1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Hardware monitoring driver for Maxim MAX16508, MAX16600, MAX16601, 4 * and MAX16602. 5 * 6 * Implementation notes: 7 * 8 * This chip series supports two rails, VCORE and VSA. Telemetry information 9 * for the two rails is reported in two subsequent I2C addresses. The driver 10 * instantiates a dummy I2C client at the second I2C address to report 11 * information for the VSA rail in a single instance of the driver. 12 * Telemetry for the VSA rail is reported to the PMBus core in PMBus page 2. 13 * 14 * The chip reports input current using two separate methods. The input current 15 * reported with the standard READ_IIN command is derived from the output 16 * current. The first method is reported to the PMBus core with PMBus page 0, 17 * the second method is reported with PMBus page 1. 18 * 19 * The chip supports reading per-phase temperatures and per-phase input/output 20 * currents for VCORE. Telemetry is reported in vendor specific registers. 21 * The driver translates the vendor specific register values to PMBus standard 22 * register values and reports per-phase information in PMBus page 0. 23 * 24 * Copyright 2019, 2020 Google LLC. 25 */ 26 27 #include <linux/bits.h> 28 #include <linux/i2c.h> 29 #include <linux/init.h> 30 #include <linux/kernel.h> 31 #include <linux/module.h> 32 33 #include "pmbus.h" 34 35 enum chips { max16508, max16600, max16601, max16602 }; 36 37 #define REG_DEFAULT_NUM_POP 0xc4 38 #define REG_SETPT_DVID 0xd1 39 #define DAC_10MV_MODE BIT(4) 40 #define REG_IOUT_AVG_PK 0xee 41 #define REG_IIN_SENSOR 0xf1 42 #define REG_TOTAL_INPUT_POWER 0xf2 43 #define REG_PHASE_ID 0xf3 44 #define CORE_RAIL_INDICATOR BIT(7) 45 #define REG_PHASE_REPORTING 0xf4 46 47 #define MAX16601_NUM_PHASES 8 48 49 struct max16601_data { 50 enum chips id; 51 struct pmbus_driver_info info; 52 struct i2c_client *vsa; 53 int iout_avg_pkg; 54 }; 55 56 #define to_max16601_data(x) container_of(x, struct max16601_data, info) 57 58 static int max16601_read_byte(struct i2c_client *client, int page, int reg) 59 { 60 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 61 struct max16601_data *data = to_max16601_data(info); 62 63 if (page > 0) { 64 if (page == 2) /* VSA */ 65 return i2c_smbus_read_byte_data(data->vsa, reg); 66 return -EOPNOTSUPP; 67 } 68 return -ENODATA; 69 } 70 71 static int max16601_read_word(struct i2c_client *client, int page, int phase, 72 int reg) 73 { 74 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 75 struct max16601_data *data = to_max16601_data(info); 76 u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; 77 int ret; 78 79 switch (page) { 80 case 0: /* VCORE */ 81 if (phase == 0xff) 82 return -ENODATA; 83 switch (reg) { 84 case PMBUS_READ_IIN: 85 case PMBUS_READ_IOUT: 86 case PMBUS_READ_TEMPERATURE_1: 87 ret = i2c_smbus_write_byte_data(client, REG_PHASE_ID, 88 phase); 89 if (ret) 90 return ret; 91 ret = i2c_smbus_read_block_data(client, 92 REG_PHASE_REPORTING, 93 buf); 94 if (ret < 0) 95 return ret; 96 if (ret < 6) 97 return -EIO; 98 switch (reg) { 99 case PMBUS_READ_TEMPERATURE_1: 100 return buf[1] << 8 | buf[0]; 101 case PMBUS_READ_IOUT: 102 return buf[3] << 8 | buf[2]; 103 case PMBUS_READ_IIN: 104 return buf[5] << 8 | buf[4]; 105 default: 106 break; 107 } 108 } 109 return -EOPNOTSUPP; 110 case 1: /* VCORE, read IIN/PIN from sensor element */ 111 switch (reg) { 112 case PMBUS_READ_IIN: 113 return i2c_smbus_read_word_data(client, REG_IIN_SENSOR); 114 case PMBUS_READ_PIN: 115 return i2c_smbus_read_word_data(client, 116 REG_TOTAL_INPUT_POWER); 117 default: 118 break; 119 } 120 return -EOPNOTSUPP; 121 case 2: /* VSA */ 122 switch (reg) { 123 case