drivers/hwmon/max6639.c

   1 /*
   2  * max6639.c - Support for Maxim MAX6639
   3  *
   4  * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
   5  *
   6  * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
   7  *
   8  * based on the initial MAX6639 support from semptian.net
   9  * by He Changqing <hechangqing@semptian.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28 #include <linux/slab.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/i2c.h>
  31 #include <linux/hwmon.h>
  32 #include <linux/hwmon-sysfs.h>
  33 #include <linux/err.h>
  34 #include <linux/mutex.h>
  35 #include <linux/i2c/max6639.h>
  36
  37 /* Addresses to scan */
  38 static unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
  39
  40 /* The MAX6639 registers, valid channel numbers: 0, 1 */
  41 #define MAX6639_REG_TEMP(ch)                    (0x00 + (ch))
  42 #define MAX6639_REG_STATUS                      0x02
  43 #define MAX6639_REG_OUTPUT_MASK                 0x03
  44 #define MAX6639_REG_GCONFIG                     0x04
  45 #define MAX6639_REG_TEMP_EXT(ch)                (0x05 + (ch))
  46 #define MAX6639_REG_ALERT_LIMIT(ch)             (0x08 + (ch))
  47 #define MAX6639_REG_OT_LIMIT(ch)                (0x0A + (ch))
  48 #define MAX6639_REG_THERM_LIMIT(ch)             (0x0C + (ch))
  49 #define MAX6639_REG_FAN_CONFIG1(ch)             (0x10 + (ch) * 4)
  50 #define MAX6639_REG_FAN_CONFIG2a(ch)            (0x11 + (ch) * 4)
  51 #define MAX6639_REG_FAN_CONFIG2b(ch)            (0x12 + (ch) * 4)
  52 #define MAX6639_REG_FAN_CONFIG3(ch)             (0x13 + (ch) * 4)
  53 #define MAX6639_REG_FAN_CNT(ch)                 (0x20 + (ch))
  54 #define MAX6639_REG_TARGET_CNT(ch)              (0x22 + (ch))
  55 #define MAX6639_REG_FAN_PPR(ch)                 (0x24 + (ch))
  56 #define MAX6639_REG_TARGTDUTY(ch)               (0x26 + (ch))
  57 #define MAX6639_REG_FAN_START_TEMP(ch)          (0x28 + (ch))
  58 #define MAX6639_REG_DEVID                       0x3D
  59 #define MAX6639_REG_MANUID                      0x3E
  60 #define MAX6639_REG_DEVREV                      0x3F
  61
  62 /* Register bits */
  63 #define MAX6639_GCONFIG_STANDBY                 0x80
  64 #define MAX6639_GCONFIG_POR                     0x40
  65 #define MAX6639_GCONFIG_DISABLE_TIMEOUT         0x20
  66 #define MAX6639_GCONFIG_CH2_LOCAL               0x10
  67 #define MAX6639_GCONFIG_PWM_FREQ_HI             0x08
  68
  69 #define MAX6639_FAN_CONFIG1_PWM                 0x80
  70
  71 #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED    0x40
  72
  73 static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
  74
  75 #define FAN_FROM_REG(val, rpm_range)    ((val) == 0 || (val) == 255 ? \
  76                                 0 : (rpm_ranges[rpm_range] * 30) / (val))
  77 #define TEMP_LIMIT_TO_REG(val)  clamp_val((val) / 1000, 0, 255)
  78
  79 /*
  80  * Client data (each client gets its own)
  81  */
  82 struct max6639_data {
  83         struct device *hwmon_dev;
  84         struct mutex update_lock;
  85         char valid;             /* !=0 if following fields are valid */
  86         unsigned long last_updated;     /* In jiffies */
  87
  88         /* Register values sampled regularly */
  89         u16 temp[2];            /* Temperature, in 1/8 C, 0..255 C */
  90         bool temp_fault[2];     /* Detected temperature diode failure */
  91         u8 fan[2];              /* Register value: TACH count for fans >=30 */
  92         u8 status;              /* Detected channel alarms and fan failures */
  93
  94         /* Register values only written to */
  95         u8 pwm[2];              /* Register value: Duty cycle 0..120 */
  96         u8 temp_therm[2];       /* THERM Temperature, 0..255 C (->_max) */
  97         u8 temp_alert[2];       /* ALERT Temperature, 0..255 C (->_crit) */
  98         u8 temp_ot[2];          /* OT Temperature, 0..255 C (->_emergency) */
  99
 100         /* Register values initialized only once */
 101         u8 ppr;                 /* Pulses per rotation 0..3 for 1..4 ppr */
 102         u8 rpm_range;           /* Index in above rpm_ranges table */
 103 };
 104
 105 static struct max6639_data *max6639_update_device(struct device *dev)
 106 {
 107         struct i2c_client *client = to_i2c_client(dev);
 108         struct max6639_data *data = i2c_get_clientdata(client);
 109         struct max6639_data *ret = data;
 110         int i;
 111         int status_reg;
 112
 113         mutex_lock(&data->update_lock);
 114
 115         if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
 116                 int res;
 117
 118                 dev_dbg(&client->dev, "Starting max6639 update\n");
 119
 120                 status_reg = i2c_smbus_read_byte_data(client,
