definitions */
#define MAX8973_VOUT					0x0
#define MAX8973_VOUT_DVS				0x1
#define MAX8973_CONTROL1				0x2
#define MAX8973_CONTROL2				0x3
#define MAX8973_CHIPID1					0x4
#define MAX8973_CHIPID2					0x5

#define MAX8973_MAX_VOUT_REG				2

/* MAX8973_VOUT */
#define MAX8973_VOUT_ENABLE				BIT(7)
#define MAX8973_VOUT_MASK				0x7F

/* MAX8973_VOUT_DVS */
#define MAX8973_DVS_VOUT_MASK				0x7F

/* MAX8973_CONTROL1 */
#define MAX8973_SNS_ENABLE				BIT(7)
#define MAX8973_FPWM_EN_M				BIT(6)
#define MAX8973_NFSR_ENABLE				BIT(5)
#define MAX8973_AD_ENABLE				BIT(4)
#define MAX8973_BIAS_ENABLE				BIT(3)
#define MAX8973_FREQSHIFT_9PER				BIT(2)

#define MAX8973_RAMP_12mV_PER_US			0x0
#define MAX8973_RAMP_25mV_PER_US			0x1
#define MAX8973_RAMP_50mV_PER_US			0x2
#define MAX8973_RAMP_200mV_PER_US			0x3

/* MAX8973_CONTROL2 */
#define MAX8973_WDTMR_ENABLE				BIT(6)
#define MAX8973_DISCH_ENBABLE				BIT(5)
#define MAX8973_FT_ENABLE				BIT(4)

#define MAX8973_CKKADV_TRIP_DISABLE			0xC
#define MAX8973_CKKADV_TRIP_75mV_PER_US			0x0
#define MAX8973_CKKADV_TRIP_150mV_PER_US		0x4
#define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS	0x8
#define MAX8973_CONTROL_CLKADV_TRIP_MASK		0x00030000

#define MAX8973_INDUCTOR_MIN_30_PER			0x0
#define MAX8973_INDUCTOR_NOMINAL			0x1
#define MAX8973_INDUCTOR_PLUS_30_PER			0x2
#define MAX8973_INDUCTOR_PLUS_60_PER			0x3
#define MAX8973_CONTROL_INDUCTOR_VALUE_MASK		0x00300000

#define MAX8973_MIN_VOLATGE				606250
#define MAX8973_MAX_VOLATGE				1400000
#define MAX8973_VOLATGE_STEP				6250
#define MAX8973_BUCK_N_VOLTAGE				0x80

/* Maxim 8973 chip information */
struct max8973_chip {
	struct device *dev;
	struct regulator_desc desc;
	struct regmap *regmap;
	bool enable_external_control;
	int dvs_gpio;
	int lru_index[MAX8973_MAX_VOUT_REG];
	int curr_vout_val[MAX8973_MAX_VOUT_REG];
	int curr_vout_reg;
	int curr_gpio_val;
	bool valid_dvs_gpio;
	struct regulator_ops ops;
};

/*
 * find_voltage_set_register: Find new voltage configuration register (VOUT).
 * The finding of the new VOUT register will be based on the LRU mechanism.
 * Each VOUT register will have different voltage configured . This
 * Function will look if any of the VOUT 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 VOUT register but need to set the proper gpios to select this
 *       VOUT register.
 *     - If requested voltage is not found then it will use the least
 *       recently mechanism to get new VOUT register for new configuration
 *       and will return not_found so that caller need to set new VOUT
 *       register and then gpios (both).
 */
static bool find_voltage_set_register(struct max8973_chip *tps,
		int req_vsel, int *vout_reg, int *gpio_val)
{
	int i;
	bool found = false;
	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
	int found_index = MAX8973_MAX_VOUT_REG - 1;

	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
		if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
			new_vout_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_vout_reg;
	*gpio_val = new_vout_reg;
	*vout_reg = MAX8973_VOUT + new_vout_reg;
	return found;
}

static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
{
	struct max8973_chip *max = rdev_get_drvdata(rdev);
	unsigned int data;
	int ret;

