drivers/hwmon/tmp513.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for Texas Instruments TMP512, TMP513 power monitor chips
   4  *
   5  * TMP513:
   6  * Thermal/Power Management with Triple Remote and
   7  * Local Temperature Sensor and Current Shunt Monitor
   8  * Datasheet: https://www.ti.com/lit/gpn/tmp513
   9  *
  10  * TMP512:
  11  * Thermal/Power Management with Dual Remote
  12  *      and Local Temperature Sensor and Current Shunt Monitor
  13  * Datasheet: https://www.ti.com/lit/gpn/tmp512
  14  *
  15  * Copyright (C) 2019 Eric Tremblay <etremblay@distech-controls.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; version 2 of the License.
  20  */
  21
  22 #include <linux/bitops.h>
  23 #include <linux/bug.h>
  24 #include <linux/device.h>
  25 #include <linux/err.h>
  26 #include <linux/hwmon.h>
  27 #include <linux/i2c.h>
  28 #include <linux/init.h>
  29 #include <linux/math.h>
  30 #include <linux/module.h>
  31 #include <linux/property.h>
  32 #include <linux/regmap.h>
  33 #include <linux/slab.h>
  34 #include <linux/types.h>
  35 #include <linux/units.h>
  36
  37 // Common register definition
  38 #define TMP51X_SHUNT_CONFIG             0x00
  39 #define TMP51X_TEMP_CONFIG              0x01
  40 #define TMP51X_STATUS                   0x02
  41 #define TMP51X_SMBUS_ALERT              0x03
  42 #define TMP51X_SHUNT_CURRENT_RESULT     0x04
  43 #define TMP51X_BUS_VOLTAGE_RESULT       0x05
  44 #define TMP51X_POWER_RESULT             0x06
  45 #define TMP51X_BUS_CURRENT_RESULT       0x07
  46 #define TMP51X_LOCAL_TEMP_RESULT        0x08
  47 #define TMP51X_REMOTE_TEMP_RESULT_1     0x09
  48 #define TMP51X_REMOTE_TEMP_RESULT_2     0x0A
  49 #define TMP51X_SHUNT_CURRENT_H_LIMIT    0x0C
  50 #define TMP51X_SHUNT_CURRENT_L_LIMIT    0x0D
  51 #define TMP51X_BUS_VOLTAGE_H_LIMIT      0x0E
  52 #define TMP51X_BUS_VOLTAGE_L_LIMIT      0x0F
  53 #define TMP51X_POWER_LIMIT              0x10
  54 #define TMP51X_LOCAL_TEMP_LIMIT 0x11
  55 #define TMP51X_REMOTE_TEMP_LIMIT_1      0x12
  56 #define TMP51X_REMOTE_TEMP_LIMIT_2      0x13
  57 #define TMP51X_SHUNT_CALIBRATION        0x15
  58 #define TMP51X_N_FACTOR_AND_HYST_1      0x16
  59 #define TMP51X_N_FACTOR_2               0x17
  60 #define TMP51X_MAN_ID_REG               0xFE
  61 #define TMP51X_DEVICE_ID_REG            0xFF
  62
  63 // TMP513 specific register definition
  64 #define TMP513_REMOTE_TEMP_RESULT_3     0x0B
  65 #define TMP513_REMOTE_TEMP_LIMIT_3      0x14
  66 #define TMP513_N_FACTOR_3               0x18
  67
  68 // Common attrs, and NULL
  69 #define TMP51X_MANUFACTURER_ID          0x55FF
  70
  71 #define TMP512_DEVICE_ID                0x22FF
  72 #define TMP513_DEVICE_ID                0x23FF
  73
  74 // Default config
  75 #define TMP51X_SHUNT_CONFIG_DEFAULT     0x399F
  76 #define TMP51X_SHUNT_VALUE_DEFAULT      1000
  77 #define TMP51X_VBUS_RANGE_DEFAULT       TMP51X_VBUS_RANGE_32V
  78 #define TMP51X_PGA_DEFAULT              8
  79 #define TMP51X_MAX_REGISTER_ADDR        0xFF
  80
  81 // Mask and shift
  82 #define CURRENT_SENSE_VOLTAGE_320_MASK  0x1800
  83 #define CURRENT_SENSE_VOLTAGE_160_MASK  0x1000
  84 #define CURRENT_SENSE_VOLTAGE_80_MASK   0x0800
  85 #define CURRENT_SENSE_VOLTAGE_40_MASK   0
  86
  87 #define TMP51X_BUS_VOLTAGE_MASK         0x2000
  88 #define TMP51X_NFACTOR_MASK             0xFF00
  89 #define TMP51X_HYST_MASK                0x00FF
  90
  91 #define TMP51X_BUS_VOLTAGE_SHIFT        3
  92 #define TMP51X_TEMP_SHIFT               3
