cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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max8998.c (22421B)


      1// SPDX-License-Identifier: GPL-2.0+
      2//
      3// max8998.c - Voltage regulator driver for the Maxim 8998
      4//
      5//  Copyright (C) 2009-2010 Samsung Electronics
      6//  Kyungmin Park <kyungmin.park@samsung.com>
      7//  Marek Szyprowski <m.szyprowski@samsung.com>
      8
      9#include <linux/module.h>
     10#include <linux/init.h>
     11#include <linux/i2c.h>
     12#include <linux/err.h>
     13#include <linux/gpio.h>
     14#include <linux/slab.h>
     15#include <linux/interrupt.h>
     16#include <linux/mutex.h>
     17#include <linux/of.h>
     18#include <linux/of_gpio.h>
     19#include <linux/platform_device.h>
     20#include <linux/regulator/driver.h>
     21#include <linux/regulator/of_regulator.h>
     22#include <linux/mfd/max8998.h>
     23#include <linux/mfd/max8998-private.h>
     24
     25struct max8998_data {
     26	struct device		*dev;
     27	struct max8998_dev	*iodev;
     28	int			num_regulators;
     29	u8                      buck1_vol[4]; /* voltages for selection */
     30	u8                      buck2_vol[2];
     31	unsigned int		buck1_idx; /* index to last changed voltage */
     32					   /* value in a set */
     33	unsigned int		buck2_idx;
     34};
     35
     36static const unsigned int charger_current_table[] = {
     37	90000, 380000, 475000, 550000, 570000, 600000, 700000, 800000,
     38};
     39
     40static int max8998_get_enable_register(struct regulator_dev *rdev,
     41					int *reg, int *shift)
     42{
     43	int ldo = rdev_get_id(rdev);
     44
     45	switch (ldo) {
     46	case MAX8998_LDO2 ... MAX8998_LDO5:
     47		*reg = MAX8998_REG_ONOFF1;
     48		*shift = 3 - (ldo - MAX8998_LDO2);
     49		break;
     50	case MAX8998_LDO6 ... MAX8998_LDO13:
     51		*reg = MAX8998_REG_ONOFF2;
     52		*shift = 7 - (ldo - MAX8998_LDO6);
     53		break;
     54	case MAX8998_LDO14 ... MAX8998_LDO17:
     55		*reg = MAX8998_REG_ONOFF3;
     56		*shift = 7 - (ldo - MAX8998_LDO14);
     57		break;
     58	case MAX8998_BUCK1 ... MAX8998_BUCK4:
     59		*reg = MAX8998_REG_ONOFF1;
     60		*shift = 7 - (ldo - MAX8998_BUCK1);
     61		break;
     62	case MAX8998_EN32KHZ_AP ... MAX8998_ENVICHG:
     63		*reg = MAX8998_REG_ONOFF4;
     64		*shift = 7 - (ldo - MAX8998_EN32KHZ_AP);
     65		break;
     66	case MAX8998_ESAFEOUT1 ... MAX8998_ESAFEOUT2:
     67		*reg = MAX8998_REG_CHGR2;
     68		*shift = 7 - (ldo - MAX8998_ESAFEOUT1);
     69		break;
     70	case MAX8998_CHARGER:
     71		*reg = MAX8998_REG_CHGR2;
     72		*shift = 0;
     73		break;
     74	default:
     75		return -EINVAL;
     76	}
     77
     78	return 0;
     79}
     80
     81static int max8998_ldo_is_enabled(struct regulator_dev *rdev)
     82{
     83	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
     84	struct i2c_client *i2c = max8998->iodev->i2c;
     85	int ret, reg, shift = 8;
     86	u8 val;
     87
     88	ret = max8998_get_enable_register(rdev, &reg, &shift);
     89	if (ret)
     90		return ret;
     91
     92	ret = max8998_read_reg(i2c, reg, &val);
     93	if (ret)
     94		return ret;
     95
     96	return val & (1 << shift);
     97}
     98
     99static int max8998_ldo_is_enabled_inverted(struct regulator_dev *rdev)
    100{
    101	return (!max8998_ldo_is_enabled(rdev));
    102}
    103
    104static int max8998_ldo_enable(struct regulator_dev *rdev)
    105{
