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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers4 *5 * Copyright (C) 2020 Nvidia Technologies Ltd.6 */7 8#include <linux/err.h>9#include <linux/i2c.h>10#include <linux/init.h>11#include <linux/kernel.h>12#include <linux/module.h>13#include "pmbus.h"14 15/* Vendor specific registers. */16#define MP2888_MFR_SYS_CONFIG 0x4417#define MP2888_MFR_READ_CS1_2 0x7318#define MP2888_MFR_READ_CS3_4 0x7419#define MP2888_MFR_READ_CS5_6 0x7520#define MP2888_MFR_READ_CS7_8 0x7621#define MP2888_MFR_READ_CS9_10 0x7722#define MP2888_MFR_VR_CONFIG1 0xe123 24#define MP2888_TOTAL_CURRENT_RESOLUTION BIT(3)25#define MP2888_PHASE_CURRENT_RESOLUTION BIT(4)26#define MP2888_DRMOS_KCS GENMASK(2, 0)27#define MP2888_TEMP_UNIT 1028#define MP2888_MAX_PHASE 1029 30struct mp2888_data {31 struct pmbus_driver_info info;32 int total_curr_resolution;33 int phase_curr_resolution;34 int curr_sense_gain;35};36 37#define to_mp2888_data(x) container_of(x, struct mp2888_data, info)38 39static int mp2888_read_byte_data(struct i2c_client *client, int page, int reg)40{41 switch (reg) {42 case PMBUS_VOUT_MODE:43 /* Enforce VOUT direct format. */44 return PB_VOUT_MODE_DIRECT;45 default:46 return -ENODATA;47 }48}49 50static int51mp2888_current_sense_gain_and_resolution_get(struct i2c_client *client, struct mp2888_data *data)52{53 int ret;54 55 /*56 * Obtain DrMOS current sense gain of power stage from the register57 * , bits 0-2. The value is selected as below:58 * 00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A. Other59 * values are reserved.60 */61 ret = i2c_smbus_read_word_data(client, MP2888_MFR_SYS_CONFIG);62 if (ret < 0)63 return ret;64 65 switch (ret & MP2888_DRMOS_KCS) {66 case 0:67 data->curr_sense_gain = 85;68 break;69 case 1:70 data->curr_sense_gain = 97;71 break;72 case 2:73 data->curr_sense_gain = 100;74 break;75 case 3:76 data->curr_sense_gain = 50;77 break;78 default:79 return -EINVAL;80 }81 82 /*83 * Obtain resolution selector for total and phase current report and protection.84 * 0: original resolution; 1: half resolution (in such case phase current value should85 * be doubled.86 */87 data->total_curr_resolution = (ret & MP2888_TOTAL_CURRENT_RESOLUTION) >> 3;88 data->phase_curr_resolution = (ret & MP2888_PHASE_CURRENT_RESOLUTION) >> 4;89 90 return 0;91}92 93static int94mp2888_read_phase(struct i2c_client *client, struct mp2888_data *data, int page, int phase, u8 reg)95{96 int ret;97 98 ret = pmbus_read_word_data(client, page, phase, reg);99 if (ret < 0)100 return ret;101 102 if (!((phase + 1) % 2))103 ret >>= 8;104 ret &= 0xff;105 106 /*107 * Output value is calculated as: (READ_CSx / 80 – 1.23) / (Kcs * Rcs)108 * where:109 * - Kcs is the DrMOS current sense gain of power stage, which is obtained from the110 * register MP2888_MFR_VR_CONFIG1, bits 13-12 with the following selection of DrMOS111 * (data->curr_sense_gain):112 * 00b - 8.5µA/A, 01b - 9.7µA/A, 1b - 10µA/A, 11b - 5µA/A.113 * - Rcs is the internal phase current sense resistor. This parameter depends on hardware114 * assembly. By default it is set to 1kΩ. In case of different assembly, user should115 * scale this parameter by dividing it by Rcs.116 * If phase current resolution bit is set to 1, READ_CSx value should be doubled.117 * Note, that current phase sensing, providing by the device is not accurate. This is118 * because sampling of current occurrence of bit weight has a big deviation, especially for119 * light load.120 */121 ret = DIV_ROUND_CLOSEST(ret * 200 - 19600, data->curr_sense_gain);122 /* Scale according to total current resolution. */123 ret = (data->total_curr_resolution) ? ret * 2 : ret;124 return ret;125}126 127static int128mp2888_read_phases(struct i2c_client *client, struct mp2888_data *data, int page, int phase)129{130 int ret;131 132 switch (phase) {133 case 0 ... 1:134 ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS1_2);135 break;136 case 2 ... 3:137 ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS3_4);138 break;139 case 4 ... 