	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
	if (ret < 0) {
		dev_err(max->dev, "register %d read failed, err = %d\n",
			max->curr_vout_reg, ret);
		return ret;
	}
	return data & MAX8973_VOUT_MASK;
}

static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
	     unsigned vsel)
{
	struct max8973_chip *max = rdev_get_drvdata(rdev);
	int ret;
	bool found = false;
	int vout_reg = max->curr_vout_reg;
	int gpio_val = max->curr_gpio_val;

	/*
	 * If gpios are available to select the VOUT register then least
	 * recently used register for new configuration.
	 */
	if (max->valid_dvs_gpio)
		found = find_voltage_set_register(max, vsel,
					&vout_reg, &gpio_val);

	if (!found) {
		ret = regmap_update_bits(max->regmap, vout_reg,
					MAX8973_VOUT_MASK, vsel);
		if (ret < 0) {
			dev_err(max->dev, "register %d update failed, err %d\n",
				 vout_reg, ret);
			return ret;
		}
		max->curr_vout_reg = vout_reg;
		max->curr_vout_val[gpio_val] = vsel;
	}

	/* Select proper VOUT register vio gpios */
	if (max->valid_dvs_gpio) {
		gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
		max->curr_gpio_val = gpio_val;
	}
	return 0;
}

static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
	struct max8973_chip *max = rdev_get_drvdata(rdev);
	int ret;
	int pwm;

	/* Enable force PWM mode in FAST mode only. */
	switch (mode) {
	case REGULATOR_MODE_FAST:
		pwm = MAX8973_FPWM_EN_M;
		break;

	case REGULATOR_MODE_NORMAL:
		pwm = 0;
		break;

	default:
		return -EINVAL;
	}

	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
				MAX8973_FPWM_EN_M, pwm);
	if (ret < 0)
		dev_err(max->dev, "register %d update failed, err %d\n",
				MAX8973_CONTROL1, ret);
	return ret;
}

static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
{
	struct max8973_chip *max = rdev_get_drvdata(rdev);
	unsigned int data;
	int ret;

	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
	if (ret < 0) {
		dev_err(max->dev, "register %d read failed, err %d\n",
				MAX8973_CONTROL1, ret);
		return ret;
	}
	return (data & MAX8973_FPWM_EN_M) ?
		REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
}

static const struct regulator_ops max8973_dcdc_ops = {
	.get_voltage_sel	= max8973_dcdc_get_voltage_sel,
	.set_voltage_sel	= max8973_dcdc_set_voltage_sel,
	.list_voltage		= regulator_list_voltage_linear,
	.set_mode		= max8973_dcdc_set_mode,
	.get_mode		= max8973_dcdc_get_mode,
};

static int max8973_init_dcdc(struct max8973_chip *max,
			     struct max8973_regulator_platform_data *pdata)
{
	int ret;
	uint8_t	control1 = 0;
	uint8_t control2 = 0;

	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
		control1 |= MAX8973_SNS_ENABLE;

	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
		control1 |= MAX8973_NFSR_ENABLE;

	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
		control1 |= MAX8973_AD_ENABLE;

	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE)
		control1 |= MAX8973_BIAS_ENABLE;

	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
		control1 |= MAX8973_FREQSHIFT_9PER;

	/* Set ramp delay */
	if (pdata->reg_init_data &&
			pdata->reg_init_data->constraints.ramp_delay) {
		if (pdata->reg_init_data->constraints.ramp_delay < 25000)
			control1 |= MAX8973_RAMP_12mV_PER_US;
		else if (pdata->reg_init_data->constraints.ramp_delay < 50000)
			control1 |= MAX8973_RAMP_25mV_PER_US;
		else if (pdata->reg_init_data->constraints.ramp_delay < 200000)
			control1 |= MAX8973_RAMP_50mV_PER_US;
		else
			control1 |= MAX8973_RAMP_200mV_PER_US;
	} else {
		control1 |= MAX8973_RAMP_12mV_PER_US;
		max->desc.ramp_delay = 12500;
	}

