drivers/hwmon/ina3221.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * INA3221 Triple Current/Voltage Monitor
   4  *
   5  * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
   6  *      Andrew F. Davis <afd@ti.com>
   7  */
   8
   9 #include <linux/hwmon.h>
  10 #include <linux/hwmon-sysfs.h>
  11 #include <linux/i2c.h>
  12 #include <linux/module.h>
  13 #include <linux/mutex.h>
  14 #include <linux/of.h>
  15 #include <linux/pm_runtime.h>
  16 #include <linux/regmap.h>
  17 #include <linux/util_macros.h>
  18
  19 #define INA3221_DRIVER_NAME             "ina3221"
  20
  21 #define INA3221_CONFIG                  0x00
  22 #define INA3221_SHUNT1                  0x01
  23 #define INA3221_BUS1                    0x02
  24 #define INA3221_SHUNT2                  0x03
  25 #define INA3221_BUS2                    0x04
  26 #define INA3221_SHUNT3                  0x05
  27 #define INA3221_BUS3                    0x06
  28 #define INA3221_CRIT1                   0x07
  29 #define INA3221_WARN1                   0x08
  30 #define INA3221_CRIT2                   0x09
  31 #define INA3221_WARN2                   0x0a
  32 #define INA3221_CRIT3                   0x0b
  33 #define INA3221_WARN3                   0x0c
  34 #define INA3221_SHUNT_SUM               0x0d
  35 #define INA3221_CRIT_SUM                0x0e
  36 #define INA3221_MASK_ENABLE             0x0f
  37
  38 #define INA3221_CONFIG_MODE_MASK        GENMASK(2, 0)
  39 #define INA3221_CONFIG_MODE_POWERDOWN   0
  40 #define INA3221_CONFIG_MODE_SHUNT       BIT(0)
  41 #define INA3221_CONFIG_MODE_BUS         BIT(1)
  42 #define INA3221_CONFIG_MODE_CONTINUOUS  BIT(2)
  43 #define INA3221_CONFIG_VSH_CT_SHIFT     3
  44 #define INA3221_CONFIG_VSH_CT_MASK      GENMASK(5, 3)
  45 #define INA3221_CONFIG_VSH_CT(x)        (((x) & GENMASK(5, 3)) >> 3)
  46 #define INA3221_CONFIG_VBUS_CT_SHIFT    6
  47 #define INA3221_CONFIG_VBUS_CT_MASK     GENMASK(8, 6)
  48 #define INA3221_CONFIG_VBUS_CT(x)       (((x) & GENMASK(8, 6)) >> 6)
  49 #define INA3221_CONFIG_AVG_SHIFT        9
  50 #define INA3221_CONFIG_AVG_MASK         GENMASK(11, 9)
  51 #define INA3221_CONFIG_AVG(x)           (((x) & GENMASK(11, 9)) >> 9)
  52 #define INA3221_CONFIG_CHs_EN_MASK      GENMASK(14, 12)
  53 #define INA3221_CONFIG_CHx_EN(x)        BIT(14 - (x))
  54
  55 #define INA3221_MASK_ENABLE_SCC_MASK    GENMASK(14, 12)
  56
  57 #define INA3221_CONFIG_DEFAULT          0x7127
  58 #define INA3221_RSHUNT_DEFAULT          10000
  59
  60 enum ina3221_fields {
  61         /* Configuration */
  62         F_RST,
  63
  64         /* Status Flags */
  65         F_CVRF,
  66
  67         /* Warning Flags */
  68         F_WF3, F_WF2, F_WF1,
  69
  70         /* Alert Flags: SF is the summation-alert flag */
  71         F_SF, F_CF3, F_CF2, F_CF1,
  72
  73         /* sentinel */
  74         F_MAX_FIELDS
  75 };
  76
  77 static const struct reg_field ina3221_reg_fields[] = {
  78         [F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
  79
  80         [F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
  81         [F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
  82         [F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
  83         [F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
  84         [F_SF] = REG_FIELD(INA3221_MASK_ENABLE, 6, 6),
  85         [F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
  86         [F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
  87         [F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
  88 };
  89
  90 enum ina3221_channels {
  91         INA3221_CHANNEL1,
  92         INA3221_CHANNEL2,
  93         INA3221_CHANNEL3,
  94         INA3221_NUM_CHANNELS
  95 };
  96
  97 /**
  98  * struct ina3221_input - channel input source specific information
  99  * @label: label of channel input source
 100  * @shunt_resistor: shunt resistor value of channel input source
 101  * @disconnected: connection status of channel input source
 102  */
 103 struct ina3221_input {
 104         const char *label;
 105         int shunt_resistor;
 106         bool disconnected;
 107 };
 108
 109 /**
 110  * struct ina3221_data - device specific information
 111  * @pm_dev: Device pointer for pm runtime
 112  * @regmap: Register map of the device
 113  * @fields: Register fields of the device
 114  * @inputs: Array of channel input source specific structures
 115  * @lock: mutex lock to serialize sysfs attribute accesses
 116  * @reg_config: Register value of INA3221_CONFIG
 117  * @summation_shunt_resistor: equivalent shunt resistor value for summation
 118  * @single_shot: running in single-shot operating mode
 119  */
 120 struct ina3221_data {
 121         struct device *pm_dev;
 122         struct regmap *regmap;
 123         struct regmap_field *fields[F_MAX_FIELDS];
 124         struct ina3221_input inputs[INA3221_NUM_CHANNELS];
 125         struct mutex lock;
 126         u32 reg_config;