 121                                                       MAX6639_REG_STATUS);
 122                 if (status_reg < 0) {
 123                         ret = ERR_PTR(status_reg);
 124                         goto abort;
 125                 }
 126
 127                 data->status = status_reg;
 128
 129                 for (i = 0; i < 2; i++) {
 130                         res = i2c_smbus_read_byte_data(client,
 131                                         MAX6639_REG_FAN_CNT(i));
 132                         if (res < 0) {
 133                                 ret = ERR_PTR(res);
 134                                 goto abort;
 135                         }
 136                         data->fan[i] = res;
 137
 138                         res = i2c_smbus_read_byte_data(client,
 139                                         MAX6639_REG_TEMP_EXT(i));
 140                         if (res < 0) {
 141                                 ret = ERR_PTR(res);
 142                                 goto abort;
 143                         }
 144                         data->temp[i] = res >> 5;
 145                         data->temp_fault[i] = res & 0x01;
 146
 147                         res = i2c_smbus_read_byte_data(client,
 148                                         MAX6639_REG_TEMP(i));
 149                         if (res < 0) {
 150                                 ret = ERR_PTR(res);
 151                                 goto abort;
 152                         }
 153                         data->temp[i] |= res << 3;
 154                 }
 155
 156                 data->last_updated = jiffies;
 157                 data->valid = 1;
 158         }
 159 abort:
 160         mutex_unlock(&data->update_lock);
 161
 162         return ret;
 163 }
 164
 165 static ssize_t show_temp_input(struct device *dev,
 166                                struct device_attribute *dev_attr, char *buf)
 167 {
 168         long temp;
 169         struct max6639_data *data = max6639_update_device(dev);
 170         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 171
 172         if (IS_ERR(data))
 173                 return PTR_ERR(data);
 174
 175         temp = data->temp[attr->index] * 125;
 176         return sprintf(buf, "%ld\n", temp);
 177 }
 178
 179 static ssize_t show_temp_fault(struct device *dev,
 180                                struct device_attribute *dev_attr, char *buf)
 181 {
 182         struct max6639_data *data = max6639_update_device(dev);
 183         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 184
 185         if (IS_ERR(data))
 186                 return PTR_ERR(data);
 187
 188         return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
 189 }
 190
 191 static ssize_t show_temp_max(struct device *dev,
 192                              struct device_attribute *dev_attr, char *buf)
 193 {
 194         struct i2c_client *client = to_i2c_client(dev);
 195         struct max6639_data *data = i2c_get_clientdata(client);
 196         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 197
 198         return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
 199 }
 200
 201 static ssize_t set_temp_max(struct device *dev,
 202                             struct device_attribute *dev_attr,
 203                             const char *buf, size_t count)
 204 {
 205         struct i2c_client *client = to_i2c_client(dev);
 206         struct max6639_data *data = i2c_get_clientdata(client);
 207         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 208         unsigned long val;
 209         int res;
 210
 211         res = kstrtoul(buf, 10, &val);
 212         if (res)
 213                 return res;
 214
 215         mutex_lock(&data->update_lock);
 216         data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
 217         i2c_smbus_write_byte_data(client,
 218                                   MAX6639_REG_THERM_LIMIT(attr->index),
 219                                   data->temp_therm[attr->index]);
 220         mutex_unlock(&data->update_lock);
 221         return count;
 222 }
 223
 224 static ssize_t show_temp_crit(struct device *dev,
 225                               struct device_attribute *dev_attr, char *buf)
 226 {
 227         struct i2c_client *client = to_i2c_client(dev);
 228         struct max6639_data *data = i2c_get_clientdata(client);
 229         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 230
 231         return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
 232 }
 233
 234 static ssize_t set_temp_crit(struct device *dev,
 235                              struct device_attribute *dev_attr,
 236                              const char *buf, size_t count)
 237 {
