drivers/hwmon/emc6w201.c

   1 /*
   2  * emc6w201.c - Hardware monitoring driver for the SMSC EMC6W201
   3  * Copyright (C) 2011  Jean Delvare <khali@linux-fr.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/i2c.h>
  25 #include <linux/hwmon.h>
  26 #include <linux/hwmon-sysfs.h>
  27 #include <linux/err.h>
  28 #include <linux/mutex.h>
  29
  30 /*
  31  * Addresses to scan
  32  */
  33
  34 static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };
  35
  36 /*
  37  * The EMC6W201 registers
  38  */
  39
  40 #define EMC6W201_REG_IN(nr)             (0x20 + (nr))
  41 #define EMC6W201_REG_TEMP(nr)           (0x26 + (nr))
  42 #define EMC6W201_REG_FAN(nr)            (0x2C + (nr) * 2)
  43 #define EMC6W201_REG_COMPANY            0x3E
  44 #define EMC6W201_REG_VERSTEP            0x3F
  45 #define EMC6W201_REG_CONFIG             0x40
  46 #define EMC6W201_REG_IN_LOW(nr)         (0x4A + (nr) * 2)
  47 #define EMC6W201_REG_IN_HIGH(nr)        (0x4B + (nr) * 2)
  48 #define EMC6W201_REG_TEMP_LOW(nr)       (0x56 + (nr) * 2)
  49 #define EMC6W201_REG_TEMP_HIGH(nr)      (0x57 + (nr) * 2)
  50 #define EMC6W201_REG_FAN_MIN(nr)        (0x62 + (nr) * 2)
  51
  52 enum { input, min, max } subfeature;
  53
  54 /*
  55  * Per-device data
  56  */
  57
  58 struct emc6w201_data {
  59         struct device *hwmon_dev;
  60         struct mutex update_lock;
  61         char valid; /* zero until following fields are valid */
  62         unsigned long last_updated; /* in jiffies */
  63
  64         /* registers values */
  65         u8 in[3][6];
  66         s8 temp[3][6];
  67         u16 fan[2][5];
  68 };
  69
  70 /*
  71  * Combine LSB and MSB registers in a single value
  72  * Locking: must be called with data->update_lock held
  73  */
  74 static u16 emc6w201_read16(struct i2c_client *client, u8 reg)
  75 {
  76         int lsb, msb;
  77
  78         lsb = i2c_smbus_read_byte_data(client, reg);
  79         msb = i2c_smbus_read_byte_data(client, reg + 1);
  80         if (unlikely(lsb < 0 || msb < 0)) {
  81                 dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
  82                         16, "read", reg);
  83                 return 0xFFFF;  /* Arbitrary value */
  84         }
  85
  86         return (msb << 8) | lsb;
  87 }
  88
  89 /*
  90  * Write 16-bit value to LSB and MSB registers
  91  * Locking: must be called with data->update_lock held
  92  */
  93 static int emc6w201_write16(struct i2c_client *client, u8 reg, u16 val)
  94 {
  95         int err;
  96
  97         err = i2c_smbus_write_byte_data(client, reg, val & 0xff);
  98         if (likely(!err))
  99                 err = i2c_smbus_write_byte_data(client, reg + 1, val >> 8);
 100         if (unlikely(err < 0))
 101                 dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
 102                         16, "write", reg);
 103
 104         return err;
 105 }
 106
 107 /* Read 8-bit value from register */
 108 static u8 emc6w201_read8(struct i2c_client *client, u8 reg)
 109 {
 110         int val;
 111
 112         val = i2c_smbus_read_byte_data(client, reg);
 113         if (unlikely(val < 0)) {
 114                 dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
 115                         8, "read", reg);
 116                 return 0x00;    /* Arbitrary value */
 117         }
 118
 119         return val;
 120 }
 121
 122 /* Write 8-bit value to register */
 123 static int emc6w201_write8(struct i2c_client *client, u8 reg, u8 val)
 124 {
 125         int err;
 126
 127         err = i2c_smbus_write_byte_data(client, reg, val);
 128         if (unlikely(err < 0))
 129                 dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
