[mirror_ubuntu-bionic-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/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/max8973-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 = client->dev.platform_data;
	if (!pdata) {
		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->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;
	}

	max->enable_external_control = pdata->enable_ext_control;
	max->dvs_gpio = pdata->dvs_gpio;
	max->curr_gpio_val = pdata->dvs_def_state;
	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
	max->lru_index[0] = max->curr_vout_reg;
	max->valid_dvs_gpio = false;

	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;
	}

	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->reg_init_data;
	config.driver_data = max;
	config.of_node = client->dev.of_node;
	config.regmap = max->regmap;

	/* Register the regulators */
	rdev = regulator_register(&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 int max8973_remove(struct i2c_client *client)
{
	struct max8973_chip *max = i2c_get_clientdata(client);

	regulator_unregister(max->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,
	.remove = max8973_remove,
	.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>
	29	#include <linux/platform_device.h>
	30	#include <linux/regulator/driver.h>
	31	#include <linux/regulator/machine.h>
	32	#include <linux/regulator/max8973-regulator.h>
	33	#include <linux/gpio.h>
	34	#include <linux/i2c.h>
	35	#include <linux/slab.h>
	36	#include <linux/regmap.h>
	37
	38	/* Register definitions */
	39	#define MAX8973_VOUT 0x0
	40	#define MAX8973_VOUT_DVS 0x1
	41	#define MAX8973_CONTROL1 0x2
	42	#define MAX8973_CONTROL2 0x3
	43	#define MAX8973_CHIPID1 0x4
	44	#define MAX8973_CHIPID2 0x5
	45
	46	#define MAX8973_MAX_VOUT_REG 2
	47
	48	/* MAX8973_VOUT */
	49	#define MAX8973_VOUT_ENABLE BIT(7)
	50	#define MAX8973_VOUT_MASK 0x7F
	51
	52	/* MAX8973_VOUT_DVS */
	53	#define MAX8973_DVS_VOUT_MASK 0x7F
	54
	55	/* MAX8973_CONTROL1 */
	56	#define MAX8973_SNS_ENABLE BIT(7)
	57	#define MAX8973_FPWM_EN_M BIT(6)
	58	#define MAX8973_NFSR_ENABLE BIT(5)
	59	#define MAX8973_AD_ENABLE BIT(4)
	60	#define MAX8973_BIAS_ENABLE BIT(3)
	61	#define MAX8973_FREQSHIFT_9PER BIT(2)
	62
	63	#define MAX8973_RAMP_12mV_PER_US 0x0
	64	#define MAX8973_RAMP_25mV_PER_US 0x1
65	#define MAX8973_RAMP_50mV_PER_US 0x2
66	#define MAX8973_RAMP_200mV_PER_US 0x3
67
68	/* MAX8973_CONTROL2 */
69	#define MAX8973_WDTMR_ENABLE BIT(6)
70	#define MAX8973_DISCH_ENBABLE BIT(5)
71	#define MAX8973_FT_ENABLE BIT(4)
72
73	#define MAX8973_CKKADV_TRIP_DISABLE 0xC
74	#define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0
75	#define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4
76	#define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8
77	#define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000
78
79	#define MAX8973_INDUCTOR_MIN_30_PER 0x0
80	#define MAX8973_INDUCTOR_NOMINAL 0x1
81	#define MAX8973_INDUCTOR_PLUS_30_PER 0x2
82	#define MAX8973_INDUCTOR_PLUS_60_PER 0x3
83	#define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000
84
85	#define MAX8973_MIN_VOLATGE 606250
86	#define MAX8973_MAX_VOLATGE 1400000
87	#define MAX8973_VOLATGE_STEP 6250
88	#define MAX8973_BUCK_N_VOLTAGE 0x80
89
90	/* Maxim 8973 chip information */
91	struct max8973_chip {
92	struct device *dev;
93	struct regulator_desc desc;
94	struct regulator_dev *rdev;
95	struct regmap *regmap;
96	bool enable_external_control;
97	int dvs_gpio;
98	int lru_index[MAX8973_MAX_VOUT_REG];
99	int curr_vout_val[MAX8973_MAX_VOUT_REG];
100	int curr_vout_reg;
101	int curr_gpio_val;
102	bool valid_dvs_gpio;
db892ff6	103	struct regulator_ops ops;
5928f538 LD	104	};
	105
	106	/*
	107	* find_voltage_set_register: Find new voltage configuration register (VOUT).
