[linux-block.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 regulator_dev *rdev;
	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) {
		dev_err(&client->dev, "Memory allocation for max failed\n");
		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);
	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;
	}

	max->rdev = rdev;
	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;
	96	struct regulator_dev *rdev;
	97	struct regmap *regmap;
	98	bool enable_external_control;
99	int dvs_gpio;
100	int lru_index[MAX8973_MAX_VOUT_REG];
101	int curr_vout_val[MAX8973_MAX_VOUT_REG];
102	int curr_vout_reg;
103	int curr_gpio_val;
104	bool valid_dvs_gpio;
db892ff6	105	struct regulator_ops ops;
5928f538 LD	106	};
	107
	108	/*
	109	* find_voltage_set_register: Find new voltage configuration register (VOUT).
	110	* The finding of the new VOUT register will be based on the LRU mechanism.
	111	* Each VOUT register will have different voltage configured . This
	112	* Function will look if any of the VOUT register have requested voltage set
	113	* or not.
	114	* - If it is already there then it will make that register as most
	115	* recently used and return as found so that caller need not to set
	116	* the VOUT register but need to set the proper gpios to select this
	117	* VOUT register.
	118	* - If requested voltage is not found then it will use the least
	119	* recently mechanism to get new VOUT register for new configuration
	120	* and will return not_found so that caller need to set new VOUT
	121	* register and then gpios (both).
	122	*/
	123	static bool find_voltage_set_register(struct max8973_chip *tps,
	124	int req_vsel, int vout_reg, int gpio_val)
	125	{
	126	int i;
	127	bool found = false;
	128	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
	129	int found_index = MAX8973_MAX_VOUT_REG - 1;
	130
	131	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
	132	if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
	133	new_vout_reg = tps->lru_index[i];
	134	found_index = i;
	135	found = true;
	136	goto update_lru_index;
	137	}
	138	}
	139
	140	update_lru_index:
	141	for (i = found_index; i > 0; i--)
	142	tps->lru_index[i] = tps->lru_index[i - 1];
	143
	144	tps->lru_index[0] = new_vout_reg;
	145	*gpio_val = new_vout_reg;
	146	*vout_reg = MAX8973_VOUT + new_vout_reg;
	147	return found;
	148	}
	149
	150	static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
	151	{
	152	struct max8973_chip *max = rdev_get_drvdata(rdev);
	153	unsigned int data;
	154	int ret;
	155
	156	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
	157	if (ret < 0) {
	158	dev_err(max->dev, "register %d read failed, err = %d\n",
	159	max->curr_vout_reg, ret);
	160	return ret;
	161	}
	162	return data & MAX8973_VOUT_MASK;
	163	}
	164
	165	static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
	166	unsigned vsel)
	167	{
	168	struct max8973_chip *max = rdev_get_drvdata(rdev);
	169	int ret;
170	bool found = false;
171	int vout_reg = max->curr_vout_reg;
172	int gpio_val = max->curr_gpio_val;
173
174	/*
175	* If gpios are available to select the VOUT register then least
176	* recently used register for new configuration.
177	*/
178	if (max->valid_dvs_gpio)
179	found = find_voltage_set_register(max, vsel,
180	&vout_reg, &gpio_val);
181
182	if (!found) {
183	ret = regmap_update_bits(max->regmap, vout_reg,
184	MAX8973_VOUT_MASK, vsel);
185	if (ret < 0) {
186	dev_err(max->dev, "register %d update failed, err %d\n",
187	vout_reg, ret);
188	return ret;
189	}
190	max->curr_vout_reg = vout_reg;
191	max->curr_vout_val[gpio_val] = vsel;
192	}
193
194	/* Select proper VOUT register vio gpios */
195	if (max->valid_dvs_gpio) {
196	gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
197	max->curr_gpio_val = gpio_val;
198	}
199	return 0;
200	}
201
202	static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
203	{
204	struct max8973_chip *max = rdev_get_drvdata(rdev);
205	int ret;
206	int pwm;
207
208	/* Enable force PWM mode in FAST mode only. */
209	switch (mode) {
210	case REGULATOR_MODE_FAST:
211	pwm = MAX8973_FPWM_EN_M;
212	break;
213
214	case REGULATOR_MODE_NORMAL:
215	pwm = 0;
216	break;
217
218	default:
219	return -EINVAL;
220	}
221
222	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
223	MAX8973_FPWM_EN_M, pwm);
224	if (ret < 0)
225	dev_err(max->dev, "register %d update failed, err %d\n",
226	MAX8973_CONTROL1, ret);
227	return ret;
228	}
229
230	static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
231	{
232	struct max8973_chip *max = rdev_get_drvdata(rdev);
233	unsigned int data;
234	int ret;
235
236	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
237	if (ret < 0) {
238	dev_err(max->dev, "register %d read failed, err %d\n",
239	MAX8973_CONTROL1, ret);
240	return ret;
241	}
242	return (data & MAX8973_FPWM_EN_M) ?