	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
		control2 |= MAX8973_DISCH_ENBABLE;

	/*  Clock advance trip configuration */
	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
		control2 |= MAX8973_CKKADV_TRIP_DISABLE;
		break;

	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US;
		break;

	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
		control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US;
		break;

	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
		control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
		break;
	}

	/* Configure inductor value */
	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
		control2 |= MAX8973_INDUCTOR_NOMINAL;
		break;

	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
		control2 |= MAX8973_INDUCTOR_MIN_30_PER;
		break;

	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
		control2 |= MAX8973_INDUCTOR_PLUS_30_PER;
		break;

	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
		control2 |= MAX8973_INDUCTOR_PLUS_60_PER;
		break;
	}

	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
	if (ret < 0) {
		dev_err(max->dev, "register %d write failed, err = %d",
				MAX8973_CONTROL1, ret);
		return ret;
	}

	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
	if (ret < 0) {
		dev_err(max->dev, "register %d write failed, err = %d",
				MAX8973_CONTROL2, ret);
		return ret;
	}

	/* If external control is enabled then disable EN bit */
	if (max->enable_external_control) {
		ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
						MAX8973_VOUT_ENABLE, 0);
		if (ret < 0)
			dev_err(max->dev, "register %d update failed, err = %d",
				MAX8973_VOUT, ret);
	}
	return ret;
}

static const struct regmap_config max8973_regmap_config = {
	.reg_bits		= 8,
	.val_bits		= 8,
	.max_register		= MAX8973_CHIPID2,
	.cache_type		= REGCACHE_RBTREE,
};

static int max8973_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct max8973_regulator_platform_data *pdata;
	struct regulator_config config = { };
	struct regulator_dev *rdev;
	struct max8973_chip *max;
	int ret;

	pdata = dev_get_platdata(&client->dev);

	if (!pdata && !client->dev.of_node) {
		dev_err(&client->dev, "No Platform data");
		return -EIO;
	}

	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
	if (!max)
		return -ENOMEM;

	max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
	if (IS_ERR(max->regmap)) {
		ret = PTR_ERR(max->regmap);
		dev_err(&client->dev, "regmap init failed, err %d\n", ret);
		return ret;
	}

	i2c_set_clientdata(client, max);
	max->ops = max8973_dcdc_ops;
	max->dev = &client->dev;
	max->desc.name = id->name;
	max->desc.id = 0;
	max->desc.ops = &max->ops;
	max->desc.type = REGULATOR_VOLTAGE;
	max->desc.owner = THIS_MODULE;
	max->desc.min_uV = MAX8973_MIN_VOLATGE;
	max->desc.uV_step = MAX8973_VOLATGE_STEP;
	max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;

	if (!pdata || !pdata->enable_ext_control) {
		max->desc.enable_reg = MAX8973_VOUT;
		max->desc.enable_mask = MAX8973_VOUT_ENABLE;
		max->ops.enable = regulator_enable_regmap;
		max->ops.disable = regulator_disable_regmap;
		max->ops.is_enabled = regulator_is_enabled_regmap;
	}

	if (pdata) {
		max->dvs_gpio = pdata->dvs_gpio;
		max->enable_external_control = pdata->enable_ext_control;
		max->curr_gpio_val = pdata->dvs_def_state;
		max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
	} else {
		max->dvs_gpio = -EINVAL;
		max->curr_vout_reg = MAX8973_VOUT;
	}

	max->lru_index[0] = max->curr_vout_reg;

	if (gpio_is_valid(max->dvs_gpio)) {
		int gpio_flags;
		int i;

		gpio_flags = (pdata->dvs_def_state) ?
				GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
		ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
				gpio_flags, "max8973-dvs");
		if (ret) {
			dev_err(&client->dev,
				"gpio_request for gpio %d failed, err = %d\n",
				max->dvs_gpio, ret);
			return ret;
		}
		max->valid_dvs_gpio = true;

