| // 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 <linux/bits.h> |
| #include <linux/i2c.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| |
| #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 <linux@roeck-us.net>"); |
| MODULE_DESCRIPTION("PMBus driver for Maxim MAX16601"); |
| MODULE_LICENSE("GPL v2"); |