 130                         8, "write", reg);
 131
 132         return err;
 133 }
 134
 135 static struct emc6w201_data *emc6w201_update_device(struct device *dev)
 136 {
 137         struct i2c_client *client = to_i2c_client(dev);
 138         struct emc6w201_data *data = i2c_get_clientdata(client);
 139         int nr;
 140
 141         mutex_lock(&data->update_lock);
 142
 143         if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 144                 for (nr = 0; nr < 6; nr++) {
 145                         data->in[input][nr] =
 146                                 emc6w201_read8(client,
 147                                                 EMC6W201_REG_IN(nr));
 148                         data->in[min][nr] =
 149                                 emc6w201_read8(client,
 150                                                 EMC6W201_REG_IN_LOW(nr));
 151                         data->in[max][nr] =
 152                                 emc6w201_read8(client,
 153                                                 EMC6W201_REG_IN_HIGH(nr));
 154                 }
 155
 156                 for (nr = 0; nr < 6; nr++) {
 157                         data->temp[input][nr] =
 158                                 emc6w201_read8(client,
 159                                                 EMC6W201_REG_TEMP(nr));
 160                         data->temp[min][nr] =
 161                                 emc6w201_read8(client,
 162                                                 EMC6W201_REG_TEMP_LOW(nr));
 163                         data->temp[max][nr] =
 164                                 emc6w201_read8(client,
 165                                                 EMC6W201_REG_TEMP_HIGH(nr));
 166                 }
 167
 168                 for (nr = 0; nr < 5; nr++) {
 169                         data->fan[input][nr] =
 170                                 emc6w201_read16(client,
 171                                                 EMC6W201_REG_FAN(nr));
 172                         data->fan[min][nr] =
 173                                 emc6w201_read16(client,
 174                                                 EMC6W201_REG_FAN_MIN(nr));
 175                 }
 176
 177                 data->last_updated = jiffies;
 178                 data->valid = 1;
 179         }
 180
 181         mutex_unlock(&data->update_lock);
 182
 183         return data;
 184 }
 185
 186 /*
 187  * Sysfs callback functions
 188  */
 189
 190 static const s16 nominal_mv[6] = { 2500, 1500, 3300, 5000, 1500, 1500 };
 191
 192 static ssize_t show_in(struct device *dev, struct device_attribute *devattr,
 193         char *buf)
 194 {
 195         struct emc6w201_data *data = emc6w201_update_device(dev);
 196         int sf = to_sensor_dev_attr_2(devattr)->index;
 197         int nr = to_sensor_dev_attr_2(devattr)->nr;
 198
 199         return sprintf(buf, "%u\n",
 200                        (unsigned)data->in[sf][nr] * nominal_mv[nr] / 0xC0);
 201 }
 202
 203 static ssize_t set_in(struct device *dev, struct device_attribute *devattr,
 204                       const char *buf, size_t count)
 205 {
 206         struct i2c_client *client = to_i2c_client(dev);
 207         struct emc6w201_data *data = i2c_get_clientdata(client);
 208         int sf = to_sensor_dev_attr_2(devattr)->index;
 209         int nr = to_sensor_dev_attr_2(devattr)->nr;
 210         int err;
 211         long val;
 212         u8 reg;
 213
 214         err = kstrtol(buf, 10, &val);
 215         if (err < 0)
 216                 return err;
 217
 218         val = DIV_ROUND_CLOSEST(val * 0xC0, nominal_mv[nr]);
 219         reg = (sf == min) ? EMC6W201_REG_IN_LOW(nr)
