// SPDX-License-Identifier: GPL-2.0+
  //
  // max8997.c - Regulator driver for the Maxim 8997/8966
  //
  // Copyright (C) 2011 Samsung Electronics
  // MyungJoo Ham <myungjoo.ham@samsung.com>
  //
  // This driver is based on max8998.c

  
  #include <linux/bug.h>

  #include <linux/err.h>
  #include <linux/gpio.h>

  #include <linux/of_gpio.h>

  #include <linux/slab.h>

  #include <linux/module.h>

  #include <linux/platform_device.h>
  #include <linux/regulator/driver.h>
  #include <linux/regulator/machine.h>
  #include <linux/mfd/max8997.h>
  #include <linux/mfd/max8997-private.h>

  #include <linux/regulator/of_regulator.h>

  
  struct max8997_data {
  	struct device *dev;
  	struct max8997_dev *iodev;
  	int num_regulators;

  	int ramp_delay; /* in mV/us */

  	bool buck1_gpiodvs;
  	bool buck2_gpiodvs;
  	bool buck5_gpiodvs;

  	u8 buck1_vol[8];
  	u8 buck2_vol[8];
  	u8 buck5_vol[8];

  	int buck125_gpios[3];

  	int buck125_gpioindex;

  	bool ignore_gpiodvs_side_effect;

  
  	u8 saved_states[MAX8997_REG_MAX];
  };

  static const unsigned int safeoutvolt[] = {
  	4850000,
  	4900000,
  	4950000,
  	3300000,
  };

  static inline void max8997_set_gpio(struct max8997_data *max8997)
  {

  	int set3 = (max8997->buck125_gpioindex) & 0x1;
  	int set2 = ((max8997->buck125_gpioindex) >> 1) & 0x1;
  	int set1 = ((max8997->buck125_gpioindex) >> 2) & 0x1;

  	gpio_set_value(max8997->buck125_gpios[0], set1);
  	gpio_set_value(max8997->buck125_gpios[1], set2);
  	gpio_set_value(max8997->buck125_gpios[2], set3);

  }
  
  struct voltage_map_desc {
  	int min;
  	int max;
  	int step;

  };

  /* Voltage maps in uV */

  static const struct voltage_map_desc ldo_voltage_map_desc = {

  	.min = 800000,	.max = 3950000,	.step = 50000,

  }; /* LDO1 ~ 18, 21 all */
  
  static const struct voltage_map_desc buck1245_voltage_map_desc = {

  	.min = 650000,	.max = 2225000,	.step = 25000,

  }; /* Buck1, 2, 4, 5 */
  
  static const struct voltage_map_desc buck37_voltage_map_desc = {

  	.min = 750000,	.max = 3900000,	.step = 50000,

  }; /* Buck3, 7 */

  /* current map in uA */

  static const struct voltage_map_desc charger_current_map_desc = {

  	.min = 200000,	.max = 950000,	.step = 50000,

  };
  
  static const struct voltage_map_desc topoff_current_map_desc = {

  	.min = 50000,	.max = 200000,	.step = 10000,

  };
  
  static const struct voltage_map_desc *reg_voltage_map[] = {
  	[MAX8997_LDO1] = &ldo_voltage_map_desc,
  	[MAX8997_LDO2] = &ldo_voltage_map_desc,
  	[MAX8997_LDO3] = &ldo_voltage_map_desc,
  	[MAX8997_LDO4] = &ldo_voltage_map_desc,
  	[MAX8997_LDO5] = &ldo_voltage_map_desc,
  	[MAX8997_LDO6] = &ldo_voltage_map_desc,
  	[MAX8997_LDO7] = &ldo_voltage_map_desc,
  	[MAX8997_LDO8] = &ldo_voltage_map_desc,
  	[MAX8997_LDO9] = &ldo_voltage_map_desc,
  	[MAX8997_LDO10] = &ldo_voltage_map_desc,
  	[MAX8997_LDO11] = &ldo_voltage_map_desc,
  	[MAX8997_LDO12] = &ldo_voltage_map_desc,
  	[MAX8997_LDO13] = &ldo_voltage_map_desc,
  	[MAX8997_LDO14] = &ldo_voltage_map_desc,
  	[MAX8997_LDO15] = &ldo_voltage_map_desc,
  	[MAX8997_LDO16] = &ldo_voltage_map_desc,
  	[MAX8997_LDO17] = &ldo_voltage_map_desc,
  	[MAX8997_LDO18] = &ldo_voltage_map_desc,
  	[MAX8997_LDO21] = &ldo_voltage_map_desc,
  	[MAX8997_BUCK1] = &buck1245_voltage_map_desc,
  	[MAX8997_BUCK2] = &buck1245_voltage_map_desc,
  	[MAX8997_BUCK3] = &buck37_voltage_map_desc,
  	[MAX8997_BUCK4] = &buck1245_voltage_map_desc,
  	[MAX8997_BUCK5] = &buck1245_voltage_map_desc,
  	[MAX8997_BUCK6] = NULL,
  	[MAX8997_BUCK7] = &buck37_voltage_map_desc,
  	[MAX8997_EN32KHZ_AP] = NULL,
  	[MAX8997_EN32KHZ_CP] = NULL,
  	[MAX8997_ENVICHG] = NULL,
  	[MAX8997_ESAFEOUT1] = NULL,
  	[MAX8997_ESAFEOUT2] = NULL,
  	[MAX8997_CHARGER_CV] = NULL,
  	[MAX8997_CHARGER] = &charger_current_map_desc,
  	[MAX8997_CHARGER_TOPOFF] = &topoff_current_map_desc,
  };

