drivers/regulator/max5970-regulator.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Device driver for regulators in MAX5970 and MAX5978 IC
   4  *
   5  * Copyright (c) 2022 9elements GmbH
   6  *
   7  * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
   8  */
   9
  10 #include <linux/bitops.h>
  11 #include <linux/device.h>
  12 #include <linux/err.h>
  13 #include <linux/hwmon.h>
  14 #include <linux/module.h>
  15 #include <linux/io.h>
  16 #include <linux/of.h>
  17 #include <linux/i2c.h>
  18 #include <linux/regmap.h>
  19 #include <linux/regulator/driver.h>
  20 #include <linux/regulator/machine.h>
  21 #include <linux/regulator/of_regulator.h>
  22 #include <linux/platform_device.h>
  23
  24 #include <linux/mfd/max5970.h>
  25
  26 struct max5970_regulator {
  27         int num_switches, mon_rng, irng, shunt_micro_ohms, lim_uA;
  28         struct regmap *regmap;
  29 };
  30
  31 enum max597x_regulator_id {
  32         MAX597X_sw0,
  33         MAX597X_sw1,
  34 };
  35
  36 static int max5970_read_adc(struct regmap *regmap, int reg, long *val)
  37 {
  38         u8 reg_data[2];
  39         int ret;
  40
  41         ret = regmap_bulk_read(regmap, reg, &reg_data[0], 2);
  42         if (ret < 0)
  43                 return ret;
  44
  45         *val = (reg_data[0] << 2) | (reg_data[1] & 3);
  46
  47         return 0;
  48 }
  49
  50 static int max5970_read(struct device *dev, enum hwmon_sensor_types type,
  51                         u32 attr, int channel, long *val)
  52 {
  53         struct regulator_dev **rdevs = dev_get_drvdata(dev);
  54         struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]);
  55         struct regmap *regmap = ddata->regmap;
  56         int ret;
  57
  58         switch (type) {
  59         case hwmon_curr:
  60                 switch (attr) {
  61                 case hwmon_curr_input:
  62                         ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val);
  63                         if (ret < 0)
  64                                 return ret;
  65                         /*
  66                          * Calculate current from ADC value, IRNG range & shunt resistor value.
  67                          * ddata->irng holds the voltage corresponding to the maximum value the
  68                          * 10-bit ADC can measure.
  69                          * To obtain the output, multiply the ADC value by the IRNG range (in
  70                          * millivolts) and then divide it by the maximum value of the 10-bit ADC.
  71                          */
  72                         *val = (*val * ddata->irng) >> 10;
  73                         /* Convert the voltage measurement across shunt resistor to current */
  74                         *val = (*val * 1000) / ddata->shunt_micro_ohms;
  75                         return 0;
  76                 default:
  77                         return -EOPNOTSUPP;
  78                 }
  79
  80         case hwmon_in:
  81                 switch (attr) {
  82                 case hwmon_in_input:
  83                         ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val);
  84                         if (ret < 0)
  85                                 return ret;
  86                         /*
  87                          * Calculate voltage from ADC value and MON range.
  88                          * ddata->mon_rng holds the voltage corresponding to the maximum value the
  89                          * 10-bit ADC can measure.
  90                          * To obtain the output, multiply the ADC value by the MON range (in
  91                          * microvolts) and then divide it by the maximum value of the 10-bit ADC.