    106	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    107	struct i2c_client *i2c = max8998->iodev->i2c;
    108	int reg, shift = 8, ret;
    109
    110	ret = max8998_get_enable_register(rdev, &reg, &shift);
    111	if (ret)
    112		return ret;
    113
    114	return max8998_update_reg(i2c, reg, 1<<shift, 1<<shift);
    115}
    116
    117static int max8998_ldo_disable(struct regulator_dev *rdev)
    118{
    119	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    120	struct i2c_client *i2c = max8998->iodev->i2c;
    121	int reg, shift = 8, ret;
    122
    123	ret = max8998_get_enable_register(rdev, &reg, &shift);
    124	if (ret)
    125		return ret;
    126
    127	return max8998_update_reg(i2c, reg, 0, 1<<shift);
    128}
    129
    130static int max8998_get_voltage_register(struct regulator_dev *rdev,
    131				int *_reg, int *_shift, int *_mask)
    132{
    133	int ldo = rdev_get_id(rdev);
    134	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    135	int reg, shift = 0, mask = 0xff;
    136
    137	switch (ldo) {
    138	case MAX8998_LDO2 ... MAX8998_LDO3:
    139		reg = MAX8998_REG_LDO2_LDO3;
    140		mask = 0xf;
    141		if (ldo == MAX8998_LDO2)
    142			shift = 4;
    143		else
    144			shift = 0;
    145		break;
    146	case MAX8998_LDO4 ... MAX8998_LDO7:
    147		reg = MAX8998_REG_LDO4 + (ldo - MAX8998_LDO4);
    148		break;
    149	case MAX8998_LDO8 ... MAX8998_LDO9:
    150		reg = MAX8998_REG_LDO8_LDO9;
    151		mask = 0xf;
    152		if (ldo == MAX8998_LDO8)
    153			shift = 4;
    154		else
    155			shift = 0;
    156		break;
    157	case MAX8998_LDO10 ... MAX8998_LDO11:
    158		reg = MAX8998_REG_LDO10_LDO11;
    159		if (ldo == MAX8998_LDO10) {
    160			shift = 5;
    161			mask = 0x7;
    162		} else {
    163			shift = 0;
    164			mask = 0x1f;
    165		}
    166		break;
    167	case MAX8998_LDO12 ... MAX8998_LDO17:
    168		reg = MAX8998_REG_LDO12 + (ldo - MAX8998_LDO12);
    169		break;
    170	case MAX8998_BUCK1:
    171		reg = MAX8998_REG_BUCK1_VOLTAGE1 + max8998->buck1_idx;
    172		break;
    173	case MAX8998_BUCK2:
    174		reg = MAX8998_REG_BUCK2_VOLTAGE1 + max8998->buck2_idx;
    175		break;
    176	case MAX8998_BUCK3:
    177		reg = MAX8998_REG_BUCK3;
    178		break;
    179	case MAX8998_BUCK4:
    180		reg = MAX8998_REG_BUCK4;
    181		break;
    182	default:
    183		return -EINVAL;
    184	}
    185
    186	*_reg = reg;
    187	*_shift = shift;
    188	*_mask = mask;
    189
    190	return 0;
    191}
    192
    193static int max8998_get_voltage_sel(struct regulator_dev *rdev)
    194{
    195	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    196	struct i2c_client *i2c = max8998->iodev->i2c;
    197	int reg, shift = 0, mask, ret;
    198	u8 val;
    199
    200	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
    201	if (ret)
    202		return ret;
    203
    204	ret = max8998_read_reg(i2c, reg, &val);
    205	if (ret)
    206		return ret;
    207
    208	val >>= shift;
    209	val &= mask;
    210
    211	return val;
    212}
    213
    214static int max8998_set_voltage_ldo_sel(struct regulator_dev *rdev,
    215				       unsigned selector)
    216{
    217	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    218	struct i2c_client *i2c = max8998->iodev->i2c;
    219	int reg, shift = 0, mask, ret;
    220
    221	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
    222	if (ret)
    223		return ret;
    224
    225	ret = max8998_update_reg(i2c, reg, selector<<shift, mask<<shift);
    226