  static int max8997_list_voltage_charger_cv(struct regulator_dev *rdev,
  		unsigned int selector)
  {

  	int rid = rdev_get_id(rdev);

  
  	if (rid != MAX8997_CHARGER_CV)
  		goto err;
  
  	switch (selector) {
  	case 0x00:
  		return 4200000;
  	case 0x01 ... 0x0E:
  		return 4000000 + 20000 * (selector - 0x01);
  	case 0x0F:
  		return 4350000;
  	default:
  		return -EINVAL;
  	}
  err:
  	return -EINVAL;
  }
  
  static int max8997_list_voltage(struct regulator_dev *rdev,
  		unsigned int selector)
  {
  	const struct voltage_map_desc *desc;

  	int rid = rdev_get_id(rdev);

  	int val;

  	if (rid < 0 || rid >= ARRAY_SIZE(reg_voltage_map))

  		return -EINVAL;
  
  	desc = reg_voltage_map[rid];
  	if (desc == NULL)
  		return -EINVAL;
  
  	val = desc->min + desc->step * selector;
  	if (val > desc->max)
  		return -EINVAL;

  	return val;

  }
  
  static int max8997_get_enable_register(struct regulator_dev *rdev,
  		int *reg, int *mask, int *pattern)
  {

  	int rid = rdev_get_id(rdev);

  
  	switch (rid) {
  	case MAX8997_LDO1 ... MAX8997_LDO21:
  		*reg = MAX8997_REG_LDO1CTRL + (rid - MAX8997_LDO1);
  		*mask = 0xC0;
  		*pattern = 0xC0;
  		break;
  	case MAX8997_BUCK1:
  		*reg = MAX8997_REG_BUCK1CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK2:
  		*reg = MAX8997_REG_BUCK2CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK3:
  		*reg = MAX8997_REG_BUCK3CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK4:
  		*reg = MAX8997_REG_BUCK4CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK5:
  		*reg = MAX8997_REG_BUCK5CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK6:
  		*reg = MAX8997_REG_BUCK6CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_BUCK7:
  		*reg = MAX8997_REG_BUCK7CTRL;
  		*mask = 0x01;
  		*pattern = 0x01;
  		break;
  	case MAX8997_EN32KHZ_AP ... MAX8997_EN32KHZ_CP:
  		*reg = MAX8997_REG_MAINCON1;
  		*mask = 0x01 << (rid - MAX8997_EN32KHZ_AP);
  		*pattern = 0x01 << (rid - MAX8997_EN32KHZ_AP);
  		break;
  	case MAX8997_ENVICHG:
  		*reg = MAX8997_REG_MBCCTRL1;
  		*mask = 0x80;
  		*pattern = 0x80;
  		break;
  	case MAX8997_ESAFEOUT1 ... MAX8997_ESAFEOUT2:
  		*reg = MAX8997_REG_SAFEOUTCTRL;
  		*mask = 0x40 << (rid - MAX8997_ESAFEOUT1);
  		*pattern = 0x40 << (rid - MAX8997_ESAFEOUT1);
  		break;
  	case MAX8997_CHARGER:
  		*reg = MAX8997_REG_MBCCTRL2;
  		*mask = 0x40;
  		*pattern = 0x40;
  		break;
  	default:
  		/* Not controllable or not exists */
  		return -EINVAL;

  	}
  
  	return 0;
  }
  
  static int max8997_reg_is_enabled(struct regulator_dev *rdev)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;
  	int ret, reg, mask, pattern;
  	u8 val;
  
  	ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);

  	if (ret)

  		return ret;
  
  	ret = max8997_read_reg(i2c, reg, &val);
  	if (ret)
  		return ret;
  
  	return (val & mask) == pattern;
  }
  
  static int max8997_reg_enable(struct regulator_dev *rdev)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;
  	int ret, reg, mask, pattern;
  
  	ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
  	if (ret)
  		return ret;
  
  	return max8997_update_reg(i2c, reg, pattern, mask);
  }
  
  static int max8997_reg_disable(struct regulator_dev *rdev)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;
  	int ret, reg, mask, pattern;
  
  	ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
  	if (ret)
  		return ret;
  
  	return max8997_update_reg(i2c, reg, ~pattern, mask);
  }
  
  static int max8997_get_voltage_register(struct regulator_dev *rdev,
  		int *_reg, int *_shift, int *_mask)
  {

  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);

  	int rid = rdev_get_id(rdev);

  	int reg, shift = 0, mask = 0x3f;
  
  	switch (rid) {
  	case MAX8997_LDO1 ... MAX8997_LDO21:
  		reg = MAX8997_REG_LDO1CTRL + (rid - MAX8997_LDO1);
  		break;
  	case MAX8997_BUCK1:
  		reg = MAX8997_REG_BUCK1DVS1;

  		if (max8997->buck1_gpiodvs)
  			reg += max8997->buck125_gpioindex;

  		break;
  	case MAX8997_BUCK2:
  		reg = MAX8997_REG_BUCK2DVS1;

  		if (max8997->buck2_gpiodvs)
  			reg += max8997->buck125_gpioindex;