 127         int summation_shunt_resistor;
 128
 129         bool single_shot;
 130 };
 131
 132 static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
 133 {
 134         /* Summation channel checks shunt resistor values */
 135         if (channel > INA3221_CHANNEL3)
 136                 return ina->summation_shunt_resistor != 0;
 137
 138         return pm_runtime_active(ina->pm_dev) &&
 139                (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
 140 }
 141
 142 /*
 143  * Helper function to return the resistor value for current summation.
 144  *
 145  * There is a condition to calculate current summation -- all the shunt
 146  * resistor values should be the same, so as to simply fit the formula:
 147  *     current summation = shunt voltage summation / shunt resistor
 148  *
 149  * Returns the equivalent shunt resistor value on success or 0 on failure
 150  */
 151 static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
 152 {
 153         struct ina3221_input *input = ina->inputs;
 154         int i, shunt_resistor = 0;
 155
 156         for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
 157                 if (input[i].disconnected || !input[i].shunt_resistor)
 158                         continue;
 159                 if (!shunt_resistor) {
 160                         /* Found the reference shunt resistor value */
 161                         shunt_resistor = input[i].shunt_resistor;
 162                 } else {
 163                         /* No summation if resistor values are different */
 164                         if (shunt_resistor != input[i].shunt_resistor)
 165                                 return 0;
 166                 }
 167         }
 168
 169         return shunt_resistor;
 170 }
 171
 172 /* Lookup table for Bus and Shunt conversion times in usec */
 173 static const u16 ina3221_conv_time[] = {
 174         140, 204, 332, 588, 1100, 2116, 4156, 8244,
 175 };
 176
 177 /* Lookup table for number of samples using in averaging mode */
 178 static const int ina3221_avg_samples[] = {
 179         1, 4, 16, 64, 128, 256, 512, 1024,
 180 };
 181
 182 /* Converting update_interval in msec to conversion time in usec */
 183 static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)
 184 {
 185         u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
 186         u32 samples_idx = INA3221_CONFIG_AVG(config);
 187         u32 samples = ina3221_avg_samples[samples_idx];
 188
 189         /* Bisect the result to Bus and Shunt conversion times */
 190         return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);
 191 }
 192
 193 /* Converting CONFIG register value to update_interval in usec */
 194 static inline u32 ina3221_reg_to_interval_us(u16 config)
 195 {
 196         u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
 197         u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);
 198         u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);
 199         u32 samples_idx = INA3221_CONFIG_AVG(config);
 200         u32 samples = ina3221_avg_samples[samples_idx];
 201         u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
 202         u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
 203
 204         /* Calculate total conversion time */
 205         return channels * (vbus_ct + vsh_ct) * samples;
 206 }
 207
 208 static inline int ina3221_wait_for_data(struct ina3221_data *ina)
 209 {
 210         u32 wait, cvrf;
 211
 212         wait = ina3221_reg_to_interval_us(ina->reg_config);
 213
 214         /* Polling the CVRF bit to make sure read data is ready */
 215         return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
 216                                               cvrf, cvrf, wait, wait * 2);
 217 }
 218
 219 static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
 220                               int *val)
 221 {
 222         unsigned int regval;
 223         int ret;
 224
 225         ret = regmap_read(ina->regmap, reg, &regval);
 226         if (ret)
 227                 return ret;
 228
 229         /*
 230          * Shunt Voltage Sum register has 14-bit value with 1-bit shift
 231          * Other Shunt Voltage registers have 12 bits with 3-bit shift
 232          */
 233         if (reg == INA3221_SHUNT_SUM)
 234                 *val = sign_extend32(regval >> 1, 14);
 235         else
 236                 *val = sign_extend32(regval >> 3, 12);
 237
 238         return 0;
 239 }
 240
 241 static const u8 ina3221_in_reg[] = {
 242         INA3221_BUS1,
 243         INA3221_BUS2,
 244         INA3221_BUS3,
 245         INA3221_SHUNT1,
 246         INA3221_SHUNT2,
 247         INA3221_SHUNT3,
 248         INA3221_SHUNT_SUM,
 249 };
 250
 251 static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
 252 {
 253         struct ina3221_data *ina = dev_get_drvdata(dev);
 254         int regval;
 255
 256         switch (attr) {
 257         case hwmon_chip_samples:
 258                 regval = INA3221_CONFIG_AVG(ina->reg_config);