  93
  94 // Alarms
  95 #define TMP51X_SHUNT_CURRENT_H_LIMIT_POS        15
  96 #define TMP51X_SHUNT_CURRENT_L_LIMIT_POS        14
  97 #define TMP51X_BUS_VOLTAGE_H_LIMIT_POS          13
  98 #define TMP51X_BUS_VOLTAGE_L_LIMIT_POS          12
  99 #define TMP51X_POWER_LIMIT_POS                  11
 100 #define TMP51X_LOCAL_TEMP_LIMIT_POS             10
 101 #define TMP51X_REMOTE_TEMP_LIMIT_1_POS          9
 102 #define TMP51X_REMOTE_TEMP_LIMIT_2_POS          8
 103 #define TMP513_REMOTE_TEMP_LIMIT_3_POS          7
 104
 105 #define TMP51X_VBUS_RANGE_32V           (32 * MICRO)
 106 #define TMP51X_VBUS_RANGE_16V           (16 * MICRO)
 107
 108 // Max and Min value
 109 #define MAX_BUS_VOLTAGE_32_LIMIT        32764
 110 #define MAX_BUS_VOLTAGE_16_LIMIT        16382
 111
 112 // Max possible value is -256 to +256 but datasheet indicated -40 to 125.
 113 #define MAX_TEMP_LIMIT                  125000
 114 #define MIN_TEMP_LIMIT                  -40000
 115
 116 #define MAX_TEMP_HYST                   127500
 117
 118 #define TMP512_MAX_CHANNELS             3
 119 #define TMP513_MAX_CHANNELS             4
 120
 121 #define TMP51X_TEMP_CONFIG_CONV_RATE    GENMASK(9, 7)
 122 #define TMP51X_TEMP_CONFIG_RC           BIT(10)
 123 #define TMP51X_TEMP_CHANNEL_MASK(n)     (GENMASK((n) - 1, 0) << 11)
 124 #define TMP51X_TEMP_CONFIG_CONT         BIT(15)
 125 #define TMP51X_TEMP_CONFIG_DEFAULT(n)                                   \
 126         (TMP51X_TEMP_CHANNEL_MASK(n) | TMP51X_TEMP_CONFIG_CONT |        \
 127          TMP51X_TEMP_CONFIG_CONV_RATE | TMP51X_TEMP_CONFIG_RC)
 128
 129 static const u8 TMP51X_TEMP_INPUT[4] = {
 130         TMP51X_LOCAL_TEMP_RESULT,
 131         TMP51X_REMOTE_TEMP_RESULT_1,
 132         TMP51X_REMOTE_TEMP_RESULT_2,
 133         TMP513_REMOTE_TEMP_RESULT_3
 134 };
 135
 136 static const u8 TMP51X_TEMP_CRIT[4] = {
 137         TMP51X_LOCAL_TEMP_LIMIT,
 138         TMP51X_REMOTE_TEMP_LIMIT_1,
 139         TMP51X_REMOTE_TEMP_LIMIT_2,
 140         TMP513_REMOTE_TEMP_LIMIT_3
 141 };
 142
 143 static const u8 TMP51X_TEMP_CRIT_ALARM[4] = {
 144         TMP51X_LOCAL_TEMP_LIMIT_POS,
 145         TMP51X_REMOTE_TEMP_LIMIT_1_POS,
 146         TMP51X_REMOTE_TEMP_LIMIT_2_POS,
 147         TMP513_REMOTE_TEMP_LIMIT_3_POS
 148 };
 149
 150 static const u8 TMP51X_TEMP_CRIT_HYST[4] = {
 151         TMP51X_N_FACTOR_AND_HYST_1,
 152         TMP51X_N_FACTOR_AND_HYST_1,
 153         TMP51X_N_FACTOR_AND_HYST_1,
 154         TMP51X_N_FACTOR_AND_HYST_1
 155 };
 156
 157 static const u8 TMP51X_CURR_INPUT[2] = {
 158         TMP51X_SHUNT_CURRENT_RESULT,
 159         TMP51X_BUS_CURRENT_RESULT
 160 };
 161
 162 static struct regmap_config tmp51x_regmap_config = {
 163         .reg_bits = 8,
 164         .val_bits = 16,
 165         .max_register = TMP51X_MAX_REGISTER_ADDR,
 166 };
 167
 168 struct tmp51x_data {
 169         u16 shunt_config;
 170         u16 pga_gain;
 171         u32 vbus_range_uvolt;
 172
 173         u16 temp_config;
 174         u32 nfactor[3];
 175
 176         u32 shunt_uohms;
 177
 178         u32 curr_lsb_ua;
 179         u32 pwr_lsb_uw;
 180
 181         u8 max_channels;
 182         struct regmap *regmap;
 183 };
 184
 185 // Set the shift based on the gain 8=4, 4=3, 2=2, 1=1
 186 static inline u8 tmp51x_get_pga_shift(struct tmp51x_data *data)
 187 {
 188         return 5 - ffs(data->pga_gain);
 189 }
 190
 191 static int tmp51x_get_value(struct tmp51x_data *data, u8 reg, u8 pos,
 192                             unsigned int regval, long *val)
