drivers/hwmon/lineage-pem.c

   1 /*
   2  * Driver for Lineage Compact Power Line series of power entry modules.
   3  *
   4  * Copyright (C) 2010, 2011 Ericsson AB.
   5  *
   6  * Documentation:
   7  *  http://www.lineagepower.com/oem/pdf/CPLI2C.pdf
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/err.h>
  28 #include <linux/slab.h>
  29 #include <linux/i2c.h>
  30 #include <linux/hwmon.h>
  31 #include <linux/hwmon-sysfs.h>
  32
  33 /*
  34  * This driver supports various Lineage Compact Power Line DC/DC and AC/DC
  35  * converters such as CP1800, CP2000AC, CP2000DC, CP2100DC, and others.
  36  *
  37  * The devices are nominally PMBus compliant. However, most standard PMBus
  38  * commands are not supported. Specifically, all hardware monitoring and
  39  * status reporting commands are non-standard. For this reason, a standard
  40  * PMBus driver can not be used.
  41  *
  42  * All Lineage CPL devices have a built-in I2C bus master selector (PCA9541).
  43  * To ensure device access, this driver should only be used as client driver
  44  * to the pca9541 I2C master selector driver.
  45  */
  46
  47 /* Command codes */
  48 #define PEM_OPERATION           0x01
  49 #define PEM_CLEAR_INFO_FLAGS    0x03
  50 #define PEM_VOUT_COMMAND        0x21
  51 #define PEM_VOUT_OV_FAULT_LIMIT 0x40
  52 #define PEM_READ_DATA_STRING    0xd0
  53 #define PEM_READ_INPUT_STRING   0xdc
  54 #define PEM_READ_FIRMWARE_REV   0xdd
  55 #define PEM_READ_RUN_TIMER      0xde
  56 #define PEM_FAN_HI_SPEED        0xdf
  57 #define PEM_FAN_NORMAL_SPEED    0xe0
  58 #define PEM_READ_FAN_SPEED      0xe1
  59
  60 /* offsets in data string */
  61 #define PEM_DATA_STATUS_2       0
  62 #define PEM_DATA_STATUS_1       1
  63 #define PEM_DATA_ALARM_2        2
  64 #define PEM_DATA_ALARM_1        3
  65 #define PEM_DATA_VOUT_LSB       4
  66 #define PEM_DATA_VOUT_MSB       5
  67 #define PEM_DATA_CURRENT        6
  68 #define PEM_DATA_TEMP           7
  69
  70 /* Virtual entries, to report constants */
  71 #define PEM_DATA_TEMP_MAX       10
  72 #define PEM_DATA_TEMP_CRIT      11
  73
  74 /* offsets in input string */
  75 #define PEM_INPUT_VOLTAGE       0
  76 #define PEM_INPUT_POWER_LSB     1
  77 #define PEM_INPUT_POWER_MSB     2
  78
  79 /* offsets in fan data */
  80 #define PEM_FAN_ADJUSTMENT      0
  81 #define PEM_FAN_FAN1            1
  82 #define PEM_FAN_FAN2            2
  83 #define PEM_FAN_FAN3            3
  84
  85 /* Status register bits */
  86 #define STS1_OUTPUT_ON          (1 << 0)
  87 #define STS1_LEDS_FLASHING      (1 << 1)
  88 #define STS1_EXT_FAULT          (1 << 2)
  89 #define STS1_SERVICE_LED_ON     (1 << 3)
  90 #define STS1_SHUTDOWN_OCCURRED  (1 << 4)
  91 #define STS1_INT_FAULT          (1 << 5)
  92 #define STS1_ISOLATION_TEST_OK  (1 << 6)
  93
  94 #define STS2_ENABLE_PIN_HI      (1 << 0)
  95 #define STS2_DATA_OUT_RANGE     (1 << 1)
  96 #define STS2_RESTARTED_OK       (1 << 1)
  97 #define STS2_ISOLATION_TEST_FAIL (1 << 3)
  98 #define STS2_HIGH_POWER_CAP     (1 << 4)
  99 #define STS2_INVALID_INSTR      (1 << 5)
 100 #define STS2_WILL_RESTART       (1 << 6)
 101 #define STS2_PEC_ERR            (1 << 7)
 102
 103 /* Alarm register bits */