243	REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
244	}
245
db892ff6	246	static const struct regulator_ops max8973_dcdc_ops = {
5928f538 LD	247	.get_voltage_sel = max8973_dcdc_get_voltage_sel,
	248	.set_voltage_sel = max8973_dcdc_set_voltage_sel,
	249	.list_voltage = regulator_list_voltage_linear,
	250	.set_mode = max8973_dcdc_set_mode,
	251	.get_mode = max8973_dcdc_get_mode,
	252	};
	253
3d68dfe3 GKH	254	static int max8973_init_dcdc(struct max8973_chip *max,
3d68dfe3 GKH	255	struct max8973_regulator_platform_data *pdata)
5928f538 LD	256	{
	257	int ret;
	258	uint8_t control1 = 0;
	259	uint8_t control2 = 0;
	260
	261	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
	262	control1 \|= MAX8973_SNS_ENABLE;
	263
	264	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
	265	control1 \|= MAX8973_NFSR_ENABLE;
	266
	267	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
	268	control1 \|= MAX8973_AD_ENABLE;
	269
	270	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE)
	271	control1 \|= MAX8973_BIAS_ENABLE;
	272
	273	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
	274	control1 \|= MAX8973_FREQSHIFT_9PER;
	275
	276	/* Set ramp delay */
	277	if (pdata->reg_init_data &&
	278	pdata->reg_init_data->constraints.ramp_delay) {
	279	if (pdata->reg_init_data->constraints.ramp_delay < 25000)
b27032ca	280	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538	281	else if (pdata->reg_init_data->constraints.ramp_delay < 50000)
b27032ca	282	control1 \|= MAX8973_RAMP_25mV_PER_US;
5928f538	283	else if (pdata->reg_init_data->constraints.ramp_delay < 200000)
b27032ca	284	control1 \|= MAX8973_RAMP_50mV_PER_US;
5928f538	285	else
b27032ca	286	control1 \|= MAX8973_RAMP_200mV_PER_US;
5928f538	287	} else {
b27032ca	288	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538 LD	289	max->desc.ramp_delay = 12500;
	290	}
	291
	292	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
	293	control2 \|= MAX8973_DISCH_ENBABLE;
	294
	295	/* Clock advance trip configuration */
	296	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
	297	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
	298	control2 \|= MAX8973_CKKADV_TRIP_DISABLE;
	299	break;
	300
	301	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
	302	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US;
	303	break;
	304
	305	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
	306	control2 \|= MAX8973_CKKADV_TRIP_150mV_PER_US;
	307	break;
	308
	309	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
	310	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
	311	break;
	312	}
	313
	314	/* Configure inductor value */
	315	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
	316	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
	317	control2 \|= MAX8973_INDUCTOR_NOMINAL;
	318	break;
	319
	320	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
	321	control2 \|= MAX8973_INDUCTOR_MIN_30_PER;
	322	break;
	323
	324	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
	325	control2 \|= MAX8973_INDUCTOR_PLUS_30_PER;
	326	break;
	327
	328	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
	329	control2 \|= MAX8973_INDUCTOR_PLUS_60_PER;
	330	break;
	331	}
	332
	333	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
	334	if (ret < 0) {
	335	dev_err(max->dev, "register %d write failed, err = %d",
	336	MAX8973_CONTROL1, ret);
	337	return ret;
	338	}
	339
	340	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
	341	if (ret < 0) {
	342	dev_err(max->dev, "register %d write failed, err = %d",
	343	MAX8973_CONTROL2, ret);
	344	return ret;
	345	}
	346
	347	/* If external control is enabled then disable EN bit */
	348	if (max->enable_external_control) {
	349	ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
	350	MAX8973_VOUT_ENABLE, 0);
	351	if (ret < 0)
	352	dev_err(max->dev, "register %d update failed, err = %d",
353	MAX8973_VOUT, ret);
354	}
355	return ret;
356	}
357
358	static const struct regmap_config max8973_regmap_config = {
359	.reg_bits = 8,
360	.val_bits = 8,
361	.max_register = MAX8973_CHIPID2,
362	.cache_type = REGCACHE_RBTREE,
363	};
364
3d68dfe3 GKH	365	static int max8973_probe(struct i2c_client *client,
3d68dfe3 GKH	366	const struct i2c_device_id *id)
5928f538 LD	367	{
	368	struct max8973_regulator_platform_data *pdata;
	369	struct regulator_config config = { };
	370	struct regulator_dev *rdev;
	371	struct max8973_chip *max;