 193 {
 194         switch (reg) {
 195         case TMP51X_STATUS:
 196                 *val = (regval >> pos) & 1;
 197                 break;
 198         case TMP51X_SHUNT_CURRENT_RESULT:
 199         case TMP51X_SHUNT_CURRENT_H_LIMIT:
 200         case TMP51X_SHUNT_CURRENT_L_LIMIT:
 201                 /*
 202                  * The valus is read in voltage in the chip but reported as
 203                  * current to the user.
 204                  * 2's complement number shifted by one to four depending
 205                  * on the pga gain setting. 1lsb = 10uV
 206                  */
 207                 *val = sign_extend32(regval, 17 - tmp51x_get_pga_shift(data));
 208                 *val = DIV_ROUND_CLOSEST(*val * 10 * MILLI, data->shunt_uohms);
 209                 break;
 210         case TMP51X_BUS_VOLTAGE_RESULT:
 211         case TMP51X_BUS_VOLTAGE_H_LIMIT:
 212         case TMP51X_BUS_VOLTAGE_L_LIMIT:
 213                 // 1lsb = 4mV
 214                 *val = (regval >> TMP51X_BUS_VOLTAGE_SHIFT) * 4;
 215                 break;
 216         case TMP51X_POWER_RESULT:
 217         case TMP51X_POWER_LIMIT:
 218                 // Power = (current * BusVoltage) / 5000
 219                 *val = regval * data->pwr_lsb_uw;
 220                 break;
 221         case TMP51X_BUS_CURRENT_RESULT:
 222                 // Current = (ShuntVoltage * CalibrationRegister) / 4096
 223                 *val = sign_extend32(regval, 16) * data->curr_lsb_ua;
 224                 *val = DIV_ROUND_CLOSEST(*val, MILLI);
 225                 break;
 226         case TMP51X_LOCAL_TEMP_RESULT:
 227         case TMP51X_REMOTE_TEMP_RESULT_1:
 228         case TMP51X_REMOTE_TEMP_RESULT_2:
 229         case TMP513_REMOTE_TEMP_RESULT_3:
 230         case TMP51X_LOCAL_TEMP_LIMIT:
 231         case TMP51X_REMOTE_TEMP_LIMIT_1:
 232         case TMP51X_REMOTE_TEMP_LIMIT_2:
 233         case TMP513_REMOTE_TEMP_LIMIT_3:
 234                 // 1lsb = 0.0625 degrees centigrade
 235                 *val = sign_extend32(regval, 16) >> TMP51X_TEMP_SHIFT;
 236                 *val = DIV_ROUND_CLOSEST(*val * 625, 10);
 237                 break;
 238         case TMP51X_N_FACTOR_AND_HYST_1:
 239                 // 1lsb = 0.5 degrees centigrade
 240                 *val = (regval & TMP51X_HYST_MASK) * 500;
 241                 break;
 242         default:
 243                 // Programmer goofed
 244                 WARN_ON_ONCE(1);
 245                 *val = 0;
 246                 return -EOPNOTSUPP;
 247         }
 248
 249         return 0;
 250 }
 251
 252 static int tmp51x_set_value(struct tmp51x_data *data, u8 reg, long val)
 253 {
 254         int regval, max_val;
 255         u32 mask = 0;
 256
 257         switch (reg) {
 258         case TMP51X_SHUNT_CURRENT_H_LIMIT:
 259         case TMP51X_SHUNT_CURRENT_L_LIMIT:
 260                 /*
 261                  * The user enter current value and we convert it to
 262                  * voltage. 1lsb = 10uV
 263                  */
 264                 val = DIV_ROUND_CLOSEST(val * data->shunt_uohms, 10 * MILLI);
 265                 max_val = U16_MAX >> tmp51x_get_pga_shift(data);
 266                 regval = clamp_val(val, -max_val, max_val);
 267                 break;
 268         case TMP51X_BUS_VOLTAGE_H_LIMIT:
 269         case TMP51X_BUS_VOLTAGE_L_LIMIT:
 270                 // 1lsb = 4mV
 271                 max_val = (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) ?