 220                           : EMC6W201_REG_IN_HIGH(nr);
 221
 222         mutex_lock(&data->update_lock);
 223         data->in[sf][nr] = clamp_val(val, 0, 255);
 224         err = emc6w201_write8(client, reg, data->in[sf][nr]);
 225         mutex_unlock(&data->update_lock);
 226
 227         return err < 0 ? err : count;
 228 }
 229
 230 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 231         char *buf)
 232 {
 233         struct emc6w201_data *data = emc6w201_update_device(dev);
 234         int sf = to_sensor_dev_attr_2(devattr)->index;
 235         int nr = to_sensor_dev_attr_2(devattr)->nr;
 236
 237         return sprintf(buf, "%d\n", (int)data->temp[sf][nr] * 1000);
 238 }
 239
 240 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 241                         const char *buf, size_t count)
 242 {
 243         struct i2c_client *client = to_i2c_client(dev);
 244         struct emc6w201_data *data = i2c_get_clientdata(client);
 245         int sf = to_sensor_dev_attr_2(devattr)->index;
 246         int nr = to_sensor_dev_attr_2(devattr)->nr;
 247         int err;
 248         long val;
 249         u8 reg;
 250
 251         err = kstrtol(buf, 10, &val);
 252         if (err < 0)
 253                 return err;
 254
 255         val /= 1000;
 256         reg = (sf == min) ? EMC6W201_REG_TEMP_LOW(nr)
 257                           : EMC6W201_REG_TEMP_HIGH(nr);
 258
 259         mutex_lock(&data->update_lock);
 260         data->temp[sf][nr] = clamp_val(val, -127, 128);
 261         err = emc6w201_write8(client, reg, data->temp[sf][nr]);
 262         mutex_unlock(&data->update_lock);
 263
 264         return err < 0 ? err : count;
 265 }
 266
 267 static ssize_t show_fan(struct device *dev, struct device_attribute *devattr,
 268         char *buf)
 269 {
 270         struct emc6w201_data *data = emc6w201_update_device(dev);
 271         int sf = to_sensor_dev_attr_2(devattr)->index;
 272         int nr = to_sensor_dev_attr_2(devattr)->nr;
 273         unsigned rpm;
 274
 275         if (data->fan[sf][nr] == 0 || data->fan[sf][nr] == 0xFFFF)
 276                 rpm = 0;
 277         else
 278                 rpm = 5400000U / data->fan[sf][nr];
 279
 280         return sprintf(buf, "%u\n", rpm);
 281 }
 282
 283 static ssize_t set_fan(struct device *dev, struct device_attribute *devattr,
 284                        const char *buf, size_t count)
 285 {
 286         struct i2c_client *client = to_i2c_client(dev);
 287         struct emc6w201_data *data = i2c_get_clientdata(client);
 288         int sf = to_sensor_dev_attr_2(devattr)->index;
 289         int nr = to_sensor_dev_attr_2(devattr)->nr;
 290         int err;
 291         unsigned long val;
 292
 293         err = kstrtoul(buf, 10, &val);
 294         if (err < 0)
 295                 return err;
 296
 297         if (val == 0) {
 298                 val = 0xFFFF;
 299         } else {
 300                 val = DIV_ROUND_CLOSEST(5400000U, val);
 301                 val = clamp_val(val, 0, 0xFFFE);
 302         }
 303
 304         mutex_lock(&data->update_lock);
 305         data->fan[sf][nr] = val;
 306         err = emc6w201_write16(client, EMC6W201_REG_FAN_MIN(nr),
 307                                data->fan[sf][nr]);
 308         mutex_unlock(&data->update_lock);
 309
 310         return err < 0 ? err : count;
 311 }
 312
 313 static SENSOR_DEVICE_ATTR_2(in0_input, S_IRUGO, show_in, NULL, 0, input);
 314 static SENSOR_DEVICE_ATTR_2(in0_min, S_IRUGO | S_IWUSR, show_in, set_in,
 315                             0, min);
 316 static SENSOR_DEVICE_ATTR_2(in0_max, S_IRUGO | S_IWUSR, show_in, set_in,
 317                             0, max);