  		break;
  	case MAX8997_BUCK3:
  		reg = MAX8997_REG_BUCK3DVS;
  		break;
  	case MAX8997_BUCK4:
  		reg = MAX8997_REG_BUCK4DVS;
  		break;
  	case MAX8997_BUCK5:
  		reg = MAX8997_REG_BUCK5DVS1;

  		if (max8997->buck5_gpiodvs)
  			reg += max8997->buck125_gpioindex;

  		break;
  	case MAX8997_BUCK7:
  		reg = MAX8997_REG_BUCK7DVS;
  		break;
  	case MAX8997_ESAFEOUT1 ...  MAX8997_ESAFEOUT2:
  		reg = MAX8997_REG_SAFEOUTCTRL;
  		shift = (rid == MAX8997_ESAFEOUT2) ? 2 : 0;
  		mask = 0x3;
  		break;
  	case MAX8997_CHARGER_CV:
  		reg = MAX8997_REG_MBCCTRL3;
  		shift = 0;
  		mask = 0xf;
  		break;
  	case MAX8997_CHARGER:
  		reg = MAX8997_REG_MBCCTRL4;
  		shift = 0;
  		mask = 0xf;
  		break;
  	case MAX8997_CHARGER_TOPOFF:
  		reg = MAX8997_REG_MBCCTRL5;
  		shift = 0;
  		mask = 0xf;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	*_reg = reg;
  	*_shift = shift;
  	*_mask = mask;
  
  	return 0;
  }

  static int max8997_get_voltage_sel(struct regulator_dev *rdev)

  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);

  	struct i2c_client *i2c = max8997->iodev->i2c;
  	int reg, shift, mask, ret;

  	u8 val;
  
  	ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
  	if (ret)
  		return ret;

  	ret = max8997_read_reg(i2c, reg, &val);
  	if (ret)
  		return ret;
  
  	val >>= shift;
  	val &= mask;

  	return val;

  }
  
  static inline int max8997_get_voltage_proper_val(
  		const struct voltage_map_desc *desc,
  		int min_vol, int max_vol)
  {

  	int i;

  
  	if (desc == NULL)
  		return -EINVAL;
  
  	if (max_vol < desc->min || min_vol > desc->max)
  		return -EINVAL;

  	if (min_vol < desc->min)
  		min_vol = desc->min;

  	i = DIV_ROUND_UP(min_vol - desc->min, desc->step);

  	if (desc->min + desc->step * i > max_vol)

  		return -EINVAL;
  
  	return i;
  }
  
  static int max8997_set_voltage_charger_cv(struct regulator_dev *rdev,
  		int min_uV, int max_uV, unsigned *selector)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;

  	int rid = rdev_get_id(rdev);

  	int lb, ub;
  	int reg, shift = 0, mask, ret = 0;
  	u8 val = 0x0;
  
  	if (rid != MAX8997_CHARGER_CV)
  		return -EINVAL;
  
  	ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
  	if (ret)
  		return ret;
  
  	if (max_uV < 4000000 || min_uV > 4350000)
  		return -EINVAL;

  	if (min_uV <= 4000000)
  		val = 0x1;
  	else if (min_uV <= 4200000 && max_uV >= 4200000)

  		val = 0x0;
  	else {
  		lb = (min_uV - 4000001) / 20000 + 2;
  		ub = (max_uV - 4000000) / 20000 + 1;
  
  		if (lb > ub)
  			return -EINVAL;
  
  		if (lb < 0xf)
  			val = lb;
  		else {
  			if (ub >= 0xf)
  				val = 0xf;
  			else
  				return -EINVAL;
  		}
  	}
  
  	*selector = val;
  
  	ret = max8997_update_reg(i2c, reg, val << shift, mask);
  
  	return ret;
  }
  
  /*
   * For LDO1 ~ LDO21, BUCK1~5, BUCK7, CHARGER, CHARGER_TOPOFF
   * BUCK1, 2, and 5 are available if they are not controlled by gpio
   */
  static int max8997_set_voltage_ldobuck(struct regulator_dev *rdev,
  		int min_uV, int max_uV, unsigned *selector)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;

  	const struct voltage_map_desc *desc;

  	int rid = rdev_get_id(rdev);

  	int i, reg, shift, mask, ret;

  
  	switch (rid) {
  	case MAX8997_LDO1 ... MAX8997_LDO21:
  		break;
  	case MAX8997_BUCK1 ... MAX8997_BUCK5:
  		break;
  	case MAX8997_BUCK6:
  		return -EINVAL;
  	case MAX8997_BUCK7:
  		break;
  	case MAX8997_CHARGER:
  		break;
  	case MAX8997_CHARGER_TOPOFF:
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	desc = reg_voltage_map[rid];

  	i = max8997_get_voltage_proper_val(desc, min_uV, max_uV);

  	if (i < 0)
  		return i;
  
  	ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
  	if (ret)
  		return ret;

  	ret = max8997_update_reg(i2c, reg, i << shift, mask << shift);
  	*selector = i;

  	return ret;
  }

  static int max8997_set_voltage_buck_time_sel(struct regulator_dev *rdev,

  						unsigned int old_selector,
  						unsigned int new_selector)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	int rid = rdev_get_id(rdev);
  	const struct voltage_map_desc *desc = reg_voltage_map[rid];
  
  	/* Delay is required only if the voltage is increasing */
  	if (old_selector >= new_selector)
  		return 0;
  
