// SPDX-License-Identifier: GPL-2.0 /* * Hardware monitoring driver for Maxim MAX16601 * * Implementation notes: * * Ths chip supports two rails, VCORE and VSA. Telemetry information for the * two rails is reported in two subsequent I2C addresses. The driver * instantiates a dummy I2C client at the second I2C address to report * information for the VSA rail in a single instance of the driver. * Telemetry for the VSA rail is reported to the PMBus core in PMBus page 2. * * The chip reports input current using two separate methods. The input current * reported with the standard READ_IIN command is derived from the output * current. The first method is reported to the PMBus core with PMBus page 0, * the second method is reported with PMBus page 1. * * The chip supports reading per-phase temperatures and per-phase input/output * currents for VCORE. Telemetry is reported in vendor specific registers. * The driver translates the vendor specific register values to PMBus standard * register values and reports per-phase information in PMBus page 0. * * Copyright 2019, 2020 Google LLC. */ #include #include #include #include #include #include "pmbus.h" #define REG_SETPT_DVID 0xd1 #define DAC_10MV_MODE BIT(4) #define REG_IOUT_AVG_PK 0xee #define REG_IIN_SENSOR 0xf1 #define REG_TOTAL_INPUT_POWER 0xf2 #define REG_PHASE_ID 0xf3 #define CORE_RAIL_INDICATOR BIT(7) #define REG_PHASE_REPORTING 0xf4 struct max16601_data { struct pmbus_driver_info info; struct i2c_client *vsa; int iout_avg_pkg; }; #define to_max16601_data(x) container_of(x, struct max16601_data, info) static int max16601_read_byte(struct i2c_client *client, int page, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max16601_data *data = to_max16601_data(info); if (page > 0) { if (page == 2) /* VSA */ return i2c_smbus_read_byte_data(data->vsa, reg); return -EOPNOTSUPP; } return -ENODATA; } static int max16601_read_word(struct i2c_client *client, int page, int phase, int reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max16601_data *data = to_max16601_data(info); u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; int ret; switch (page) { case 0: /* VCORE */ if (phase == 0xff) return -ENODATA; switch (reg) { case PMBUS_READ_IIN: case PMBUS_READ_IOUT: case PMBUS_READ_TEMPERATURE_1: ret = i2c_smbus_write_byte_data(client, REG_PHASE_ID, phase); if (ret) return ret; ret = i2c_smbus_read_block_data(client, REG_PHASE_REPORTING, buf); if (ret < 0) return ret; if (ret < 6) return -EIO; switch (reg) { case PMBUS_READ_TEMPERATURE_1: return buf[1] << 8 | buf[0]; case PMBUS_READ_IOUT: return buf[3] << 8 | buf[2]; case PMBUS_READ_IIN: return buf[5] << 8 | buf[4]; default: break; } } return -EOPNOTSUPP; case 1: /* VCORE, read IIN/PIN from sensor element */ switch (reg) { case PMBUS_READ_IIN: return i2c_smbus_read_word_data(client, REG_IIN_SENSOR); case PMBUS_READ_PIN: return i2c_smbus_read_word_data(client, REG_TOTAL_INPUT_POWER); default: break; } return -EOPNOTSUPP; case 2: /* VSA */ switch (reg) { case PMBUS_VIRT_READ_IOUT_MAX: ret = i2c_smbus_read_word_data(data->vsa, REG_IOUT_AVG_PK); if (ret < 0) return ret; if (sign_extend32(ret, 10) > sign_extend32(data->iout_avg_pkg, 10)) data->iout_avg_pkg = ret; return data->iout_avg_pkg; case PMBUS_VIRT_RESET_IOUT_HISTORY: return 0; case PMBUS_IOUT_OC_FAULT_LIMIT: case PMBUS_IOUT_OC_WARN_LIMIT: case PMBUS_OT_FAULT_LIMIT: case PMBUS_OT_WARN_LIMIT: case PMBUS_READ_IIN: case PMBUS_READ_IOUT: case PMBUS_READ_TEMPERATURE_1: case PMBUS_STATUS_WORD: return i2c_smbus_read_word_data(data->vsa, reg); default: return -EOPNOTSUPP; } default: return -EOPNOTSUPP; } } static int max16601_write_byte(struct i2c_client *client, int page, u8 reg) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max16601_data *data = to_max16601_data(info); if (page == 2) { if (reg == PMBUS_CLEAR_FAULTS) return i2c_smbus_write_byte(data->vsa, reg); return -EOPNOTSUPP; } return -ENODATA; } static int max16601_write_word(struct i2c_client *client, int page, int reg, u16 value) { const struct pmbus_driver_info *info = pmbus_get_driver_info(client); struct max16601_data *data = to_max16601_data(info); switch (page) { case 0: /* VCORE */ return -ENODATA; case 1: /* VCORE IIN/PIN from sensor element */ default: return -EOPNOTSUPP; case 2: /* VSA */ switch (reg) { case PMBUS_VIRT_RESET_IOUT_HISTORY: data->iout_avg_pkg = 0xfc00; return 0; case PMBUS_IOUT_OC_FAULT_LIMIT: case PMBUS_IOUT_OC_WARN_LIMIT: case PMBUS_OT_FAULT_LIMIT: case PMBUS_OT_WARN_LIMIT: return i2c_smbus_write_word_data(data->vsa, reg, value); default: return -EOPNOTSUPP; } } } static int max16601_identify(struct i2c_client *client, struct pmbus_driver_info *info) { int reg; reg = i2c_smbus_read_byte_data(client, REG_SETPT_DVID); if (reg < 0) return reg; if (reg & DAC_10MV_MODE) info->vrm_version[0] = vr13; else info->vrm_version[0] = vr12; return 0; } static struct pmbus_driver_info max16601_info = { .pages = 3, .format[PSC_VOLTAGE_IN] = linear, .format[PSC_VOLTAGE_OUT] = vid, .format[PSC_CURRENT_IN] = linear, .format[PSC_CURRENT_OUT] = linear, .format[PSC_TEMPERATURE] = linear, .format[PSC_POWER] = linear, .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT | PMBUS_PAGE_VIRTUAL | PMBUS_PHASE_VIRTUAL, .func[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_PIN | PMBUS_PAGE_VIRTUAL, .func[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_PAGE_VIRTUAL, .phases[0] = 8, .pfunc[0] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, .pfunc[1] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, .pfunc[2] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, .pfunc[3] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, .pfunc[4] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, .pfunc[5] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, .pfunc[6] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP, .pfunc[7] = PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT, .identify = max16601_identify, .read_byte_data = max16601_read_byte, .read_word_data = max16601_read_word, .write_byte = max16601_write_byte, .write_word_data = max16601_write_word, }; static void max16601_remove(void *_data) { struct max16601_data *data = _data; i2c_unregister_device(data->vsa); } static int max16601_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct device *dev = &client->dev; u8 buf[I2C_SMBUS_BLOCK_MAX + 1]; struct max16601_data *data; int ret; if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_READ_BLOCK_DATA)) return -ENODEV; ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf); if (ret < 0) return -ENODEV; /* PMBUS_IC_DEVICE_ID is expected to return "MAX16601y.xx" */ if (ret < 11 || strncmp(buf, "MAX16601", 8)) { buf[ret] = '\0'; dev_err(dev, "Unsupported chip '%s'\n", buf); return -ENODEV; } ret = i2c_smbus_read_byte_data(client, REG_PHASE_ID); if (ret < 0) return ret; if (!(ret & CORE_RAIL_INDICATOR)) { dev_err(dev, "Driver must be instantiated on CORE rail I2C address\n"); return -ENODEV; } data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; data->iout_avg_pkg = 0xfc00; data->vsa = i2c_new_dummy_device(client->adapter, client->addr + 1); if (IS_ERR(data->vsa)) { dev_err(dev, "Failed to register VSA client\n"); return PTR_ERR(data->vsa); } ret = devm_add_action_or_reset(dev, max16601_remove, data); if (ret) return ret; data->info = max16601_info; return pmbus_do_probe(client, id, &data->info); } static const struct i2c_device_id max16601_id[] = { {"max16601", 0}, {} }; MODULE_DEVICE_TABLE(i2c, max16601_id); static struct i2c_driver max16601_driver = { .driver = { .name = "max16601", }, .probe = max16601_probe, .remove = pmbus_do_remove, .id_table = max16601_id, }; module_i2c_driver(max16601_driver); MODULE_AUTHOR("Guenter Roeck "); MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601"); MODULE_LICENSE("GPL v2");