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1// SPDX-License-Identifier: GPL-2.0-or-later2//3// max20086-regulator.c - MAX20086-MAX20089 camera power protector driver4//5// Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@idesonboard.com>6// Copyright (C) 2018 Avnet, Inc.7 8#include <linux/err.h>9#include <linux/gpio/consumer.h>10#include <linux/i2c.h>11#include <linux/module.h>12#include <linux/regmap.h>13#include <linux/regulator/driver.h>14#include <linux/regulator/machine.h>15#include <linux/regulator/of_regulator.h>16#include <linux/slab.h>17 18/* Register Offset */19#define MAX20086_REG_MASK 0x0020#define MAX20086_REG_CONFIG 0x0121#define MAX20086_REG_ID 0x0222#define MAX20086_REG_STAT1 0x0323#define MAX20086_REG_STAT2_L 0x0424#define MAX20086_REG_STAT2_H 0x0525#define MAX20086_REG_ADC1 0x0626#define MAX20086_REG_ADC2 0x0727#define MAX20086_REG_ADC3 0x0828#define MAX20086_REG_ADC4 0x0929 30/* DEVICE IDs */31#define MAX20086_DEVICE_ID_MAX20086 0x4032#define MAX20086_DEVICE_ID_MAX20087 0x2033#define MAX20086_DEVICE_ID_MAX20088 0x1034#define MAX20086_DEVICE_ID_MAX20089 0x0035#define DEVICE_ID_MASK 0xf036 37/* Register bits */38#define MAX20086_EN_MASK 0x0f39#define MAX20086_EN_OUT1 0x0140#define MAX20086_EN_OUT2 0x0241#define MAX20086_EN_OUT3 0x0442#define MAX20086_EN_OUT4 0x0843#define MAX20086_INT_DISABLE_ALL 0x3f44 45#define MAX20086_MAX_REGULATORS 446 47struct max20086_chip_info {48 u8 id;49 unsigned int num_outputs;50};51 52struct max20086_regulator {53 struct device_node *of_node;54 struct regulator_init_data *init_data;55 const struct regulator_desc *desc;56 struct regulator_dev *rdev;57};58 59struct max20086 {60 struct device *dev;61 struct regmap *regmap;62 struct gpio_desc *ena_gpiod;63 64 const struct max20086_chip_info *info;65 66 struct max20086_regulator regulators[MAX20086_MAX_REGULATORS];67};68 69static const struct regulator_ops max20086_buck_ops = {70 .enable = regulator_enable_regmap,71 .disable = regulator_disable_regmap,72 .is_enabled = regulator_is_enabled_regmap,73};74 75#define MAX20086_REGULATOR_DESC(n) \76{ \77 .name = "OUT"#n, \78 .supply_name = "in", \79 .id = (n) - 1, \80 .ops = &max20086_buck_ops, \81 .type = REGULATOR_VOLTAGE, \82 .owner = THIS_MODULE, \83 .enable_reg = MAX20086_REG_CONFIG, \84 .enable_mask = 1 << ((n) - 1), \85 .enable_val = 1 << ((n) - 1), \86 .disable_val = 0, \87}88 89static const char * const max20086_output_names[] = {90 "OUT1",91 "OUT2",92 "OUT3",93 "OUT4",94};95 96static const struct regulator_desc max20086_regulators[] = {97 MAX20086_REGULATOR_DESC(1),98 MAX20086_REGULATOR_DESC(2),99 MAX20086_REGULATOR_DESC(3),100 MAX20086_REGULATOR_DESC(4),101};102 103static int max20086_regulators_register(struct max20086 *chip)104{105 unsigned int i;106 107 for (i = 0; i < chip->info->num_outputs; i++) {108 struct max20086_regulator *reg = &chip->regulators[i];109 struct regulator_config config = { };110 struct regulator_dev *rdev;111 112 config.dev = chip->dev;113 config.init_data = reg->init_data;114 config.driver_data = chip;115 config.of_node = reg->of_node;116 config.regmap = chip->regmap;117 config.ena_gpiod = chip->ena_gpiod;118 119 rdev = devm_regulator_register(chip->dev, reg->desc, &config);120 if (IS_ERR(rdev)) {121 dev_err(chip->dev,122 "Failed to register regulator output %s\n",123 reg->desc->name);124 return PTR_ERR(rdev);125 }126 127 reg->rdev = rdev;128 }129 130 return 0;131}132 133static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on)134{135 struct of_regulator_match matches[MAX20086_MAX_REGULATORS] = { };136 struct device_node *node;137 unsigned int i;138 int ret;139 140 node = of_get_child_by_name(chip->dev->of_node, "regulators");141 if (!node) {142 dev_err(chip->dev, "regulators node not found\n");143 return -ENODEV;144 }145 146 for (i = 0; i < chip->info->num_outputs; ++i)147 matches[i].name = max20086_output_names[i];148 149 ret = of_regulator_match(chip->dev, node, matches,150 chip->info->num_outputs);151 of_node_put(node);152 if (ret < 0) {153 dev_err(chip->dev, "Failed to match regulators\n");154 return -EINVAL;155 }156 157 *boot_on = false;158 159 for (i = 0; i < chip->info->num_outputs; i++) {160 struct max20086_regulator *reg = &chip->regulators[i];161 162 reg->init_data = matches[i].init_data;163 reg->of_node = matches[i].of_node;164 reg->desc = &max20086_regulators[i];165 166 if (reg->init_data) {167 if (reg->init_data->constraints.always_on ||168 reg->init_data->constraints.boot_on)169 *boot_on = true;170 }171 }172 173 return 0;174}175 176static int max20086_detect(struct max20086 *chip)177{178 unsigned int data;179 int ret;180 181 ret = regmap_read(chip->regmap, MAX20086_REG_ID, &data);182 if (ret < 0) {183 dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n", ret);184 return ret;185 }186 187 if ((data & DEVICE_ID_MASK) != chip->info->id) {188 dev_err(chip->dev, "Invalid device ID 0x%02x\n", data);189 return -ENXIO;190 }191 192 return 0;193}194 195static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg)196{197 switch (reg) {198 case MAX20086_REG_MASK:199 case MAX20086_REG_CONFIG:200 return true;201 default:202 return false;203 }204}205 206static const struct regmap_config max20086_regmap_config = {207 .reg_bits = 8,208 .val_bits = 8,209 .writeable_reg = max20086_gen_is_writeable_reg,210 .max_register = 0x9,211 .cache_type = REGCACHE_NONE,212};213 214static int max20086_i2c_probe(struct i2c_client *i2c)215{216 struct max20086 *chip;217 enum gpiod_flags flags;218 bool boot_on;219 int ret;220 221 chip = devm_kzalloc(&i2c->dev, sizeof(*chip), GFP_KERNEL);222 if (!chip)223 return -ENOMEM;224 225 chip->dev = &i2c->dev;226 chip->info = i2c_get_match_data(i2c);227 228 i2c_set_clientdata(i2c, chip);229 230 chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config);231 if (IS_ERR(chip->regmap)) {232 ret = PTR_ERR(chip->regmap);233 dev_err(chip->dev, "Failed to allocate register map: %d\n", ret);234 return ret;235 }236 237 ret = max20086_parse_regulators_dt(chip, &boot_on);238 if (ret < 0)239 return ret;240 241 ret = max20086_detect(chip);242 if (ret < 0)243 return ret;244 245 /* Until IRQ support is added, just disable all interrupts. */246 ret = regmap_update_bits(chip->regmap, MAX20086_REG_MASK,247 MAX20086_INT_DISABLE_ALL,248 MAX20086_INT_DISABLE_ALL);249 if (ret < 0) {250 dev_err(chip->dev, "Failed to disable interrupts: %d\n", ret);251 return ret;252 }253 254 /*255 * Get the enable GPIO. If any of the outputs is marked as being256 * enabled at boot, request the GPIO with an initial high state to257 * avoid disabling outputs that may have been turned on by the boot258 * loader. Otherwise, request it with a low state to enter lower-power259 * shutdown.260 */261 flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;262 chip->ena_gpiod = devm_gpiod_get(chip->dev, "enable", flags);263 if (IS_ERR(chip->ena_gpiod)) {264 ret = PTR_ERR(chip->ena_gpiod);265 dev_err(chip->dev, "Failed to get enable GPIO: %d\n", ret);266 return ret;267 }268 269 ret = max20086_regulators_register(chip);270 if (ret < 0) {271 dev_err(chip->dev, "Failed to register regulators: %d\n", ret);272 return ret;273 }274 275 return 0;276}277 278static const struct max20086_chip_info max20086_chip_info = {279 .id = MAX20086_DEVICE_ID_MAX20086,280 .num_outputs = 4,281};282 283static const struct max20086_chip_info max20087_chip_info = {284 .id = MAX20086_DEVICE_ID_MAX20087,285 .num_outputs = 4,286};287 288static const struct max20086_chip_info max20088_chip_info = {289 .id = MAX20086_DEVICE_ID_MAX20088,290 .num_outputs = 2,291};292 293static const struct max20086_chip_info max20089_chip_info = {294 .id = MAX20086_DEVICE_ID_MAX20089,295 .num_outputs = 2,296};297 298static const struct i2c_device_id max20086_i2c_id[] = {299 { "max20086", (kernel_ulong_t)&max20086_chip_info },300 { "max20087", (kernel_ulong_t)&max20087_chip_info },301 { "max20088", (kernel_ulong_t)&max20088_chip_info },302 { "max20089", (kernel_ulong_t)&max20089_chip_info },303 { /* Sentinel */ }304};305MODULE_DEVICE_TABLE(i2c, max20086_i2c_id);306 307static const struct of_device_id max20086_dt_ids[] __maybe_unused = {308 { .compatible = "maxim,max20086", .data = &max20086_chip_info },309 { .compatible = "maxim,max20087", .data = &max20087_chip_info },310 { .compatible = "maxim,max20088", .data = &max20088_chip_info },311 { .compatible = "maxim,max20089", .data = &max20089_chip_info },312 { /* Sentinel */ }313};314MODULE_DEVICE_TABLE(of, max20086_dt_ids);315 316static struct i2c_driver max20086_regulator_driver = {317 .driver = {318 .name = "max20086",319 .probe_type = PROBE_PREFER_ASYNCHRONOUS,320 .of_match_table = of_match_ptr(max20086_dt_ids),321 },322 .probe = max20086_i2c_probe,323 .id_table = max20086_i2c_id,324};325 326module_i2c_driver(max20086_regulator_driver);327 328MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>");329MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");330MODULE_LICENSE("GPL");331