  	/* No need to delay if gpio_dvs_mode */
  	switch (rid) {
  	case MAX8997_BUCK1:
  		if (max8997->buck1_gpiodvs)
  			return 0;
  		break;
  	case MAX8997_BUCK2:
  		if (max8997->buck2_gpiodvs)
  			return 0;
  		break;
  	case MAX8997_BUCK5:
  		if (max8997->buck5_gpiodvs)
  			return 0;
  		break;

  	}

  	switch (rid) {
  	case MAX8997_BUCK1:
  	case MAX8997_BUCK2:
  	case MAX8997_BUCK4:
  	case MAX8997_BUCK5:
  		return DIV_ROUND_UP(desc->step * (new_selector - old_selector),

  				    max8997->ramp_delay * 1000);

  	}

  	return 0;

  }
  
  /*
   * Assess the damage on the voltage setting of BUCK1,2,5 by the change.
   *
   * When GPIO-DVS mode is used for multiple bucks, changing the voltage value
   * of one of the bucks may affect that of another buck, which is the side
   * effect of the change (set_voltage). This function examines the GPIO-DVS
   * configurations and checks whether such side-effect exists.
   */
  static int max8997_assess_side_effect(struct regulator_dev *rdev,
  		u8 new_val, int *best)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);

  	int rid = rdev_get_id(rdev);

  	u8 *buckx_val[3];
  	bool buckx_gpiodvs[3];
  	int side_effect[8];
  	int min_side_effect = INT_MAX;
  	int i;
  
  	*best = -1;
  
  	switch (rid) {
  	case MAX8997_BUCK1:
  		rid = 0;
  		break;
  	case MAX8997_BUCK2:
  		rid = 1;
  		break;
  	case MAX8997_BUCK5:
  		rid = 2;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	buckx_val[0] = max8997->buck1_vol;
  	buckx_val[1] = max8997->buck2_vol;
  	buckx_val[2] = max8997->buck5_vol;

  	buckx_gpiodvs[0] = max8997->buck1_gpiodvs;
  	buckx_gpiodvs[1] = max8997->buck2_gpiodvs;
  	buckx_gpiodvs[2] = max8997->buck5_gpiodvs;

  
  	for (i = 0; i < 8; i++) {
  		int others;
  
  		if (new_val != (buckx_val[rid])[i]) {
  			side_effect[i] = -1;
  			continue;
  		}
  
  		side_effect[i] = 0;
  		for (others = 0; others < 3; others++) {
  			int diff;
  
  			if (others == rid)
  				continue;
  			if (buckx_gpiodvs[others] == false)
  				continue; /* Not affected */
  			diff = (buckx_val[others])[i] -
  				(buckx_val[others])[max8997->buck125_gpioindex];
  			if (diff > 0)
  				side_effect[i] += diff;
  			else if (diff < 0)
  				side_effect[i] -= diff;
  		}
  		if (side_effect[i] == 0) {
  			*best = i;
  			return 0; /* NO SIDE EFFECT! Use This! */
  		}
  		if (side_effect[i] < min_side_effect) {
  			min_side_effect = side_effect[i];
  			*best = i;
  		}
  	}
  
  	if (*best == -1)
  		return -EINVAL;
  
  	return side_effect[*best];
  }
  
  /*
   * For Buck 1 ~ 5 and 7. If it is not controlled by GPIO, this calls
   * max8997_set_voltage_ldobuck to do the job.
   */
  static int max8997_set_voltage_buck(struct regulator_dev *rdev,
  		int min_uV, int max_uV, unsigned *selector)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);

  	int rid = rdev_get_id(rdev);

  	const struct voltage_map_desc *desc;
  	int new_val, new_idx, damage, tmp_val, tmp_idx, tmp_dmg;
  	bool gpio_dvs_mode = false;

  
  	if (rid < MAX8997_BUCK1 || rid > MAX8997_BUCK7)
  		return -EINVAL;
  
  	switch (rid) {
  	case MAX8997_BUCK1:

  		if (max8997->buck1_gpiodvs)

  			gpio_dvs_mode = true;
  		break;
  	case MAX8997_BUCK2:

  		if (max8997->buck2_gpiodvs)

  			gpio_dvs_mode = true;
  		break;
  	case MAX8997_BUCK5:

  		if (max8997->buck5_gpiodvs)

  			gpio_dvs_mode = true;
  		break;
  	}
  
  	if (!gpio_dvs_mode)
  		return max8997_set_voltage_ldobuck(rdev, min_uV, max_uV,
  						selector);
  
  	desc = reg_voltage_map[rid];

  	new_val = max8997_get_voltage_proper_val(desc, min_uV, max_uV);

  	if (new_val < 0)
  		return new_val;
  
  	tmp_dmg = INT_MAX;
  	tmp_idx = -1;
  	tmp_val = -1;
  	do {
  		damage = max8997_assess_side_effect(rdev, new_val, &new_idx);
  		if (damage == 0)
  			goto out;
  
  		if (tmp_dmg > damage) {
  			tmp_idx = new_idx;
  			tmp_val = new_val;
  			tmp_dmg = damage;
  		}
  
  		new_val++;

  	} while (desc->min + desc->step * new_val <= desc->max);

  
  	new_idx = tmp_idx;
  	new_val = tmp_val;

  	if (max8997->ignore_gpiodvs_side_effect == false)

  		return -EINVAL;

  	dev_warn(&rdev->dev,
  		"MAX8997 GPIO-DVS Side Effect Warning: GPIO SET:  %d -> %d
  ",
  		max8997->buck125_gpioindex, tmp_idx);

  
  out:
  	if (new_idx < 0 || new_val < 0)
  		return -EINVAL;
  
  	max8997->buck125_gpioindex = new_idx;
  	max8997_set_gpio(max8997);
  	*selector = new_val;
  
  	return 0;
  }

  /* For SAFEOUT1 and SAFEOUT2 */

  static int max8997_set_voltage_safeout_sel(struct regulator_dev *rdev,
  					   unsigned selector)