 259                 *val = ina3221_avg_samples[regval];
 260                 return 0;
 261         case hwmon_chip_update_interval:
 262                 /* Return in msec */
 263                 *val = ina3221_reg_to_interval_us(ina->reg_config);
 264                 *val = DIV_ROUND_CLOSEST(*val, 1000);
 265                 return 0;
 266         default:
 267                 return -EOPNOTSUPP;
 268         }
 269 }
 270
 271 static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
 272 {
 273         const bool is_shunt = channel > INA3221_CHANNEL3;
 274         struct ina3221_data *ina = dev_get_drvdata(dev);
 275         u8 reg = ina3221_in_reg[channel];
 276         int regval, ret;
 277
 278         /*
 279          * Translate shunt channel index to sensor channel index except
 280          * the 7th channel (6 since being 0-aligned) is for summation.
 281          */
 282         if (channel != 6)
 283                 channel %= INA3221_NUM_CHANNELS;
 284
 285         switch (attr) {
 286         case hwmon_in_input:
 287                 if (!ina3221_is_enabled(ina, channel))
 288                         return -ENODATA;
 289
 290                 /* Write CONFIG register to trigger a single-shot measurement */
 291                 if (ina->single_shot)
 292                         regmap_write(ina->regmap, INA3221_CONFIG,
 293                                      ina->reg_config);
 294
 295                 ret = ina3221_wait_for_data(ina);
 296                 if (ret)
 297                         return ret;
 298
 299                 ret = ina3221_read_value(ina, reg, &regval);
 300                 if (ret)
 301                         return ret;
 302
 303                 /*
 304                  * Scale of shunt voltage (uV): LSB is 40uV
 305                  * Scale of bus voltage (mV): LSB is 8mV
 306                  */
 307                 *val = regval * (is_shunt ? 40 : 8);
 308                 return 0;
 309         case hwmon_in_enable:
 310                 *val = ina3221_is_enabled(ina, channel);
 311                 return 0;
 312         default:
 313                 return -EOPNOTSUPP;
 314         }
 315 }
 316
 317 static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS + 1] = {
 318         [hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2,
 319                                INA3221_SHUNT3, INA3221_SHUNT_SUM },
 320         [hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3, 0 },
 321         [hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2,
 322                               INA3221_CRIT3, INA3221_CRIT_SUM },
 323         [hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3, 0 },
 324         [hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3, F_SF },
 325 };
 326
 327 static int ina3221_read_curr(struct device *dev, u32 attr,
 328                              int channel, long *val)
 329 {
 330         struct ina3221_data *ina = dev_get_drvdata(dev);
 331         struct ina3221_input *input = ina->inputs;
 332         u8 reg = ina3221_curr_reg[attr][channel];
 333         int resistance_uo, voltage_nv;
 334         int regval, ret;
 335
 336         if (channel > INA3221_CHANNEL3)
 337                 resistance_uo = ina->summation_shunt_resistor;
 338         else
 339                 resistance_uo = input[channel].shunt_resistor;
 340
 341         switch (attr) {
 342         case hwmon_curr_input:
 343                 if (!ina3221_is_enabled(ina, channel))
 344                         return -ENODATA;
 345
 346                 /* Write CONFIG register to trigger a single-shot measurement */
 347                 if (ina->single_shot)
 348                         regmap_write(ina->regmap, INA3221_CONFIG,
 349                                      ina->reg_config);
 350
 351                 ret = ina3221_wait_for_data(ina);
 352                 if (ret)
 353                         return ret;
 354
 355                 fallthrough;
 356         case hwmon_curr_crit:
 357         case hwmon_curr_max:
 358                 if (!resistance_uo)
 359                         return -ENODATA;
 360
 361                 ret = ina3221_read_value(ina, reg, &regval);
 362                 if (ret)
 363                         return ret;
 364
 365                 /* Scale of shunt voltage: LSB is 40uV (40000nV) */
 366                 voltage_nv = regval * 40000;
 367                 /* Return current in mA */
 368                 *val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
 369                 return 0;
 370         case hwmon_curr_crit_alarm:
 371         case hwmon_curr_max_alarm:
 372                 /* No actual register read if channel is disabled */
 373                 if (!ina3221_is_enabled(ina, channel)) {
 374                         /* Return 0 for alert flags */
 375                         *val = 0;
 376                         return 0;
 377                 }