5:140 ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS5_6);141 break;142 case 6 ... 7:143 ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS7_8);144 break;145 case 8 ... 9:146 ret = mp2888_read_phase(client, data, page, phase, MP2888_MFR_READ_CS9_10);147 break;148 default:149 return -ENODATA;150 }151 return ret;152}153 154static int mp2888_read_word_data(struct i2c_client *client, int page, int phase, int reg)155{156 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);157 struct mp2888_data *data = to_mp2888_data(info);158 int ret;159 160 switch (reg) {161 case PMBUS_READ_VIN:162 ret = pmbus_read_word_data(client, page, phase, reg);163 if (ret <= 0)164 return ret;165 166 /*167 * READ_VIN requires fixup to scale it to linear11 format. Register data format168 * provides 10 bits for mantissa and 6 bits for exponent. Bits 15:10 are set with169 * the fixed value 111011b.170 */171 ret = (ret & GENMASK(9, 0)) | ((ret & GENMASK(31, 10)) << 1);172 break;173 case PMBUS_OT_WARN_LIMIT:174 ret = pmbus_read_word_data(client, page, phase, reg);175 if (ret < 0)176 return ret;177 /*178 * Chip reports limits in degrees C, but the actual temperature in 10th of179 * degrees C - scaling is needed to match both.180 */181 ret *= MP2888_TEMP_UNIT;182 break;183 case PMBUS_READ_IOUT:184 if (phase != 0xff)185 return mp2888_read_phases(client, data, page, phase);186 187 ret = pmbus_read_word_data(client, page, phase, reg);188 if (ret < 0)189 return ret;190 /*191 * READ_IOUT register has unused bits 15:12 with fixed value 1110b. Clear these192 * bits and scale with total current resolution. Data is provided in direct format.193 */194 ret &= GENMASK(11, 0);195 ret = data->total_curr_resolution ? ret * 2 : ret;196 break;197 case PMBUS_IOUT_OC_WARN_LIMIT:198 ret = pmbus_read_word_data(client, page, phase, reg);199 if (ret < 0)200 return ret;201 ret &= GENMASK(9, 0);202 /*203 * Chip reports limits with resolution 1A or 2A, if total current resolution bit is204 * set 1. Actual current is reported with 0.25A or respectively 0.5A resolution.205 * Scaling is needed to match both.206 */207 ret = data->total_curr_resolution ? ret * 8 : ret * 4;208 break;209 case PMBUS_READ_POUT:210 case PMBUS_READ_PIN:211 ret = pmbus_read_word_data(client, page, phase, reg);212 if (ret < 0)213 return ret;214 ret = data->total_curr_resolution ? ret : DIV_ROUND_CLOSEST(ret, 2);215 break;216 case PMBUS_POUT_OP_WARN_LIMIT:217 ret = pmbus_read_word_data(client, page, phase, reg);218 if (ret < 0)219 return ret;220 /*221 * Chip reports limits with resolution 1W or 2W, if total current resolution bit is222 * set 1. Actual power is reported with 0.5W or 1W respectively resolution. Scaling223 * is needed to match both.224 */225 ret = data->total_curr_resolution ? ret * 2 : ret;226 break;227 /*228 * The below registers are not implemented by device or implemented not according to the229 * spec. Skip all of them to avoid exposing non-relevant inputs to sysfs.230 */231 case PMBUS_OT_FAULT_LIMIT:232 case PMBUS_UT_WARN_LIMIT:233 case PMBUS_UT_FAULT_LIMIT:234 case PMBUS_VIN_UV_FAULT_LIMIT:235 case PMBUS_VOUT_UV_WARN_LIMIT:236 case PMBUS_VOUT_OV_WARN_LIMIT:237 case PMBUS_VOUT_UV_FAULT_LIMIT:238 case PMBUS_VOUT_OV_FAULT_LIMIT:239 case PMBUS_VIN_OV_WARN_LIMIT:240 case PMBUS_IOUT_OC_LV_FAULT_LIMIT:241 case PMBUS_IOUT_OC_FAULT_LIMIT:242 case PMBUS_POUT_MAX:243 case PMBUS_IOUT_UC_FAULT_LIMIT:244 case PMBUS_POUT_OP_FAULT_LIMIT:245 case PMBUS_PIN_OP_WARN_LIMIT:246 case PMBUS_MFR_VIN_MIN:247 case PMBUS_MFR_VOUT_MIN:248 case PMBUS_MFR_VIN_MAX:249 case PMBUS_MFR_VOUT_MAX:250 case PMBUS_MFR_IIN_MAX:251 case PMBUS_MFR_IOUT_MAX:252 case PMBUS_MFR_PIN_MAX:253 case PMBUS_MFR_POUT_MAX:254 case PMBUS_MFR_MAX_TEMP_1:255 return -ENXIO;256 default:257 return -ENODATA;258 }259 260 return ret;261}262 263static int mp2888_write_word_data(struct i2c_client *client, int page, int reg, u16 word)264{265 const struct pmbus_driver_info *info = pmbus_get_driver_info(client);266 struct mp2888_data *data = to_mp2888_data(info);267 268 