  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;

  	int rid = rdev_get_id(rdev);

  	int reg, shift = 0, mask, ret;

  
  	if (rid != MAX8997_ESAFEOUT1 && rid != MAX8997_ESAFEOUT2)
  		return -EINVAL;

  	ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
  	if (ret)
  		return ret;

  	return max8997_update_reg(i2c, reg, selector << shift, mask << shift);

  }

  static int max8997_reg_disable_suspend(struct regulator_dev *rdev)
  {
  	struct max8997_data *max8997 = rdev_get_drvdata(rdev);
  	struct i2c_client *i2c = max8997->iodev->i2c;
  	int ret, reg, mask, pattern;

  	int rid = rdev_get_id(rdev);

  
  	ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
  	if (ret)
  		return ret;
  
  	max8997_read_reg(i2c, reg, &max8997->saved_states[rid]);
  
  	if (rid == MAX8997_LDO1 ||
  			rid == MAX8997_LDO10 ||
  			rid == MAX8997_LDO21) {
  		dev_dbg(&rdev->dev, "Conditional Power-Off for %s
  ",
  				rdev->desc->name);
  		return max8997_update_reg(i2c, reg, 0x40, mask);
  	}
  
  	dev_dbg(&rdev->dev, "Full Power-Off for %s (%xh -> %xh)
  ",
  			rdev->desc->name, max8997->saved_states[rid] & mask,
  			(~pattern) & mask);
  	return max8997_update_reg(i2c, reg, ~pattern, mask);
  }

  static const struct regulator_ops max8997_ldo_ops = {

  	.list_voltage		= max8997_list_voltage,
  	.is_enabled		= max8997_reg_is_enabled,
  	.enable			= max8997_reg_enable,
  	.disable		= max8997_reg_disable,

  	.get_voltage_sel	= max8997_get_voltage_sel,

  	.set_voltage		= max8997_set_voltage_ldobuck,

  	.set_suspend_disable	= max8997_reg_disable_suspend,
  };

  static const struct regulator_ops max8997_buck_ops = {

  	.list_voltage		= max8997_list_voltage,
  	.is_enabled		= max8997_reg_is_enabled,
  	.enable			= max8997_reg_enable,
  	.disable		= max8997_reg_disable,

  	.get_voltage_sel	= max8997_get_voltage_sel,

  	.set_voltage		= max8997_set_voltage_buck,

  	.set_voltage_time_sel	= max8997_set_voltage_buck_time_sel,

  	.set_suspend_disable	= max8997_reg_disable_suspend,
  };

  static const struct regulator_ops max8997_fixedvolt_ops = {

  	.list_voltage		= max8997_list_voltage,
  	.is_enabled		= max8997_reg_is_enabled,
  	.enable			= max8997_reg_enable,
  	.disable		= max8997_reg_disable,

  	.set_suspend_disable	= max8997_reg_disable_suspend,
  };

  static const struct regulator_ops max8997_safeout_ops = {

  	.list_voltage		= regulator_list_voltage_table,

  	.is_enabled		= max8997_reg_is_enabled,
  	.enable			= max8997_reg_enable,
  	.disable		= max8997_reg_disable,

  	.get_voltage_sel	= max8997_get_voltage_sel,

  	.set_voltage_sel	= max8997_set_voltage_safeout_sel,

  	.set_suspend_disable	= max8997_reg_disable_suspend,
  };

  static const struct regulator_ops max8997_fixedstate_ops = {

  	.list_voltage		= max8997_list_voltage_charger_cv,

  	.get_voltage_sel	= max8997_get_voltage_sel,

  	.set_voltage		= max8997_set_voltage_charger_cv,
  };

  static int max8997_set_current_limit(struct regulator_dev *rdev,
  				     int min_uA, int max_uA)

  {
  	unsigned dummy;

  	int rid = rdev_get_id(rdev);

  	if (rid != MAX8997_CHARGER && rid != MAX8997_CHARGER_TOPOFF)
  		return -EINVAL;

  	/* Reuse max8997_set_voltage_ldobuck to set current_limit. */
  	return max8997_set_voltage_ldobuck(rdev, min_uA, max_uA, &dummy);

  }

  static int max8997_get_current_limit(struct regulator_dev *rdev)
  {
  	int sel, rid = rdev_get_id(rdev);
  
  	if (rid != MAX8997_CHARGER && rid != MAX8997_CHARGER_TOPOFF)
  		return -EINVAL;
  
  	sel = max8997_get_voltage_sel(rdev);
  	if (sel < 0)
  		return sel;
  
  	/* Reuse max8997_list_voltage to get current_limit. */
  	return max8997_list_voltage(rdev, sel);
  }

  static const struct regulator_ops max8997_charger_ops = {

  	.is_enabled		= max8997_reg_is_enabled,
  	.enable			= max8997_reg_enable,
  	.disable		= max8997_reg_disable,

  	.get_current_limit	= max8997_get_current_limit,
  	.set_current_limit	= max8997_set_current_limit,