  92                          */
  93                         *val = mul_u64_u32_shr(*val, ddata->mon_rng, 10);
  94                         /* uV to mV */
  95                         *val = *val / 1000;
  96                         return 0;
  97                 default:
  98                         return -EOPNOTSUPP;
  99                 }
 100         default:
 101                 return -EOPNOTSUPP;
 102         }
 103 }
 104
 105 static umode_t max5970_is_visible(const void *data,
 106                                   enum hwmon_sensor_types type,
 107                                   u32 attr, int channel)
 108 {
 109         struct regulator_dev **rdevs = (struct regulator_dev **)data;
 110         struct max5970_regulator *ddata;
 111
 112         if (channel >= MAX5970_NUM_SWITCHES || !rdevs[channel])
 113                 return 0;
 114
 115         ddata = rdev_get_drvdata(rdevs[channel]);
 116
 117         if (channel >= ddata->num_switches)
 118                 return 0;
 119
 120         switch (type) {
 121         case hwmon_in:
 122                 switch (attr) {
 123                 case hwmon_in_input:
 124                         return 0444;
 125                 default:
 126                         break;
 127                 }
 128                 break;
 129         case hwmon_curr:
 130                 switch (attr) {
 131                 case hwmon_curr_input:
 132                         /* Current measurement requires knowledge of the shunt resistor value. */
 133                         if (ddata->shunt_micro_ohms)
 134                                 return 0444;
 135                         break;
 136                 default:
 137                         break;
 138                 }
 139                 break;
 140         default:
 141                 break;
 142         }
 143         return 0;
 144 }
 145
 146 static const struct hwmon_ops max5970_hwmon_ops = {
 147         .is_visible = max5970_is_visible,
 148         .read = max5970_read,
 149 };
 150
 151 static const struct hwmon_channel_info *max5970_info[] = {
 152         HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT),
 153         HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT),
 154         NULL
 155 };
 156
 157 static const struct hwmon_chip_info max5970_chip_info = {
 158         .ops = &max5970_hwmon_ops,
 159         .info = max5970_info,
 160 };
 161
 162 static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity)
 163 {
 164         int ret, reg;
 165
 166         /* Status1 register contains the soft strap values sampled at POR */
 167         ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS1, &reg);
 168         if (ret)
 169                 return ret;
 170
 171         /* Check soft straps match requested mode */
 172         if (severity == REGULATOR_SEVERITY_PROT) {
 173                 if (STATUS1_PROT(reg) != STATUS1_PROT_SHUTDOWN)
 174                         return -EOPNOTSUPP;
 175
 176                 return 0;
 177         }
 178         if (STATUS1_PROT(reg) == STATUS1_PROT_SHUTDOWN)
 179                 return -EOPNOTSUPP;
 180
 181         return 0;
 182 }
 183
 184 static int max597x_set_vp(struct regulator_dev *rdev, int lim_uV, int severity,
 185                           bool enable, bool overvoltage)
 186 {
 187         int off_h, off_l, reg, ret;
 188         struct max5970_regulator *data = rdev_get_drvdata(rdev);
 189         int channel = rdev_get_id(rdev);
 190
 191         if (overvoltage) {
 192                 if (severity == REGULATOR_SEVERITY_WARN) {
 193                         off_h = MAX5970_REG_CH_OV_WARN_H(channel);
 194                         off_l = MAX5970_REG_CH_OV_WARN_L(channel);
 195                 } else {
 196                         off_h = MAX5970_REG_CH_OV_CRIT_H(channel);
 197                         off_l = MAX5970_REG_CH_OV_CRIT_L(channel);
 198                 }
 199         } else {
 200                 if (severity == REGULATOR_SEVERITY_WARN) {
 201                         off_h = MAX5970_REG_CH_UV_WARN_H(channel);
 202                         off_l = MAX5970_REG_CH_UV_WARN_L(channel);
 203                 } else {
 204                         off_h = MAX5970_REG_CH_UV_CRIT_H(channel);
 205                         off_l = MAX5970_REG_CH_UV_CRIT_L(channel);
 206                 }
 207         }
 208
 209         if (enable)
 210                 /* reg = ADC_MASK * (lim_uV / 1000000) / (data->mon_rng / 1000000) */
 211                 reg = ADC_MASK * lim_uV / data->mon_rng;
 212         else
 213                 reg = 0;
 214
 215         ret = regmap_write(rdev->regmap, off_h, MAX5970_VAL2REG_H(reg));
 216         if (ret)
 217                 return ret;
 218
 219         ret = regmap_write(rdev->regmap, off_l, MAX5970_VAL2REG_L(reg));
 220         if (ret)
 221                 return ret;
 222
 223         return 0;
 224 }
 225
 226 static int max597x_set_uvp(struct regulator_dev *rdev, int lim_uV, int severity,
 227                            bool enable)
 228 {
 229         int ret;
 230
 231         /*
 232          * MAX5970 has enable control as a special value in limit reg. Can't
 233          * set limit but keep feature disabled or enable W/O given limit.