	108	* The finding of the new VOUT register will be based on the LRU mechanism.
	109	* Each VOUT register will have different voltage configured . This
	110	* Function will look if any of the VOUT register have requested voltage set
	111	* or not.
	112	* - If it is already there then it will make that register as most
	113	* recently used and return as found so that caller need not to set
	114	* the VOUT register but need to set the proper gpios to select this
	115	* VOUT register.
	116	* - If requested voltage is not found then it will use the least
	117	* recently mechanism to get new VOUT register for new configuration
	118	* and will return not_found so that caller need to set new VOUT
	119	* register and then gpios (both).
	120	*/
	121	static bool find_voltage_set_register(struct max8973_chip *tps,
	122	int req_vsel, int vout_reg, int gpio_val)
	123	{
	124	int i;
	125	bool found = false;
	126	int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
	127	int found_index = MAX8973_MAX_VOUT_REG - 1;
	128
	129	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
	130	if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
	131	new_vout_reg = tps->lru_index[i];
	132	found_index = i;
	133	found = true;
	134	goto update_lru_index;
	135	}
	136	}
	137
	138	update_lru_index:
	139	for (i = found_index; i > 0; i--)
	140	tps->lru_index[i] = tps->lru_index[i - 1];
	141
	142	tps->lru_index[0] = new_vout_reg;
	143	*gpio_val = new_vout_reg;
	144	*vout_reg = MAX8973_VOUT + new_vout_reg;
	145	return found;
	146	}
	147
	148	static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
	149	{
	150	struct max8973_chip *max = rdev_get_drvdata(rdev);
	151	unsigned int data;
	152	int ret;
	153
	154	ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
	155	if (ret < 0) {
	156	dev_err(max->dev, "register %d read failed, err = %d\n",
	157	max->curr_vout_reg, ret);
	158	return ret;
	159	}
	160	return data & MAX8973_VOUT_MASK;
	161	}
	162
	163	static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
	164	unsigned vsel)
	165	{
	166	struct max8973_chip *max = rdev_get_drvdata(rdev);
	167	int ret;
168	bool found = false;
169	int vout_reg = max->curr_vout_reg;
170	int gpio_val = max->curr_gpio_val;
171
172	/*
173	* If gpios are available to select the VOUT register then least
174	* recently used register for new configuration.
175	*/
176	if (max->valid_dvs_gpio)
177	found = find_voltage_set_register(max, vsel,
178	&vout_reg, &gpio_val);
179
180	if (!found) {
181	ret = regmap_update_bits(max->regmap, vout_reg,
182	MAX8973_VOUT_MASK, vsel);
183	if (ret < 0) {
184	dev_err(max->dev, "register %d update failed, err %d\n",
185	vout_reg, ret);
186	return ret;
187	}
188	max->curr_vout_reg = vout_reg;
189	max->curr_vout_val[gpio_val] = vsel;
190	}
191
192	/* Select proper VOUT register vio gpios */
193	if (max->valid_dvs_gpio) {
194	gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
195	max->curr_gpio_val = gpio_val;
196	}
197	return 0;
198	}
199
200	static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
201	{
202	struct max8973_chip *max = rdev_get_drvdata(rdev);
203	int ret;
204	int pwm;
205
206	/* Enable force PWM mode in FAST mode only. */
207	switch (mode) {
208	case REGULATOR_MODE_FAST:
209	pwm = MAX8973_FPWM_EN_M;
210	break;
211
212	case REGULATOR_MODE_NORMAL:
213	pwm = 0;
214	break;
215
216	default:
217	return -EINVAL;
218	}
219
220	ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
221	MAX8973_FPWM_EN_M, pwm);
222	if (ret < 0)
223	dev_err(max->dev, "register %d update failed, err %d\n",
224	MAX8973_CONTROL1, ret);
225	return ret;
226	}
227
228	static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
229	{
230	struct max8973_chip *max = rdev_get_drvdata(rdev);
231	unsigned int data;
232	int ret;
233
234	ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
235	if (ret < 0) {
236	dev_err(max->dev, "register %d read failed, err %d\n",
237	MAX8973_CONTROL1, ret);
238	return ret;
239	}
240	return (data & MAX8973_FPWM_EN_M) ?