		/*
		 * Initialize the lru index with vout_reg id
		 * The index 0 will be most recently used and
		 * set with the max->curr_vout_reg */
		for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
			max->lru_index[i] = i;
		max->lru_index[0] = max->curr_vout_reg;
		max->lru_index[max->curr_vout_reg] = 0;
	} else {
		max->valid_dvs_gpio = false;
	}

	if (pdata) {
		ret = max8973_init_dcdc(max, pdata);
		if (ret < 0) {
			dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
			return ret;
		}
	}

	config.dev = &client->dev;
	config.init_data = pdata ? pdata->reg_init_data :
		of_get_regulator_init_data(&client->dev, client->dev.of_node,
					   &max->desc);
	config.driver_data = max;
	config.of_node = client->dev.of_node;
	config.regmap = max->regmap;

	/* Register the regulators */
	rdev = devm_regulator_register(&client->dev, &max->desc, &config);
	if (IS_ERR(rdev)) {
		ret = PTR_ERR(rdev);
		dev_err(max->dev, "regulator register failed, err %d\n", ret);
		return ret;
	}

	return 0;
}

static const struct i2c_device_id max8973_id[] = {
	{.name = "max8973",},
	{},
};

MODULE_DEVICE_TABLE(i2c, max8973_id);

static struct i2c_driver max8973_i2c_driver = {
	.driver = {
		.name = "max8973",
		.owner = THIS_MODULE,
	},
	.probe = max8973_probe,
	.id_table = max8973_id,
};

static int __init max8973_init(void)
{
	return i2c_add_driver(&max8973_i2c_driver);
}
subsys_initcall(max8973_init);

static void __exit max8973_cleanup(void)
{
	i2c_del_driver(&max8973_i2c_driver);
}
module_exit(max8973_cleanup);

MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
5928f538 LD	1	/*
	2	* max8973-regulator.c -- Maxim max8973
	3	*
	4	* Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
	5	*
	6	* Copyright (c) 2012, NVIDIA Corporation.
	7	*
	8	* Author: Laxman Dewangan <ldewangan@nvidia.com>
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License as
	12	* published by the Free Software Foundation version 2.
	13	*
	14	* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
	15	* whether express or implied; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU General Public License
	20	* along with this program; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	22	* 02111-1307, USA
	23	*/
	24
	25	#include <linux/kernel.h>
	26	#include <linux/module.h>
	27	#include <linux/init.h>
	28	#include <linux/err.h>
42dc3023	29	#include <linux/of.h>
5928f538 LD	30	#include <linux/platform_device.h>
	31	#include <linux/regulator/driver.h>
	32	#include <linux/regulator/machine.h>
	33	#include <linux/regulator/max8973-regulator.h>
42dc3023	34	#include <linux/regulator/of_regulator.h>
5928f538 LD	35	#include <linux/gpio.h>
	36	#include <linux/i2c.h>
	37	#include <linux/slab.h>
	38	#include <linux/regmap.h>
	39
	40	/* Register definitions */
	41	#define MAX8973_VOUT 0x0
	42	#define MAX8973_VOUT_DVS 0x1
	43	#define MAX8973_CONTROL1 0x2
	44	#define MAX8973_CONTROL2 0x3
	45	#define MAX8973_CHIPID1 0x4
	46	#define MAX8973_CHIPID2 0x5
	47
	48	#define MAX8973_MAX_VOUT_REG 2
	49
	50	/* MAX8973_VOUT */
	51	#define MAX8973_VOUT_ENABLE BIT(7)
	52	#define MAX8973_VOUT_MASK 0x7F
	53
	54	/* MAX8973_VOUT_DVS */
	55	#define MAX8973_DVS_VOUT_MASK 0x7F
	56
	57	/* MAX8973_CONTROL1 */
	58	#define MAX8973_SNS_ENABLE BIT(7)
	59	#define MAX8973_FPWM_EN_M BIT(6)
	60	#define MAX8973_NFSR_ENABLE BIT(5)
	61	#define MAX8973_AD_ENABLE BIT(4)
	62	#define MAX8973_BIAS_ENABLE BIT(3)
	63	#define MAX8973_FREQSHIFT_9PER BIT(2)
	64
	65	#define MAX8973_RAMP_12mV_PER_US 0x0
	66	#define MAX8973_RAMP_25mV_PER_US 0x1
	67	#define MAX8973_RAMP_50mV_PER_US 0x2
	68	#define MAX8973_RAMP_200mV_PER_US 0x3
	69
	70	/* MAX8973_CONTROL2 */
	71	#define MAX8973_WDTMR_ENABLE BIT(6)
	72	#define MAX8973_DISCH_ENBABLE BIT(5)
	73	#define MAX8973_FT_ENABLE BIT(4)
	74
	75	#define MAX8973_CKKADV_TRIP_DISABLE 0xC
	76	#define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0
	77	#define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4
	78	#define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8
	79	#define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000
	80
	81	#define MAX8973_INDUCTOR_MIN_30_PER 0x0
	82	#define MAX8973_INDUCTOR_NOMINAL 0x1
	83	#define MAX8973_INDUCTOR_PLUS_30_PER 0x2
	84	#define MAX8973_INDUCTOR_PLUS_60_PER 0x3
	85	#define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000
	86
	87	#define MAX8973_MIN_VOLATGE 606250
	88	#define MAX8973_MAX_VOLATGE 1400000
	89	#define MAX8973_VOLATGE_STEP 6250
	90	#define MAX8973_BUCK_N_VOLTAGE 0x80
	91
	92	/* Maxim 8973 chip information */
	93	struct max8973_chip {
	94	struct device *dev;
	95	struct regulator_desc desc;
5928f538 LD	96	struct regmap *regmap;
	97	bool enable_external_control;
	98	int dvs_gpio;
	99	int lru_index[MAX8973_MAX_VOUT_REG];
	100	int curr_vout_val[MAX8973_MAX_VOUT_REG];
	101	int curr_vout_reg;
	102	int curr_gpio_val;
	103	bool valid_dvs_gpio;
db892ff6	104	struct regulator_ops ops;
5928f538 LD	105	};
	106
	107	/*
	108	* find_voltage_set_register: Find new voltage configuration register (VOUT).
	109	* The finding of the new VOUT register will be based on the LRU mechanism.
	110	* Each VOUT register will have different voltage configured . This
	111	* Function will look if any of the VOUT register have requested voltage set
	112	* or not.
	113	* - If it is already there then it will make that register as most
	114	* recently used and return as found so that caller need not to set
	115	* the VOUT register but need to set the proper gpios to select this
	116	* VOUT register.
	117	* - If requested voltage is not found then it will use the least