 234          */
 235         if ((lim_uV && !enable) || (!lim_uV && enable))
 236                 return -EINVAL;
 237
 238         ret = max597x_uvp_ovp_check_mode(rdev, severity);
 239         if (ret)
 240                 return ret;
 241
 242         return max597x_set_vp(rdev, lim_uV, severity, enable, false);
 243 }
 244
 245 static int max597x_set_ovp(struct regulator_dev *rdev, int lim_uV, int severity,
 246                            bool enable)
 247 {
 248         int ret;
 249
 250         /*
 251          * MAX5970 has enable control as a special value in limit reg. Can't
 252          * set limit but keep feature disabled or enable W/O given limit.
 253          */
 254         if ((lim_uV && !enable) || (!lim_uV && enable))
 255                 return -EINVAL;
 256
 257         ret = max597x_uvp_ovp_check_mode(rdev, severity);
 258         if (ret)
 259                 return ret;
 260
 261         return max597x_set_vp(rdev, lim_uV, severity, enable, true);
 262 }
 263
 264 static int max597x_set_ocp(struct regulator_dev *rdev, int lim_uA,
 265                            int severity, bool enable)
 266 {
 267         int val, reg;
 268         unsigned int vthst, vthfst;
 269
 270         struct max5970_regulator *data = rdev_get_drvdata(rdev);
 271         int rdev_id = rdev_get_id(rdev);
 272         /*
 273          * MAX5970 doesn't has enable control for ocp.
 274          * If limit is specified but enable is not set then hold the value in
 275          * variable & later use it when ocp needs to be enabled.
 276          */
 277         if (lim_uA != 0 && lim_uA != data->lim_uA)
 278                 data->lim_uA = lim_uA;
 279
 280         if (severity != REGULATOR_SEVERITY_PROT)
 281                 return -EINVAL;
 282
 283         if (enable) {
 284
 285                 /* Calc Vtrip threshold in uV. */
 286                 vthst =
 287                     div_u64(mul_u32_u32(data->shunt_micro_ohms, data->lim_uA),
 288                             1000000);
 289
 290                 /*
 291                  * As recommended in datasheed, add 20% margin to avoid
 292                  * spurious event & passive component tolerance.
 293                  */
 294                 vthst = div_u64(mul_u32_u32(vthst, 120), 100);
 295
 296                 /* Calc fast Vtrip threshold in uV */
 297                 vthfst = vthst * (MAX5970_FAST2SLOW_RATIO / 100);
 298
 299                 if (vthfst > data->irng) {
 300                         dev_err(&rdev->dev, "Current limit out of range\n");
 301                         return -EINVAL;
 302                 }
 303                 /* Fast trip threshold to be programmed */
 304                 val = div_u64(mul_u32_u32(0xFF, vthfst), data->irng);
 305         } else
 306                 /*
 307                  * Since there is no option to disable ocp, set limit to max
 308                  * value
 309                  */
 310                 val = 0xFF;
 311
 312         reg = MAX5970_REG_DAC_FAST(rdev_id);
 313
 314         return regmap_write(rdev->regmap, reg, val);
 315 }
 316
 317 static int max597x_get_status(struct regulator_dev *rdev)
 318 {
 319         int val, ret;
 320
 321         ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS3, &val);
 322         if (ret)
 323                 return ret;
 324
 325         if (val & MAX5970_STATUS3_ALERT)
 326                 return REGULATOR_STATUS_ERROR;
 327
 328         ret = regulator_is_enabled_regmap(rdev);
 329         if (ret < 0)
 330                 return ret;
 331
 332         if (ret)
 333                 return REGULATOR_STATUS_ON;
 334
 335         return REGULATOR_STATUS_OFF;
 336 }
 337
 338 static const struct regulator_ops max597x_switch_ops = {
 339         .enable = regulator_enable_regmap,
 340         .disable = regulator_disable_regmap,
 341         .is_enabled = regulator_is_enabled_regmap,
 342         .get_status = max597x_get_status,
 343         .set_over_voltage_protection = max597x_set_ovp,