 104 #define ALRM1_VIN_OUT_LIMIT     (1 << 0)
 105 #define ALRM1_VOUT_OUT_LIMIT    (1 << 1)
 106 #define ALRM1_OV_VOLT_SHUTDOWN  (1 << 2)
 107 #define ALRM1_VIN_OVERCURRENT   (1 << 3)
 108 #define ALRM1_TEMP_WARNING      (1 << 4)
 109 #define ALRM1_TEMP_SHUTDOWN     (1 << 5)
 110 #define ALRM1_PRIMARY_FAULT     (1 << 6)
 111 #define ALRM1_POWER_LIMIT       (1 << 7)
 112
 113 #define ALRM2_5V_OUT_LIMIT      (1 << 1)
 114 #define ALRM2_TEMP_FAULT        (1 << 2)
 115 #define ALRM2_OV_LOW            (1 << 3)
 116 #define ALRM2_DCDC_TEMP_HIGH    (1 << 4)
 117 #define ALRM2_PRI_TEMP_HIGH     (1 << 5)
 118 #define ALRM2_NO_PRIMARY        (1 << 6)
 119 #define ALRM2_FAN_FAULT         (1 << 7)
 120
 121 #define FIRMWARE_REV_LEN        4
 122 #define DATA_STRING_LEN         9
 123 #define INPUT_STRING_LEN        5       /* 4 for most devices   */
 124 #define FAN_SPEED_LEN           5
 125
 126 struct pem_data {
 127         struct device *hwmon_dev;
 128
 129         struct mutex update_lock;
 130         bool valid;
 131         bool fans_supported;
 132         int input_length;
 133         unsigned long last_updated;     /* in jiffies */
 134
 135         u8 firmware_rev[FIRMWARE_REV_LEN];
 136         u8 data_string[DATA_STRING_LEN];
 137         u8 input_string[INPUT_STRING_LEN];
 138         u8 fan_speed[FAN_SPEED_LEN];
 139 };
 140
 141 static int pem_read_block(struct i2c_client *client, u8 command, u8 *data,
 142                           int data_len)
 143 {
 144         u8 block_buffer[I2C_SMBUS_BLOCK_MAX];
 145         int result;
 146
 147         result = i2c_smbus_read_block_data(client, command, block_buffer);
 148         if (unlikely(result < 0))
 149                 goto abort;
 150         if (unlikely(result == 0xff || result != data_len)) {
 151                 result = -EIO;
 152                 goto abort;
 153         }
 154         memcpy(data, block_buffer, data_len);
 155         result = 0;
 156 abort:
 157         return result;
 158 }
 159
 160 static struct pem_data *pem_update_device(struct device *dev)
 161 {
 162         struct i2c_client *client = to_i2c_client(dev);
 163         struct pem_data *data = i2c_get_clientdata(client);
 164         struct pem_data *ret = data;
 165
 166         mutex_lock(&data->update_lock);
 167
 168         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 169                 int result;
 170
 171                 /* Read data string */
 172                 result = pem_read_block(client, PEM_READ_DATA_STRING,
 173                                         data->data_string,
 174                                         sizeof(data->data_string));
 175                 if (unlikely(result < 0)) {
 176                         ret = ERR_PTR(result);
 177                         goto abort;
 178                 }
 179
 180                 /* Read input string */
 181                 if (data->input_length) {
 182                         result = pem_read_block(client, PEM_READ_INPUT_STRING,
 183                                                 data->input_string,
 184                                                 data->input_length);
 185                         if (unlikely(result < 0)) {
