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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 | // SPDX-License-Identifier: GPL-2.0-or-later /* * Voltage and current regulation for AD5398 and AD5821 * * Copyright 2010 Analog Devices Inc. * * Enter bugs at http://blackfin.uclinux.org/ */ #include <linux/module.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/slab.h> #include <linux/platform_device.h> #include <linux/regulator/driver.h> #include <linux/regulator/machine.h> #define AD5398_CURRENT_EN_MASK 0x8000 struct ad5398_chip_info { struct i2c_client *client; int min_uA; int max_uA; unsigned int current_level; unsigned int current_mask; unsigned int current_offset; struct regulator_dev *rdev; }; static int ad5398_calc_current(struct ad5398_chip_info *chip, unsigned selector) { unsigned range_uA = chip->max_uA - chip->min_uA; return chip->min_uA + (selector * range_uA / chip->current_level); } static int ad5398_read_reg(struct i2c_client *client, unsigned short *data) { unsigned short val; int ret; ret = i2c_master_recv(client, (char *)&val, 2); if (ret < 0) { dev_err(&client->dev, "I2C read error\n"); return ret; } *data = be16_to_cpu(val); return ret; } static int ad5398_write_reg(struct i2c_client *client, const unsigned short data) { unsigned short val; int ret; val = cpu_to_be16(data); ret = i2c_master_send(client, (char *)&val, 2); if (ret != 2) { dev_err(&client->dev, "I2C write error\n"); return ret < 0 ? ret : -EIO; } return 0; } static int ad5398_get_current_limit(struct regulator_dev *rdev) { struct ad5398_chip_info *chip = rdev_get_drvdata(rdev); struct i2c_client *client = chip->client; unsigned short data; int ret; ret = ad5398_read_reg(client, &data); if (ret < 0) return ret; ret = (data & chip->current_mask) >> chip->current_offset; return ad5398_calc_current(chip, ret); } static int ad5398_set_current_limit(struct regulator_dev *rdev, int min_uA, int max_uA) { struct ad5398_chip_info *chip = rdev_get_drvdata(rdev); struct i2c_client *client = chip->client; unsigned range_uA = chip->max_uA - chip->min_uA; unsigned selector; unsigned short data; int ret; if (min_uA < chip->min_uA) min_uA = chip->min_uA; if (max_uA > chip->max_uA) max_uA = chip->max_uA; if (min_uA > chip->max_uA || max_uA < chip->min_uA) return -EINVAL; selector = DIV_ROUND_UP((min_uA - chip->min_uA) * chip->current_level, range_uA); if (ad5398_calc_current(chip, selector) > max_uA) return -EINVAL; dev_dbg(&client->dev, "changing current %duA\n", ad5398_calc_current(chip, selector)); /* read chip enable bit */ ret = ad5398_read_reg(client, &data); if (ret < 0) return ret; /* prepare register data */ selector = (selector << chip->current_offset) & chip->current_mask; data = (unsigned short)selector | (data & AD5398_CURRENT_EN_MASK); /* write the new current value back as well as enable bit */ ret = ad5398_write_reg(client, data); return ret; } static int ad5398_is_enabled(struct regulator_dev *rdev) { struct ad5398_chip_info *chip = rdev_get_drvdata(rdev); struct i2c_client *client = chip->client; unsigned short data; int ret; ret = ad5398_read_reg(client, &data); if (ret < 0) return ret; if (data & AD5398_CURRENT_EN_MASK) return 1; else return 0; } static int ad5398_enable(struct regulator_dev *rdev) { struct ad5398_chip_info *chip = rdev_get_drvdata(rdev); struct i2c_client *client = chip->client; unsigned short data; int ret; ret = ad5398_read_reg(client, &data); if (ret < 0) return ret; if (data & AD5398_CURRENT_EN_MASK) return 0; data |= AD5398_CURRENT_EN_MASK; ret = ad5398_write_reg(client, data); return ret; } static int ad5398_disable(struct regulator_dev *rdev) { struct ad5398_chip_info *chip = rdev_get_drvdata(rdev); struct i2c_client *client = chip->client; unsigned short data; int ret; ret = ad5398_read_reg(client, &data); if (ret < 0) return ret; if (!(data & AD5398_CURRENT_EN_MASK)) return 0; data &= ~AD5398_CURRENT_EN_MASK; ret = ad5398_write_reg(client, data); return ret; } static const struct regulator_ops ad5398_ops = { .get_current_limit = ad5398_get_current_limit, .set_current_limit = ad5398_set_current_limit, .enable = ad5398_enable, .disable = ad5398_disable, .is_enabled = ad5398_is_enabled, }; static const struct regulator_desc ad5398_reg = { .name = "isink", .id = 0, .ops = &ad5398_ops, .type = REGULATOR_CURRENT, .owner = THIS_MODULE, }; struct ad5398_current_data_format { int current_bits; int current_offset; int min_uA; int max_uA; }; static const struct ad5398_current_data_format df_10_4_120 = {10, 4, 0, 120000}; static const struct i2c_device_id ad5398_id[] = { { "ad5398", (kernel_ulong_t)&df_10_4_120 }, { "ad5821", (kernel_ulong_t)&df_10_4_120 }, { } }; MODULE_DEVICE_TABLE(i2c, ad5398_id); static int ad5398_probe(struct i2c_client *client) { const struct i2c_device_id *id = i2c_client_get_device_id(client); struct regulator_init_data *init_data = dev_get_platdata(&client->dev); struct regulator_config config = { }; struct ad5398_chip_info *chip; const struct ad5398_current_data_format *df = (struct ad5398_current_data_format *)id->driver_data; if (!init_data) return -EINVAL; chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; config.dev = &client->dev; config.init_data = init_data; config.driver_data = chip; chip->client = client; chip->min_uA = df->min_uA; chip->max_uA = df->max_uA; chip->current_level = 1 << df->current_bits; chip->current_offset = df->current_offset; chip->current_mask = (chip->current_level - 1) << chip->current_offset; chip->rdev = devm_regulator_register(&client->dev, &ad5398_reg, &config); if (IS_ERR(chip->rdev)) { dev_err(&client->dev, "failed to register %s %s\n", id->name, ad5398_reg.name); return PTR_ERR(chip->rdev); } i2c_set_clientdata(client, chip); dev_dbg(&client->dev, "%s regulator driver is registered.\n", id->name); return 0; } static struct i2c_driver ad5398_driver = { .probe = ad5398_probe, .driver = { .name = "ad5398", .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .id_table = ad5398_id, }; static int __init ad5398_init(void) { return i2c_add_driver(&ad5398_driver); } subsys_initcall(ad5398_init); static void __exit ad5398_exit(void) { i2c_del_driver(&ad5398_driver); } module_exit(ad5398_exit); MODULE_DESCRIPTION("AD5398 and AD5821 current regulator driver"); MODULE_AUTHOR("Sonic Zhang"); MODULE_LICENSE("GPL"); |