drivers/regulator/max20086-regulator.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 //
0003 // max20086-regulator.c - MAX20086-MAX20089 camera power protector driver
0004 //
0005 // Copyright (C) 2022 Laurent Pinchart <laurent.pinchart@idesonboard.com>
0006 // Copyright (C) 2018 Avnet, Inc.
0007
0008 #include <linux/err.h>
0009 #include <linux/gpio.h>
0010 #include <linux/gpio/consumer.h>
0011 #include <linux/i2c.h>
0012 #include <linux/module.h>
0013 #include <linux/regmap.h>
0014 #include <linux/regulator/driver.h>
0015 #include <linux/regulator/machine.h>
0016 #include <linux/regulator/of_regulator.h>
0017 #include <linux/slab.h>
0018
0019 /* Register Offset */
0020 #define MAX20086_REG_MASK       0x00
0021 #define MAX20086_REG_CONFIG     0x01
0022 #define MAX20086_REG_ID         0x02
0023 #define MAX20086_REG_STAT1      0x03
0024 #define MAX20086_REG_STAT2_L        0x04
0025 #define MAX20086_REG_STAT2_H        0x05
0026 #define MAX20086_REG_ADC1       0x06
0027 #define MAX20086_REG_ADC2       0x07
0028 #define MAX20086_REG_ADC3       0x08
0029 #define MAX20086_REG_ADC4       0x09
0030
0031 /* DEVICE IDs */
0032 #define MAX20086_DEVICE_ID_MAX20086 0x40
0033 #define MAX20086_DEVICE_ID_MAX20087 0x20
0034 #define MAX20086_DEVICE_ID_MAX20088 0x10
0035 #define MAX20086_DEVICE_ID_MAX20089 0x00
0036 #define DEVICE_ID_MASK          0xf0
0037
0038 /* Register bits */
0039 #define MAX20086_EN_MASK        0x0f
0040 #define MAX20086_EN_OUT1        0x01
0041 #define MAX20086_EN_OUT2        0x02
0042 #define MAX20086_EN_OUT3        0x04
0043 #define MAX20086_EN_OUT4        0x08
0044 #define MAX20086_INT_DISABLE_ALL    0x3f
0045
0046 #define MAX20086_MAX_REGULATORS     4
0047
0048 struct max20086_chip_info {
0049     u8 id;
0050     unsigned int num_outputs;
0051 };
0052
0053 struct max20086_regulator {
0054     struct device_node *of_node;
0055     struct regulator_init_data *init_data;
0056     const struct regulator_desc *desc;
0057     struct regulator_dev *rdev;
0058 };
0059
0060 struct max20086 {
0061     struct device *dev;
0062     struct regmap *regmap;
0063     struct gpio_desc *ena_gpiod;
0064
0065     const struct max20086_chip_info *info;
0066
0067     struct max20086_regulator regulators[MAX20086_MAX_REGULATORS];
0068 };
0069
0070 static const struct regulator_ops max20086_buck_ops = {
0071     .enable = regulator_enable_regmap,
0072     .disable = regulator_disable_regmap,
0073     .is_enabled = regulator_is_enabled_regmap,
0074 };
0075
0076 #define MAX20086_REGULATOR_DESC(n)      \
0077 {                       \
0078     .name = "OUT"#n,            \
0079     .supply_name = "in",            \
0080     .id = (n) - 1,              \
0081     .ops = &max20086_buck_ops,      \
0082     .type = REGULATOR_VOLTAGE,      \
0083     .owner = THIS_MODULE,           \
0084     .enable_reg = MAX20086_REG_CONFIG,  \
0085     .enable_mask = 1 << ((n) - 1),      \
0086     .enable_val = 1 << ((n) - 1),       \
0087     .disable_val = 0,           \
0088 }
0089
0090 static const char * const max20086_output_names[] = {
0091     "OUT1",
0092     "OUT2",
0093     "OUT3",
0094     "OUT4",
0095 };
0096
0097 static const struct regulator_desc max20086_regulators[] = {
0098     MAX20086_REGULATOR_DESC(1),
0099     MAX20086_REGULATOR_DESC(2),
0100     MAX20086_REGULATOR_DESC(3),
0101     MAX20086_REGULATOR_DESC(4),
0102 };
0103
0104 static int max20086_regulators_register(struct max20086 *chip)
0105 {
0106     unsigned int i;
0107
0108     for (i = 0; i < chip->info->num_outputs; i++) {
0109         struct max20086_regulator *reg = &chip->regulators[i];