	118	* recently mechanism to get new VOUT register for new configuration
	119	* and will return not_found so that caller need to set new VOUT
	120	* register and then gpios (both).
	121	*/
	122	static bool find_voltage_set_register(struct max8973_chip *tps,
	123	int req_vsel, int vout_reg, int gpio_val)
	124	{
	125	int i;
	126	bool found = false;
	127	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
	128	int found_index = MAX8973_MAX_VOUT_REG - 1;
	129
	130	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
	131	if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
	132	new_vout_reg = tps->lru_index[i];
	133	found_index = i;
	134	found = true;
	135	goto update_lru_index;
	136	}
	137	}
	138
	139	update_lru_index:
	140	for (i = found_index; i > 0; i--)
	141	tps->lru_index[i] = tps->lru_index[i - 1];
	142
	143	tps->lru_index[0] = new_vout_reg;
	144	*gpio_val = new_vout_reg;
	145	*vout_reg = MAX8973_VOUT + new_vout_reg;
	146	return found;
	147	}
	148
	149	static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
	150	{
	151	struct max8973_chip *max = rdev_get_drvdata(rdev);
	152	unsigned int data;
	153	int ret;
	154
	155	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
	156	if (ret < 0) {
	157	dev_err(max->dev, "register %d read failed, err = %d\n",
	158	max->curr_vout_reg, ret);
	159	return ret;
	160	}
	161	return data & MAX8973_VOUT_MASK;
	162	}
	163
	164	static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
	165	unsigned vsel)
	166	{
	167	struct max8973_chip *max = rdev_get_drvdata(rdev);
	168	int ret;
169	bool found = false;
170	int vout_reg = max->curr_vout_reg;
171	int gpio_val = max->curr_gpio_val;
172
173	/*
174	* If gpios are available to select the VOUT register then least
175	* recently used register for new configuration.
176	*/
177	if (max->valid_dvs_gpio)
178	found = find_voltage_set_register(max, vsel,
179	&vout_reg, &gpio_val);
180
181	if (!found) {
182	ret = regmap_update_bits(max->regmap, vout_reg,
183	MAX8973_VOUT_MASK, vsel);
184	if (ret < 0) {
185	dev_err(max->dev, "register %d update failed, err %d\n",
186	vout_reg, ret);
187	return ret;
188	}
189	max->curr_vout_reg = vout_reg;
190	max->curr_vout_val[gpio_val] = vsel;
191	}
192
193	/* Select proper VOUT register vio gpios */
194	if (max->valid_dvs_gpio) {
195	gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
196	max->curr_gpio_val = gpio_val;
197	}
198	return 0;
199	}
200
201	static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
202	{
203	struct max8973_chip *max = rdev_get_drvdata(rdev);
204	int ret;
205	int pwm;
206
207	/* Enable force PWM mode in FAST mode only. */
208	switch (mode) {
209	case REGULATOR_MODE_FAST:
210	pwm = MAX8973_FPWM_EN_M;
211	break;
212
213	case REGULATOR_MODE_NORMAL:
214	pwm = 0;
215	break;
216
217	default:
218	return -EINVAL;
219	}
220
221	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
222	MAX8973_FPWM_EN_M, pwm);
223	if (ret < 0)
224	dev_err(max->dev, "register %d update failed, err %d\n",
225	MAX8973_CONTROL1, ret);
226	return ret;
227	}
228
229	static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
230	{
231	struct max8973_chip *max = rdev_get_drvdata(rdev);
232	unsigned int data;
233	int ret;
234
235	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
236	if (ret < 0) {
237	dev_err(max->dev, "register %d read failed, err %d\n",
238	MAX8973_CONTROL1, ret);
239	return ret;
240	}
241	return (data & MAX8973_FPWM_EN_M) ?
242	REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
243	}
244
db892ff6	245	static const struct regulator_ops max8973_dcdc_ops = {
5928f538 LD	246	.get_voltage_sel = max8973_dcdc_get_voltage_sel,
	247	.set_voltage_sel = max8973_dcdc_set_voltage_sel,
	248	.list_voltage = regulator_list_voltage_linear,
	249	.set_mode = max8973_dcdc_set_mode,
	250	.get_mode = max8973_dcdc_get_mode,
	251	};
	252
3d68dfe3 GKH	253	static int max8973_init_dcdc(struct max8973_chip *max,
3d68dfe3 GKH	254	struct max8973_regulator_platform_data *pdata)
5928f538 LD	255	{
	256	int ret;
	257	uint8_t control1 = 0;
	258	uint8_t control2 = 0;
	259