 378                 ret = regmap_field_read(ina->fields[reg], &regval);
 379                 if (ret)
 380                         return ret;
 381                 *val = regval;
 382                 return 0;
 383         default:
 384                 return -EOPNOTSUPP;
 385         }
 386 }
 387
 388 static int ina3221_write_chip(struct device *dev, u32 attr, long val)
 389 {
 390         struct ina3221_data *ina = dev_get_drvdata(dev);
 391         int ret, idx;
 392         u32 tmp;
 393
 394         switch (attr) {
 395         case hwmon_chip_samples:
 396                 idx = find_closest(val, ina3221_avg_samples,
 397                                    ARRAY_SIZE(ina3221_avg_samples));
 398
 399                 tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
 400                       (idx << INA3221_CONFIG_AVG_SHIFT);
 401                 ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
 402                 if (ret)
 403                         return ret;
 404
 405                 /* Update reg_config accordingly */
 406                 ina->reg_config = tmp;
 407                 return 0;
 408         case hwmon_chip_update_interval:
 409                 tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);
 410                 idx = find_closest(tmp, ina3221_conv_time,
 411                                    ARRAY_SIZE(ina3221_conv_time));
 412
 413                 /* Update Bus and Shunt voltage conversion times */
 414                 tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;
 415                 tmp = (ina->reg_config & ~tmp) |
 416                       (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |
 417                       (idx << INA3221_CONFIG_VSH_CT_SHIFT);
 418                 ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
 419                 if (ret)
 420                         return ret;
 421
 422                 /* Update reg_config accordingly */
 423                 ina->reg_config = tmp;
 424                 return 0;
 425         default:
 426                 return -EOPNOTSUPP;
 427         }
 428 }
 429
 430 static int ina3221_write_curr(struct device *dev, u32 attr,
 431                               int channel, long val)
 432 {
 433         struct ina3221_data *ina = dev_get_drvdata(dev);
 434         struct ina3221_input *input = ina->inputs;
 435         u8 reg = ina3221_curr_reg[attr][channel];
 436         int resistance_uo, current_ma, voltage_uv;
 437         int regval;
 438
 439         if (channel > INA3221_CHANNEL3)
 440                 resistance_uo = ina->summation_shunt_resistor;
 441         else
 442                 resistance_uo = input[channel].shunt_resistor;
 443
 444         if (!resistance_uo)
 445                 return -EOPNOTSUPP;
 446
 447         /* clamp current */
 448         current_ma = clamp_val(val,
 449                                INT_MIN / resistance_uo,
 450                                INT_MAX / resistance_uo);
 451
 452         voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
 453
 454         /* clamp voltage */
 455         voltage_uv = clamp_val(voltage_uv, -163800, 163800);
 456
 457         /*
 458          * Formula to convert voltage_uv to register value:
 459          *     regval = (voltage_uv / scale) << shift
 460          * Note:
 461          *     The scale is 40uV for all shunt voltage registers
 462          *     Shunt Voltage Sum register left-shifts 1 bit
 463          *     All other Shunt Voltage registers shift 3 bits
 464          * Results:
 465          *     SHUNT_SUM: (1 / 40uV) << 1 = 1 / 20uV
 466          *     SHUNT[1-3]: (1 / 40uV) << 3 = 1 / 5uV
 467          */
 468         if (reg == INA3221_SHUNT_SUM)
 469                 regval = DIV_ROUND_CLOSEST(voltage_uv, 20) & 0xfffe;
 470         else
 471                 regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
 472
 473         return regmap_write(ina->regmap, reg, regval);
 474 }
 475
 476 static int ina3221_write_enable(struct device *dev, int channel, bool enable)
 477 {
 478         struct ina3221_data *ina = dev_get_drvdata(dev);
 479         u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
 480         u16 config_old = ina->reg_config & mask;
 481         u32 tmp;
 482         int ret;
 483
 484         config = enable ? mask : 0;
 485
 486         /* Bypass if enable status is not being changed */
 487         if (config_old == config)
 488                 return 0;
 489
 490         /* For enabling routine, increase refcount and resume() at first */
 491         if (enable) {
 492                 ret = pm_runtime_resume_and_get(ina->pm_dev);
 493                 if (ret < 0) {
 494                         dev_err(dev, "Failed to get PM runtime\n");
 495                         return ret;
 496                 }
 497         }
 498
 499         /* Enable or disable the channel */
 500         tmp = (ina->reg_config & ~mask) | (config & mask);
 501         ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