 186                                 ret = ERR_PTR(result);
 187                                 goto abort;
 188                         }
 189                 }
 190
 191                 /* Read fan speeds */
 192                 if (data->fans_supported) {
 193                         result = pem_read_block(client, PEM_READ_FAN_SPEED,
 194                                                 data->fan_speed,
 195                                                 sizeof(data->fan_speed));
 196                         if (unlikely(result < 0)) {
 197                                 ret = ERR_PTR(result);
 198                                 goto abort;
 199                         }
 200                 }
 201
 202                 i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);
 203
 204                 data->last_updated = jiffies;
 205                 data->valid = 1;
 206         }
 207 abort:
 208         mutex_unlock(&data->update_lock);
 209         return ret;
 210 }
 211
 212 static long pem_get_data(u8 *data, int len, int index)
 213 {
 214         long val;
 215
 216         switch (index) {
 217         case PEM_DATA_VOUT_LSB:
 218                 val = (data[index] + (data[index+1] << 8)) * 5 / 2;
 219                 break;
 220         case PEM_DATA_CURRENT:
 221                 val = data[index] * 200;
 222                 break;
 223         case PEM_DATA_TEMP:
 224                 val = data[index] * 1000;
 225                 break;
 226         case PEM_DATA_TEMP_MAX:
 227                 val = 97 * 1000;        /* 97 degrees C per datasheet */
 228                 break;
 229         case PEM_DATA_TEMP_CRIT:
 230                 val = 107 * 1000;       /* 107 degrees C per datasheet */
 231                 break;
 232         default:
 233                 WARN_ON_ONCE(1);
 234                 val = 0;
 235         }
 236         return val;
 237 }
 238
 239 static long pem_get_input(u8 *data, int len, int index)
 240 {
 241         long val;
 242
 243         switch (index) {
 244         case PEM_INPUT_VOLTAGE:
 245                 if (len == INPUT_STRING_LEN)
 246                         val = (data[index] + (data[index+1] << 8) - 75) * 1000;
 247                 else
 248                         val = (data[index] - 75) * 1000;
 249                 break;
 250         case PEM_INPUT_POWER_LSB:
 251                 if (len == INPUT_STRING_LEN)
 252                         index++;
 253                 val = (data[index] + (data[index+1] << 8)) * 1000000L;
 254                 break;
 255         default:
 256                 WARN_ON_ONCE(1);
 257                 val = 0;
 258         }
 259         return val;
 260 }
 261
 262 static long pem_get_fan(u8 *data, int len, int index)
 263 {
 264         long val;
 265
 266         switch (index) {
 267         case PEM_FAN_FAN1:
 268         case PEM_FAN_FAN2:
 269         case PEM_FAN_FAN3:
 270                 val = data[index] * 100;
 271                 break;
 272         default:
 273                 WARN_ON_ONCE(1);
 274                 val = 0;
 275         }
 276         return val;
 277 }
 278
 279 /*
 280  * Show boolean, either a fault or an alarm.
