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1// SPDX-License-Identifier: GPL-2.02/*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 information9 * for the two rails is reported in two subsequent I2C addresses. The driver10 * instantiates a dummy I2C client at the second I2C address to report11 * 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 current15 * reported with the standard READ_IIN command is derived from the output16 * 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/output20 * currents for VCORE. Telemetry is reported in vendor specific registers.21 * The driver translates the vendor specific register values to PMBus standard22 * 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 35enum chips { max16508, max16600, max16601, max16602 };36 37#define REG_DEFAULT_NUM_POP 0xc438#define REG_SETPT_DVID 0xd139#define DAC_10MV_MODE BIT(4)40#define REG_IOUT_AVG_PK 0xee41#define REG_IIN_SENSOR 0xf142#define REG_TOTAL_INPUT_POWER 0xf243#define REG_PHASE_ID 0xf344#define CORE_RAIL_INDICATOR BIT(7)45#define REG_PHASE_REPORTING 0xf446 47#define MAX16601_NUM_PHASES 848 49struct 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 58static 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 71static 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 151static 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 164static 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 192static 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 else204 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 phases215 * 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 224static 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 258static void max16601_remove(void *_data)259{260 struct max16601_data *data = _data;261 262 i2c_unregister_device(data->vsa);263}264 265static const struct i2c_device_id max16601_id[] = {266 {"max16508", max16508},267 {"max16600", max16600},268 {"max16601", max16601},269 {"max16602", max16602},270 {}271};272MODULE_DEVICE_TABLE(i2c, max16601_id);273 274static 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",287 * "MAX16500y.xx".cdxxcccccccccc, or "MAX16508y.xx".288 */289 if (!strncmp(buf, "MAX16500", 8) || !strncmp(buf, "MAX16508", 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 305static 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 356static struct i2c_driver max16601_driver = {357 .driver = {358 .name = "max16601",359 },360 .probe = max16601_probe,361 .id_table = max16601_id,362};363 364module_i2c_driver(max16601_driver);365 366MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");367MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601");368MODULE_LICENSE("GPL v2");369MODULE_IMPORT_NS(PMBUS);370