0110         struct regulator_config config = { };
0111         struct regulator_dev *rdev;
0112
0113         config.dev = chip->dev;
0114         config.init_data = reg->init_data;
0115         config.driver_data = chip;
0116         config.of_node = reg->of_node;
0117         config.regmap = chip->regmap;
0118         config.ena_gpiod = chip->ena_gpiod;
0119
0120         rdev = devm_regulator_register(chip->dev, reg->desc, &config);
0121         if (IS_ERR(rdev)) {
0122             dev_err(chip->dev,
0123                 "Failed to register regulator output %s\n",
0124                 reg->desc->name);
0125             return PTR_ERR(rdev);
0126         }
0127
0128         reg->rdev = rdev;
0129     }
0130
0131     return 0;
0132 }
0133
0134 static int max20086_parse_regulators_dt(struct max20086 *chip, bool *boot_on)
0135 {
0136     struct of_regulator_match matches[MAX20086_MAX_REGULATORS] = { };
0137     struct device_node *node;
0138     unsigned int i;
0139     int ret;
0140
0141     node = of_get_child_by_name(chip->dev->of_node, "regulators");
0142     if (!node) {
0143         dev_err(chip->dev, "regulators node not found\n");
0144         return -ENODEV;
0145     }
0146
0147     for (i = 0; i < chip->info->num_outputs; ++i)
0148         matches[i].name = max20086_output_names[i];
0149
0150     ret = of_regulator_match(chip->dev, node, matches,
0151                  chip->info->num_outputs);
0152     of_node_put(node);
0153     if (ret < 0) {
0154         dev_err(chip->dev, "Failed to match regulators\n");
0155         return -EINVAL;
0156     }
0157
0158     *boot_on = false;
0159
0160     for (i = 0; i < chip->info->num_outputs; i++) {
0161         struct max20086_regulator *reg = &chip->regulators[i];
0162
0163         reg->init_data = matches[i].init_data;
0164         reg->of_node = matches[i].of_node;
0165         reg->desc = &max20086_regulators[i];
0166
0167         if (reg->init_data) {
0168             if (reg->init_data->constraints.always_on ||
0169                 reg->init_data->constraints.boot_on)
0170                 *boot_on = true;
0171         }
0172     }
0173
0174     return 0;
0175 }
0176
0177 static int max20086_detect(struct max20086 *chip)
0178 {
0179     unsigned int data;
0180     int ret;
0181
0182     ret = regmap_read(chip->regmap, MAX20086_REG_ID, &data);
0183     if (ret < 0) {
0184         dev_err(chip->dev, "Failed to read DEVICE_ID reg: %d\n", ret);
0185         return ret;
0186     }
0187
0188     if ((data & DEVICE_ID_MASK) != chip->info->id) {
0189         dev_err(chip->dev, "Invalid device ID 0x%02x\n", data);
0190         return -ENXIO;
0191     }
0192
0193     return 0;
0194 }
0195
0196 static bool max20086_gen_is_writeable_reg(struct device *dev, unsigned int reg)
0197 {
0198     switch (reg) {
0199     case MAX20086_REG_MASK:
0200     case MAX20086_REG_CONFIG:
0201         return true;
0202     default:
0203         return false;
0204     }
0205 }
0206
0207 static const struct regmap_config max20086_regmap_config = {
0208     .reg_bits = 8,
0209     .val_bits = 8,
0210     .writeable_reg = max20086_gen_is_writeable_reg,
0211     .max_register = 0x9,
0212     .cache_type = REGCACHE_NONE,
0213 };
0214
0215 static int max20086_i2c_probe(struct i2c_client *i2c)
0216 {
0217     struct max20086 *chip;
0218     enum gpiod_flags flags;
0219     bool boot_on;
0220     int ret;
0221
0222     chip = devm_kzalloc(&i2c->dev, sizeof(*chip), GFP_KERNEL);
0223     if (!chip)
0224         return -ENOMEM;
0225
0226     chip->dev = &i2c->dev;
0227     chip->info = device_get_match_data(chip->dev);
0228