 272                         MAX_BUS_VOLTAGE_32_LIMIT : MAX_BUS_VOLTAGE_16_LIMIT;
 273
 274                 val = clamp_val(DIV_ROUND_CLOSEST(val, 4), 0, max_val);
 275                 regval = val << TMP51X_BUS_VOLTAGE_SHIFT;
 276                 break;
 277         case TMP51X_POWER_LIMIT:
 278                 regval = clamp_val(DIV_ROUND_CLOSEST(val, data->pwr_lsb_uw), 0,
 279                                    U16_MAX);
 280                 break;
 281         case TMP51X_LOCAL_TEMP_LIMIT:
 282         case TMP51X_REMOTE_TEMP_LIMIT_1:
 283         case TMP51X_REMOTE_TEMP_LIMIT_2:
 284         case TMP513_REMOTE_TEMP_LIMIT_3:
 285                 // 1lsb = 0.0625 degrees centigrade
 286                 val = clamp_val(val, MIN_TEMP_LIMIT, MAX_TEMP_LIMIT);
 287                 regval = DIV_ROUND_CLOSEST(val * 10, 625) << TMP51X_TEMP_SHIFT;
 288                 break;
 289         case TMP51X_N_FACTOR_AND_HYST_1:
 290                 // 1lsb = 0.5 degrees centigrade
 291                 val = clamp_val(val, 0, MAX_TEMP_HYST);
 292                 regval = DIV_ROUND_CLOSEST(val, 500);
 293                 mask = TMP51X_HYST_MASK;
 294                 break;
 295         default:
 296                 // Programmer goofed
 297                 WARN_ON_ONCE(1);
 298                 return -EOPNOTSUPP;
 299         }
 300
 301         if (mask == 0)
 302                 return regmap_write(data->regmap, reg, regval);
 303         else
 304                 return regmap_update_bits(data->regmap, reg, mask, regval);
 305 }
 306
 307 static u8 tmp51x_get_reg(enum hwmon_sensor_types type, u32 attr, int channel)
 308 {
 309         switch (type) {
 310         case hwmon_temp:
 311                 switch (attr) {
 312                 case hwmon_temp_input:
 313                         return TMP51X_TEMP_INPUT[channel];
 314                 case hwmon_temp_crit_alarm:
 315                         return TMP51X_STATUS;
 316                 case hwmon_temp_crit:
 317                         return TMP51X_TEMP_CRIT[channel];
 318                 case hwmon_temp_crit_hyst:
 319                         return TMP51X_TEMP_CRIT_HYST[channel];
 320                 }
 321                 break;
 322         case hwmon_in:
 323                 switch (attr) {
 324                 case hwmon_in_input:
 325                         return TMP51X_BUS_VOLTAGE_RESULT;
 326                 case hwmon_in_lcrit_alarm:
 327                 case hwmon_in_crit_alarm:
 328                         return TMP51X_STATUS;
 329                 case hwmon_in_lcrit:
 330                         return TMP51X_BUS_VOLTAGE_L_LIMIT;
 331                 case hwmon_in_crit:
 332                         return TMP51X_BUS_VOLTAGE_H_LIMIT;
 333                 }
 334                 break;
 335         case hwmon_curr:
 336                 switch (attr) {
 337                 case hwmon_curr_input:
 338                         return TMP51X_CURR_INPUT[channel];
 339                 case hwmon_curr_lcrit_alarm:
 340                 case hwmon_curr_crit_alarm:
 341                         return TMP51X_STATUS;
 342                 case hwmon_curr_lcrit:
 343                         return TMP51X_SHUNT_CURRENT_L_LIMIT;
 344                 case hwmon_curr_crit:
 345                         return TMP51X_SHUNT_CURRENT_H_LIMIT;
 346                 }
 347                 break;
 348         case hwmon_power:
 349                 switch (attr) {
 350                 case hwmon_power_input:
 351                         return TMP51X_POWER_RESULT;
 352                 case hwmon_power_crit_alarm:
 353                         return TMP51X_STATUS;
 354                 case hwmon_power_crit:
 355                         return TMP51X_POWER_LIMIT;
 356                 }
 357                 break;