	372	int ret;
	373
dff91d0b	374	pdata = dev_get_platdata(&client->dev);
42dc3023 GL	375
42dc3023 GL	376	if (!pdata && !client->dev.of_node) {
5928f538 LD	377	dev_err(&client->dev, "No Platform data");
	378	return -EIO;
	379	}
	380
	381	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
	382	if (!max) {
	383	dev_err(&client->dev, "Memory allocation for max failed\n");
	384	return -ENOMEM;
	385	}
	386
	387	max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
	388	if (IS_ERR(max->regmap)) {
	389	ret = PTR_ERR(max->regmap);
	390	dev_err(&client->dev, "regmap init failed, err %d\n", ret);
	391	return ret;
	392	}
	393
	394	i2c_set_clientdata(client, max);
db892ff6	395	max->ops = max8973_dcdc_ops;
5928f538 LD	396	max->dev = &client->dev;
	397	max->desc.name = id->name;
	398	max->desc.id = 0;
db892ff6	399	max->desc.ops = &max->ops;
5928f538 LD	400	max->desc.type = REGULATOR_VOLTAGE;
	401	max->desc.owner = THIS_MODULE;
	402	max->desc.min_uV = MAX8973_MIN_VOLATGE;
	403	max->desc.uV_step = MAX8973_VOLATGE_STEP;
	404	max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
	405
42dc3023	406	if (!pdata \|\| !pdata->enable_ext_control) {
5928f538 LD	407	max->desc.enable_reg = MAX8973_VOUT;
5928f538 LD	408	max->desc.enable_mask = MAX8973_VOUT_ENABLE;
db892ff6 GL	409	max->ops.enable = regulator_enable_regmap;
	410	max->ops.disable = regulator_disable_regmap;
	411	max->ops.is_enabled = regulator_is_enabled_regmap;
5928f538 LD	412	}
5928f538 LD	413
42dc3023 GL	414	if (pdata) {
	415	max->dvs_gpio = pdata->dvs_gpio;
	416	max->enable_external_control = pdata->enable_ext_control;
	417	max->curr_gpio_val = pdata->dvs_def_state;
	418	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
	419	} else {
	420	max->dvs_gpio = -EINVAL;
	421	max->curr_vout_reg = MAX8973_VOUT;
	422	}
	423
5928f538	424	max->lru_index[0] = max->curr_vout_reg;
5928f538 LD	425
	426	if (gpio_is_valid(max->dvs_gpio)) {
	427	int gpio_flags;
	428	int i;
	429
	430	gpio_flags = (pdata->dvs_def_state) ?
	431	GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
	432	ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
	433	gpio_flags, "max8973-dvs");
	434	if (ret) {
	435	dev_err(&client->dev,
	436	"gpio_request for gpio %d failed, err = %d\n",
	437	max->dvs_gpio, ret);
	438	return ret;
	439	}
	440	max->valid_dvs_gpio = true;
	441
	442	/*
	443	* Initialize the lru index with vout_reg id
	444	* The index 0 will be most recently used and
	445	* set with the max->curr_vout_reg */
	446	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
	447	max->lru_index[i] = i;
	448	max->lru_index[0] = max->curr_vout_reg;
	449	max->lru_index[max->curr_vout_reg] = 0;
42dc3023 GL	450	} else {
42dc3023 GL	451	max->valid_dvs_gpio = false;
5928f538 LD	452	}
5928f538 LD	453
42dc3023 GL	454	if (pdata) {
	455	ret = max8973_init_dcdc(max, pdata);
	456	if (ret < 0) {
	457	dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
	458	return ret;
	459	}
5928f538 LD	460	}
	461
	462	config.dev = &client->dev;
42dc3023 GL	463	config.init_data = pdata ? pdata->reg_init_data :
42dc3023 GL	464	of_get_regulator_init_data(&client->dev, client->dev.of_node);
5928f538 LD	465	config.driver_data = max;
	466	config.of_node = client->dev.of_node;
	467	config.regmap = max->regmap;
	468
	469	/* Register the regulators */
8d581fd0	470	rdev = devm_regulator_register(&client->dev, &max->desc, &config);
5928f538 LD	471	if (IS_ERR(rdev)) {
	472	ret = PTR_ERR(rdev);
	473	dev_err(max->dev, "regulator register failed, err %d\n", ret);
	474	return ret;
	475	}
	476
	477	max->rdev = rdev;
	478	return 0;
	479	}
	480
5928f538 LD	481	static const struct i2c_device_id max8973_id[] = {
	482	{.name = "max8973",},
	483	{},
	484	};
	485
	486	MODULE_DEVICE_TABLE(i2c, max8973_id);
	487
	488	static struct i2c_driver max8973_i2c_driver = {
	489	.driver = {
	490	.name = "max8973",
	491	.owner = THIS_MODULE,
	492	},
	493	.probe = max8973_probe,
5928f538 LD	494	.id_table = max8973_id,
	495	};
	496
	497	static int __init max8973_init(void)
	498	{
	499	return i2c_add_driver(&max8973_i2c_driver);
	500	}
	501	subsys_initcall(max8973_init);
	502
	503	static void __exit max8973_cleanup(void)
	504	{
	505	i2c_del_driver(&max8973_i2c_driver);
	506	}
	507	module_exit(max8973_cleanup);
	508
	509	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
	510	MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
	511	MODULE_LICENSE("GPL v2");