 281  * .nr points to the register, .index is the bit mask to check
 282  */
 283 static ssize_t pem_show_bool(struct device *dev,
 284                              struct device_attribute *da, char *buf)
 285 {
 286         struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
 287         struct pem_data *data = pem_update_device(dev);
 288         u8 status;
 289
 290         if (IS_ERR(data))
 291                 return PTR_ERR(data);
 292
 293         status = data->data_string[attr->nr] & attr->index;
 294         return snprintf(buf, PAGE_SIZE, "%d\n", !!status);
 295 }
 296
 297 static ssize_t pem_show_data(struct device *dev, struct device_attribute *da,
 298                              char *buf)
 299 {
 300         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 301         struct pem_data *data = pem_update_device(dev);
 302         long value;
 303
 304         if (IS_ERR(data))
 305                 return PTR_ERR(data);
 306
 307         value = pem_get_data(data->data_string, sizeof(data->data_string),
 308                              attr->index);
 309
 310         return snprintf(buf, PAGE_SIZE, "%ld\n", value);
 311 }
 312
 313 static ssize_t pem_show_input(struct device *dev, struct device_attribute *da,
 314                               char *buf)
 315 {
 316         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 317         struct pem_data *data = pem_update_device(dev);
 318         long value;
 319
 320         if (IS_ERR(data))
 321                 return PTR_ERR(data);
 322
 323         value = pem_get_input(data->input_string, sizeof(data->input_string),
 324                               attr->index);
 325
 326         return snprintf(buf, PAGE_SIZE, "%ld\n", value);
 327 }
 328
 329 static ssize_t pem_show_fan(struct device *dev, struct device_attribute *da,
 330                             char *buf)
 331 {
 332         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
 333         struct pem_data *data = pem_update_device(dev);
 334         long value;
 335
 336         if (IS_ERR(data))
 337                 return PTR_ERR(data);
 338
 339         value = pem_get_fan(data->fan_speed, sizeof(data->fan_speed),
 340                             attr->index);
 341
 342         return snprintf(buf, PAGE_SIZE, "%ld\n", value);
 343 }
 344
 345 /* Voltages */
 346 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, pem_show_data, NULL,
 347                           PEM_DATA_VOUT_LSB);
 348 static SENSOR_DEVICE_ATTR_2(in1_min_alarm, S_IRUGO, pem_show_bool, NULL,
 349                             PEM_DATA_ALARM_2, ALRM2_OV_LOW);
 350 static SENSOR_DEVICE_ATTR_2(in1_max_alarm, S_IRUGO, pem_show_bool, NULL,
 351                             PEM_DATA_ALARM_1, ALRM1_VOUT_OUT_LIMIT);
 352 static SENSOR_DEVICE_ATTR_2(in1_crit_alarm, S_IRUGO, pem_show_bool, NULL,
 353                             PEM_DATA_ALARM_1, ALRM1_OV_VOLT_SHUTDOWN);
 354 static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, pem_show_input, NULL,
 355                           PEM_INPUT_VOLTAGE);
 356 static SENSOR_DEVICE_ATTR_2(in2_alarm, S_IRUGO, pem_show_bool, NULL,
 357                             PEM_DATA_ALARM_1,
 358                             ALRM1_VIN_OUT_LIMIT | ALRM1_PRIMARY_FAULT);
 359
 360 /* Currents */
 361 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, pem_show_data, NULL,
 362                           PEM_DATA_CURRENT);
 363 static SENSOR_DEVICE_ATTR_2(curr1_alarm, S_IRUGO, pem_show_bool, NULL,
 364                             PEM_DATA_ALARM_1, ALRM1_VIN_OVERCURRENT);
 365
 366 /* Power */
 367 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, pem_show_input, NULL,
 368                           PEM_INPUT_POWER_LSB);
 369 static SENSOR_DEVICE_ATTR_2(power1_alarm, S_IRUGO, pem_show_bool, NULL,
 370                             PEM_DATA_ALARM_1, ALRM1_POWER_LIMIT);
 371
 372 /* Fans */
 373 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, pem_show_fan, NULL,
 374                           PEM_FAN_FAN1);
 375 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, pem_show_fan, NULL,
 376                           PEM_FAN_FAN2);
 377 static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, pem_show_fan, NULL,
 378                           PEM_FAN_FAN3);
 379 static SENSOR_DEVICE_ATTR_2(fan1_alarm, S_IRUGO, pem_show_bool, NULL,