 502         if (ret)
 503                 goto fail;
 504
 505         /* Cache the latest config register value */
 506         ina->reg_config = tmp;
 507
 508         /* For disabling routine, decrease refcount or suspend() at last */
 509         if (!enable)
 510                 pm_runtime_put_sync(ina->pm_dev);
 511
 512         return 0;
 513
 514 fail:
 515         if (enable) {
 516                 dev_err(dev, "Failed to enable channel %d: error %d\n",
 517                         channel, ret);
 518                 pm_runtime_put_sync(ina->pm_dev);
 519         }
 520
 521         return ret;
 522 }
 523
 524 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
 525                         u32 attr, int channel, long *val)
 526 {
 527         struct ina3221_data *ina = dev_get_drvdata(dev);
 528         int ret;
 529
 530         mutex_lock(&ina->lock);
 531
 532         switch (type) {
 533         case hwmon_chip:
 534                 ret = ina3221_read_chip(dev, attr, val);
 535                 break;
 536         case hwmon_in:
 537                 /* 0-align channel ID */
 538                 ret = ina3221_read_in(dev, attr, channel - 1, val);
 539                 break;
 540         case hwmon_curr:
 541                 ret = ina3221_read_curr(dev, attr, channel, val);
 542                 break;
 543         default:
 544                 ret = -EOPNOTSUPP;
 545                 break;
 546         }
 547
 548         mutex_unlock(&ina->lock);
 549
 550         return ret;
 551 }
 552
 553 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
 554                          u32 attr, int channel, long val)
 555 {
 556         struct ina3221_data *ina = dev_get_drvdata(dev);
 557         int ret;
 558
 559         mutex_lock(&ina->lock);
 560
 561         switch (type) {
 562         case hwmon_chip:
 563                 ret = ina3221_write_chip(dev, attr, val);
 564                 break;
 565         case hwmon_in:
 566                 /* 0-align channel ID */
 567                 ret = ina3221_write_enable(dev, channel - 1, val);
 568                 break;
 569         case hwmon_curr:
 570                 ret = ina3221_write_curr(dev, attr, channel, val);
 571                 break;
 572         default:
 573                 ret = -EOPNOTSUPP;
 574                 break;
 575         }
 576
 577         mutex_unlock(&ina->lock);
 578
 579         return ret;
 580 }
 581
 582 static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
 583                                u32 attr, int channel, const char **str)
 584 {
 585         struct ina3221_data *ina = dev_get_drvdata(dev);
 586         int index = channel - 1;
 587
 588         if (channel == 7)
 589                 *str = "sum of shunt voltages";
 590         else
 591                 *str = ina->inputs[index].label;
 592
 593         return 0;
 594 }
 595
 596 static umode_t ina3221_is_visible(const void *drvdata,
 597                                   enum hwmon_sensor_types type,
 598                                   u32 attr, int channel)
 599 {
 600         const struct ina3221_data *ina = drvdata;
 601         const struct ina3221_input *input = NULL;
 602
 603         switch (type) {
 604         case hwmon_chip:
 605                 switch (attr) {
 606                 case hwmon_chip_samples:
 607                 case hwmon_chip_update_interval:
 608                         return 0644;
 609                 default:
 610                         return 0;
 611                 }
 612         case hwmon_in:
 613                 /* Ignore in0_ */
 614                 if (channel == 0)
 615                         return 0;
 616
 617                 switch (attr) {
 618                 case hwmon_in_label:
 619                         if (channel - 1 <= INA3221_CHANNEL3)
 620                                 input = &ina->inputs[channel - 1];
 621                         else if (channel == 7)
 622                                 return 0444;
 623                         /* Hide label node if label is not provided */
 624                         return (input && input->label) ? 0444 : 0;
 625                 case hwmon_in_input:
 626                         return 0444;
 627                 case hwmon_in_enable:
 628                         return 0644;
 629                 default:
 630                         return 0;
 631                 }
 632         case hwmon_curr:
 633                 switch (attr) {
 634                 case hwmon_curr_input:
 635                 case hwmon_curr_crit_alarm:
 636                 case hwmon_curr_max_alarm:
 637                         return 0444;
 638                 case hwmon_curr_crit:
 639                 case hwmon_curr_max:
 640                         return 0644;
 641                 default:
 642                         return 0;
 643                 }
 644         default:
 645                 return 0;
 646         }
 647 }
 648