switch (reg) {269 case PMBUS_OT_WARN_LIMIT:270 word = DIV_ROUND_CLOSEST(word, MP2888_TEMP_UNIT);271 /* Drop unused bits 15:8. */272 word = clamp_val(word, 0, GENMASK(7, 0));273 break;274 case PMBUS_IOUT_OC_WARN_LIMIT:275 /* Fix limit according to total curent resolution. */276 word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 8) :277 DIV_ROUND_CLOSEST(word, 4);278 /* Drop unused bits 15:10. */279 word = clamp_val(word, 0, GENMASK(9, 0));280 break;281 case PMBUS_POUT_OP_WARN_LIMIT:282 /* Fix limit according to total curent resolution. */283 word = data->total_curr_resolution ? DIV_ROUND_CLOSEST(word, 4) :284 DIV_ROUND_CLOSEST(word, 2);285 /* Drop unused bits 15:10. */286 word = clamp_val(word, 0, GENMASK(9, 0));287 break;288 default:289 return -ENODATA;290 }291 return pmbus_write_word_data(client, page, reg, word);292}293 294static int295mp2888_identify_multiphase(struct i2c_client *client, struct mp2888_data *data,296 struct pmbus_driver_info *info)297{298 int ret;299 300 ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);301 if (ret < 0)302 return ret;303 304 /* Identify multiphase number - could be from 1 to 10. */305 ret = i2c_smbus_read_word_data(client, MP2888_MFR_VR_CONFIG1);306 if (ret <= 0)307 return ret;308 309 info->phases[0] = ret & GENMASK(3, 0);310 311 /*312 * The device provides a total of 10 PWM pins, and can be configured to different phase313 * count applications for rail.314 */315 if (info->phases[0] > MP2888_MAX_PHASE)316 return -EINVAL;317 318 return 0;319}320 321static struct pmbus_driver_info mp2888_info = {322 .pages = 1,323 .format[PSC_VOLTAGE_IN] = linear,324 .format[PSC_VOLTAGE_OUT] = direct,325 .format[PSC_TEMPERATURE] = direct,326 .format[PSC_CURRENT_IN] = linear,327 .format[PSC_CURRENT_OUT] = direct,328 .format[PSC_POWER] = direct,329 .m[PSC_TEMPERATURE] = 1,330 .R[PSC_TEMPERATURE] = 1,331 .m[PSC_VOLTAGE_OUT] = 1,332 .R[PSC_VOLTAGE_OUT] = 3,333 .m[PSC_CURRENT_OUT] = 4,334 .m[PSC_POWER] = 1,335 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_IOUT |336 PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP |337 PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT |338 PMBUS_PHASE_VIRTUAL,339 .pfunc[0] = PMBUS_HAVE_IOUT,340 .pfunc[1] = PMBUS_HAVE_IOUT,341 .pfunc[2] = PMBUS_HAVE_IOUT,342 .pfunc[3] = PMBUS_HAVE_IOUT,343 .pfunc[4] = PMBUS_HAVE_IOUT,344 .pfunc[5] = PMBUS_HAVE_IOUT,345 .pfunc[6] = PMBUS_HAVE_IOUT,346 .pfunc[7] = PMBUS_HAVE_IOUT,347 .pfunc[8] = PMBUS_HAVE_IOUT,348 .pfunc[9] = PMBUS_HAVE_IOUT,349 .read_byte_data = mp2888_read_byte_data,350 .read_word_data = mp2888_read_word_data,351 .write_word_data = mp2888_write_word_data,352};353 354static int mp2888_probe(struct i2c_client *client)355{356 struct pmbus_driver_info *info;357 struct mp2888_data *data;358 int ret;359 360 data = devm_kzalloc(&client->dev, sizeof(struct mp2888_data), GFP_KERNEL);361 if (!data)362 return -ENOMEM;363 364 memcpy(&data->info, &mp2888_info, sizeof(*info));365 info = &data->info;366 367 /* Identify multiphase configuration. */368 ret = mp2888_identify_multiphase(client, data, info);369 if (ret)370 return ret;371 372 /* Obtain current sense gain of power stage and current resolution. */373 ret = mp2888_current_sense_gain_and_resolution_get(client, data);374 if (ret)375 return ret;376 377 return pmbus_do_probe(client, info);378}379 380static const struct i2c_device_id mp2888_id[] = {381 {"mp2888"},382 {}383};384 385MODULE_DEVICE_TABLE(i2c, mp2888_id);386 387static const struct of_device_id __maybe_unused mp2888_of_match[] = {388 {.compatible = "mps,mp2888"},389 {}390};391MODULE_DEVICE_TABLE(of, mp2888_of_match);392 393static struct i2c_driver mp2888_driver = {394 .driver = {395 .name = "mp2888",396 .of_match_table = of_match_ptr(mp2888_of_match),397 },398 .probe = mp2888_probe,399 .id_table = mp2888_id,400};401 402module_i2c_driver(mp2888_driver);403 404MODULE_AUTHOR("Vadim Pasternak <vadimp@nvidia.com>");405MODULE_DESCRIPTION("PMBus driver for MPS MP2888 device");406MODULE_LICENSE("GPL");407MODULE_IMPORT_NS(PMBUS);408