  };

  static const struct regulator_ops max8997_charger_fixedstate_ops = {

  	.get_current_limit	= max8997_get_current_limit,
  	.set_current_limit	= max8997_set_current_limit,

  };

  #define MAX8997_VOLTAGE_REGULATOR(_name, _ops) {\
  	.name		= #_name,		\
  	.id		= MAX8997_##_name,	\
  	.ops		= &_ops,		\

  	.type		= REGULATOR_VOLTAGE,	\
  	.owner		= THIS_MODULE,		\
  }

  
  #define MAX8997_CURRENT_REGULATOR(_name, _ops) {\
  	.name		= #_name,		\
  	.id		= MAX8997_##_name,	\
  	.ops		= &_ops,		\
  	.type		= REGULATOR_CURRENT,	\

  	.owner		= THIS_MODULE,		\
  }
  
  static struct regulator_desc regulators[] = {

  	MAX8997_VOLTAGE_REGULATOR(LDO1, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO2, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO3, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO4, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO5, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO6, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO7, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO8, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO9, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO10, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO11, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO12, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO13, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO14, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO15, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO16, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO17, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO18, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(LDO21, max8997_ldo_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK1, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK2, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK3, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK4, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK5, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK6, max8997_fixedvolt_ops),
  	MAX8997_VOLTAGE_REGULATOR(BUCK7, max8997_buck_ops),
  	MAX8997_VOLTAGE_REGULATOR(EN32KHZ_AP, max8997_fixedvolt_ops),
  	MAX8997_VOLTAGE_REGULATOR(EN32KHZ_CP, max8997_fixedvolt_ops),
  	MAX8997_VOLTAGE_REGULATOR(ENVICHG, max8997_fixedvolt_ops),
  	MAX8997_VOLTAGE_REGULATOR(ESAFEOUT1, max8997_safeout_ops),
  	MAX8997_VOLTAGE_REGULATOR(ESAFEOUT2, max8997_safeout_ops),
  	MAX8997_VOLTAGE_REGULATOR(CHARGER_CV, max8997_fixedstate_ops),
  	MAX8997_CURRENT_REGULATOR(CHARGER, max8997_charger_ops),
  	MAX8997_CURRENT_REGULATOR(CHARGER_TOPOFF,
  				  max8997_charger_fixedstate_ops),

  };

  #ifdef CONFIG_OF

  static int max8997_pmic_dt_parse_dvs_gpio(struct platform_device *pdev,

  			struct max8997_platform_data *pdata,
  			struct device_node *pmic_np)
  {
  	int i, gpio;
  
  	for (i = 0; i < 3; i++) {
  		gpio = of_get_named_gpio(pmic_np,
  					"max8997,pmic-buck125-dvs-gpios", i);
  		if (!gpio_is_valid(gpio)) {

  			dev_err(&pdev->dev, "invalid gpio[%d]: %d
  ", i, gpio);

  			return -EINVAL;
  		}
  		pdata->buck125_gpios[i] = gpio;
  	}
  	return 0;
  }

  static int max8997_pmic_dt_parse_pdata(struct platform_device *pdev,

  					struct max8997_platform_data *pdata)
  {

  	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);

  	struct device_node *pmic_np, *regulators_np, *reg_np;
  	struct max8997_regulator_data *rdata;
  	unsigned int i, dvs_voltage_nr = 1, ret;

  	pmic_np = iodev->dev->of_node;

  	if (!pmic_np) {

  		dev_err(&pdev->dev, "could not find pmic sub-node
  ");

  		return -ENODEV;
  	}

  	regulators_np = of_get_child_by_name(pmic_np, "regulators");

  	if (!regulators_np) {

  		dev_err(&pdev->dev, "could not find regulators sub-node
  ");

  		return -EINVAL;
  	}
  
  	/* count the number of regulators to be supported in pmic */

  	pdata->num_regulators = of_get_child_count(regulators_np);

  	rdata = devm_kcalloc(&pdev->dev,
  			     pdata->num_regulators, sizeof(*rdata),
  			     GFP_KERNEL);

  	if (!rdata) {

  		of_node_put(regulators_np);

  		return -ENOMEM;
  	}
  
  	pdata->regulators = rdata;
  	for_each_child_of_node(regulators_np, reg_np) {
  		for (i = 0; i < ARRAY_SIZE(regulators); i++)

  			if (of_node_name_eq(reg_np, regulators[i].name))

  				break;
  
  		if (i == ARRAY_SIZE(regulators)) {

  			dev_warn(&pdev->dev, "don't know how to configure regulator %pOFn
  ",
  				 reg_np);

  			continue;
  		}
  
  		rdata->id = i;

  		rdata->initdata = of_get_regulator_init_data(&pdev->dev,

  							     reg_np,
  							     &regulators[i]);

  		rdata->reg_node = reg_np;
  		rdata++;
  	}

  	of_node_put(regulators_np);

  
  	if (of_get_property(pmic_np, "max8997,pmic-buck1-uses-gpio-dvs", NULL))
  		pdata->buck1_gpiodvs = true;
  
  	if (of_get_property(pmic_np, "max8997,pmic-buck2-uses-gpio-dvs", NULL))
  		pdata->buck2_gpiodvs = true;
  
  	if (of_get_property(pmic_np, "max8997,pmic-buck5-uses-gpio-dvs", NULL))
  		pdata->buck5_gpiodvs = true;
  
  	if (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
  						pdata->buck5_gpiodvs) {

  		ret = max8997_pmic_dt_parse_dvs_gpio(pdev, pdata, pmic_np);

  		if (ret)
  			return -EINVAL;
  
  		if (of_property_read_u32(pmic_np,
  				"max8997,pmic-buck125-default-dvs-idx",
  				&pdata->buck125_default_idx)) {
  			pdata->buck125_default_idx = 0;
  		} else {
  			if (pdata->buck125_default_idx >= 8) {
  				pdata->buck125_default_idx = 0;

  				dev_info(&pdev->dev, "invalid value for default dvs index, using 0 instead
  ");