 649 #define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
 650                                    HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
 651                                    HWMON_C_MAX | HWMON_C_MAX_ALARM)
 652
 653 static const struct hwmon_channel_info *ina3221_info[] = {
 654         HWMON_CHANNEL_INFO(chip,
 655                            HWMON_C_SAMPLES,
 656                            HWMON_C_UPDATE_INTERVAL),
 657         HWMON_CHANNEL_INFO(in,
 658                            /* 0: dummy, skipped in is_visible */
 659                            HWMON_I_INPUT,
 660                            /* 1-3: input voltage Channels */
 661                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 662                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 663                            HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
 664                            /* 4-6: shunt voltage Channels */
 665                            HWMON_I_INPUT,
 666                            HWMON_I_INPUT,
 667                            HWMON_I_INPUT,
 668                            /* 7: summation of shunt voltage channels */
 669                            HWMON_I_INPUT | HWMON_I_LABEL),
 670         HWMON_CHANNEL_INFO(curr,
 671                            /* 1-3: current channels*/
 672                            INA3221_HWMON_CURR_CONFIG,
 673                            INA3221_HWMON_CURR_CONFIG,
 674                            INA3221_HWMON_CURR_CONFIG,
 675                            /* 4: summation of current channels */
 676                            HWMON_C_INPUT | HWMON_C_CRIT | HWMON_C_CRIT_ALARM),
 677         NULL
 678 };
 679
 680 static const struct hwmon_ops ina3221_hwmon_ops = {
 681         .is_visible = ina3221_is_visible,
 682         .read_string = ina3221_read_string,
 683         .read = ina3221_read,
 684         .write = ina3221_write,
 685 };
 686
 687 static const struct hwmon_chip_info ina3221_chip_info = {
 688         .ops = &ina3221_hwmon_ops,
 689         .info = ina3221_info,
 690 };
 691
 692 /* Extra attribute groups */
 693 static ssize_t ina3221_shunt_show(struct device *dev,
 694                                   struct device_attribute *attr, char *buf)
 695 {
 696         struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
 697         struct ina3221_data *ina = dev_get_drvdata(dev);
 698         unsigned int channel = sd_attr->index;
 699         struct ina3221_input *input = &ina->inputs[channel];
 700
 701         return snprintf(buf, PAGE_SIZE, "%d\n", input->shunt_resistor);
 702 }
 703
 704 static ssize_t ina3221_shunt_store(struct device *dev,
 705                                    struct device_attribute *attr,
 706                                    const char *buf, size_t count)
 707 {
 708         struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
 709         struct ina3221_data *ina = dev_get_drvdata(dev);
 710         unsigned int channel = sd_attr->index;
 711         struct ina3221_input *input = &ina->inputs[channel];
 712         int val;
 713         int ret;
 714
 715         ret = kstrtoint(buf, 0, &val);
 716         if (ret)
 717                 return ret;
 718
 719         val = clamp_val(val, 1, INT_MAX);
 720
 721         input->shunt_resistor = val;
 722
 723         /* Update summation_shunt_resistor for summation channel */
 724         ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
 725
 726         return count;
 727 }
 728
 729 /* shunt resistance */
 730 static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
 731 static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
 732 static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
 733
 734 static struct attribute *ina3221_attrs[] = {
 735         &sensor_dev_attr_shunt1_resistor.dev_attr.attr,
 736         &sensor_dev_attr_shunt2_resistor.dev_attr.attr,
 737         &sensor_dev_attr_shunt3_resistor.dev_attr.attr,
 738         NULL,
 739 };
 740 ATTRIBUTE_GROUPS(ina3221);
 741
 742 static const struct regmap_range ina3221_yes_ranges[] = {
 743         regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
 744         regmap_reg_range(INA3221_SHUNT_SUM, INA3221_SHUNT_SUM),
 745         regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
 746 };
 747
 748 static const struct regmap_access_table ina3221_volatile_table = {
 749         .yes_ranges = ina3221_yes_ranges,
 750         .n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
 751 };
 752
 753 static const struct regmap_config ina3221_regmap_config = {
 754         .reg_bits = 8,
 755         .val_bits = 16,
 756
 757         .cache_type = REGCACHE_RBTREE,
 758         .volatile_table = &ina3221_volatile_table,
 759 };
 760
 761 static int ina3221_probe_child_from_dt(struct device *dev,
 762                                        struct device_node *child,
 763                                        struct ina3221_data *ina)
 764 {
 765         struct ina3221_input *input;