    227	return ret;
    228}
    229
    230static inline void buck1_gpio_set(int gpio1, int gpio2, int v)
    231{
    232	gpio_set_value(gpio1, v & 0x1);
    233	gpio_set_value(gpio2, (v >> 1) & 0x1);
    234}
    235
    236static inline void buck2_gpio_set(int gpio, int v)
    237{
    238	gpio_set_value(gpio, v & 0x1);
    239}
    240
    241static int max8998_set_voltage_buck_sel(struct regulator_dev *rdev,
    242					unsigned selector)
    243{
    244	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    245	struct max8998_platform_data *pdata = max8998->iodev->pdata;
    246	struct i2c_client *i2c = max8998->iodev->i2c;
    247	int buck = rdev_get_id(rdev);
    248	int reg, shift = 0, mask, ret, j;
    249	static u8 buck1_last_val;
    250
    251	ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
    252	if (ret)
    253		return ret;
    254
    255	switch (buck) {
    256	case MAX8998_BUCK1:
    257		dev_dbg(max8998->dev,
    258			"BUCK1, selector:%d, buck1_vol1:%d, buck1_vol2:%d\n"
    259			"buck1_vol3:%d, buck1_vol4:%d\n",
    260			selector, max8998->buck1_vol[0], max8998->buck1_vol[1],
    261			max8998->buck1_vol[2], max8998->buck1_vol[3]);
    262
    263		if (gpio_is_valid(pdata->buck1_set1) &&
    264		    gpio_is_valid(pdata->buck1_set2)) {
    265
    266			/* check if requested voltage */
    267			/* value is already defined */
    268			for (j = 0; j < ARRAY_SIZE(max8998->buck1_vol); j++) {
    269				if (max8998->buck1_vol[j] == selector) {
    270					max8998->buck1_idx = j;
    271					buck1_gpio_set(pdata->buck1_set1,
    272						       pdata->buck1_set2, j);
    273					goto buck1_exit;
    274				}
    275			}
    276
    277			if (pdata->buck_voltage_lock)
    278				return -EINVAL;
    279
    280			/* no predefine regulator found */
    281			max8998->buck1_idx = (buck1_last_val % 2) + 2;
    282			dev_dbg(max8998->dev, "max8998->buck1_idx:%d\n",
    283				max8998->buck1_idx);
    284			max8998->buck1_vol[max8998->buck1_idx] = selector;
    285			ret = max8998_get_voltage_register(rdev, &reg,
    286							   &shift,
    287							   &mask);
    288			ret = max8998_write_reg(i2c, reg, selector);
    289			buck1_gpio_set(pdata->buck1_set1,
    290				       pdata->buck1_set2, max8998->buck1_idx);
    291			buck1_last_val++;
    292buck1_exit:
    293			dev_dbg(max8998->dev, "%s: SET1:%d, SET2:%d\n",
    294				i2c->name, gpio_get_value(pdata->buck1_set1),
    295				gpio_get_value(pdata->buck1_set2));
    296			break;
    297		} else {
    298			ret = max8998_write_reg(i2c, reg, selector);
    299		}
    300		break;
    301
    302	case MAX8998_BUCK2:
    303		dev_dbg(max8998->dev,
    304			"BUCK2, selector:%d buck2_vol1:%d, buck2_vol2:%d\n",
    305			selector, max8998->buck2_vol[0], max8998->buck2_vol[1]);
    306		if (gpio_is_valid(pdata->buck2_set3)) {
    307
    308			/* check if requested voltage */
    309			/* value is already defined */
    310			for (j = 0; j < ARRAY_SIZE(max8998->buck2_vol); j++) {
    311				if (max8998->buck2_vol[j] == selector) {
    312					max8998->buck2_idx = j;
    313					buck2_gpio_set(pdata->buck2_set3, j);
    314					goto buck2_exit;
    315				}
    316			}
    317
    318			if (pdata->buck_voltage_lock)
    319				return -EINVAL;
    320
    321			max8998_get_voltage_register(rdev,
    322					&reg, &shift, &mask);
    323			ret = max8998_write_reg(i2c, reg, selector);
    324			max8998->buck2_vol[max8998->buck2_idx] = selector;
    325			buck2_gpio_set(pdata->buck2_set3, max8998->buck2_idx);