  			}
  		}
  
  		if (of_get_property(pmic_np,
  			"max8997,pmic-ignore-gpiodvs-side-effect", NULL))
  			pdata->ignore_gpiodvs_side_effect = true;
  
  		dvs_voltage_nr = 8;
  	}
  
  	if (of_property_read_u32_array(pmic_np,
  				"max8997,pmic-buck1-dvs-voltage",
  				pdata->buck1_voltage, dvs_voltage_nr)) {

  		dev_err(&pdev->dev, "buck1 voltages not specified
  ");

  		return -EINVAL;
  	}
  
  	if (of_property_read_u32_array(pmic_np,
  				"max8997,pmic-buck2-dvs-voltage",
  				pdata->buck2_voltage, dvs_voltage_nr)) {

  		dev_err(&pdev->dev, "buck2 voltages not specified
  ");

  		return -EINVAL;
  	}
  
  	if (of_property_read_u32_array(pmic_np,
  				"max8997,pmic-buck5-dvs-voltage",
  				pdata->buck5_voltage, dvs_voltage_nr)) {

  		dev_err(&pdev->dev, "buck5 voltages not specified
  ");

  		return -EINVAL;
  	}
  
  	return 0;
  }
  #else

  static int max8997_pmic_dt_parse_pdata(struct platform_device *pdev,

  					struct max8997_platform_data *pdata)
  {
  	return 0;
  }
  #endif /* CONFIG_OF */

  static int max8997_pmic_probe(struct platform_device *pdev)

  {
  	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);

  	struct max8997_platform_data *pdata = iodev->pdata;

  	struct regulator_config config = { };

  	struct regulator_dev *rdev;

  	struct max8997_data *max8997;
  	struct i2c_client *i2c;

  	int i, ret, nr_dvs;

  	u8 max_buck1 = 0, max_buck2 = 0, max_buck5 = 0;

  	if (!pdata) {
  		dev_err(&pdev->dev, "No platform init data supplied.
  ");

  		return -ENODEV;
  	}

  	if (iodev->dev->of_node) {

  		ret = max8997_pmic_dt_parse_pdata(pdev, pdata);

  		if (ret)
  			return ret;
  	}

  	max8997 = devm_kzalloc(&pdev->dev, sizeof(struct max8997_data),
  			       GFP_KERNEL);

  	if (!max8997)
  		return -ENOMEM;

  	max8997->dev = &pdev->dev;
  	max8997->iodev = iodev;
  	max8997->num_regulators = pdata->num_regulators;
  	platform_set_drvdata(pdev, max8997);
  	i2c = max8997->iodev->i2c;
  
  	max8997->buck125_gpioindex = pdata->buck125_default_idx;

  	max8997->buck1_gpiodvs = pdata->buck1_gpiodvs;
  	max8997->buck2_gpiodvs = pdata->buck2_gpiodvs;
  	max8997->buck5_gpiodvs = pdata->buck5_gpiodvs;
  	memcpy(max8997->buck125_gpios, pdata->buck125_gpios, sizeof(int) * 3);
  	max8997->ignore_gpiodvs_side_effect = pdata->ignore_gpiodvs_side_effect;

  	nr_dvs = (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
  			pdata->buck5_gpiodvs) ? 8 : 1;
  
  	for (i = 0; i < nr_dvs; i++) {

  		max8997->buck1_vol[i] = ret =
  			max8997_get_voltage_proper_val(
  					&buck1245_voltage_map_desc,

  					pdata->buck1_voltage[i],
  					pdata->buck1_voltage[i] +

  					buck1245_voltage_map_desc.step);
  		if (ret < 0)

  			return ret;

  
  		max8997->buck2_vol[i] = ret =
  			max8997_get_voltage_proper_val(
  					&buck1245_voltage_map_desc,

  					pdata->buck2_voltage[i],
  					pdata->buck2_voltage[i] +

  					buck1245_voltage_map_desc.step);
  		if (ret < 0)

  			return ret;

  
  		max8997->buck5_vol[i] = ret =
  			max8997_get_voltage_proper_val(
  					&buck1245_voltage_map_desc,

  					pdata->buck5_voltage[i],
  					pdata->buck5_voltage[i] +

  					buck1245_voltage_map_desc.step);
  		if (ret < 0)

  			return ret;

  
  		if (max_buck1 < max8997->buck1_vol[i])
  			max_buck1 = max8997->buck1_vol[i];
  		if (max_buck2 < max8997->buck2_vol[i])
  			max_buck2 = max8997->buck2_vol[i];
  		if (max_buck5 < max8997->buck5_vol[i])
  			max_buck5 = max8997->buck5_vol[i];
  	}
  