PMBUS_VIRT_READ_IOUT_MAX: 124 ret = i2c_smbus_read_word_data(data->vsa, 125 REG_IOUT_AVG_PK); 126 if (ret < 0) 127 return ret; 128 if (sign_extend32(ret, 10) > 129 sign_extend32(data->iout_avg_pkg, 10)) 130 data->iout_avg_pkg = ret; 131 return data->iout_avg_pkg; 132 case PMBUS_VIRT_RESET_IOUT_HISTORY: 133 return 0; 134 case PMBUS_IOUT_OC_FAULT_LIMIT: 135 case PMBUS_IOUT_OC_WARN_LIMIT: 136 case PMBUS_OT_FAULT_LIMIT: 137 case PMBUS_OT_WARN_LIMIT: 138 case PMBUS_READ_IIN: 139 case PMBUS_READ_IOUT: 140 case PMBUS_READ_TEMPERATURE_1: 141 case PMBUS_STATUS_WORD: 142 return i2c_smbus_read_word_data(data->vsa, reg); 143 default: 144 return -EOPNOTSUPP; 145 } 146 default: 147 return -EOPNOTSUPP; 148 } 149 } 150 151 static int max16601_write_byte(struct i2c_client *client, int page, u8 reg) 152 { 153 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 154 struct max16601_data *data = to_max16601_data(info); 155 156 if (page == 2) { 157 if (reg == PMBUS_CLEAR_FAULTS) 158 return i2c_smbus_write_byte(data->vsa, reg); 159 return -EOPNOTSUPP; 160 } 161 return -ENODATA; 162 } 163 164 static int max16601_write_word(struct i2c_client *client, int page, int reg, 165 u16 value) 166 { 167 const struct pmbus_driver_info *info = pmbus_get_driver_info(client); 168 struct max16601_data *data = to_max16601_data(info); 169 170 switch (page) { 171 case 0: /* VCORE */ 172 return -ENODATA; 173 case 1: /* VCORE IIN/PIN from sensor element */ 174 default: 175 return -EOPNOTSUPP; 176 case 2: /* VSA */ 177 switch (reg) { 178 case PMBUS_VIRT_RESET_IOUT_HISTORY: 179 data->iout_avg_pkg = 0xfc00; 180 return 0; 181 case PMBUS_IOUT_OC_FAULT_LIMIT: 182 case PMBUS_IOUT_OC_WARN_LIMIT: 183 case PMBUS_OT_FAULT_LIMIT: 184 case PMBUS_OT_WARN_LIMIT: 185 return i2c_smbus_write_word_data(data->vsa, reg, value); 186 default: 187 return -EOPNOTSUPP; 188 } 189 } 190 } 191 192 static int max16601_identify(struct i2c_client *client, 193 struct pmbus_driver_info *info) 194 { 195 struct max16601_data *data = to_max16601_data(info); 196 int reg; 197 198 reg = i2c_smbus_read_byte_data(client, REG_SETPT_DVID); 199 if (reg < 0) 200 return reg; 201 if (reg & DAC_10MV_MODE) 202 info->vrm_version[0] = vr13; 203 else 204 info->vrm_version[0] = vr12; 205 206 if (data->id != max16600 && data->id != max16601 && data->id != max16602) 207 return 0; 208 209 reg = i2c_smbus_read_byte_data(client, REG_DEFAULT_NUM_POP); 210 if (reg < 0) 211 return reg; 212 213 /* 214 * If REG_DEFAULT_NUM_POP returns 0, we don't know how many phases 215 * are populated. Stick with the default in that case. 216 */ 217 reg &= 0x0f; 218 if (reg && reg <= MAX16601_NUM_PHASES) 219 info->phases[0] = reg; 220 221 return 0; 222 } 223 224 static struct pmbus_driver_info max16601_info = { 225 .pages = 3, 226 .format[PSC_VOLTAGE_IN] = linear, 227 .format[PSC_VOLTAGE_OUT] = vid, 228 .format[PSC_CURRENT_IN] = linear, 229 .format[PSC_CURRENT_OUT] = linear, 230 .format[PSC_TEMPERATURE] = linear, 231 .format[PSC_POWER] = linear, 232 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | 233 PMBUS_HAVE_STATUS_INPUT | 234 PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | 235 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | 236 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | 237 PMBUS_HAVE_POUT | PMBUS_PAGE_VIRTUAL | PMBUS_PHASE_VIRTUAL, 238 .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_PAGE_VIRTUAL, 239 .