    326buck2_exit:
    327			dev_dbg(max8998->dev, "%s: SET3:%d\n", i2c->name,
    328				gpio_get_value(pdata->buck2_set3));
    329		} else {
    330			ret = max8998_write_reg(i2c, reg, selector);
    331		}
    332		break;
    333
    334	case MAX8998_BUCK3:
    335	case MAX8998_BUCK4:
    336		ret = max8998_update_reg(i2c, reg, selector<<shift,
    337					 mask<<shift);
    338		break;
    339	}
    340
    341	return ret;
    342}
    343
    344static int max8998_set_voltage_buck_time_sel(struct regulator_dev *rdev,
    345					     unsigned int old_selector,
    346					     unsigned int new_selector)
    347{
    348	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    349	struct i2c_client *i2c = max8998->iodev->i2c;
    350	int buck = rdev_get_id(rdev);
    351	u8 val = 0;
    352	int difference, ret;
    353
    354	if (buck < MAX8998_BUCK1 || buck > MAX8998_BUCK4)
    355		return -EINVAL;
    356
    357	/* Voltage stabilization */
    358	ret = max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
    359	if (ret)
    360		return ret;
    361
    362	/* lp3974 hasn't got ENRAMP bit - ramp is assumed as true */
    363	/* MAX8998 has ENRAMP bit implemented, so test it*/
    364	if (max8998->iodev->type == TYPE_MAX8998 && !(val & MAX8998_ENRAMP))
    365		return 0;
    366
    367	difference = (new_selector - old_selector) * rdev->desc->uV_step / 1000;
    368	if (difference > 0)
    369		return DIV_ROUND_UP(difference, (val & 0x0f) + 1);
    370
    371	return 0;
    372}
    373
    374static int max8998_set_current_limit(struct regulator_dev *rdev,
    375				     int min_uA, int max_uA)
    376{
    377	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    378	struct i2c_client *i2c = max8998->iodev->i2c;
    379	unsigned int n_currents = rdev->desc->n_current_limits;
    380	int i, sel = -1;
    381
    382	if (n_currents == 0)
    383		return -EINVAL;
    384
    385	if (rdev->desc->curr_table) {
    386		const unsigned int *curr_table = rdev->desc->curr_table;
    387		bool ascend = curr_table[n_currents - 1] > curr_table[0];
    388
    389		/* search for closest to maximum */
    390		if (ascend) {
    391			for (i = n_currents - 1; i >= 0; i--) {
    392				if (min_uA <= curr_table[i] &&
    393				    curr_table[i] <= max_uA) {
    394					sel = i;
    395					break;
    396				}
    397			}
    398		} else {
    399			for (i = 0; i < n_currents; i++) {
    400				if (min_uA <= curr_table[i] &&
    401				    curr_table[i] <= max_uA) {
    402					sel = i;
    403					break;
    404				}
    405			}
    406		}
    407	}
    408
    409	if (sel < 0)
    410		return -EINVAL;
    411
    412	sel <<= ffs(rdev->desc->csel_mask) - 1;
    413
    414	return max8998_update_reg(i2c, rdev->desc->csel_reg,
    415				  sel, rdev->desc->csel_mask);
    416}
    417
    418static int max8998_get_current_limit(struct regulator_dev *rdev)
    419{
    420	struct max8998_data *max8998 = rdev_get_drvdata(rdev);
    421	struct i2c_client *i2c = max8998->iodev->i2c;
    422	u8 val;
    423	int ret;
    424
    425	ret = max8998_read_reg(i2c, rdev->desc->csel_reg, &val);
    426	if (ret != 0)
    427		return ret;
    428
    429	val &= rdev->desc->csel_mask;
    430	val >>= ffs(rdev->desc->csel_mask) - 1;
    431
    432	if (rdev->desc->curr_table) {
    433		if (val >= rdev->desc->n_current_limits)
    434			return -EINVAL;
    435
    436		return rdev->desc->curr_table[val];
    437	}
    438
    439	return -EINVAL;
    440}
    441