 380                             PEM_DATA_ALARM_2, ALRM2_FAN_FAULT);
 381
 382 /* Temperatures */
 383 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, pem_show_data, NULL,
 384                           PEM_DATA_TEMP);
 385 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, pem_show_data, NULL,
 386                           PEM_DATA_TEMP_MAX);
 387 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, pem_show_data, NULL,
 388                           PEM_DATA_TEMP_CRIT);
 389 static SENSOR_DEVICE_ATTR_2(temp1_alarm, S_IRUGO, pem_show_bool, NULL,
 390                             PEM_DATA_ALARM_1, ALRM1_TEMP_WARNING);
 391 static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO, pem_show_bool, NULL,
 392                             PEM_DATA_ALARM_1, ALRM1_TEMP_SHUTDOWN);
 393 static SENSOR_DEVICE_ATTR_2(temp1_fault, S_IRUGO, pem_show_bool, NULL,
 394                             PEM_DATA_ALARM_2, ALRM2_TEMP_FAULT);
 395
 396 static struct attribute *pem_attributes[] = {
 397         &sensor_dev_attr_in1_input.dev_attr.attr,
 398         &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
 399         &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
 400         &sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
 401         &sensor_dev_attr_in2_alarm.dev_attr.attr,
 402
 403         &sensor_dev_attr_curr1_alarm.dev_attr.attr,
 404
 405         &sensor_dev_attr_power1_alarm.dev_attr.attr,
 406
 407         &sensor_dev_attr_fan1_alarm.dev_attr.attr,
 408
 409         &sensor_dev_attr_temp1_input.dev_attr.attr,
 410         &sensor_dev_attr_temp1_max.dev_attr.attr,
 411         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 412         &sensor_dev_attr_temp1_alarm.dev_attr.attr,
 413         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 414         &sensor_dev_attr_temp1_fault.dev_attr.attr,
 415
 416         NULL,
 417 };
 418
 419 static const struct attribute_group pem_group = {
 420         .attrs = pem_attributes,
 421 };
 422
 423 static struct attribute *pem_input_attributes[] = {
 424         &sensor_dev_attr_in2_input.dev_attr.attr,
 425         &sensor_dev_attr_curr1_input.dev_attr.attr,
 426         &sensor_dev_attr_power1_input.dev_attr.attr,
 427 };
 428
 429 static const struct attribute_group pem_input_group = {
 430         .attrs = pem_input_attributes,
 431 };
 432
 433 static struct attribute *pem_fan_attributes[] = {
 434         &sensor_dev_attr_fan1_input.dev_attr.attr,
 435         &sensor_dev_attr_fan2_input.dev_attr.attr,
 436         &sensor_dev_attr_fan3_input.dev_attr.attr,
 437 };
 438
 439 static const struct attribute_group pem_fan_group = {
 440         .attrs = pem_fan_attributes,
 441 };
 442
 443 static int pem_probe(struct i2c_client *client,
 444                      const struct i2c_device_id *id)
 445 {
 446         struct i2c_adapter *adapter = client->adapter;
 447         struct pem_data *data;
 448         int ret;
 449
 450         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BLOCK_DATA
 451                                      | I2C_FUNC_SMBUS_WRITE_BYTE))
 452                 return -ENODEV;
 453
 454         data = kzalloc(sizeof(*data), GFP_KERNEL);
 455         if (!data)
 456                 return -ENOMEM;
 457
 458         i2c_set_clientdata(client, data);
 459         mutex_init(&data->update_lock);
 460
 461         /*
 462          * We use the next two commands to determine if the device is really
 463          * there.
 464          */
 465         ret = pem_read_block(client, PEM_READ_FIRMWARE_REV,
 466                              data->firmware_rev, sizeof(data->firmware_rev));
 467         if (ret < 0)
 468                 goto out_kfree;
 469
 470         ret = i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);
 471         if (ret < 0)
 472                 goto out_kfree;
 473
 474         dev_info(&client->dev, "Firmware revision %d.%d.%d\n",
 475                  data->firmware_rev[0], data->firmware_rev[1],
 476                  data->firmware_rev[2]);
 477
 478         /* Register sysfs hooks */
 479         ret = sysfs_create_group(&client->dev.kobj, &pem_group);
 480         if (ret)
 481                 goto out_kfree;
 482
 483         /*
 484          * Check if input readings are supported.
 485          * This is the case if we can read input data,
 486          * and if the returned data is not all zeros.
