drivers/hwmon/ltc2945.c

   1 /*
   2  * Driver for Linear Technology LTC2945 I2C Power Monitor
   3  *
   4  * Copyright (c) 2014 Guenter Roeck
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/err.h>
  20 #include <linux/slab.h>
  21 #include <linux/i2c.h>
  22 #include <linux/hwmon.h>
  23 #include <linux/hwmon-sysfs.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/regmap.h>
  26
  27 /* chip registers */
  28 #define LTC2945_CONTROL                 0x00
  29 #define LTC2945_ALERT                   0x01
  30 #define LTC2945_STATUS                  0x02
  31 #define LTC2945_FAULT                   0x03
  32 #define LTC2945_POWER_H                 0x05
  33 #define LTC2945_MAX_POWER_H             0x08
  34 #define LTC2945_MIN_POWER_H             0x0b
  35 #define LTC2945_MAX_POWER_THRES_H       0x0e
  36 #define LTC2945_MIN_POWER_THRES_H       0x11
  37 #define LTC2945_SENSE_H                 0x14
  38 #define LTC2945_MAX_SENSE_H             0x16
  39 #define LTC2945_MIN_SENSE_H             0x18
  40 #define LTC2945_MAX_SENSE_THRES_H       0x1a
  41 #define LTC2945_MIN_SENSE_THRES_H       0x1c
  42 #define LTC2945_VIN_H                   0x1e
  43 #define LTC2945_MAX_VIN_H               0x20
  44 #define LTC2945_MIN_VIN_H               0x22
  45 #define LTC2945_MAX_VIN_THRES_H         0x24
  46 #define LTC2945_MIN_VIN_THRES_H         0x26
  47 #define LTC2945_ADIN_H                  0x28
  48 #define LTC2945_MAX_ADIN_H              0x2a
  49 #define LTC2945_MIN_ADIN_H              0x2c
  50 #define LTC2945_MAX_ADIN_THRES_H        0x2e
  51 #define LTC2945_MIN_ADIN_THRES_H        0x30
  52 #define LTC2945_MIN_ADIN_THRES_L        0x31
  53
  54 /* Fault register bits */
  55
  56 #define FAULT_ADIN_UV           (1 << 0)
  57 #define FAULT_ADIN_OV           (1 << 1)
  58 #define FAULT_VIN_UV            (1 << 2)
  59 #define FAULT_VIN_OV            (1 << 3)
  60 #define FAULT_SENSE_UV          (1 << 4)
  61 #define FAULT_SENSE_OV          (1 << 5)
  62 #define FAULT_POWER_UV          (1 << 6)
  63 #define FAULT_POWER_OV          (1 << 7)
  64
  65 /* Control register bits */
  66
  67 #define CONTROL_MULT_SELECT     (1 << 0)
  68 #define CONTROL_TEST_MODE       (1 << 4)
  69
  70 static inline bool is_power_reg(u8 reg)
  71 {
  72         return reg < LTC2945_SENSE_H;
  73 }
  74
  75 /* Return the value from the given register in uW, mV, or mA */
  76 static long long ltc2945_reg_to_val(struct device *dev, u8 reg)
  77 {
  78         struct regmap *regmap = dev_get_drvdata(dev);
  79         unsigned int control;
  80         u8 buf[3];
  81         long long val;
  82         int ret;
  83
  84         ret = regmap_bulk_read(regmap, reg, buf,
  85                                is_power_reg(reg) ? 3 : 2);
  86         if (ret < 0)
  87                 return ret;
  88
  89         if (is_power_reg(reg)) {
  90                 /* power */
  91                 val = (buf[0] << 16) + (buf[1] << 8) + buf[2];
  92         } else {
  93                 /* current, voltage */
  94                 val = (buf[0] << 4) + (buf[1] >> 4);
  95         }
  96
  97         switch (reg) {
  98         case LTC2945_POWER_H:
  99         case LTC2945_MAX_POWER_H:
 100         case LTC2945_MIN_POWER_H:
 101         case LTC2945_MAX_POWER_THRES_H:
 102         case LTC2945_MIN_POWER_THRES_H:
 103                 /*
 104                  * Convert to uW by assuming current is measured with
 105                  * an 1mOhm sense resistor, similar to current
 106                  * measurements.
 107                  * Control register bit 0 selects if voltage at SENSE+/VDD
 108                  * or voltage at ADIN is used to measure power.