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT | 240 PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | 241 PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_PAGE_VIRTUAL, 242 .phases[0] = MAX16601_NUM_PHASES, 243 .pfunc[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, 244 .pfunc[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, 245 .pfunc[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, 246 .pfunc[3] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, 247 .pfunc[4] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, 248 .pfunc[5] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, 249 .pfunc[6] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, 250 .pfunc[7] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, 251 .identify = max16601_identify, 252 .read_byte_data = max16601_read_byte, 253 .read_word_data = max16601_read_word, 254 .write_byte = max16601_write_byte, 255 .write_word_data = max16601_write_word, 256 }; 257 258 static void max16601_remove(void *_data) 259 { 260 struct max16601_data *data = _data; 261 262 i2c_unregister_device(data->vsa); 263 } 264 265 static const struct i2c_device_id max16601_id[] = { 266 {"max16508", max16508}, 267 {"max16600", max16600}, 268 {"max16601", max16601}, 269 {"max16602", max16602}, 270 {} 271 }; 272 MODULE_DEVICE_TABLE(i2c, max16601_id); 273 274 static int max16601_get_id(struct i2c_client *client) 275 { 276 struct device *dev = &client->dev; 277 u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; 278 enum chips id; 279 int ret; 280 281 ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf); 282 if (ret < 0 || ret < 11) 283 return -ENODEV; 284 285 /* 286 * PMBUS_IC_DEVICE_ID is expected to return MAX1660[012]y.xx" or 287 * "MAX16500y.xx".cdxxcccccccccc 288 */ 289 if (!strncmp(buf, "MAX16500", 8)) { 290 id = max16508; 291 } else if (!strncmp(buf, "MAX16600", 8)) { 292 id = max16600; 293 } else if (!strncmp(buf, "MAX16601", 8)) { 294 id = max16601; 295 } else if (!strncmp(buf, "MAX16602", 8)) { 296 id = max16602; 297 } else { 298 buf[ret] = '\0'; 299 dev_err(dev, "Unsupported chip '%s'\n", buf); 300 return -ENODEV; 301 } 302 return id; 303 } 304 305 static int max16601_probe(struct i2c_client *client) 306 { 307 struct device *dev = &client->dev; 308 const struct i2c_device_id *id; 309 struct max16601_data *data; 310 int ret, chip_id; 311 312 if (!i2c_check_functionality(client->adapter, 313 I2C_FUNC_SMBUS_READ_BYTE_DATA | 314 I2C_FUNC_SMBUS_READ_BLOCK_DATA)) 315 return -ENODEV; 316 317 chip_id = max16601_get_id(client); 318 if (chip_id < 0) 319 return chip_id; 320 321 id = i2c_match_id(max16601_id, client); 322 if (chip_id != id->driver_data) 323 dev_warn(&client->dev, 324 "Device mismatch: Configured %s (%d), detected %d\n", 325 id->name, (int) id->driver_data, chip_id); 326 327 ret = i2c_smbus_read_byte_data(client, REG_PHASE_ID); 328 if (ret < 0) 329 return ret; 330 if (!(ret & CORE_RAIL_INDICATOR)) { 331 dev_err(dev, 332 "Driver must be instantiated on CORE rail I2C address\n"); 333 return -ENODEV; 334 } 335 336 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); 337 if (!data) 338 return -ENOMEM; 339 340 data->id = chip_id; 341 data->iout_avg_pkg = 0xfc00; 342 data->vsa = i2c_new_dummy_device(client->adapter, client->addr + 1); 343 if (IS_ERR(data->vsa)) { 344 dev_err(dev, "Failed to register VSA client\n"); 345 return PTR_ERR(data->vsa); 346 } 347 ret = devm_add_action_or_reset(dev, max16601_remove, data); 348 if (ret) 349 return ret; 350 351 data->info = max16601_info; 352 353 return pmbus_do_probe(client, &data->info); 354 } 355 356 static struct i2c_driver max16601_driver = { 357 .driver = { 358 .name = "max16601", 359 }, 360 .probe_new = max16601_probe, 361 .id_table = max16601_id, 362 }; 363 364 module_i2c_driver(max16601_driver); 365 366 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>"); 367 MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601"); 368 MODULE_LICENSE("GPL v2"); 369 MODULE_IMPORT_NS(PMBUS); 370