 318 static SENSOR_DEVICE_ATTR_2(in1_input, S_IRUGO, show_in, NULL, 1, input);
 319 static SENSOR_DEVICE_ATTR_2(in1_min, S_IRUGO | S_IWUSR, show_in, set_in,
 320                             1, min);
 321 static SENSOR_DEVICE_ATTR_2(in1_max, S_IRUGO | S_IWUSR, show_in, set_in,
 322                             1, max);
 323 static SENSOR_DEVICE_ATTR_2(in2_input, S_IRUGO, show_in, NULL, 2, input);
 324 static SENSOR_DEVICE_ATTR_2(in2_min, S_IRUGO | S_IWUSR, show_in, set_in,
 325                             2, min);
 326 static SENSOR_DEVICE_ATTR_2(in2_max, S_IRUGO | S_IWUSR, show_in, set_in,
 327                             2, max);
 328 static SENSOR_DEVICE_ATTR_2(in3_input, S_IRUGO, show_in, NULL, 3, input);
 329 static SENSOR_DEVICE_ATTR_2(in3_min, S_IRUGO | S_IWUSR, show_in, set_in,
 330                             3, min);
 331 static SENSOR_DEVICE_ATTR_2(in3_max, S_IRUGO | S_IWUSR, show_in, set_in,
 332                             3, max);
 333 static SENSOR_DEVICE_ATTR_2(in4_input, S_IRUGO, show_in, NULL, 4, input);
 334 static SENSOR_DEVICE_ATTR_2(in4_min, S_IRUGO | S_IWUSR, show_in, set_in,
 335                             4, min);
 336 static SENSOR_DEVICE_ATTR_2(in4_max, S_IRUGO | S_IWUSR, show_in, set_in,
 337                             4, max);
 338 static SENSOR_DEVICE_ATTR_2(in5_input, S_IRUGO, show_in, NULL, 5, input);
 339 static SENSOR_DEVICE_ATTR_2(in5_min, S_IRUGO | S_IWUSR, show_in, set_in,
 340                             5, min);
 341 static SENSOR_DEVICE_ATTR_2(in5_max, S_IRUGO | S_IWUSR, show_in, set_in,
 342                             5, max);
 343
 344 static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, input);
 345 static SENSOR_DEVICE_ATTR_2(temp1_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 346                             0, min);
 347 static SENSOR_DEVICE_ATTR_2(temp1_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 348                             0, max);
 349 static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, 1, input);
 350 static SENSOR_DEVICE_ATTR_2(temp2_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 351                             1, min);
 352 static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 353                             1, max);
 354 static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, 2, input);
 355 static SENSOR_DEVICE_ATTR_2(temp3_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 356                             2, min);
 357 static SENSOR_DEVICE_ATTR_2(temp3_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 358                             2, max);
 359 static SENSOR_DEVICE_ATTR_2(temp4_input, S_IRUGO, show_temp, NULL, 3, input);
 360 static SENSOR_DEVICE_ATTR_2(temp4_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 361                             3, min);
 362 static SENSOR_DEVICE_ATTR_2(temp4_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 363                             3, max);
 364 static SENSOR_DEVICE_ATTR_2(temp5_input, S_IRUGO, show_temp, NULL, 4, input);
 365 static SENSOR_DEVICE_ATTR_2(temp5_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 366                             4, min);
 367 static SENSOR_DEVICE_ATTR_2(temp5_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 368                             4, max);
 369 static SENSOR_DEVICE_ATTR_2(temp6_input, S_IRUGO, show_temp, NULL, 5, input);
 370 static SENSOR_DEVICE_ATTR_2(temp6_min, S_IRUGO | S_IWUSR, show_temp, set_temp,
 371                             5, min);
 372 static SENSOR_DEVICE_ATTR_2(temp6_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
 373                             5, max);
 374
 375 static SENSOR_DEVICE_ATTR_2(fan1_input, S_IRUGO, show_fan, NULL, 0, input);