241	REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
242	}
243
db892ff6	244	static const struct regulator_ops max8973_dcdc_ops = {
5928f538 LD	245	.get_voltage_sel = max8973_dcdc_get_voltage_sel,
	246	.set_voltage_sel = max8973_dcdc_set_voltage_sel,
	247	.list_voltage = regulator_list_voltage_linear,
	248	.set_mode = max8973_dcdc_set_mode,
	249	.get_mode = max8973_dcdc_get_mode,
	250	};
	251
3d68dfe3 GKH	252	static int max8973_init_dcdc(struct max8973_chip *max,
3d68dfe3 GKH	253	struct max8973_regulator_platform_data *pdata)
5928f538 LD	254	{
	255	int ret;
	256	uint8_t control1 = 0;
	257	uint8_t control2 = 0;
	258
	259	if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
	260	control1 \|= MAX8973_SNS_ENABLE;
	261
	262	if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
	263	control1 \|= MAX8973_NFSR_ENABLE;
	264
	265	if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
	266	control1 \|= MAX8973_AD_ENABLE;
	267
	268	if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE)
	269	control1 \|= MAX8973_BIAS_ENABLE;
	270
	271	if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
	272	control1 \|= MAX8973_FREQSHIFT_9PER;
	273
	274	/* Set ramp delay */
	275	if (pdata->reg_init_data &&
	276	pdata->reg_init_data->constraints.ramp_delay) {
	277	if (pdata->reg_init_data->constraints.ramp_delay < 25000)
b27032ca	278	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538	279	else if (pdata->reg_init_data->constraints.ramp_delay < 50000)
b27032ca	280	control1 \|= MAX8973_RAMP_25mV_PER_US;
5928f538	281	else if (pdata->reg_init_data->constraints.ramp_delay < 200000)
b27032ca	282	control1 \|= MAX8973_RAMP_50mV_PER_US;
5928f538	283	else
b27032ca	284	control1 \|= MAX8973_RAMP_200mV_PER_US;
5928f538	285	} else {
b27032ca	286	control1 \|= MAX8973_RAMP_12mV_PER_US;
5928f538 LD	287	max->desc.ramp_delay = 12500;
	288	}
	289
	290	if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
	291	control2 \|= MAX8973_DISCH_ENBABLE;
	292
	293	/* Clock advance trip configuration */
	294	switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
	295	case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
	296	control2 \|= MAX8973_CKKADV_TRIP_DISABLE;
	297	break;
	298
	299	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
	300	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US;
	301	break;
	302
	303	case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
	304	control2 \|= MAX8973_CKKADV_TRIP_150mV_PER_US;
	305	break;
	306
	307	case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
	308	control2 \|= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
	309	break;
	310	}
	311
	312	/* Configure inductor value */
	313	switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
	314	case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
	315	control2 \|= MAX8973_INDUCTOR_NOMINAL;
	316	break;
	317
	318	case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
	319	control2 \|= MAX8973_INDUCTOR_MIN_30_PER;
	320	break;
	321
	322	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
	323	control2 \|= MAX8973_INDUCTOR_PLUS_30_PER;
	324	break;
	325
	326	case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
	327	control2 \|= MAX8973_INDUCTOR_PLUS_60_PER;
	328	break;
	329	}
	330
	331	ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
	332	if (ret < 0) {
	333	dev_err(max->dev, "register %d write failed, err = %d",
	334	MAX8973_CONTROL1, ret);
	335	return ret;
	336	}
	337
	338	ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
	339	if (ret < 0) {
	340	dev_err(max->dev, "register %d write failed, err = %d",
	341	MAX8973_CONTROL2, ret);
	342	return ret;
	343	}
	344
	345	/* If external control is enabled then disable EN bit */
	346	if (max->enable_external_control) {
	347	ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
	348	MAX8973_VOUT_ENABLE, 0);
	349	if (ret < 0)