 358         default:
 359                 break;
 360         }
 361
 362         return 0;
 363 }
 364
 365 static u8 tmp51x_get_status_pos(enum hwmon_sensor_types type, u32 attr,
 366                                 int channel)
 367 {
 368         switch (type) {
 369         case hwmon_temp:
 370                 switch (attr) {
 371                 case hwmon_temp_crit_alarm:
 372                         return TMP51X_TEMP_CRIT_ALARM[channel];
 373                 }
 374                 break;
 375         case hwmon_in:
 376                 switch (attr) {
 377                 case hwmon_in_lcrit_alarm:
 378                         return TMP51X_BUS_VOLTAGE_L_LIMIT_POS;
 379                 case hwmon_in_crit_alarm:
 380                         return TMP51X_BUS_VOLTAGE_H_LIMIT_POS;
 381                 }
 382                 break;
 383         case hwmon_curr:
 384                 switch (attr) {
 385                 case hwmon_curr_lcrit_alarm:
 386                         return TMP51X_SHUNT_CURRENT_L_LIMIT_POS;
 387                 case hwmon_curr_crit_alarm:
 388                         return TMP51X_SHUNT_CURRENT_H_LIMIT_POS;
 389                 }
 390                 break;
 391         case hwmon_power:
 392                 switch (attr) {
 393                 case hwmon_power_crit_alarm:
 394                         return TMP51X_POWER_LIMIT_POS;
 395                 }
 396                 break;
 397         default:
 398                 break;
 399         }
 400
 401         return 0;
 402 }
 403
 404 static int tmp51x_read(struct device *dev, enum hwmon_sensor_types type,
 405                        u32 attr, int channel, long *val)
 406 {
 407         struct tmp51x_data *data = dev_get_drvdata(dev);
 408         int ret;
 409         u32 regval;
 410         u8 pos = 0, reg = 0;
 411
 412         reg = tmp51x_get_reg(type, attr, channel);
 413         if (reg == 0)
 414                 return -EOPNOTSUPP;
 415
 416         if (reg == TMP51X_STATUS)
 417                 pos = tmp51x_get_status_pos(type, attr, channel);
 418
 419         ret = regmap_read(data->regmap, reg, &regval);
 420         if (ret < 0)
 421                 return ret;
 422
 423         return tmp51x_get_value(data, reg, pos, regval, val);
 424 }
 425
 426 static int tmp51x_write(struct device *dev, enum hwmon_sensor_types type,
 427                         u32 attr, int channel, long val)
 428 {
 429         u8 reg = 0;
 430
 431         reg = tmp51x_get_reg(type, attr, channel);
 432         if (reg == 0)
 433                 return -EOPNOTSUPP;
 434
 435         return tmp51x_set_value(dev_get_drvdata(dev), reg, val);
 436 }
 437
 438 static umode_t tmp51x_is_visible(const void *_data,
 439                                  enum hwmon_sensor_types type, u32 attr,
 440                                  int channel)
 441 {
 442         const struct tmp51x_data *data = _data;
 443
 444         switch (type) {
 445         case hwmon_temp:
 446                 if (channel >= data->max_channels)
 447                         return 0;
 448                 switch (attr) {
 449                 case hwmon_temp_input:
 450                 case hwmon_temp_crit_alarm:
 451                         return 0444;
 452                 case hwmon_temp_crit:
 453                         return 0644;
 454                 case hwmon_temp_crit_hyst:
 455                         if (channel == 0)
 456                                 return 0644;
 457                         return 0444;
 458                 }
 459                 break;
 460         case hwmon_in:
 461                 switch (attr) {
 462                 case hwmon_in_input:
 463                 case hwmon_in_lcrit_alarm:
 464                 case hwmon_in_crit_alarm:
 465                         return 0444;