 109                  */
 110                 ret = regmap_read(regmap, LTC2945_CONTROL, &control);
 111                 if (ret < 0)
 112                         return ret;
 113                 if (control & CONTROL_MULT_SELECT) {
 114                         /* 25 mV * 25 uV = 0.625 uV resolution. */
 115                         val *= 625LL;
 116                 } else {
 117                         /* 0.5 mV * 25 uV = 0.0125 uV resolution. */
 118                         val = (val * 25LL) >> 1;
 119                 }
 120                 break;
 121         case LTC2945_VIN_H:
 122         case LTC2945_MAX_VIN_H:
 123         case LTC2945_MIN_VIN_H:
 124         case LTC2945_MAX_VIN_THRES_H:
 125         case LTC2945_MIN_VIN_THRES_H:
 126                 /* 25 mV resolution. Convert to mV. */
 127                 val *= 25;
 128                 break;
 129         case LTC2945_ADIN_H:
 130         case LTC2945_MAX_ADIN_H:
 131         case LTC2945_MIN_ADIN_THRES_H:
 132         case LTC2945_MAX_ADIN_THRES_H:
 133         case LTC2945_MIN_ADIN_H:
 134                 /* 0.5mV resolution. Convert to mV. */
 135                 val = val >> 1;
 136                 break;
 137         case LTC2945_SENSE_H:
 138         case LTC2945_MAX_SENSE_H:
 139         case LTC2945_MIN_SENSE_H:
 140         case LTC2945_MAX_SENSE_THRES_H:
 141         case LTC2945_MIN_SENSE_THRES_H:
 142                 /*
 143                  * 25 uV resolution. Convert to current as measured with
 144                  * an 1 mOhm sense resistor, in mA. If a different sense
 145                  * resistor is installed, calculate the actual current by
 146                  * dividing the reported current by the sense resistor value
 147                  * in mOhm.
 148                  */
 149                 val *= 25;
 150                 break;
 151         default:
 152                 return -EINVAL;
 153         }
 154         return val;
 155 }
 156
 157 static int ltc2945_val_to_reg(struct device *dev, u8 reg,
 158                               unsigned long val)
 159 {
 160         struct regmap *regmap = dev_get_drvdata(dev);
 161         unsigned int control;
 162         int ret;
 163
 164         switch (reg) {
 165         case LTC2945_POWER_H:
 166         case LTC2945_MAX_POWER_H:
 167         case LTC2945_MIN_POWER_H:
 168         case LTC2945_MAX_POWER_THRES_H:
 169         case LTC2945_MIN_POWER_THRES_H:
 170                 /*
 171                  * Convert to register value by assuming current is measured
 172                  * with an 1mOhm sense resistor, similar to current
 173                  * measurements.
 174                  * Control register bit 0 selects if voltage at SENSE+/VDD
 175                  * or voltage at ADIN is used to measure power, which in turn
 176                  * determines register calculations.
 177                  */
 178                 ret = regmap_read(regmap, LTC2945_CONTROL, &control);
 179                 if (ret < 0)
 180                         return ret;
 181                 if (control & CONTROL_MULT_SELECT) {
 182                         /* 25 mV * 25 uV = 0.625 uV resolution. */
 183                         val = DIV_ROUND_CLOSEST(val, 625);
 184                 } else {
 185                         /*
 186                          * 0.5 mV * 25 uV = 0.0125 uV resolution.
 187                          * Divide first to avoid overflow;
 188                          * accept loss of accuracy.
 189                          */
 190                         val = DIV_ROUND_CLOSEST(val, 25) * 2;
 191                 }
 192                 break;
 193         case LTC2945_VIN_H:
 194         case LTC2945_MAX_VIN_H:
 195         case LTC2945_MIN_VIN_H:
 196         case LTC2945_MAX_VIN_THRES_H:
 197         case LTC2945_MIN_VIN_THRES_H:
 198                 /* 25 mV resolution. */
 199                 val /= 25;
 200                 break;
 201         case LTC2945_ADIN_H:
 202         case LTC2945_MAX_ADIN_H:
 203         case LTC2945_MIN_ADIN_THRES_H:
 204         case LTC2945_MAX_ADIN_THRES_H:
 205         case LTC2945_MIN_ADIN_H:
 206                 /* 0.5mV resolution. */
 207                 val *= 2;
 208                 break;
 209         case LTC2945_SENSE_H:
 210         case LTC2945_MAX_SENSE_H:
 211         case LTC2945_MIN_SENSE_H:
 212         case LTC2945_MAX_SENSE_THRES_H:
 213         case LTC2945_MIN_SENSE_THRES_H:
 214                 /*
 215                  * 25 uV resolution. Convert to current as measured with
 216                  * an 1 mOhm sense resistor, in mA. If a different sense
 217                  * resistor is installed, calculate the actual current by
 218                  * dividing the reported current by the sense resistor value
 219                  * in mOhm.