	260	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
	261	control1 \|= MAX8973_SNS_ENABLE;
	262
	263	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
	264	control1 \|= MAX8973_NFSR_ENABLE;
	265
	266	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
	267	control1 \|= MAX8973_AD_ENABLE;
	268
	269	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE)
	270	control1 \|= MAX8973_BIAS_ENABLE;
	271
	272	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
	273	control1 \|= MAX8973_FREQSHIFT_9PER;
	274
	275	/* Set ramp delay */
	276	if (pdata->reg_init_data &&
	277	pdata->reg_init_data->constraints.ramp_delay) {
	278	if (pdata->reg_init_data->constraints.ramp_delay < 25000)
b27032ca	279	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538	280	else if (pdata->reg_init_data->constraints.ramp_delay < 50000)
b27032ca	281	control1 \|= MAX8973_RAMP_25mV_PER_US;
5928f538	282	else if (pdata->reg_init_data->constraints.ramp_delay < 200000)
b27032ca	283	control1 \|= MAX8973_RAMP_50mV_PER_US;
5928f538	284	else
b27032ca	285	control1 \|= MAX8973_RAMP_200mV_PER_US;
5928f538	286	} else {
b27032ca	287	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538 LD	288	max->desc.ramp_delay = 12500;
	289	}
	290
	291	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
	292	control2 \|= MAX8973_DISCH_ENBABLE;
	293
	294	/* Clock advance trip configuration */
	295	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
	296	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
	297	control2 \|= MAX8973_CKKADV_TRIP_DISABLE;
	298	break;
	299
	300	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
	301	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US;
	302	break;
	303
	304	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
	305	control2 \|= MAX8973_CKKADV_TRIP_150mV_PER_US;
	306	break;
	307
	308	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
	309	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
	310	break;
	311	}
	312
	313	/* Configure inductor value */
	314	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
	315	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
	316	control2 \|= MAX8973_INDUCTOR_NOMINAL;
	317	break;
	318
	319	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
	320	control2 \|= MAX8973_INDUCTOR_MIN_30_PER;
	321	break;
	322
	323	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
	324	control2 \|= MAX8973_INDUCTOR_PLUS_30_PER;
	325	break;
	326
	327	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
	328	control2 \|= MAX8973_INDUCTOR_PLUS_60_PER;
	329	break;
	330	}
	331
	332	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
	333	if (ret < 0) {
	334	dev_err(max->dev, "register %d write failed, err = %d",
	335	MAX8973_CONTROL1, ret);
	336	return ret;
	337	}
	338
	339	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
	340	if (ret < 0) {
	341	dev_err(max->dev, "register %d write failed, err = %d",
	342	MAX8973_CONTROL2, ret);
	343	return ret;
	344	}
	345
	346	/* If external control is enabled then disable EN bit */
	347	if (max->enable_external_control) {
	348	ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
	349	MAX8973_VOUT_ENABLE, 0);
	350	if (ret < 0)
	351	dev_err(max->dev, "register %d update failed, err = %d",
352	MAX8973_VOUT, ret);
353	}
354	return ret;
355	}
356
357	static const struct regmap_config max8973_regmap_config = {
358	.reg_bits = 8,
359	.val_bits = 8,
360	.max_register = MAX8973_CHIPID2,
361	.cache_type = REGCACHE_RBTREE,
362	};
363
3d68dfe3 GKH	364	static int max8973_probe(struct i2c_client *client,
3d68dfe3 GKH	365	const struct i2c_device_id *id)
5928f538 LD	366	{
	367	struct max8973_regulator_platform_data *pdata;
	368	struct regulator_config config = { };
	369	struct regulator_dev *rdev;
	370	struct max8973_chip *max;
	371	int ret;
	372
dff91d0b	373	pdata = dev_get_platdata(&client->dev);
42dc3023 GL	374
42dc3023 GL	375	if (!pdata && !client->dev.of_node) {
5928f538 LD	376	dev_err(&client->dev, "No Platform data");
	377	return -EIO;
	378	}
	379
	380	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
21024dee	381	if (!max)