 466                 case hwmon_in_lcrit:
 467                 case hwmon_in_crit:
 468                         return 0644;
 469                 }
 470                 break;
 471         case hwmon_curr:
 472                 if (!data->shunt_uohms)
 473                         return 0;
 474
 475                 switch (attr) {
 476                 case hwmon_curr_input:
 477                 case hwmon_curr_lcrit_alarm:
 478                 case hwmon_curr_crit_alarm:
 479                         return 0444;
 480                 case hwmon_curr_lcrit:
 481                 case hwmon_curr_crit:
 482                         return 0644;
 483                 }
 484                 break;
 485         case hwmon_power:
 486                 if (!data->shunt_uohms)
 487                         return 0;
 488
 489                 switch (attr) {
 490                 case hwmon_power_input:
 491                 case hwmon_power_crit_alarm:
 492                         return 0444;
 493                 case hwmon_power_crit:
 494                         return 0644;
 495                 }
 496                 break;
 497         default:
 498                 break;
 499         }
 500         return 0;
 501 }
 502
 503 static const struct hwmon_channel_info * const tmp51x_info[] = {
 504         HWMON_CHANNEL_INFO(temp,
 505                            HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
 506                            HWMON_T_CRIT_HYST,
 507                            HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
 508                            HWMON_T_CRIT_HYST,
 509                            HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
 510                            HWMON_T_CRIT_HYST,
 511                            HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_ALARM |
 512                            HWMON_T_CRIT_HYST),
 513         HWMON_CHANNEL_INFO(in,
 514                            HWMON_I_INPUT | HWMON_I_LCRIT | HWMON_I_LCRIT_ALARM |
 515                            HWMON_I_CRIT | HWMON_I_CRIT_ALARM),
 516         HWMON_CHANNEL_INFO(curr,
 517                            HWMON_C_INPUT | HWMON_C_LCRIT | HWMON_C_LCRIT_ALARM |
 518                            HWMON_C_CRIT | HWMON_C_CRIT_ALARM,
 519                            HWMON_C_INPUT),
 520         HWMON_CHANNEL_INFO(power,
 521                            HWMON_P_INPUT | HWMON_P_CRIT | HWMON_P_CRIT_ALARM),
 522         NULL
 523 };
 524
 525 static const struct hwmon_ops tmp51x_hwmon_ops = {
 526         .is_visible = tmp51x_is_visible,
 527         .read = tmp51x_read,
 528         .write = tmp51x_write,
 529 };
 530
 531 static const struct hwmon_chip_info tmp51x_chip_info = {
 532         .ops = &tmp51x_hwmon_ops,
 533         .info = tmp51x_info,
 534 };
 535
 536 /*
 537  * Calibrate the tmp51x following the datasheet method
 538  */
 539 static int tmp51x_calibrate(struct tmp51x_data *data)
 540 {
 541         int vshunt_max = data->pga_gain * 40;
 542         u64 max_curr_ma;
 543         u32 div;
 544
 545         /*
 546          * If shunt_uohms is equal to 0, the calibration should be set to 0.
 547          * The consequence will be that the current and power measurement engine
 548          * of the sensor will not work. Temperature and voltage sensing will
 549          * continue to work.
 550          */
 551         if (data->shunt_uohms == 0)
 552                 return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION, 0);
 553
 554         max_curr_ma = DIV_ROUND_CLOSEST_ULL(vshunt_max * MICRO, data->shunt_uohms);
 555
 556         /*
 557          * Calculate the minimal bit resolution for the current and the power.
 558          * Those values will be used during register interpretation.