 220                  */
 221                 val = DIV_ROUND_CLOSEST(val, 25);
 222                 break;
 223         default:
 224                 return -EINVAL;
 225         }
 226         return val;
 227 }
 228
 229 static ssize_t ltc2945_show_value(struct device *dev,
 230                                   struct device_attribute *da, char *buf)
 231 {
 232         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 233         long long value;
 234
 235         value = ltc2945_reg_to_val(dev, attr->index);
 236         if (value < 0)
 237                 return value;
 238         return snprintf(buf, PAGE_SIZE, "%lld\n", value);
 239 }
 240
 241 static ssize_t ltc2945_set_value(struct device *dev,
 242                                      struct device_attribute *da,
 243                                      const char *buf, size_t count)
 244 {
 245         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 246         struct regmap *regmap = dev_get_drvdata(dev);
 247         u8 reg = attr->index;
 248         unsigned long val;
 249         u8 regbuf[3];
 250         int num_regs;
 251         int regval;
 252         int ret;
 253
 254         ret = kstrtoul(buf, 10, &val);
 255         if (ret)
 256                 return ret;
 257
 258         /* convert to register value, then clamp and write result */
 259         regval = ltc2945_val_to_reg(dev, reg, val);
 260         if (is_power_reg(reg)) {
 261                 regval = clamp_val(regval, 0, 0xffffff);
 262                 regbuf[0] = regval >> 16;
 263                 regbuf[1] = (regval >> 8) & 0xff;
 264                 regbuf[2] = regval;
 265                 num_regs = 3;
 266         } else {
 267                 regval = clamp_val(regval, 0, 0xfff) << 4;
 268                 regbuf[0] = regval >> 8;
 269                 regbuf[1] = regval & 0xff;
 270                 num_regs = 2;
 271         }
 272         ret = regmap_bulk_write(regmap, reg, regbuf, num_regs);
 273         return ret < 0 ? ret : count;
 274 }
 275
 276 static ssize_t ltc2945_reset_history(struct device *dev,
 277                                      struct device_attribute *da,
 278                                      const char *buf, size_t count)
 279 {
 280         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 281         struct regmap *regmap = dev_get_drvdata(dev);
 282         u8 reg = attr->index;
 283         int num_regs = is_power_reg(reg) ? 3 : 2;
 284         u8 buf_min[3] = { 0xff, 0xff, 0xff };
 285         u8 buf_max[3] = { 0, 0, 0 };
 286         unsigned long val;
 287         int ret;
 288
 289         ret = kstrtoul(buf, 10, &val);
 290         if (ret)
 291                 return ret;
 292         if (val != 1)
 293                 return -EINVAL;
 294
 295         ret = regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE,
 296                                  CONTROL_TEST_MODE);
 297
 298         /* Reset minimum */
 299         ret = regmap_bulk_write(regmap, reg, buf_min, num_regs);
 300         if (ret)
 301                 return ret;
 302
 303         switch (reg) {
 304         case LTC2945_MIN_POWER_H:
 305                 reg = LTC2945_MAX_POWER_H;
 306                 break;
 307         case LTC2945_MIN_SENSE_H:
 308                 reg = LTC2945_MAX_SENSE_H;
 309                 break;
 310         case LTC2945_MIN_VIN_H:
 311                 reg = LTC2945_MAX_VIN_H;
 312                 break;
 313         case LTC2945_MIN_ADIN_H:
 314                 reg = LTC2945_MAX_ADIN_H;
 315                 break;
 316         default:
 317                 WARN_ONCE(1, "Bad register: 0x%x\n", reg);
 318                 return -EINVAL;
 319         }
 320         /* Reset maximum */
 321         ret = regmap_bulk_write(regmap, reg, buf_max, num_regs);
 322
 323         /* Try resetting test mode even if there was an error */
 324         regmap_update_bits(regmap, LTC2945_CONTROL, CONTROL_TEST_MODE, 0);
 325
 326         return ret ? : count;
 327 }
 328
 329 static ssize_t ltc2945_show_bool(struct device *dev,
 330                                  struct device_attribute *da, char *buf)
 331 {
 332         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 333         struct regmap *regmap = dev_get_drvdata(dev);
 334         unsigned int fault;
 335         int ret;
 336
 337         ret = regmap_read(regmap, LTC2945_FAULT, &fault);