    442static const struct regulator_ops max8998_ldo_ops = {
    443	.list_voltage		= regulator_list_voltage_linear,
    444	.map_voltage		= regulator_map_voltage_linear,
    445	.is_enabled		= max8998_ldo_is_enabled,
    446	.enable			= max8998_ldo_enable,
    447	.disable		= max8998_ldo_disable,
    448	.get_voltage_sel	= max8998_get_voltage_sel,
    449	.set_voltage_sel	= max8998_set_voltage_ldo_sel,
    450};
    451
    452static const struct regulator_ops max8998_buck_ops = {
    453	.list_voltage		= regulator_list_voltage_linear,
    454	.map_voltage		= regulator_map_voltage_linear,
    455	.is_enabled		= max8998_ldo_is_enabled,
    456	.enable			= max8998_ldo_enable,
    457	.disable		= max8998_ldo_disable,
    458	.get_voltage_sel	= max8998_get_voltage_sel,
    459	.set_voltage_sel	= max8998_set_voltage_buck_sel,
    460	.set_voltage_time_sel	= max8998_set_voltage_buck_time_sel,
    461};
    462
    463static const struct regulator_ops max8998_charger_ops = {
    464	.set_current_limit	= max8998_set_current_limit,
    465	.get_current_limit	= max8998_get_current_limit,
    466	.is_enabled		= max8998_ldo_is_enabled_inverted,
    467	/* Swapped as register is inverted */
    468	.enable			= max8998_ldo_disable,
    469	.disable		= max8998_ldo_enable,
    470};
    471
    472static const struct regulator_ops max8998_others_ops = {
    473	.is_enabled		= max8998_ldo_is_enabled,
    474	.enable			= max8998_ldo_enable,
    475	.disable		= max8998_ldo_disable,
    476};
    477
    478#define MAX8998_LINEAR_REG(_name, _ops, _min, _step, _max) \
    479	{ \
    480		.name = #_name, \
    481		.id = MAX8998_##_name, \
    482		.ops = _ops, \
    483		.min_uV = (_min), \
    484		.uV_step = (_step), \
    485		.n_voltages = ((_max) - (_min)) / (_step) + 1, \
    486		.type = REGULATOR_VOLTAGE, \
    487		.owner = THIS_MODULE, \
    488	}
    489
    490#define MAX8998_CURRENT_REG(_name, _ops, _table, _reg, _mask) \
    491	{ \
    492		.name = #_name, \
    493		.id = MAX8998_##_name, \
    494		.ops = _ops, \
    495		.curr_table = _table, \
    496		.n_current_limits = ARRAY_SIZE(_table), \
    497		.csel_reg = _reg, \
    498		.csel_mask = _mask, \
    499		.type = REGULATOR_CURRENT, \
    500		.owner = THIS_MODULE, \
    501	}
    502
    503#define MAX8998_OTHERS_REG(_name, _id) \
    504	{ \
    505		.name = #_name, \
    506		.id = _id, \
    507		.ops = &max8998_others_ops, \
    508		.type = REGULATOR_VOLTAGE, \
    509		.owner = THIS_MODULE, \
    510	}
    511
    512static const struct regulator_desc regulators[] = {
    513	MAX8998_LINEAR_REG(LDO2, &max8998_ldo_ops, 800000, 50000, 1300000),
    514	MAX8998_LINEAR_REG(LDO3, &max8998_ldo_ops, 800000, 50000, 1300000),
    515	MAX8998_LINEAR_REG(LDO4, &max8998_ldo_ops, 1600000, 100000, 3600000),
    516	MAX8998_LINEAR_REG(LDO5, &max8998_ldo_ops, 1600000, 100000, 3600000),
    517	MAX8998_LINEAR_REG(LDO6, &max8998_ldo_ops, 1600000, 100000, 3600000),
    518	MAX8998_LINEAR_REG(LDO7, &max8998_ldo_ops, 1600000, 100000, 3600000),
    519	MAX8998_LINEAR_REG(LDO8, &max8998_ldo_ops, 3000000, 100000, 3600000),
    520	MAX8998_LINEAR_REG(LDO9, &max8998_ldo_ops, 2800000, 100000, 3100000),
    521	MAX8998_LINEAR_REG(LDO10, &max8998_ldo_ops, 950000, 50000, 1300000),
    522	MAX8998_LINEAR_REG(LDO11, &max8998_ldo_ops, 1600000, 100000, 3600000),
    523	MAX8998_LINEAR_REG(LDO12, &max8998_ldo_ops, 800000, 100000, 3300000),
    524	MAX8998_LINEAR_REG(LDO13, &max8998_ldo_ops, 800000, 100000, 3300000),