5928f538	382	return -ENOMEM;
5928f538 LD	383
	384	max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
	385	if (IS_ERR(max->regmap)) {
	386	ret = PTR_ERR(max->regmap);
	387	dev_err(&client->dev, "regmap init failed, err %d\n", ret);
	388	return ret;
	389	}
	390
	391	i2c_set_clientdata(client, max);
db892ff6	392	max->ops = max8973_dcdc_ops;
5928f538 LD	393	max->dev = &client->dev;
	394	max->desc.name = id->name;
	395	max->desc.id = 0;
db892ff6	396	max->desc.ops = &max->ops;
5928f538 LD	397	max->desc.type = REGULATOR_VOLTAGE;
	398	max->desc.owner = THIS_MODULE;
	399	max->desc.min_uV = MAX8973_MIN_VOLATGE;
	400	max->desc.uV_step = MAX8973_VOLATGE_STEP;
	401	max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
	402
42dc3023	403	if (!pdata \|\| !pdata->enable_ext_control) {
5928f538 LD	404	max->desc.enable_reg = MAX8973_VOUT;
5928f538 LD	405	max->desc.enable_mask = MAX8973_VOUT_ENABLE;
db892ff6 GL	406	max->ops.enable = regulator_enable_regmap;
	407	max->ops.disable = regulator_disable_regmap;
	408	max->ops.is_enabled = regulator_is_enabled_regmap;
5928f538 LD	409	}
5928f538 LD	410
42dc3023 GL	411	if (pdata) {
	412	max->dvs_gpio = pdata->dvs_gpio;
	413	max->enable_external_control = pdata->enable_ext_control;
	414	max->curr_gpio_val = pdata->dvs_def_state;
	415	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
	416	} else {
	417	max->dvs_gpio = -EINVAL;
	418	max->curr_vout_reg = MAX8973_VOUT;
	419	}
	420
5928f538	421	max->lru_index[0] = max->curr_vout_reg;
5928f538 LD	422
	423	if (gpio_is_valid(max->dvs_gpio)) {
	424	int gpio_flags;
	425	int i;
	426
	427	gpio_flags = (pdata->dvs_def_state) ?
	428	GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
	429	ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
	430	gpio_flags, "max8973-dvs");
	431	if (ret) {
	432	dev_err(&client->dev,
	433	"gpio_request for gpio %d failed, err = %d\n",
	434	max->dvs_gpio, ret);
	435	return ret;
	436	}
	437	max->valid_dvs_gpio = true;
	438
	439	/*
	440	* Initialize the lru index with vout_reg id
	441	* The index 0 will be most recently used and
	442	* set with the max->curr_vout_reg */
	443	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
	444	max->lru_index[i] = i;
	445	max->lru_index[0] = max->curr_vout_reg;
	446	max->lru_index[max->curr_vout_reg] = 0;
42dc3023 GL	447	} else {
42dc3023 GL	448	max->valid_dvs_gpio = false;
5928f538 LD	449	}
5928f538 LD	450
42dc3023 GL	451	if (pdata) {
	452	ret = max8973_init_dcdc(max, pdata);
	453	if (ret < 0) {
	454	dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
	455	return ret;
	456	}
5928f538 LD	457	}
	458
	459	config.dev = &client->dev;
42dc3023	460	config.init_data = pdata ? pdata->reg_init_data :
072e78b1 JMC	461	of_get_regulator_init_data(&client->dev, client->dev.of_node,
072e78b1 JMC	462	&max->desc);
5928f538 LD	463	config.driver_data = max;
	464	config.of_node = client->dev.of_node;
	465	config.regmap = max->regmap;
	466
	467	/* Register the regulators */
8d581fd0	468	rdev = devm_regulator_register(&client->dev, &max->desc, &config);
5928f538 LD	469	if (IS_ERR(rdev)) {
	470	ret = PTR_ERR(rdev);
	471	dev_err(max->dev, "regulator register failed, err %d\n", ret);
	472	return ret;
	473	}
	474
5928f538 LD	475	return 0;
	476	}
	477
5928f538 LD	478	static const struct i2c_device_id max8973_id[] = {
	479	{.name = "max8973",},
	480	{},
	481	};
	482
	483	MODULE_DEVICE_TABLE(i2c, max8973_id);
	484
	485	static struct i2c_driver max8973_i2c_driver = {
	486	.driver = {
	487	.name = "max8973",
	488	.owner = THIS_MODULE,
	489	},
	490	.probe = max8973_probe,
5928f538 LD	491	.id_table = max8973_id,
	492	};
	493
	494	static int __init max8973_init(void)
	495	{
	496	return i2c_add_driver(&max8973_i2c_driver);
	497	}
	498	subsys_initcall(max8973_init);
	499
	500	static void __exit max8973_cleanup(void)
	501	{
	502	i2c_del_driver(&max8973_i2c_driver);
	503	}
	504	module_exit(max8973_cleanup);
	505
	506	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
	507	MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
	508	MODULE_LICENSE("GPL v2");