 338         if (ret < 0)
 339                 return ret;
 340
 341         fault &= attr->index;
 342         if (fault)              /* Clear reported faults in chip register */
 343                 regmap_update_bits(regmap, LTC2945_FAULT, attr->index, 0);
 344
 345         return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
 346 }
 347
 348 /* Input voltages */
 349
 350 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2945_show_value, NULL,
 351                           LTC2945_VIN_H);
 352 static SENSOR_DEVICE_ATTR(in1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
 353                           ltc2945_set_value, LTC2945_MIN_VIN_THRES_H);
 354 static SENSOR_DEVICE_ATTR(in1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
 355                           ltc2945_set_value, LTC2945_MAX_VIN_THRES_H);
 356 static SENSOR_DEVICE_ATTR(in1_lowest, S_IRUGO, ltc2945_show_value, NULL,
 357                           LTC2945_MIN_VIN_H);
 358 static SENSOR_DEVICE_ATTR(in1_highest, S_IRUGO, ltc2945_show_value, NULL,
 359                           LTC2945_MAX_VIN_H);
 360 static SENSOR_DEVICE_ATTR(in1_reset_history, S_IWUSR, NULL,
 361                           ltc2945_reset_history, LTC2945_MIN_VIN_H);
 362
 363 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2945_show_value, NULL,
 364                           LTC2945_ADIN_H);
 365 static SENSOR_DEVICE_ATTR(in2_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
 366                           ltc2945_set_value, LTC2945_MIN_ADIN_THRES_H);
 367 static SENSOR_DEVICE_ATTR(in2_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
 368                           ltc2945_set_value, LTC2945_MAX_ADIN_THRES_H);
 369 static SENSOR_DEVICE_ATTR(in2_lowest, S_IRUGO, ltc2945_show_value, NULL,
 370                           LTC2945_MIN_ADIN_H);
 371 static SENSOR_DEVICE_ATTR(in2_highest, S_IRUGO, ltc2945_show_value, NULL,
 372                           LTC2945_MAX_ADIN_H);
 373 static SENSOR_DEVICE_ATTR(in2_reset_history, S_IWUSR, NULL,
 374                           ltc2945_reset_history, LTC2945_MIN_ADIN_H);
 375
 376 /* Voltage alarms */
 377
 378 static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 379                           FAULT_VIN_UV);
 380 static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 381                           FAULT_VIN_OV);
 382 static SENSOR_DEVICE_ATTR(in2_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 383                           FAULT_ADIN_UV);
 384 static SENSOR_DEVICE_ATTR(in2_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 385                           FAULT_ADIN_OV);
 386
 387 /* Currents (via sense resistor) */
 388
 389 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2945_show_value, NULL,
 390                           LTC2945_SENSE_H);
 391 static SENSOR_DEVICE_ATTR(curr1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
 392                           ltc2945_set_value, LTC2945_MIN_SENSE_THRES_H);
 393 static SENSOR_DEVICE_ATTR(curr1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
 394                           ltc2945_set_value, LTC2945_MAX_SENSE_THRES_H);
 395 static SENSOR_DEVICE_ATTR(curr1_lowest, S_IRUGO, ltc2945_show_value, NULL,
 396                           LTC2945_MIN_SENSE_H);
 397 static SENSOR_DEVICE_ATTR(curr1_highest, S_IRUGO, ltc2945_show_value, NULL,
 398                           LTC2945_MAX_SENSE_H);
 399 static SENSOR_DEVICE_ATTR(curr1_reset_history, S_IWUSR, NULL,
 400                           ltc2945_reset_history, LTC2945_MIN_SENSE_H);
 401
 402 /* Current alarms */
 403
 404 static SENSOR_DEVICE_ATTR(curr1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 405                           FAULT_SENSE_UV);
 406 static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 407                           FAULT_SENSE_OV);
 408
 409 /* Power */
 410
 411 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ltc2945_show_value, NULL,
 412                           LTC2945_POWER_H);
 413 static SENSOR_DEVICE_ATTR(power1_min, S_IRUGO | S_IWUSR, ltc2945_show_value,
 414                           ltc2945_set_value, LTC2945_MIN_POWER_THRES_H);
 415 static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO | S_IWUSR, ltc2945_show_value,
 416                           ltc2945_set_value, LTC2945_MAX_POWER_THRES_H);