 559          */
 560         data->curr_lsb_ua = DIV_ROUND_CLOSEST_ULL(max_curr_ma * MILLI, 32767);
 561         data->pwr_lsb_uw = 20 * data->curr_lsb_ua;
 562
 563         div = DIV_ROUND_CLOSEST_ULL(data->curr_lsb_ua * data->shunt_uohms, MICRO);
 564
 565         return regmap_write(data->regmap, TMP51X_SHUNT_CALIBRATION,
 566                             DIV_ROUND_CLOSEST(40960, div));
 567 }
 568
 569 /*
 570  * Initialize the configuration and calibration registers.
 571  */
 572 static int tmp51x_init(struct tmp51x_data *data)
 573 {
 574         unsigned int regval;
 575         int ret = regmap_write(data->regmap, TMP51X_SHUNT_CONFIG,
 576                                data->shunt_config);
 577         if (ret < 0)
 578                 return ret;
 579
 580         ret = regmap_write(data->regmap, TMP51X_TEMP_CONFIG, data->temp_config);
 581         if (ret < 0)
 582                 return ret;
 583
 584         // nFactor configuration
 585         ret = regmap_update_bits(data->regmap, TMP51X_N_FACTOR_AND_HYST_1,
 586                                  TMP51X_NFACTOR_MASK, data->nfactor[0] << 8);
 587         if (ret < 0)
 588                 return ret;
 589
 590         ret = regmap_write(data->regmap, TMP51X_N_FACTOR_2,
 591                            data->nfactor[1] << 8);
 592         if (ret < 0)
 593                 return ret;
 594
 595         if (data->max_channels == TMP513_MAX_CHANNELS) {
 596                 ret = regmap_write(data->regmap, TMP513_N_FACTOR_3,
 597                                    data->nfactor[2] << 8);
 598                 if (ret < 0)
 599                         return ret;
 600         }
 601
 602         ret = tmp51x_calibrate(data);
 603         if (ret < 0)
 604                 return ret;
 605
 606         // Read the status register before using as the datasheet propose
 607         return regmap_read(data->regmap, TMP51X_STATUS, &regval);
 608 }
 609
 610 static const struct i2c_device_id tmp51x_id[] = {
 611         { "tmp512", TMP512_MAX_CHANNELS },
 612         { "tmp513", TMP513_MAX_CHANNELS },
 613         { }
 614 };
 615 MODULE_DEVICE_TABLE(i2c, tmp51x_id);
 616
 617 static const struct of_device_id tmp51x_of_match[] = {
 618         { .compatible = "ti,tmp512", .data = (void *)TMP512_MAX_CHANNELS },
 619         { .compatible = "ti,tmp513", .data = (void *)TMP513_MAX_CHANNELS },
 620         { }
 621 };
 622 MODULE_DEVICE_TABLE(of, tmp51x_of_match);
 623
 624 static int tmp51x_vbus_range_to_reg(struct device *dev,
 625                                     struct tmp51x_data *data)
 626 {
 627         if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_32V) {
 628                 data->shunt_config |= TMP51X_BUS_VOLTAGE_MASK;
 629         } else if (data->vbus_range_uvolt == TMP51X_VBUS_RANGE_16V) {
 630                 data->shunt_config &= ~TMP51X_BUS_VOLTAGE_MASK;
 631         } else {
 632                 return dev_err_probe(dev, -EINVAL,
 633                                      "ti,bus-range-microvolt is invalid: %u\n",
 634                                      data->vbus_range_uvolt);
 635         }
 636         return 0;
 637 }
 638
 639 static int tmp51x_pga_gain_to_reg(struct device *dev, struct tmp51x_data *data)
 640 {
 641         if (data->pga_gain == 8) {
 642                 data->shunt_config |= CURRENT_SENSE_VOLTAGE_320_MASK;
 643         } else if (data->pga_gain == 4) {
 644                 data->shunt_config |= CURRENT_SENSE_VOLTAGE_160_MASK;
 645         } else if (data->pga_gain == 2) {
 646                 data->shunt_config |= CURRENT_SENSE_VOLTAGE_80_MASK;
 647         } else if (data->pga_gain == 1) {
 648                 data->shunt_config |= CURRENT_SENSE_VOLTAGE_40_MASK;
 649         } else {
 650                 return dev_err_probe(dev, -EINVAL,
 651                                      "ti,pga-gain is invalid: %u\n", data->pga_gain);
 652         }
 653         return 0;
 654 }
 655
 656 static int tmp51x_read_properties(struct device *dev, struct tmp51x_data *data)