 344         .set_under_voltage_protection = max597x_set_uvp,
 345         .set_over_current_protection = max597x_set_ocp,
 346 };
 347
 348 static int max597x_dt_parse(struct device_node *np,
 349                             const struct regulator_desc *desc,
 350                             struct regulator_config *cfg)
 351 {
 352         struct max5970_regulator *data = cfg->driver_data;
 353         int ret = 0;
 354
 355         ret =
 356             of_property_read_u32(np, "shunt-resistor-micro-ohms",
 357                                  &data->shunt_micro_ohms);
 358         if (ret < 0)
 359                 dev_err(cfg->dev,
 360                         "property 'shunt-resistor-micro-ohms' not found, err %d\n",
 361                         ret);
 362         return ret;
 363
 364 }
 365
 366 #define MAX597X_SWITCH(_ID, _ereg, _chan, _supply) {     \
 367         .name            = #_ID,                         \
 368         .of_match        = of_match_ptr(#_ID),           \
 369         .ops             = &max597x_switch_ops,          \
 370         .regulators_node = of_match_ptr("regulators"),   \
 371         .type            = REGULATOR_VOLTAGE,            \
 372         .id              = MAX597X_##_ID,                \
 373         .owner           = THIS_MODULE,                  \
 374         .supply_name     = _supply,                      \
 375         .enable_reg      = _ereg,                        \
 376         .enable_mask     = CHXEN((_chan)),               \
 377         .of_parse_cb     = max597x_dt_parse,             \
 378 }
 379
 380 static const struct regulator_desc regulators[] = {
 381         MAX597X_SWITCH(sw0, MAX5970_REG_CHXEN, 0, "vss1"),
 382         MAX597X_SWITCH(sw1, MAX5970_REG_CHXEN, 1, "vss2"),
 383 };
 384
 385 static int max597x_regmap_read_clear(struct regmap *map, unsigned int reg,
 386                                      unsigned int *val)
 387 {
 388         int ret;
 389
 390         ret = regmap_read(map, reg, val);
 391         if (ret)
 392                 return ret;
 393
 394         if (*val)
 395                 return regmap_write(map, reg, 0);
 396
 397         return 0;
 398 }
 399
 400 static int max597x_irq_handler(int irq, struct regulator_irq_data *rid,
 401                                unsigned long *dev_mask)
 402 {
 403         struct regulator_err_state *stat;
 404         struct max5970_regulator *d = (struct max5970_regulator *)rid->data;
 405         int val, ret, i;
 406
 407         ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT0, &val);
 408         if (ret)
 409                 return REGULATOR_FAILED_RETRY;
 410
 411         *dev_mask = 0;
 412         for (i = 0; i < d->num_switches; i++) {
 413                 stat = &rid->states[i];
 414                 stat->notifs = 0;
 415                 stat->errors = 0;
 416         }
 417
 418         for (i = 0; i < d->num_switches; i++) {
 419                 stat = &rid->states[i];
 420
 421                 if (val & UV_STATUS_CRIT(i)) {
 422                         *dev_mask |= 1 << i;
 423                         stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE;
 424                         stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE;
 425                 } else if (val & UV_STATUS_WARN(i)) {
 426                         *dev_mask |= 1 << i;
 427                         stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE_WARN;
 428                         stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE_WARN;
 429                 }
 430         }
 431
 432         ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT1, &val);
 433         if (ret)
 434                 return REGULATOR_FAILED_RETRY;
 435
 436         for (i = 0; i < d->num_switches; i++) {
 437                 stat = &rid->states[i];
 438
 439                 if (val & OV_STATUS_CRIT(i)) {
 440                         *dev_mask |= 1 << i;
 441                         stat->notifs |= REGULATOR_EVENT_REGULATION_OUT;