    525	MAX8998_LINEAR_REG(LDO14, &max8998_ldo_ops, 1200000, 100000, 3300000),
    526	MAX8998_LINEAR_REG(LDO15, &max8998_ldo_ops, 1200000, 100000, 3300000),
    527	MAX8998_LINEAR_REG(LDO16, &max8998_ldo_ops, 1600000, 100000, 3600000),
    528	MAX8998_LINEAR_REG(LDO17, &max8998_ldo_ops, 1600000, 100000, 3600000),
    529	MAX8998_LINEAR_REG(BUCK1, &max8998_buck_ops, 750000, 25000, 1525000),
    530	MAX8998_LINEAR_REG(BUCK2, &max8998_buck_ops, 750000, 25000, 1525000),
    531	MAX8998_LINEAR_REG(BUCK3, &max8998_buck_ops, 1600000, 100000, 3600000),
    532	MAX8998_LINEAR_REG(BUCK4, &max8998_buck_ops, 800000, 100000, 2300000),
    533	MAX8998_OTHERS_REG(EN32KHz-AP, MAX8998_EN32KHZ_AP),
    534	MAX8998_OTHERS_REG(EN32KHz-CP, MAX8998_EN32KHZ_CP),
    535	MAX8998_OTHERS_REG(ENVICHG, MAX8998_ENVICHG),
    536	MAX8998_OTHERS_REG(ESAFEOUT1, MAX8998_ESAFEOUT1),
    537	MAX8998_OTHERS_REG(ESAFEOUT2, MAX8998_ESAFEOUT2),
    538	MAX8998_CURRENT_REG(CHARGER, &max8998_charger_ops,
    539			    charger_current_table, MAX8998_REG_CHGR1, 0x7),
    540};
    541
    542static int max8998_pmic_dt_parse_dvs_gpio(struct max8998_dev *iodev,
    543			struct max8998_platform_data *pdata,
    544			struct device_node *pmic_np)
    545{
    546	int gpio;
    547
    548	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 0);
    549	if (!gpio_is_valid(gpio)) {
    550		dev_err(iodev->dev, "invalid buck1 gpio[0]: %d\n", gpio);
    551		return -EINVAL;
    552	}
    553	pdata->buck1_set1 = gpio;
    554
    555	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck1-dvs-gpios", 1);
    556	if (!gpio_is_valid(gpio)) {
    557		dev_err(iodev->dev, "invalid buck1 gpio[1]: %d\n", gpio);
    558		return -EINVAL;
    559	}
    560	pdata->buck1_set2 = gpio;
    561
    562	gpio = of_get_named_gpio(pmic_np, "max8998,pmic-buck2-dvs-gpio", 0);
    563	if (!gpio_is_valid(gpio)) {
    564		dev_err(iodev->dev, "invalid buck 2 gpio: %d\n", gpio);
    565		return -EINVAL;
    566	}
    567	pdata->buck2_set3 = gpio;
    568
    569	return 0;
    570}
    571
    572static int max8998_pmic_dt_parse_pdata(struct max8998_dev *iodev,
    573					struct max8998_platform_data *pdata)
    574{
    575	struct device_node *pmic_np = iodev->dev->of_node;
    576	struct device_node *regulators_np, *reg_np;
    577	struct max8998_regulator_data *rdata;
    578	unsigned int i;
    579	int ret;
    580
    581	regulators_np = of_get_child_by_name(pmic_np, "regulators");
    582	if (!regulators_np) {
    583		dev_err(iodev->dev, "could not find regulators sub-node\n");
    584		return -EINVAL;
    585	}
    586
    587	/* count the number of regulators to be supported in pmic */
    588	pdata->num_regulators = of_get_child_count(regulators_np);
    589
    590	rdata = devm_kcalloc(iodev->dev,
    591			     pdata->num_regulators, sizeof(*rdata),
    592			     GFP_KERNEL);
    593	if (!rdata) {
    594		of_node_put(regulators_np);
    595		return -ENOMEM;
    596	}
    597
    598	pdata->regulators = rdata;
    599	for (i = 0; i < ARRAY_SIZE(regulators); ++i) {
    600		reg_np = of_get_child_by_name(regulators_np,
    601							regulators[i].name);
    602		if (!reg_np)
    603			continue;
    604
    605		rdata->id = regulators[i].id;
    606		rdata->initdata = of_get_regulator_init_data(iodev->dev,
    607							     reg_np,
    608							     &regulators[i]);
    609		rdata->reg_node = reg_np;
    610		++rdata;
    611	}
    612	pdata->num_regulators = rdata - pdata->regulators;
    613
    614	of_node_put(reg_np);
    615	of_node_put(regulators_np);