0229     i2c_set_clientdata(i2c, chip);
0230
0231     chip->regmap = devm_regmap_init_i2c(i2c, &max20086_regmap_config);
0232     if (IS_ERR(chip->regmap)) {
0233         ret = PTR_ERR(chip->regmap);
0234         dev_err(chip->dev, "Failed to allocate register map: %d\n", ret);
0235         return ret;
0236     }
0237
0238     ret = max20086_parse_regulators_dt(chip, &boot_on);
0239     if (ret < 0)
0240         return ret;
0241
0242     ret = max20086_detect(chip);
0243     if (ret < 0)
0244         return ret;
0245
0246     /* Until IRQ support is added, just disable all interrupts. */
0247     ret = regmap_update_bits(chip->regmap, MAX20086_REG_MASK,
0248                  MAX20086_INT_DISABLE_ALL,
0249                  MAX20086_INT_DISABLE_ALL);
0250     if (ret < 0) {
0251         dev_err(chip->dev, "Failed to disable interrupts: %d\n", ret);
0252         return ret;
0253     }
0254
0255     /*
0256      * Get the enable GPIO. If any of the outputs is marked as being
0257      * enabled at boot, request the GPIO with an initial high state to
0258      * avoid disabling outputs that may have been turned on by the boot
0259      * loader. Otherwise, request it with a low state to enter lower-power
0260      * shutdown.
0261      */
0262     flags = boot_on ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
0263     chip->ena_gpiod = devm_gpiod_get(chip->dev, "enable", flags);
0264     if (IS_ERR(chip->ena_gpiod)) {
0265         ret = PTR_ERR(chip->ena_gpiod);
0266         dev_err(chip->dev, "Failed to get enable GPIO: %d\n", ret);
0267         return ret;
0268     }
0269
0270     ret = max20086_regulators_register(chip);
0271     if (ret < 0) {
0272         dev_err(chip->dev, "Failed to register regulators: %d\n", ret);
0273         return ret;
0274     }
0275
0276     return 0;
0277 }
0278
0279 static const struct i2c_device_id max20086_i2c_id[] = {
0280     { "max20086" },
0281     { "max20087" },
0282     { "max20088" },
0283     { "max20089" },
0284     { /* Sentinel */ },
0285 };
0286
0287 MODULE_DEVICE_TABLE(i2c, max20086_i2c_id);
0288
0289 static const struct of_device_id max20086_dt_ids[] = {
0290     {
0291         .compatible = "maxim,max20086",
0292         .data = &(const struct max20086_chip_info) {
0293             .id = MAX20086_DEVICE_ID_MAX20086,
0294             .num_outputs = 4,
0295         }
0296     }, {
0297         .compatible = "maxim,max20087",
0298         .data = &(const struct max20086_chip_info) {
0299             .id = MAX20086_DEVICE_ID_MAX20087,
0300             .num_outputs = 4,
0301         }
0302     }, {
0303         .compatible = "maxim,max20088",
0304         .data = &(const struct max20086_chip_info) {
0305             .id = MAX20086_DEVICE_ID_MAX20088,
0306             .num_outputs = 2,
0307         }
0308     }, {
0309         .compatible = "maxim,max20089",
0310         .data = &(const struct max20086_chip_info) {
0311             .id = MAX20086_DEVICE_ID_MAX20089,
0312             .num_outputs = 2,
0313         }
0314     },
0315     { /* Sentinel */ },
0316 };
0317
0318 MODULE_DEVICE_TABLE(of, max20086_dt_ids);
0319
0320 static struct i2c_driver max20086_regulator_driver = {
0321     .driver = {
0322         .name = "max20086",
0323         .of_match_table = of_match_ptr(max20086_dt_ids),
0324     },
0325     .probe_new = max20086_i2c_probe,
0326     .id_table = max20086_i2c_id,
0327 };
0328
0329 module_i2c_driver(max20086_regulator_driver);
0330
0331 MODULE_AUTHOR("Watson Chow <watson.chow@avnet.com>");
0332 MODULE_DESCRIPTION("MAX20086-MAX20089 Camera Power Protector Driver");
0333 MODULE_LICENSE("GPL");