 238         struct i2c_client *client = to_i2c_client(dev);
 239         struct max6639_data *data = i2c_get_clientdata(client);
 240         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 241         unsigned long val;
 242         int res;
 243
 244         res = kstrtoul(buf, 10, &val);
 245         if (res)
 246                 return res;
 247
 248         mutex_lock(&data->update_lock);
 249         data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
 250         i2c_smbus_write_byte_data(client,
 251                                   MAX6639_REG_ALERT_LIMIT(attr->index),
 252                                   data->temp_alert[attr->index]);
 253         mutex_unlock(&data->update_lock);
 254         return count;
 255 }
 256
 257 static ssize_t show_temp_emergency(struct device *dev,
 258                                    struct device_attribute *dev_attr,
 259                                    char *buf)
 260 {
 261         struct i2c_client *client = to_i2c_client(dev);
 262         struct max6639_data *data = i2c_get_clientdata(client);
 263         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 264
 265         return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
 266 }
 267
 268 static ssize_t set_temp_emergency(struct device *dev,
 269                                   struct device_attribute *dev_attr,
 270                                   const char *buf, size_t count)
 271 {
 272         struct i2c_client *client = to_i2c_client(dev);
 273         struct max6639_data *data = i2c_get_clientdata(client);
 274         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 275         unsigned long val;
 276         int res;
 277
 278         res = kstrtoul(buf, 10, &val);
 279         if (res)
 280                 return res;
 281
 282         mutex_lock(&data->update_lock);
 283         data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
 284         i2c_smbus_write_byte_data(client,
 285                                   MAX6639_REG_OT_LIMIT(attr->index),
 286                                   data->temp_ot[attr->index]);
 287         mutex_unlock(&data->update_lock);
 288         return count;
 289 }
 290
 291 static ssize_t show_pwm(struct device *dev,
 292                         struct device_attribute *dev_attr, char *buf)
 293 {
 294         struct i2c_client *client = to_i2c_client(dev);
 295         struct max6639_data *data = i2c_get_clientdata(client);
 296         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 297
 298         return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
 299 }
 300
 301 static ssize_t set_pwm(struct device *dev,
 302                        struct device_attribute *dev_attr,
 303                        const char *buf, size_t count)
 304 {
 305         struct i2c_client *client = to_i2c_client(dev);
 306         struct max6639_data *data = i2c_get_clientdata(client);
 307         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 308         unsigned long val;
 309         int res;
 310
 311         res = kstrtoul(buf, 10, &val);
 312         if (res)
 313                 return res;
 314
 315         val = clamp_val(val, 0, 255);
 316
 317         mutex_lock(&data->update_lock);
 318         data->pwm[attr->index] = (u8)(val * 120 / 255);
 319         i2c_smbus_write_byte_data(client,
 320                                   MAX6639_REG_TARGTDUTY(attr->index),
 321                                   data->pwm[attr->index]);
 322         mutex_unlock(&data->update_lock);
 323         return count;
 324 }
 325
 326 static ssize_t show_fan_input(struct device *dev,
 327                               struct device_attribute *dev_attr, char *buf)
 328 {
 329         struct max6639_data *data = max6639_update_device(dev);
 330         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 331
 332         if (IS_ERR(data))
 333                 return PTR_ERR(data);
 334
 335         return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
 336                        data->rpm_range));
 337 }
 338
 339 static ssize_t show_alarm(struct device *dev,
 340                           struct device_attribute *dev_attr, char *buf)
 341 {
 342         struct max6639_data *data = max6639_update_device(dev);
 343         struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
 344
 345         if (IS_ERR(data))
 346                 return PTR_ERR(data);
 347
 348         return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
 349 }
 350
 351 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
 352 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input, NULL, 1);
 353 static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
 354 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