    616
    617	ret = max8998_pmic_dt_parse_dvs_gpio(iodev, pdata, pmic_np);
    618	if (ret)
    619		return -EINVAL;
    620
    621	if (of_find_property(pmic_np, "max8998,pmic-buck-voltage-lock", NULL))
    622		pdata->buck_voltage_lock = true;
    623
    624	ret = of_property_read_u32(pmic_np,
    625					"max8998,pmic-buck1-default-dvs-idx",
    626					&pdata->buck1_default_idx);
    627	if (!ret && pdata->buck1_default_idx >= 4) {
    628		pdata->buck1_default_idx = 0;
    629		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
    630	}
    631
    632	ret = of_property_read_u32(pmic_np,
    633					"max8998,pmic-buck2-default-dvs-idx",
    634					&pdata->buck2_default_idx);
    635	if (!ret && pdata->buck2_default_idx >= 2) {
    636		pdata->buck2_default_idx = 0;
    637		dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
    638	}
    639
    640	ret = of_property_read_u32_array(pmic_np,
    641					"max8998,pmic-buck1-dvs-voltage",
    642					pdata->buck1_voltage,
    643					ARRAY_SIZE(pdata->buck1_voltage));
    644	if (ret) {
    645		dev_err(iodev->dev, "buck1 voltages not specified\n");
    646		return -EINVAL;
    647	}
    648
    649	ret = of_property_read_u32_array(pmic_np,
    650					"max8998,pmic-buck2-dvs-voltage",
    651					pdata->buck2_voltage,
    652					ARRAY_SIZE(pdata->buck2_voltage));
    653	if (ret) {
    654		dev_err(iodev->dev, "buck2 voltages not specified\n");
    655		return -EINVAL;
    656	}
    657
    658	return 0;
    659}
    660
    661static int max8998_pmic_probe(struct platform_device *pdev)
    662{
    663	struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
    664	struct max8998_platform_data *pdata = iodev->pdata;
    665	struct regulator_config config = { };
    666	struct regulator_dev *rdev;
    667	struct max8998_data *max8998;
    668	struct i2c_client *i2c;
    669	int i, ret;
    670	unsigned int v;
    671
    672	if (!pdata) {
    673		dev_err(pdev->dev.parent, "No platform init data supplied\n");
    674		return -ENODEV;
    675	}
    676
    677	if (IS_ENABLED(CONFIG_OF) && iodev->dev->of_node) {
    678		ret = max8998_pmic_dt_parse_pdata(iodev, pdata);
    679		if (ret)
    680			return ret;
    681	}
    682
    683	max8998 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_data),
    684			       GFP_KERNEL);
    685	if (!max8998)
    686		return -ENOMEM;
    687
    688	max8998->dev = &pdev->dev;
    689	max8998->iodev = iodev;
    690	max8998->num_regulators = pdata->num_regulators;
    691	platform_set_drvdata(pdev, max8998);
    692	i2c = max8998->iodev->i2c;
    693
    694	max8998->buck1_idx = pdata->buck1_default_idx;
    695	max8998->buck2_idx = pdata->buck2_default_idx;
    696
    697	/* NOTE: */
    698	/* For unused GPIO NOT marked as -1 (thereof equal to 0)  WARN_ON */
    699	/* will be displayed */
    700
    701	/* Check if MAX8998 voltage selection GPIOs are defined */
    702	if (gpio_is_valid(pdata->buck1_set1) &&
    703	    gpio_is_valid(pdata->buck1_set2)) {
    704		/* Check if SET1 is not equal to 0 */
    705		if (!pdata->buck1_set1) {
    706			dev_err(&pdev->dev,
    707				"MAX8998 SET1 GPIO defined as 0 !\n");
    708			WARN_ON(!pdata->buck1_set1);
    709			return -EIO;
    710		}
    711		/* Check if SET2 is not equal to 0 */
    712		if (!pdata->buck1_set2) {
    713			dev_err(&pdev->dev,
    714				"MAX8998 SET2 GPIO defined as 0 !\n");
    715			WARN_ON(!pdata->buck1_set2);
    716			return -EIO;
    717		}
    718
