diff options
Diffstat (limited to 'drivers/hwmon/pmbus/mp2888.c')
| -rw-r--r-- | drivers/hwmon/pmbus/mp2888.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/hwmon/pmbus/mp2888.c b/drivers/hwmon/pmbus/mp2888.c new file mode 100644 index 000000000..24e519470 --- /dev/null +++ b/drivers/hwmon/pmbus/mp2888.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers + * + * Copyright (C) 2020 Nvidia Technologies Ltd. + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include "pmbus.h" + +/* Vendor specific registers. */ +#define MP2888_MFR_SYS_CONFIG 0x44 +#define MP2888_MFR_READ_CS1_2 0x73 +#define MP2888_MFR_READ_CS3_4 0x74 +#define MP2888_MFR_READ_CS5_6 0x75 +#define MP2888_MFR_READ_CS7_8 0x76 +#define MP2888_MFR_READ_CS9_10 0x77 +#define MP2888_MFR_VR_CONFIG1 0xe1 + +#define MP2888_TOTAL_CURRENT_RESOLUTION BIT(3) +#define MP2888_PHASE_CURRENT_RESOLUTION BIT(4) +#define MP2888_DRMOS_KCS GENMASK(2, 0) +#define MP2888_TEMP_UNIT 10 +#define MP2888_MAX_PHASE 10 + +struct mp2888_data { + struct pmbus_driver_info info; + int total_curr_resolution; + int phase_curr_resolution; + int curr_sense_gain; +}; + +#define to_mp2888_data(x) container_of(x, struct mp2888_data, info) + +static int mp2888_read_byte_data(struct i2c_client *client, int page, int reg) +{ + switch (reg) { + case PMBUS_VOUT_MODE: + /* Enforce VOUT direct format. */ + return PB_VOUT_MODE_DIRECT; + default: + return -ENODATA; + } +} + +static int +mp2888_current_sense_gain_and_resolution_get(struct i2c_client *client, struct mp2888_data *data) +{ + int ret; + + /* + * Obtain DrMOS current sense gain of power stage from the register + * , bits 0-2. The value is selected as below: + * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other + * values are reserved. + */ + ret = i2c_smbus_read_word_data(client, MP2888_MFR_SYS_CONFIG); + if (ret < 0) + return ret; + + switch (ret & MP2888_DRMOS_KCS) { + case 0: + data->curr_sense_gain = 85; + break; + case 1: + data->curr_sense_gain = 97; + break; + case 2: + data->curr_sense_gain = 100; + break; + case 3: + data->curr_sense_gain = 50; + break; + default: + return -EINVAL; + } + + /* + * Obtain resolution selector for total and phase current report and protection. + * 0: original resolution; 1: half resolution (in such case phase current value should + * be doubled. + */ + data->total_curr_resolution = (ret & MP2888_TOTAL_CURRENT_RESOLUTION) >> 3; + data->phase_curr_resolution = (ret & MP2888_PHASE_CURRENT_RESOLUTION) >> 4; + + return 0; +} + +static int +mp2888_read_phase(struct i2c_client *client, struct mp2888_data *data, int page, int phase, u8 reg) +{ + int ret; + + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + + if (!((phase + 1) % 2)) + ret >>= 8; + ret &= 0xff; + + /* + * Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs) + * where: + * - Kcs is the DrMOS current sense gain of power stage, which is obtained from the + * register MP2888_MFR_VR_CONFIG1, bits 13-12 with the following selection of DrMOS + * (data->curr_sense_gain): + * 00b - 8.5µA/A, 01b - 9.7µA/A, 1b - 10µA/A, 11b - 5µA/A. + * - Rcs is the internal phase current sense resistor. This parameter depends on hardware + * assembly. By default it is set to 1kΩ. In case of different assembly, user should + * scale this parameter by dividing it by Rcs. + * If phase current resolution bit is set to 1, READ_CSx value should be doubled. + * Note, that current phase sensing, providing by the device is not accurate. This is + * because sampling of current occurrence of bit weight has a big deviation, especially for + * light load. + */ + ret = DIV_ROUND_CLOSEST(ret * 200 - 19600, data->curr_sense_gain); + /* Scale according to total current resolution. */ + ret = (data->total_curr_resolution) ? ret * 2 : ret; + return ret; +} + +static int +mp2888_read_phases(struct i2c_client *client, struct mp2888_data *data, int page, int phase) +{ + int ret; + + switch (phase) { + case 0 ... 