 487          * Note that input alarms are always supported.
 488          */
 489         ret = pem_read_block(client, PEM_READ_INPUT_STRING,
 490                              data->input_string,
 491                              sizeof(data->input_string) - 1);
 492         if (!ret && (data->input_string[0] || data->input_string[1] ||
 493                      data->input_string[2]))
 494                 data->input_length = sizeof(data->input_string) - 1;
 495         else if (ret < 0) {
 496                 /* Input string is one byte longer for some devices */
 497                 ret = pem_read_block(client, PEM_READ_INPUT_STRING,
 498                                     data->input_string,
 499                                     sizeof(data->input_string));
 500                 if (!ret && (data->input_string[0] || data->input_string[1] ||
 501                             data->input_string[2] || data->input_string[3]))
 502                         data->input_length = sizeof(data->input_string);
 503         }
 504         ret = 0;
 505         if (data->input_length) {
 506                 ret = sysfs_create_group(&client->dev.kobj, &pem_input_group);
 507                 if (ret)
 508                         goto out_remove_groups;
 509         }
 510
 511         /*
 512          * Check if fan speed readings are supported.
 513          * This is the case if we can read fan speed data,
 514          * and if the returned data is not all zeros.
 515          * Note that the fan alarm is always supported.
 516          */
 517         ret = pem_read_block(client, PEM_READ_FAN_SPEED,
 518                              data->fan_speed,
 519                              sizeof(data->fan_speed));
 520         if (!ret && (data->fan_speed[0] || data->fan_speed[1] ||
 521                      data->fan_speed[2] || data->fan_speed[3])) {
 522                 data->fans_supported = true;
 523                 ret = sysfs_create_group(&client->dev.kobj, &pem_fan_group);
 524                 if (ret)
 525                         goto out_remove_groups;
 526         }
 527
 528         data->hwmon_dev = hwmon_device_register(&client->dev);
 529         if (IS_ERR(data->hwmon_dev)) {
 530                 ret = PTR_ERR(data->hwmon_dev);
 531                 goto out_remove_groups;
 532         }
 533
 534         return 0;
 535
 536 out_remove_groups:
 537         sysfs_remove_group(&client->dev.kobj, &pem_input_group);
 538         sysfs_remove_group(&client->dev.kobj, &pem_fan_group);
 539         sysfs_remove_group(&client->dev.kobj, &pem_group);
 540 out_kfree:
 541         kfree(data);
 542         return ret;
 543 }
 544
 545 static int pem_remove(struct i2c_client *client)
 546 {
 547         struct pem_data *data = i2c_get_clientdata(client);
 548
 549         hwmon_device_unregister(data->hwmon_dev);
 550
 551         sysfs_remove_group(&client->dev.kobj, &pem_input_group);
 552         sysfs_remove_group(&client->dev.kobj, &pem_fan_group);
 553         sysfs_remove_group(&client->dev.kobj, &pem_group);
 554
 555         kfree(data);
 556         return 0;
 557 }
 558
 559 static const struct i2c_device_id pem_id[] = {
 560         {"lineage_pem", 0},
 561         {}
 562 };
 563 MODULE_DEVICE_TABLE(i2c, pem_id);
 564
 565 static struct i2c_driver pem_driver = {
 566         .driver = {
 567                    .name = "lineage_pem",
 568                    },
 569         .probe = pem_probe,
 570         .remove = pem_remove,
 571         .id_table = pem_id,
 572 };
 573
 574 static int __init pem_init(void)
 575 {
 576         return i2c_add_driver(&pem_driver);
 577 }
 578
 579 static void __exit pem_exit(void)
 580 {
 581         i2c_del_driver(&pem_driver);
 582 }
 583
 584 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
 585 MODULE_DESCRIPTION("Lineage CPL PEM hardware monitoring driver");
 586 MODULE_LICENSE("GPL");
 587
 588 module_init(pem_init);
 589 module_exit(pem_exit);