drivers/regulator/max20086-regulator.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 //
   3 // max20086-regulator.c - MAX20086-MAX20089 camera power protector driver
   4 //
   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               0x00
  20 #define MAX20086_REG_CONFIG             0x01
  21 #define MAX20086_REG_ID                 0x02
  22 #define MAX20086_REG_STAT1              0x03
  23 #define MAX20086_REG_STAT2_L            0x04
  24 #define MAX20086_REG_STAT2_H            0x05
  25 #define MAX20086_REG_ADC1               0x06
  26 #define MAX20086_REG_ADC2               0x07
  27 #define MAX20086_REG_ADC3               0x08
  28 #define MAX20086_REG_ADC4               0x09
  29
  30 /* DEVICE IDs */
  31 #define MAX20086_DEVICE_ID_MAX20086     0x40
  32 #define MAX20086_DEVICE_ID_MAX20087     0x20
  33 #define MAX20086_DEVICE_ID_MAX20088     0x10
  34 #define MAX20086_DEVICE_ID_MAX20089     0x00
  35 #define DEVICE_ID_MASK                  0xf0
  36
  37 /* Register bits */
  38 #define MAX20086_EN_MASK                0x0f
  39 #define MAX20086_EN_OUT1                0x01
  40 #define MAX20086_EN_OUT2                0x02
  41 #define MAX20086_EN_OUT3                0x04
  42 #define MAX20086_EN_OUT4                0x08
  43 #define MAX20086_INT_DISABLE_ALL        0x3f
  44
  45 #define MAX20086_MAX_REGULATORS         4
  46
  47 struct max20086_chip_info {
  48         u8 id;
  49         unsigned int num_outputs;
  50 };
  51
  52 struct 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
  59 struct 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
  69 static 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
  89 static const char * const max20086_output_names[] = {
  90         "OUT1",
  91         "OUT2",
  92         "OUT3",
  93         "OUT4",
  94 };
  95
  96 static 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
 103 static 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
 133 static 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
 176 static 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
 195 static 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
 206 static 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
 214 static 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 being
 256          * enabled at boot, request the GPIO with an initial high state to
 257          * avoid disabling outputs that may have been turned on by the boot
 258          * loader. Otherwise, request it with a low state to enter lower-power
 259          * 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
 278 static const struct max20086_chip_info max20086_chip_info = {
 279         .id = MAX20086_DEVICE_ID_MAX20086,
 280         .num_outputs = 4,
 281 };
 282
 283 static const struct max20086_chip_info max20087_chip_info = {
 284         .id = MAX20086_DEVICE_ID_MAX20087,
 285         .num_outputs = 4,
 286 };
 287
 288 static const struct max20086_chip_info max20088_chip_info = {
 289         .id = MAX20086_DEVICE_ID_MAX20088,
 290         .num_outputs = 2,
 291 };
 292
 293 static const struct max20086_chip_info max20089_chip_info = {
 294         .id = MAX20086_DEVICE_ID_MAX20089,
 295         .num_outputs = 2,
 296 };
 297
 298 static 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 };
 305 MODULE_DEVICE_TABLE(i2c, max20086_i2c_id);
 306
 307 static 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 };
 314 MODULE_DEVICE_TABLE(of, max20086_dt_ids);
 315
 316 static 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
 326 module_i2c_driver(max20086_regulator_driver);
 327
 328 MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>");
 329 MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");
 330 MODULE_LICENSE("GPL");