    719		gpio_request(pdata->buck1_set1, "MAX8998 BUCK1_SET1");
    720		gpio_direction_output(pdata->buck1_set1,
    721				      max8998->buck1_idx & 0x1);
    722
    723
    724		gpio_request(pdata->buck1_set2, "MAX8998 BUCK1_SET2");
    725		gpio_direction_output(pdata->buck1_set2,
    726				      (max8998->buck1_idx >> 1) & 0x1);
    727
    728		/* Set predefined values for BUCK1 registers */
    729		for (v = 0; v < ARRAY_SIZE(pdata->buck1_voltage); ++v) {
    730			int index = MAX8998_BUCK1 - MAX8998_LDO2;
    731
    732			i = 0;
    733			while (regulators[index].min_uV +
    734			       regulators[index].uV_step * i
    735			       < pdata->buck1_voltage[v])
    736				i++;
    737
    738			max8998->buck1_vol[v] = i;
    739			ret = max8998_write_reg(i2c,
    740					MAX8998_REG_BUCK1_VOLTAGE1 + v, i);
    741			if (ret)
    742				return ret;
    743		}
    744	}
    745
    746	if (gpio_is_valid(pdata->buck2_set3)) {
    747		/* Check if SET3 is not equal to 0 */
    748		if (!pdata->buck2_set3) {
    749			dev_err(&pdev->dev,
    750				"MAX8998 SET3 GPIO defined as 0 !\n");
    751			WARN_ON(!pdata->buck2_set3);
    752			return -EIO;
    753		}
    754		gpio_request(pdata->buck2_set3, "MAX8998 BUCK2_SET3");
    755		gpio_direction_output(pdata->buck2_set3,
    756				      max8998->buck2_idx & 0x1);
    757
    758		/* Set predefined values for BUCK2 registers */
    759		for (v = 0; v < ARRAY_SIZE(pdata->buck2_voltage); ++v) {
    760			int index = MAX8998_BUCK2 - MAX8998_LDO2;
    761
    762			i = 0;
    763			while (regulators[index].min_uV +
    764			       regulators[index].uV_step * i
    765			       < pdata->buck2_voltage[v])
    766				i++;
    767
    768			max8998->buck2_vol[v] = i;
    769			ret = max8998_write_reg(i2c,
    770					MAX8998_REG_BUCK2_VOLTAGE1 + v, i);
    771			if (ret)
    772				return ret;
    773		}
    774	}
    775
    776	for (i = 0; i < pdata->num_regulators; i++) {
    777		int index = pdata->regulators[i].id - MAX8998_LDO2;
    778
    779		config.dev = max8998->dev;
    780		config.of_node = pdata->regulators[i].reg_node;
    781		config.init_data = pdata->regulators[i].initdata;
    782		config.driver_data = max8998;
    783
    784		rdev = devm_regulator_register(&pdev->dev, &regulators[index],
    785					       &config);
    786		if (IS_ERR(rdev)) {
    787			ret = PTR_ERR(rdev);
    788			dev_err(max8998->dev, "regulator %s init failed (%d)\n",
    789						regulators[index].name, ret);
    790			return ret;
    791		}
    792	}
    793
    794	return 0;
    795}
    796
    797static const struct platform_device_id max8998_pmic_id[] = {
    798	{ "max8998-pmic", TYPE_MAX8998 },
    799	{ "lp3974-pmic", TYPE_LP3974 },
    800	{ }
    801};
    802MODULE_DEVICE_TABLE(platform, max8998_pmic_id);
    803
    804static struct platform_driver max8998_pmic_driver = {
    805	.driver = {
    806		.name = "max8998-pmic",
    807	},
    808	.probe = max8998_pmic_probe,
    809	.id_table = max8998_pmic_id,
    810};
    811
    812static int __init max8998_pmic_init(void)
    813{
    814	return platform_driver_register(&max8998_pmic_driver);
    815}
    816subsys_initcall(max8998_pmic_init);
    817
    818static void __exit max8998_pmic_cleanup(void)
    819{
    820	platform_driver_unregister(&max8998_pmic_driver);
    821}
    822module_exit(max8998_pmic_cleanup);
    823
    824MODULE_DESCRIPTION("MAXIM 8998 voltage regulator driver");
    825MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
    826MODULE_LICENSE("GPL");