 376 static SENSOR_DEVICE_ATTR_2(fan1_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
 377                             0, min);
 378 static SENSOR_DEVICE_ATTR_2(fan2_input, S_IRUGO, show_fan, NULL, 1, input);
 379 static SENSOR_DEVICE_ATTR_2(fan2_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
 380                             1, min);
 381 static SENSOR_DEVICE_ATTR_2(fan3_input, S_IRUGO, show_fan, NULL, 2, input);
 382 static SENSOR_DEVICE_ATTR_2(fan3_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
 383                             2, min);
 384 static SENSOR_DEVICE_ATTR_2(fan4_input, S_IRUGO, show_fan, NULL, 3, input);
 385 static SENSOR_DEVICE_ATTR_2(fan4_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
 386                             3, min);
 387 static SENSOR_DEVICE_ATTR_2(fan5_input, S_IRUGO, show_fan, NULL, 4, input);
 388 static SENSOR_DEVICE_ATTR_2(fan5_min, S_IRUGO | S_IWUSR, show_fan, set_fan,
 389                             4, min);
 390
 391 static struct attribute *emc6w201_attributes[] = {
 392         &sensor_dev_attr_in0_input.dev_attr.attr,
 393         &sensor_dev_attr_in0_min.dev_attr.attr,
 394         &sensor_dev_attr_in0_max.dev_attr.attr,
 395         &sensor_dev_attr_in1_input.dev_attr.attr,
 396         &sensor_dev_attr_in1_min.dev_attr.attr,
 397         &sensor_dev_attr_in1_max.dev_attr.attr,
 398         &sensor_dev_attr_in2_input.dev_attr.attr,
 399         &sensor_dev_attr_in2_min.dev_attr.attr,
 400         &sensor_dev_attr_in2_max.dev_attr.attr,
 401         &sensor_dev_attr_in3_input.dev_attr.attr,
 402         &sensor_dev_attr_in3_min.dev_attr.attr,
 403         &sensor_dev_attr_in3_max.dev_attr.attr,
 404         &sensor_dev_attr_in4_input.dev_attr.attr,
 405         &sensor_dev_attr_in4_min.dev_attr.attr,
 406         &sensor_dev_attr_in4_max.dev_attr.attr,
 407         &sensor_dev_attr_in5_input.dev_attr.attr,
 408         &sensor_dev_attr_in5_min.dev_attr.attr,
 409         &sensor_dev_attr_in5_max.dev_attr.attr,
 410
 411         &sensor_dev_attr_temp1_input.dev_attr.attr,
 412         &sensor_dev_attr_temp1_min.dev_attr.attr,
 413         &sensor_dev_attr_temp1_max.dev_attr.attr,
 414         &sensor_dev_attr_temp2_input.dev_attr.attr,
 415         &sensor_dev_attr_temp2_min.dev_attr.attr,
 416         &sensor_dev_attr_temp2_max.dev_attr.attr,
 417         &sensor_dev_attr_temp3_input.dev_attr.attr,
 418         &sensor_dev_attr_temp3_min.dev_attr.attr,
 419         &sensor_dev_attr_temp3_max.dev_attr.attr,
 420         &sensor_dev_attr_temp4_input.dev_attr.attr,
 421         &sensor_dev_attr_temp4_min.dev_attr.attr,
 422         &sensor_dev_attr_temp4_max.dev_attr.attr,
 423         &sensor_dev_attr_temp5_input.dev_attr.attr,
 424         &sensor_dev_attr_temp5_min.dev_attr.attr,
 425         &sensor_dev_attr_temp5_max.dev_attr.attr,
 426         &sensor_dev_attr_temp6_input.dev_attr.attr,
 427         &sensor_dev_attr_temp6_min.dev_attr.attr,
 428         &sensor_dev_attr_temp6_max.dev_attr.attr,
 429
 430         &sensor_dev_attr_fan1_input.dev_attr.attr,
 431         &sensor_dev_attr_fan1_min.dev_attr.attr,
 432         &sensor_dev_attr_fan2_input.dev_attr.attr,
 433         &sensor_dev_attr_fan2_min.dev_attr.attr,
 434         &sensor_dev_attr_fan3_input.dev_attr.attr,
 435         &sensor_dev_attr_fan3_min.dev_attr.attr,
 436         &sensor_dev_attr_fan4_input.dev_attr.attr,
 437         &sensor_dev_attr_fan4_min.dev_attr.attr,
 438         &sensor_dev_attr_fan5_input.dev_attr.attr,
 439         &sensor_dev_attr_fan5_min.dev_attr.attr,
 440         NULL
 441 };
 442
 443 static const struct attribute_group emc6w201_group = {
 444         .attrs = emc6w201_attributes,