1: + ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS1_2); + break; + case 2 ... 3: + ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS3_4); + break; + case 4 ... 5: + ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS5_6); + break; + case 6 ... 7: + ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS7_8); + break; + case 8 ... 9: + ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS9_10); + break; + default: + return -ENODATA; + } + return ret; +} + +static int mp2888_read_word_data(struct i2c_client *client, int page, int phase, int reg) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct mp2888_data *data = to_mp2888_data(info); + int ret; + + switch (reg) { + case PMBUS_READ_VIN: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret <= 0) + return ret; + + /* + * READ_VIN requires fixup to scale it to linear11 format. Register data format + * provides 10 bits for mantissa and 6 bits for exponent. Bits 15:10 are set with + * the fixed value 111011b. + */ + ret = (ret & GENMASK(9, 0)) | ((ret & GENMASK(31, 10)) << 1); + break; + case PMBUS_OT_WARN_LIMIT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + /* + * Chip reports limits in degrees C, but the actual temperature in 10th of + * degrees C - scaling is needed to match both. + */ + ret *= MP2888_TEMP_UNIT; + break; + case PMBUS_READ_IOUT: + if (phase != 0xff) + return mp2888_read_phases(client, data, page, phase); + + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + /* + * READ_IOUT register has unused bits 15:12 with fixed value 1110b. Clear these + * bits and scale with total current resolution. Data is provided in direct format. + */ + ret &= GENMASK(11, 0); + ret = data->total_curr_resolution ? ret * 2 : ret; + break; + case PMBUS_IOUT_OC_WARN_LIMIT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + ret &= GENMASK(9, 0); + /* + * Chip reports limits with resolution 1A or 2A, if total current resolution bit is + * set 1. Actual current is reported with 0.25A or respectively 0.5A resolution. + * Scaling is needed to match both. + */ + ret = data->total_curr_resolution ? ret * 8 : ret * 4; + break; + case PMBUS_READ_POUT: + case PMBUS_READ_PIN: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + ret = data->total_curr_resolution ? ret : DIV_ROUND_CLOSEST(ret, 2); + break; + case PMBUS_POUT_OP_WARN_LIMIT: + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret < 0) + return ret; + /* + * Chip reports limits with resolution 1W or 2W, if total current resolution bit is + * set 1. Actual power is reported with 0.5W or 1W respectively resolution. Scaling + * is needed to match both. + */ + ret = data->total_curr_resolution ? ret * 2 : ret; + break; + /* + * The below registers are not implemented by device or implemented not according to the + * spec. Skip all of them to avoid exposing non-relevant inputs to sysfs. + */ + case PMBUS_OT_FAULT_LIMIT: + case PMBUS_UT_WARN_LIMIT: + case PMBUS_UT_FAULT_LIMIT: + case PMBUS_VIN_UV_FAULT_LIMIT: + case PMBUS_VOUT_UV_WARN_LIMIT: + case PMBUS_VOUT_OV_WARN_LIMIT: + case PMBUS_VOUT_UV_FAULT_LIMIT: + case PMBUS_VOUT_OV_FAULT_LIMIT: + case PMBUS_VIN_OV_WARN_LIMIT: + case PMBUS_IOUT_OC_LV_FAULT_LIMIT: + case PMBUS_IOUT_OC_FAULT_LIMIT: + case PMBUS_POUT_MAX: + case PMBUS_IOUT_UC_FAULT_LIMIT: + case PMBUS_POUT_OP_FAULT_LIMIT: + case PMBUS_PIN_OP_WARN_LIMIT: + case PMBUS_MFR_VIN_MIN: + case PMBUS_MFR_VOUT_MIN: + case PMBUS_MFR_VIN_MAX: + case PMBUS_MFR_VOUT_MAX: + case PMBUS_MFR_IIN_MAX: + case PMBUS_MFR_IOUT_MAX: + case PMBUS_MFR_PIN_MAX: + case PMBUS_MFR_POUT_MAX: + case PMBUS_MFR_MAX_TEMP_1: + return -ENXIO; + default: + return -ENODATA; + } + + return ret; +} + +static int mp2888_write_word_data(struct i2c_client *client, int page, int reg, u16 word) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + struct mp2888_data *data = to_mp2888_data(info); + + switch (reg) { + case PMBUS_OT_WARN_LIMIT: + word = DIV_ROUND_CLOSEST(word, MP2888_TEMP_UNIT); + /* Drop unused bits 15:8. */ + word = clamp_val(word, 0, GENMASK(7, 0)); + break; + case PMBUS_IOUT_OC_WARN_LIMIT: + /* Fix limit according to total curent resolution. */ + word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 8) : + DIV_ROUND_CLOSEST(word, 4); + /* Drop unused bits 15:10. */ + word = clamp_val(word, 0, GENMASK(9, 0)); + break; + case PMBUS_POUT_OP_WARN_LIMIT: + /* Fix limit according to total curent resolution. */ + word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 4) : + DIV_ROUND_CLOSEST(word, 2); + /* Drop unused bits 15:10. */ + word = clamp_val(word, 0, GENMASK(9, 0)); + break; + default: + return -ENODATA; + } + return pmbus_write_word_data(client, page, reg, word); +} + +static int +mp2888_identify_multiphase(struct i2c_client *client, struct mp2888_data *data, + struct pmbus_driver_info *info) +{ + int ret; + + ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0); + if (ret < 0) + return ret; + + /* Identify multiphase number - could be from 1 to 10. */ + ret = i2c_smbus_read_word_data(client, MP2888_MFR_VR_CONFIG1); + if (ret <= 0) + return ret; + + info->phases[0] = ret & GENMASK(3, 0); + + /* + * The device provides a total of 10 PWM pins, and can be configured to different phase + * count applications for rail. + */ + if (info->phases[0] > MP2888_MAX_PHASE) + return -EINVAL; + + return 0; +} + +static struct pmbus_driver_info mp2888_info = { + .pages = 1, + .format[PSC_VOLTAGE_IN] = linear, + .format[PSC_VOLTAGE_OUT] = direct, + .format[PSC_TEMPERATURE] = direct, + .format[PSC_CURRENT_IN] = linear, + .format[PSC_CURRENT_OUT] = direct, + .format[PSC_POWER] = direct, + .m[PSC_TEMPERATURE] = 1, + .R[PSC_TEMPERATURE] = 1, + .m[PSC_VOLTAGE_OUT] = 1, + .R[PSC_VOLTAGE_OUT] = 3, + .m[PSC_CURRENT_OUT] = 4, + .m[PSC_POWER] = 1, + .func[0] = PMBUS_HAVE_VIN | 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_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | + PMBUS_PHASE_VIRTUAL, + .pfunc[0] = PMBUS_HAVE_IOUT, + .pfunc[1] = PMBUS_HAVE_IOUT, + .pfunc[2] = PMBUS_HAVE_IOUT, + .pfunc[3] = PMBUS_HAVE_IOUT, + .pfunc[4] = PMBUS_HAVE_IOUT, + .pfunc[5] = PMBUS_HAVE_IOUT, + .pfunc[6] = PMBUS_HAVE_IOUT, + .pfunc[7] = PMBUS_HAVE_IOUT, + .pfunc[8] = PMBUS_HAVE_IOUT, + .pfunc[9] = PMBUS_HAVE_IOUT, + .read_byte_data = mp2888_read_byte_data, + .read_word_data = mp2888_read_word_data, + .write_word_data = mp2888_write_word_data, +}; + +static int mp2888_probe(struct i2c_client *client) +{ + struct pmbus_driver_info *info; + struct mp2888_data *data; + int ret; + + data = devm_kzalloc(&client->dev, sizeof(struct mp2888_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + memcpy(&data->info, &mp2888_info, sizeof(*info)); + info = &data->info; + + /* Identify multiphase configuration. */ + ret = mp2888_identify_multiphase(client, data, info); + if (ret) + return ret; + + /* Obtain current sense gain of power stage and current resolution. */ + ret = mp2888_current_sense_gain_and_resolution_get(client, data); + if (ret) + return ret; + + return pmbus_do_probe(client, info); +} + +static const struct i2c_device_id mp2888_id[] = { + {"mp2888", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, mp2888_id); + +static const struct of_device_id __maybe_unused mp2888_of_match[] = { + {.compatible = "mps,mp2888"}, + {} +}; +MODULE_DEVICE_TABLE(of, mp2888_of_match); + +static struct i2c_driver mp2888_driver = { + .driver = { + .name = "mp2888", + .of_match_table = of_match_ptr(mp2888_of_match), + }, + .probe_new = mp2888_probe, + .id_table = mp2888_id, +}; + +module_i2c_driver(mp2888_driver); + +MODULE_AUTHOR("Vadim Pasternak <vadimp@nvidia.com>"); +MODULE_DESCRIPTION("PMBus driver for MPS MP2888 device"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(PMBUS); |