 766         u32 val;
 767         int ret;
 768
 769         ret = of_property_read_u32(child, "reg", &val);
 770         if (ret) {
 771                 dev_err(dev, "missing reg property of %pOFn\n", child);
 772                 return ret;
 773         } else if (val > INA3221_CHANNEL3) {
 774                 dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
 775                 return ret;
 776         }
 777
 778         input = &ina->inputs[val];
 779
 780         /* Log the disconnected channel input */
 781         if (!of_device_is_available(child)) {
 782                 input->disconnected = true;
 783                 return 0;
 784         }
 785
 786         /* Save the connected input label if available */
 787         of_property_read_string(child, "label", &input->label);
 788
 789         /* Overwrite default shunt resistor value optionally */
 790         if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
 791                 if (val < 1 || val > INT_MAX) {
 792                         dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
 793                                 val, child);
 794                         return -EINVAL;
 795                 }
 796                 input->shunt_resistor = val;
 797         }
 798
 799         return 0;
 800 }
 801
 802 static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
 803 {
 804         const struct device_node *np = dev->of_node;
 805         struct device_node *child;
 806         int ret;
 807
 808         /* Compatible with non-DT platforms */
 809         if (!np)
 810                 return 0;
 811
 812         ina->single_shot = of_property_read_bool(np, "ti,single-shot");
 813
 814         for_each_child_of_node(np, child) {
 815                 ret = ina3221_probe_child_from_dt(dev, child, ina);
 816                 if (ret) {
 817                         of_node_put(child);
 818                         return ret;
 819                 }
 820         }
 821
 822         return 0;
 823 }
 824
 825 static int ina3221_probe(struct i2c_client *client)
 826 {
 827         struct device *dev = &client->dev;
 828         struct ina3221_data *ina;
 829         struct device *hwmon_dev;
 830         int i, ret;
 831
 832         ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
 833         if (!ina)
 834                 return -ENOMEM;
 835
 836         ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
 837         if (IS_ERR(ina->regmap)) {
 838                 dev_err(dev, "Unable to allocate register map\n");
 839                 return PTR_ERR(ina->regmap);
 840         }
 841
 842         for (i = 0; i < F_MAX_FIELDS; i++) {
 843                 ina->fields[i] = devm_regmap_field_alloc(dev,
 844                                                          ina->regmap,
 845                                                          ina3221_reg_fields[i]);
 846                 if (IS_ERR(ina->fields[i])) {
 847                         dev_err(dev, "Unable to allocate regmap fields\n");
 848                         return PTR_ERR(ina->fields[i]);
 849                 }
 850         }
 851
 852         for (i = 0; i < INA3221_NUM_CHANNELS; i++)
 853                 ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
 854
 855         ret = ina3221_probe_from_dt(dev, ina);
 856         if (ret) {
 857                 dev_err(dev, "Unable to probe from device tree\n");
 858                 return ret;
 859         }
 860
 861         /* The driver will be reset, so use reset value */
 862         ina->reg_config = INA3221_CONFIG_DEFAULT;
 863
 864         /* Clear continuous bit to use single-shot mode */
 865         if (ina->single_shot)
 866                 ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
 867
 868         /* Disable channels if their inputs are disconnected */
 869         for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
 870                 if (ina->inputs[i].disconnected)
 871                         ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
 872         }
 873
 874         /* Initialize summation_shunt_resistor for summation channel control */
 875         ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
 876
 877         ina->pm_dev = dev;
 878         mutex_init(&ina->lock);
 879         dev_set_drvdata(dev, ina);
 880
 881         /* Enable PM runtime -- status is suspended by default */
 882         pm_runtime_enable(ina->pm_dev);
 883
 884         /* Initialize (resume) the device */
 885         for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
 886                 if (ina->inputs[i].disconnected)
 887                         continue;
 888                 /* Match the refcount with number of enabled channels */
 889                 ret = pm_runtime_get_sync(ina->pm_dev);
 890                 if (ret < 0)
 891                         goto fail;
 892         }
 893
 894         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