  	/* For the safety, set max voltage before setting up */
  	for (i = 0; i < 8; i++) {

  		max8997_update_reg(i2c, MAX8997_REG_BUCK1DVS1 + i,

  				max_buck1, 0x3f);

  		max8997_update_reg(i2c, MAX8997_REG_BUCK2DVS1 + i,

  				max_buck2, 0x3f);

  		max8997_update_reg(i2c, MAX8997_REG_BUCK5DVS1 + i,

  				max_buck5, 0x3f);
  	}

  	/* Initialize all the DVS related BUCK registers */

  	for (i = 0; i < nr_dvs; i++) {

  		max8997_update_reg(i2c, MAX8997_REG_BUCK1DVS1 + i,
  				max8997->buck1_vol[i],
  				0x3f);
  		max8997_update_reg(i2c, MAX8997_REG_BUCK2DVS1 + i,
  				max8997->buck2_vol[i],
  				0x3f);
  		max8997_update_reg(i2c, MAX8997_REG_BUCK5DVS1 + i,
  				max8997->buck5_vol[i],
  				0x3f);
  	}

  	/*
  	 * If buck 1, 2, and 5 do not care DVS GPIO settings, ignore them.
  	 * If at least one of them cares, set gpios.
  	 */
  	if (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
  			pdata->buck5_gpiodvs) {

  
  		if (!gpio_is_valid(pdata->buck125_gpios[0]) ||
  				!gpio_is_valid(pdata->buck125_gpios[1]) ||
  				!gpio_is_valid(pdata->buck125_gpios[2])) {
  			dev_err(&pdev->dev, "GPIO NOT VALID
  ");

  			return -EINVAL;

  		}

  		ret = devm_gpio_request(&pdev->dev, pdata->buck125_gpios[0],
  					"MAX8997 SET1");
  		if (ret)

  			return ret;

  
  		ret = devm_gpio_request(&pdev->dev, pdata->buck125_gpios[1],
  					"MAX8997 SET2");
  		if (ret)

  			return ret;

  		ret = devm_gpio_request(&pdev->dev, pdata->buck125_gpios[2],

  				"MAX8997 SET3");

  		if (ret)

  			return ret;

  
  		gpio_direction_output(pdata->buck125_gpios[0],
  				(max8997->buck125_gpioindex >> 2)
  				& 0x1); /* SET1 */
  		gpio_direction_output(pdata->buck125_gpios[1],
  				(max8997->buck125_gpioindex >> 1)
  				& 0x1); /* SET2 */
  		gpio_direction_output(pdata->buck125_gpios[2],
  				(max8997->buck125_gpioindex >> 0)
  				& 0x1); /* SET3 */

  	}
  
  	/* DVS-GPIO disabled */
  	max8997_update_reg(i2c, MAX8997_REG_BUCK1CTRL, (pdata->buck1_gpiodvs) ?
  			(1 << 1) : (0 << 1), 1 << 1);
  	max8997_update_reg(i2c, MAX8997_REG_BUCK2CTRL, (pdata->buck2_gpiodvs) ?
  			(1 << 1) : (0 << 1), 1 << 1);
  	max8997_update_reg(i2c, MAX8997_REG_BUCK5CTRL, (pdata->buck5_gpiodvs) ?
  			(1 << 1) : (0 << 1), 1 << 1);

  	/* Misc Settings */
  	max8997->ramp_delay = 10; /* set 10mV/us, which is the default */
  	max8997_write_reg(i2c, MAX8997_REG_BUCKRAMP, (0xf << 4) | 0x9);

  	for (i = 0; i < pdata->num_regulators; i++) {
  		const struct voltage_map_desc *desc;
  		int id = pdata->regulators[i].id;
  
  		desc = reg_voltage_map[id];

  		if (desc) {

  			regulators[id].n_voltages =
  				(desc->max - desc->min) / desc->step + 1;

  		} else if (id == MAX8997_ESAFEOUT1 || id == MAX8997_ESAFEOUT2) {
  			regulators[id].volt_table = safeoutvolt;
  			regulators[id].n_voltages = ARRAY_SIZE(safeoutvolt);
  		} else if (id == MAX8997_CHARGER_CV) {

  			regulators[id].n_voltages = 16;

  		}

  		config.dev = max8997->dev;
  		config.init_data = pdata->regulators[i].initdata;
  		config.driver_data = max8997;

  		config.of_node = pdata->regulators[i].reg_node;

  		rdev = devm_regulator_register(&pdev->dev, &regulators[id],
  					       &config);
  		if (IS_ERR(rdev)) {

  			dev_err(max8997->dev, "regulator init failed for %d
  ",
  					id);

  			return PTR_ERR(rdev);

  		}
  	}

  	return 0;

  }
  
  static const struct platform_device_id max8997_pmic_id[] = {
  	{ "max8997-pmic", 0},
  	{ },
  };

  MODULE_DEVICE_TABLE(platform, max8997_pmic_id);

  
  static struct platform_driver max8997_pmic_driver = {
  	.driver = {
  		.name = "max8997-pmic",

  	},
  	.probe = max8997_pmic_probe,

  	.id_table = max8997_pmic_id,
  };
  
  static int __init max8997_pmic_init(void)
  {
  	return platform_driver_register(&max8997_pmic_driver);
  }
  subsys_initcall(max8997_pmic_init);
  
  static void __exit max8997_pmic_cleanup(void)
  {
  	platform_driver_unregister(&max8997_pmic_driver);
  }
  module_exit(max8997_pmic_cleanup);
  
  MODULE_DESCRIPTION("MAXIM 8997/8966 Regulator Driver");
  MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
  MODULE_LICENSE("GPL");