 657 {
 658         int ret;
 659         u32 val;
 660
 661         ret = device_property_read_u32(dev, "shunt-resistor-micro-ohms", &val);
 662         data->shunt_uohms = (ret >= 0) ? val : TMP51X_SHUNT_VALUE_DEFAULT;
 663
 664         ret = device_property_read_u32(dev, "ti,bus-range-microvolt", &val);
 665         data->vbus_range_uvolt = (ret >= 0) ? val : TMP51X_VBUS_RANGE_DEFAULT;
 666         ret = tmp51x_vbus_range_to_reg(dev, data);
 667         if (ret < 0)
 668                 return ret;
 669
 670         ret = device_property_read_u32(dev, "ti,pga-gain", &val);
 671         data->pga_gain = (ret >= 0) ? val : TMP51X_PGA_DEFAULT;
 672         ret = tmp51x_pga_gain_to_reg(dev, data);
 673         if (ret < 0)
 674                 return ret;
 675
 676         device_property_read_u32_array(dev, "ti,nfactor", data->nfactor,
 677                                        data->max_channels - 1);
 678
 679         // Check if shunt value is compatible with pga-gain
 680         if (data->shunt_uohms > data->pga_gain * 40 * MICRO) {
 681                 return dev_err_probe(dev, -EINVAL,
 682                                      "shunt-resistor: %u too big for pga_gain: %u\n",
 683                                      data->shunt_uohms, data->pga_gain);
 684         }
 685
 686         return 0;
 687 }
 688
 689 static void tmp51x_use_default(struct tmp51x_data *data)
 690 {
 691         data->vbus_range_uvolt = TMP51X_VBUS_RANGE_DEFAULT;
 692         data->pga_gain = TMP51X_PGA_DEFAULT;
 693         data->shunt_uohms = TMP51X_SHUNT_VALUE_DEFAULT;
 694 }
 695
 696 static int tmp51x_configure(struct device *dev, struct tmp51x_data *data)
 697 {
 698         data->shunt_config = TMP51X_SHUNT_CONFIG_DEFAULT;
 699         data->temp_config = TMP51X_TEMP_CONFIG_DEFAULT(data->max_channels);
 700
 701         if (dev->of_node)
 702                 return tmp51x_read_properties(dev, data);
 703
 704         tmp51x_use_default(data);
 705
 706         return 0;
 707 }
 708
 709 static int tmp51x_probe(struct i2c_client *client)
 710 {
 711         struct device *dev = &client->dev;
 712         struct tmp51x_data *data;
 713         struct device *hwmon_dev;
 714         int ret;
 715
 716         data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 717         if (!data)
 718                 return -ENOMEM;
 719
 720         data->max_channels = (uintptr_t)i2c_get_match_data(client);
 721
 722         ret = tmp51x_configure(dev, data);
 723         if (ret < 0)
 724                 return dev_err_probe(dev, ret, "error configuring the device\n");
 725
 726         data->regmap = devm_regmap_init_i2c(client, &tmp51x_regmap_config);
 727         if (IS_ERR(data->regmap))
 728                 return dev_err_probe(dev, PTR_ERR(data->regmap),
 729                                      "failed to allocate register map\n");
 730
 731         ret = tmp51x_init(data);
 732         if (ret < 0)
 733                 return dev_err_probe(dev, ret, "error configuring the device\n");
 734
 735         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 736                                                          data,
 737                                                          &tmp51x_chip_info,
 738                                                          NULL);
 739         if (IS_ERR(hwmon_dev))
 740                 return PTR_ERR(hwmon_dev);
 741
 742         dev_dbg(dev, "power monitor %s\n", client->name);
 743
 744         return 0;
 745 }
 746
 747 static struct i2c_driver tmp51x_driver = {
 748         .driver = {
 749                 .name   = "tmp51x",
 750                 .of_match_table = tmp51x_of_match,
 751         },
 752         .probe          = tmp51x_probe,
 753         .id_table       = tmp51x_id,
 754 };
 755
 756 module_i2c_driver(tmp51x_driver);
 757
 758 MODULE_AUTHOR("Eric Tremblay <etremblay@distechcontrols.com>");
 759 MODULE_DESCRIPTION("tmp51x driver");
 760 MODULE_LICENSE("GPL");