 895                                                          &ina3221_chip_info,
 896                                                          ina3221_groups);
 897         if (IS_ERR(hwmon_dev)) {
 898                 dev_err(dev, "Unable to register hwmon device\n");
 899                 ret = PTR_ERR(hwmon_dev);
 900                 goto fail;
 901         }
 902
 903         return 0;
 904
 905 fail:
 906         pm_runtime_disable(ina->pm_dev);
 907         pm_runtime_set_suspended(ina->pm_dev);
 908         /* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
 909         for (i = 0; i < INA3221_NUM_CHANNELS; i++)
 910                 pm_runtime_put_noidle(ina->pm_dev);
 911         mutex_destroy(&ina->lock);
 912
 913         return ret;
 914 }
 915
 916 static int ina3221_remove(struct i2c_client *client)
 917 {
 918         struct ina3221_data *ina = dev_get_drvdata(&client->dev);
 919         int i;
 920
 921         pm_runtime_disable(ina->pm_dev);
 922         pm_runtime_set_suspended(ina->pm_dev);
 923
 924         /* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
 925         for (i = 0; i < INA3221_NUM_CHANNELS; i++)
 926                 pm_runtime_put_noidle(ina->pm_dev);
 927
 928         mutex_destroy(&ina->lock);
 929
 930         return 0;
 931 }
 932
 933 static int __maybe_unused ina3221_suspend(struct device *dev)
 934 {
 935         struct ina3221_data *ina = dev_get_drvdata(dev);
 936         int ret;
 937
 938         /* Save config register value and enable cache-only */
 939         ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
 940         if (ret)
 941                 return ret;
 942
 943         /* Set to power-down mode for power saving */
 944         ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
 945                                  INA3221_CONFIG_MODE_MASK,
 946                                  INA3221_CONFIG_MODE_POWERDOWN);
 947         if (ret)
 948                 return ret;
 949
 950         regcache_cache_only(ina->regmap, true);
 951         regcache_mark_dirty(ina->regmap);
 952
 953         return 0;
 954 }
 955
 956 static int __maybe_unused ina3221_resume(struct device *dev)
 957 {
 958         struct ina3221_data *ina = dev_get_drvdata(dev);
 959         int ret;
 960
 961         regcache_cache_only(ina->regmap, false);
 962
 963         /* Software reset the chip */
 964         ret = regmap_field_write(ina->fields[F_RST], true);
 965         if (ret) {
 966                 dev_err(dev, "Unable to reset device\n");
 967                 return ret;
 968         }
 969
 970         /* Restore cached register values to hardware */
 971         ret = regcache_sync(ina->regmap);
 972         if (ret)
 973                 return ret;
 974
 975         /* Restore config register value to hardware */
 976         ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
 977         if (ret)
 978                 return ret;
 979
 980         /* Initialize summation channel control */
 981         if (ina->summation_shunt_resistor) {
 982                 /*
 983                  * Take all three channels into summation by default
 984                  * Shunt measurements of disconnected channels should
 985                  * be 0, so it does not matter for summation.
 986                  */
 987                 ret = regmap_update_bits(ina->regmap, INA3221_MASK_ENABLE,
 988                                          INA3221_MASK_ENABLE_SCC_MASK,
 989                                          INA3221_MASK_ENABLE_SCC_MASK);
 990                 if (ret) {
 991                         dev_err(dev, "Unable to control summation channel\n");
 992                         return ret;
 993                 }
 994         }
 995
 996         return 0;
 997 }
 998
 999 static const struct dev_pm_ops ina3221_pm = {
1000         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1001                                 pm_runtime_force_resume)
1002         SET_RUNTIME_PM_OPS(ina3221_suspend, ina3221_resume, NULL)
1003 };
1004
1005 static const struct of_device_id ina3221_of_match_table[] = {
1006         { .compatible = "ti,ina3221", },
1007         { /* sentinel */ }
1008 };
1009 MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
1010
1011 static const struct i2c_device_id ina3221_ids[] = {
1012         { "ina3221", 0 },
1013         { /* sentinel */ }
1014 };
1015 MODULE_DEVICE_TABLE(i2c, ina3221_ids);
1016
1017 static struct i2c_driver ina3221_i2c_driver = {
1018         .probe_new = ina3221_probe,
1019         .remove = ina3221_remove,
1020         .driver = {
1021                 .name = INA3221_DRIVER_NAME,
1022                 .of_match_table = ina3221_of_match_table,
1023                 .pm = &ina3221_pm,
1024         },
1025         .id_table = ina3221_ids,
1026 };
1027 module_i2c_driver(ina3221_i2c_driver);
1028
1029 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
1030 MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
1031 MODULE_LICENSE("GPL v2");