 445 };
 446
 447 /*
 448  * Driver interface
 449  */
 450
 451 /* Return 0 if detection is successful, -ENODEV otherwise */
 452 static int emc6w201_detect(struct i2c_client *client,
 453                            struct i2c_board_info *info)
 454 {
 455         struct i2c_adapter *adapter = client->adapter;
 456         int company, verstep, config;
 457
 458         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 459                 return -ENODEV;
 460
 461         /* Identification */
 462         company = i2c_smbus_read_byte_data(client, EMC6W201_REG_COMPANY);
 463         if (company != 0x5C)
 464                 return -ENODEV;
 465         verstep = i2c_smbus_read_byte_data(client, EMC6W201_REG_VERSTEP);
 466         if (verstep < 0 || (verstep & 0xF0) != 0xB0)
 467                 return -ENODEV;
 468         if ((verstep & 0x0F) > 2) {
 469                 dev_dbg(&client->dev, "Unknwown EMC6W201 stepping %d\n",
 470                         verstep & 0x0F);
 471                 return -ENODEV;
 472         }
 473
 474         /* Check configuration */
 475         config = i2c_smbus_read_byte_data(client, EMC6W201_REG_CONFIG);
 476         if (config < 0 || (config & 0xF4) != 0x04)
 477                 return -ENODEV;
 478         if (!(config & 0x01)) {
 479                 dev_err(&client->dev, "Monitoring not enabled\n");
 480                 return -ENODEV;
 481         }
 482
 483         strlcpy(info->type, "emc6w201", I2C_NAME_SIZE);
 484
 485         return 0;
 486 }
 487
 488 static int emc6w201_probe(struct i2c_client *client,
 489                           const struct i2c_device_id *id)
 490 {
 491         struct emc6w201_data *data;
 492         int err;
 493
 494         data = devm_kzalloc(&client->dev, sizeof(struct emc6w201_data),
 495                             GFP_KERNEL);
 496         if (!data)
 497                 return -ENOMEM;
 498
 499         i2c_set_clientdata(client, data);
 500         mutex_init(&data->update_lock);
 501
 502         /* Create sysfs attribute */
 503         err = sysfs_create_group(&client->dev.kobj, &emc6w201_group);
 504         if (err)
 505                 return err;
 506
 507         /* Expose as a hwmon device */
 508         data->hwmon_dev = hwmon_device_register(&client->dev);
 509         if (IS_ERR(data->hwmon_dev)) {
 510                 err = PTR_ERR(data->hwmon_dev);
 511                 goto exit_remove;
 512         }
 513
 514         return 0;
 515
 516  exit_remove:
 517         sysfs_remove_group(&client->dev.kobj, &emc6w201_group);
 518         return err;
 519 }
 520
 521 static int emc6w201_remove(struct i2c_client *client)
 522 {
 523         struct emc6w201_data *data = i2c_get_clientdata(client);
 524
 525         hwmon_device_unregister(data->hwmon_dev);
 526         sysfs_remove_group(&client->dev.kobj, &emc6w201_group);
 527
 528         return 0;
 529 }
 530
 531 static const struct i2c_device_id emc6w201_id[] = {
 532         { "emc6w201", 0 },
 533         { }
 534 };
 535 MODULE_DEVICE_TABLE(i2c, emc6w201_id);
 536
 537 static struct i2c_driver emc6w201_driver = {
 538         .class          = I2C_CLASS_HWMON,
 539         .driver = {
 540                 .name   = "emc6w201",
 541         },
 542         .probe          = emc6w201_probe,
 543         .remove         = emc6w201_remove,
 544         .id_table       = emc6w201_id,
 545         .detect         = emc6w201_detect,
 546         .address_list   = normal_i2c,
 547 };
 548
 549 module_i2c_driver(emc6w201_driver);
 550
 551 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
 552 MODULE_DESCRIPTION("SMSC EMC6W201 hardware monitoring driver");
 553 MODULE_LICENSE("GPL");