 355 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max,
 356                 set_temp_max, 0);
 357 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_max,
 358                 set_temp_max, 1);
 359 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 360                 set_temp_crit, 0);
 361 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit,
 362                 set_temp_crit, 1);
 363 static SENSOR_DEVICE_ATTR(temp1_emergency, S_IWUSR | S_IRUGO,
 364                 show_temp_emergency, set_temp_emergency, 0);
 365 static SENSOR_DEVICE_ATTR(temp2_emergency, S_IWUSR | S_IRUGO,
 366                 show_temp_emergency, set_temp_emergency, 1);
 367 static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 0);
 368 static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, show_pwm, set_pwm, 1);
 369 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan_input, NULL, 0);
 370 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan_input, NULL, 1);
 371 static SENSOR_DEVICE_ATTR(fan1_fault, S_IRUGO, show_alarm, NULL, 1);
 372 static SENSOR_DEVICE_ATTR(fan2_fault, S_IRUGO, show_alarm, NULL, 0);
 373 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 3);
 374 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 2);
 375 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 7);
 376 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 6);
 377 static SENSOR_DEVICE_ATTR(temp1_emergency_alarm, S_IRUGO, show_alarm, NULL, 5);
 378 static SENSOR_DEVICE_ATTR(temp2_emergency_alarm, S_IRUGO, show_alarm, NULL, 4);
 379
 380
 381 static struct attribute *max6639_attributes[] = {
 382         &sensor_dev_attr_temp1_input.dev_attr.attr,
 383         &sensor_dev_attr_temp2_input.dev_attr.attr,
 384         &sensor_dev_attr_temp1_fault.dev_attr.attr,
 385         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 386         &sensor_dev_attr_temp1_max.dev_attr.attr,
 387         &sensor_dev_attr_temp2_max.dev_attr.attr,
 388         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 389         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 390         &sensor_dev_attr_temp1_emergency.dev_attr.attr,
 391         &sensor_dev_attr_temp2_emergency.dev_attr.attr,
 392         &sensor_dev_attr_pwm1.dev_attr.attr,
 393         &sensor_dev_attr_pwm2.dev_attr.attr,
 394         &sensor_dev_attr_fan1_input.dev_attr.attr,
 395         &sensor_dev_attr_fan2_input.dev_attr.attr,
 396         &sensor_dev_attr_fan1_fault.dev_attr.attr,
 397         &sensor_dev_attr_fan2_fault.dev_attr.attr,
 398         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 399         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 400         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 401         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 402         &sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
 403         &sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
 404         NULL
 405 };
 406
 407 static const struct attribute_group max6639_group = {
 408         .attrs = max6639_attributes,
 409 };
 410
 411 /*
 412  *  returns respective index in rpm_ranges table
 413  *  1 by default on invalid range
 414  */
 415 static int rpm_range_to_reg(int range)
 416 {
 417         int i;
 418
 419         for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
 420                 if (rpm_ranges[i] == range)
 421                         return i;
 422         }
 423
 424         return 1; /* default: 4000 RPM */
 425 }
 426
 427 static int max6639_init_client(struct i2c_client *client)
 428 {
 429         struct max6639_data *data = i2c_get_clientdata(client);
 430         struct max6639_platform_data *max6639_info =
 431                 dev_get_platdata(&client->dev);
 432         int i;
 433         int rpm_range = 1; /* default: 4000 RPM */
 434         int err;
 435
 436         /* Reset chip to default values, see below for GCONFIG setup */
 437         err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 438                                   MAX6639_GCONFIG_POR);
 439         if (err)
 440                 goto exit;
 441
 442         /* Fans pulse per revolution is 2 by default */
 443         if (max6639_info && max6639_info->ppr > 0 &&
 444                         max6639_info->ppr < 5)
 445                 data->ppr = max6639_info->ppr;
 446         else
 447                 data->ppr = 2;
 448         data->ppr -= 1;
 449
 450         if (max6639_info)
 451                 rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
 452         data->rpm_range = rpm_range;
 453
 454         for (i = 0; i < 2; i++) {
 455
 456                 /* Set Fan pulse per revolution */
 457                 err = i2c_smbus_write_byte_data(client,