	350	dev_err(max->dev, "register %d update failed, err = %d",
351	MAX8973_VOUT, ret);
352	}
353	return ret;
354	}
355
356	static const struct regmap_config max8973_regmap_config = {
357	.reg_bits = 8,
358	.val_bits = 8,
359	.max_register = MAX8973_CHIPID2,
360	.cache_type = REGCACHE_RBTREE,
361	};
362
3d68dfe3 GKH	363	static int max8973_probe(struct i2c_client *client,
3d68dfe3 GKH	364	const struct i2c_device_id *id)
5928f538 LD	365	{
	366	struct max8973_regulator_platform_data *pdata;
	367	struct regulator_config config = { };
	368	struct regulator_dev *rdev;
	369	struct max8973_chip *max;
	370	int ret;
	371
	372	pdata = client->dev.platform_data;
	373	if (!pdata) {
	374	dev_err(&client->dev, "No Platform data");
	375	return -EIO;
	376	}
	377
	378	max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
	379	if (!max) {
	380	dev_err(&client->dev, "Memory allocation for max failed\n");
	381	return -ENOMEM;
	382	}
	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
56968658	403	if (!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	}
	410
	411	max->enable_external_control = pdata->enable_ext_control;
	412	max->dvs_gpio = pdata->dvs_gpio;
	413	max->curr_gpio_val = pdata->dvs_def_state;
	414	max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
	415	max->lru_index[0] = max->curr_vout_reg;
	416	max->valid_dvs_gpio = false;
	417
	418	if (gpio_is_valid(max->dvs_gpio)) {
	419	int gpio_flags;
	420	int i;
	421
	422	gpio_flags = (pdata->dvs_def_state) ?
	423	GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
	424	ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
	425	gpio_flags, "max8973-dvs");
	426	if (ret) {
	427	dev_err(&client->dev,
	428	"gpio_request for gpio %d failed, err = %d\n",
	429	max->dvs_gpio, ret);
	430	return ret;
	431	}
	432	max->valid_dvs_gpio = true;
	433
	434	/*
	435	* Initialize the lru index with vout_reg id
	436	* The index 0 will be most recently used and
	437	* set with the max->curr_vout_reg */
	438	for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
	439	max->lru_index[i] = i;
	440	max->lru_index[0] = max->curr_vout_reg;
	441	max->lru_index[max->curr_vout_reg] = 0;
	442	}
	443
	444	ret = max8973_init_dcdc(max, pdata);
	445	if (ret < 0) {
	446	dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
	447	return ret;
	448	}
	449
	450	config.dev = &client->dev;
	451	config.init_data = pdata->reg_init_data;
	452	config.driver_data = max;
	453	config.of_node = client->dev.of_node;
	454	config.regmap = max->regmap;
	455
	456	/* Register the regulators */
	457	rdev = regulator_register(&max->desc, &config);
	458	if (IS_ERR(rdev)) {
	459	ret = PTR_ERR(rdev);
	460	dev_err(max->dev, "regulator register failed, err %d\n", ret);
	461	return ret;
	462	}
	463
	464	max->rdev = rdev;
	465	return 0;
	466	}
	467
3d68dfe3	468	static int max8973_remove(struct i2c_client *client)
5928f538 LD	469	{
	470	struct max8973_chip *max = i2c_get_clientdata(client);
	471
	472	regulator_unregister(max->rdev);
	473	return 0;
	474	}
	475
	476	static const struct i2c_device_id max8973_id[] = {
	477	{.name = "max8973",},
	478	{},
	479	};
	480
	481	MODULE_DEVICE_TABLE(i2c, max8973_id);
	482
	483	static struct i2c_driver max8973_i2c_driver = {
	484	.driver = {
	485	.name = "max8973",
	486	.owner = THIS_MODULE,
	487	},
	488	.probe = max8973_probe,
3d68dfe3	489	.remove = max8973_remove,
5928f538 LD	490	.id_table = max8973_id,
	491	};
	492
	493	static int __init max8973_init(void)
	494	{
	495	return i2c_add_driver(&max8973_i2c_driver);
	496	}
	497	subsys_initcall(max8973_init);
	498
	499	static void __exit max8973_cleanup(void)
	500	{
	501	i2c_del_driver(&max8973_i2c_driver);
	502	}
	503	module_exit(max8973_cleanup);
	504
	505	MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
	506	MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
	507	MODULE_LICENSE("GPL v2");