 442                         stat->errors |= REGULATOR_ERROR_REGULATION_OUT;
 443                 } else if (val & OV_STATUS_WARN(i)) {
 444                         *dev_mask |= 1 << i;
 445                         stat->notifs |= REGULATOR_EVENT_OVER_VOLTAGE_WARN;
 446                         stat->errors |= REGULATOR_ERROR_OVER_VOLTAGE_WARN;
 447                 }
 448         }
 449
 450         ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT2, &val);
 451         if (ret)
 452                 return REGULATOR_FAILED_RETRY;
 453
 454         for (i = 0; i < d->num_switches; i++) {
 455                 stat = &rid->states[i];
 456
 457                 if (val & OC_STATUS_WARN(i)) {
 458                         *dev_mask |= 1 << i;
 459                         stat->notifs |= REGULATOR_EVENT_OVER_CURRENT_WARN;
 460                         stat->errors |= REGULATOR_ERROR_OVER_CURRENT_WARN;
 461                 }
 462         }
 463
 464         ret = regmap_read(d->regmap, MAX5970_REG_STATUS0, &val);
 465         if (ret)
 466                 return REGULATOR_FAILED_RETRY;
 467
 468         for (i = 0; i < d->num_switches; i++) {
 469                 stat = &rid->states[i];
 470
 471                 if ((val & MAX5970_CB_IFAULTF(i))
 472                     || (val & MAX5970_CB_IFAULTS(i))) {
 473                         *dev_mask |= 1 << i;
 474                         stat->notifs |=
 475                             REGULATOR_EVENT_OVER_CURRENT |
 476                             REGULATOR_EVENT_DISABLE;
 477                         stat->errors |=
 478                             REGULATOR_ERROR_OVER_CURRENT | REGULATOR_ERROR_FAIL;
 479
 480                         /* Clear the sub-IRQ status */
 481                         regulator_disable_regmap(stat->rdev);
 482                 }
 483         }
 484         return 0;
 485 }
 486
 487 static int max597x_adc_range(struct regmap *regmap, const int ch,
 488                              int *irng, int *mon_rng)
 489 {
 490         unsigned int reg;
 491         int ret;
 492
 493         /* Decode current ADC range */
 494         ret = regmap_read(regmap, MAX5970_REG_STATUS2, &reg);
 495         if (ret)
 496                 return ret;
 497         switch (MAX5970_IRNG(reg, ch)) {
 498         case 0:
 499                 *irng = 100000; /* 100 mV */
 500                 break;
 501         case 1:
 502                 *irng = 50000;  /* 50 mV */
 503                 break;
 504         case 2:
 505                 *irng = 25000;  /* 25 mV */
 506                 break;
 507         default:
 508                 return -EINVAL;
 509         }
 510
 511         /* Decode current voltage monitor range */
 512         ret = regmap_read(regmap, MAX5970_REG_MON_RANGE, &reg);
 513         if (ret)
 514                 return ret;
 515
 516         *mon_rng = MAX5970_MON_MAX_RANGE_UV >> MAX5970_MON(reg, ch);
 517
 518         return 0;
 519 }
 520
 521 static int max597x_setup_irq(struct device *dev,
 522                              int irq,
 523                              struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES],
 524                              int num_switches, struct max5970_regulator *data)
 525 {
 526         struct regulator_irq_desc max597x_notif = {
 527                 .name = "max597x-irq",
 528                 .map_event = max597x_irq_handler,
 529                 .data = data,
 530         };
 531         int errs = REGULATOR_ERROR_UNDER_VOLTAGE |
 532             REGULATOR_ERROR_UNDER_VOLTAGE_WARN |
 533             REGULATOR_ERROR_OVER_VOLTAGE_WARN |
 534             REGULATOR_ERROR_REGULATION_OUT |
 535             REGULATOR_ERROR_OVER_CURRENT |
 536             REGULATOR_ERROR_OVER_CURRENT_WARN | REGULATOR_ERROR_FAIL;
 537         void *irq_helper;
 538
 539         /* Register notifiers - can fail if IRQ is not given */
 540         irq_helper = devm_regulator_irq_helper(dev, &max597x_notif,
 541                                                irq, 0, errs, NULL,