 417 static SENSOR_DEVICE_ATTR(power1_input_lowest, S_IRUGO, ltc2945_show_value,
 418                           NULL, LTC2945_MIN_POWER_H);
 419 static SENSOR_DEVICE_ATTR(power1_input_highest, S_IRUGO, ltc2945_show_value,
 420                           NULL, LTC2945_MAX_POWER_H);
 421 static SENSOR_DEVICE_ATTR(power1_reset_history, S_IWUSR, NULL,
 422                           ltc2945_reset_history, LTC2945_MIN_POWER_H);
 423
 424 /* Power alarms */
 425
 426 static SENSOR_DEVICE_ATTR(power1_min_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 427                           FAULT_POWER_UV);
 428 static SENSOR_DEVICE_ATTR(power1_max_alarm, S_IRUGO, ltc2945_show_bool, NULL,
 429                           FAULT_POWER_OV);
 430
 431 static struct attribute *ltc2945_attrs[] = {
 432         &sensor_dev_attr_in1_input.dev_attr.attr,
 433         &sensor_dev_attr_in1_min.dev_attr.attr,
 434         &sensor_dev_attr_in1_max.dev_attr.attr,
 435         &sensor_dev_attr_in1_lowest.dev_attr.attr,
 436         &sensor_dev_attr_in1_highest.dev_attr.attr,
 437         &sensor_dev_attr_in1_reset_history.dev_attr.attr,
 438         &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
 439         &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
 440
 441         &sensor_dev_attr_in2_input.dev_attr.attr,
 442         &sensor_dev_attr_in2_min.dev_attr.attr,
 443         &sensor_dev_attr_in2_max.dev_attr.attr,
 444         &sensor_dev_attr_in2_lowest.dev_attr.attr,
 445         &sensor_dev_attr_in2_highest.dev_attr.attr,
 446         &sensor_dev_attr_in2_reset_history.dev_attr.attr,
 447         &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
 448         &sensor_dev_attr_in2_max_alarm.dev_attr.attr,
 449
 450         &sensor_dev_attr_curr1_input.dev_attr.attr,
 451         &sensor_dev_attr_curr1_min.dev_attr.attr,
 452         &sensor_dev_attr_curr1_max.dev_attr.attr,
 453         &sensor_dev_attr_curr1_lowest.dev_attr.attr,
 454         &sensor_dev_attr_curr1_highest.dev_attr.attr,
 455         &sensor_dev_attr_curr1_reset_history.dev_attr.attr,
 456         &sensor_dev_attr_curr1_min_alarm.dev_attr.attr,
 457         &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
 458
 459         &sensor_dev_attr_power1_input.dev_attr.attr,
 460         &sensor_dev_attr_power1_min.dev_attr.attr,
 461         &sensor_dev_attr_power1_max.dev_attr.attr,
 462         &sensor_dev_attr_power1_input_lowest.dev_attr.attr,
 463         &sensor_dev_attr_power1_input_highest.dev_attr.attr,
 464         &sensor_dev_attr_power1_reset_history.dev_attr.attr,
 465         &sensor_dev_attr_power1_min_alarm.dev_attr.attr,
 466         &sensor_dev_attr_power1_max_alarm.dev_attr.attr,
 467
 468         NULL,
 469 };
 470 ATTRIBUTE_GROUPS(ltc2945);
 471
 472 static const struct regmap_config ltc2945_regmap_config = {
 473         .reg_bits = 8,
 474         .val_bits = 8,
 475         .max_register = LTC2945_MIN_ADIN_THRES_L,
 476 };
 477
 478 static int ltc2945_probe(struct i2c_client *client,
 479                          const struct i2c_device_id *id)
 480 {
 481         struct device *dev = &client->dev;
 482         struct device *hwmon_dev;
 483         struct regmap *regmap;
 484
 485         regmap = devm_regmap_init_i2c(client, &ltc2945_regmap_config);
 486         if (IS_ERR(regmap)) {
 487                 dev_err(dev, "failed to allocate register map\n");
 488                 return PTR_ERR(regmap);
 489         }
 490
 491         /* Clear faults */
 492         regmap_write(regmap, LTC2945_FAULT, 0x00);
 493
 494         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 495                                                            regmap,
 496                                                            ltc2945_groups);
 497         return PTR_ERR_OR_ZERO(hwmon_dev);
 498 }
 499
 500 static const struct i2c_device_id ltc2945_id[] = {
 501         {"ltc2945", 0},
 502         { }
 503 };
 504
 505 MODULE_DEVICE_TABLE(i2c, ltc2945_id);
 506
 507 static struct i2c_driver ltc2945_driver = {
 508         .driver = {
 509                    .name = "ltc2945",
 510                    },
 511         .probe = ltc2945_probe,
 512         .id_table = ltc2945_id,
 513 };
 514
 515 module_i2c_driver(ltc2945_driver);
 516
 517 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
 518 MODULE_DESCRIPTION("LTC2945 driver");
 519 MODULE_LICENSE("GPL");