 542                                                &rdevs[0], num_switches);
 543         if (IS_ERR(irq_helper)) {
 544                 if (PTR_ERR(irq_helper) == -EPROBE_DEFER)
 545                         return -EPROBE_DEFER;
 546
 547                 dev_warn(dev, "IRQ disabled %pe\n", irq_helper);
 548         }
 549
 550         return 0;
 551 }
 552
 553 static int max597x_regulator_probe(struct platform_device *pdev)
 554 {
 555         struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
 556         struct max5970_regulator *data;
 557         struct i2c_client *i2c = to_i2c_client(pdev->dev.parent);
 558         struct regulator_config config = { };
 559         struct regulator_dev *rdev;
 560         struct regulator_dev **rdevs = NULL;
 561         struct device *hwmon_dev;
 562         int num_switches;
 563         int ret, i;
 564
 565         if (!regmap)
 566                 return -EPROBE_DEFER;
 567
 568         rdevs = devm_kcalloc(&i2c->dev, MAX5970_NUM_SWITCHES, sizeof(struct regulator_dev *),
 569                              GFP_KERNEL);
 570         if (!rdevs)
 571                 return -ENOMEM;
 572
 573         if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978"))
 574                 num_switches = MAX5978_NUM_SWITCHES;
 575         else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970"))
 576                 num_switches = MAX5970_NUM_SWITCHES;
 577         else
 578                 return -ENODEV;
 579
 580         for (i = 0; i < num_switches; i++) {
 581                 data =
 582                     devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator),
 583                                  GFP_KERNEL);
 584                 if (!data)
 585                         return -ENOMEM;
 586
 587                 data->num_switches = num_switches;
 588                 data->regmap = regmap;
 589
 590                 ret = max597x_adc_range(regmap, i, &data->irng, &data->mon_rng);
 591                 if (ret < 0)
 592                         return ret;
 593
 594                 config.dev = &i2c->dev;
 595                 config.driver_data = (void *)data;
 596                 config.regmap = data->regmap;
 597                 rdev = devm_regulator_register(&i2c->dev,
 598                                                &regulators[i], &config);
 599                 if (IS_ERR(rdev)) {
 600                         dev_err(&i2c->dev, "failed to register regulator %s\n",
 601                                 regulators[i].name);
 602                         return PTR_ERR(rdev);
 603                 }
 604                 rdevs[i] = rdev;
 605         }
 606
 607         if (IS_REACHABLE(CONFIG_HWMON)) {
 608                 hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs,
 609                                                                  &max5970_chip_info, NULL);
 610                 if (IS_ERR(hwmon_dev)) {
 611                         return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev),
 612                                              "Unable to register hwmon device\n");
 613                 }
 614         }
 615
 616         if (i2c->irq) {
 617                 ret =
 618                     max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches,
 619                                       data);
 620                 if (ret) {
 621                         dev_err(&i2c->dev, "IRQ setup failed");
 622                         return ret;
 623                 }
 624         }
 625
 626         return ret;
 627 }
 628
 629 static struct platform_driver max597x_regulator_driver = {
 630         .driver = {
 631                 .name = "max5970-regulator",
 632                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 633         },
 634         .probe = max597x_regulator_probe,
 635 };
 636
 637 module_platform_driver(max597x_regulator_driver);
 638
 639
 640 MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
 641 MODULE_DESCRIPTION("MAX5970_hot-swap controller driver");
 642 MODULE_LICENSE("GPL v2");