 458                                 MAX6639_REG_FAN_PPR(i),
 459                                 data->ppr << 6);
 460                 if (err)
 461                         goto exit;
 462
 463                 /* Fans config PWM, RPM */
 464                 err = i2c_smbus_write_byte_data(client,
 465                         MAX6639_REG_FAN_CONFIG1(i),
 466                         MAX6639_FAN_CONFIG1_PWM | rpm_range);
 467                 if (err)
 468                         goto exit;
 469
 470                 /* Fans PWM polarity high by default */
 471                 if (max6639_info && max6639_info->pwm_polarity == 0)
 472                         err = i2c_smbus_write_byte_data(client,
 473                                 MAX6639_REG_FAN_CONFIG2a(i), 0x00);
 474                 else
 475                         err = i2c_smbus_write_byte_data(client,
 476                                 MAX6639_REG_FAN_CONFIG2a(i), 0x02);
 477                 if (err)
 478                         goto exit;
 479
 480                 /*
 481                  * /THERM full speed enable,
 482                  * PWM frequency 25kHz, see also GCONFIG below
 483                  */
 484                 err = i2c_smbus_write_byte_data(client,
 485                         MAX6639_REG_FAN_CONFIG3(i),
 486                         MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
 487                 if (err)
 488                         goto exit;
 489
 490                 /* Max. temp. 80C/90C/100C */
 491                 data->temp_therm[i] = 80;
 492                 data->temp_alert[i] = 90;
 493                 data->temp_ot[i] = 100;
 494                 err = i2c_smbus_write_byte_data(client,
 495                                 MAX6639_REG_THERM_LIMIT(i),
 496                                 data->temp_therm[i]);
 497                 if (err)
 498                         goto exit;
 499                 err = i2c_smbus_write_byte_data(client,
 500                                 MAX6639_REG_ALERT_LIMIT(i),
 501                                 data->temp_alert[i]);
 502                 if (err)
 503                         goto exit;
 504                 err = i2c_smbus_write_byte_data(client,
 505                                 MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
 506                 if (err)
 507                         goto exit;
 508
 509                 /* PWM 120/120 (i.e. 100%) */
 510                 data->pwm[i] = 120;
 511                 err = i2c_smbus_write_byte_data(client,
 512                                 MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
 513                 if (err)
 514                         goto exit;
 515         }
 516         /* Start monitoring */
 517         err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
 518                 MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
 519                 MAX6639_GCONFIG_PWM_FREQ_HI);
 520 exit:
 521         return err;
 522 }
 523
 524 /* Return 0 if detection is successful, -ENODEV otherwise */
 525 static int max6639_detect(struct i2c_client *client,
 526                           struct i2c_board_info *info)
 527 {
 528         struct i2c_adapter *adapter = client->adapter;
 529         int dev_id, manu_id;
 530
 531         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 532                 return -ENODEV;
 533
 534         /* Actual detection via device and manufacturer ID */
 535         dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
 536         manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
 537         if (dev_id != 0x58 || manu_id != 0x4D)
 538                 return -ENODEV;
 539
 540         strlcpy(info->type, "max6639", I2C_NAME_SIZE);
 541
 542         return 0;
 543 }
 544
 545 static int max6639_probe(struct i2c_client *client,
 546                          const struct i2c_device_id *id)
 547 {
 548         struct max6639_data *data;
 549         int err;
 550
 551         data = devm_kzalloc(&client->dev, sizeof(struct max6639_data),
 552                             GFP_KERNEL);
 553         if (!data)
 554                 return -ENOMEM;
 555
 556         i2c_set_clientdata(client, data);
 557         mutex_init(&data->update_lock);
 558
 559         /* Initialize the max6639 chip */
 560         err = max6639_init_client(client);
 561         if (err < 0)
 562                 return err;
 563
 564         /* Register sysfs hooks */
 565         err = sysfs_create_group(&client->dev.kobj, &max6639_group);
 566         if (err)
 567                 return err;
 568
 569         data->hwmon_dev = hwmon_device_register(&client->dev);
 570         if (IS_ERR(data->hwmon_dev)) {
 571                 err = PTR_ERR(data->hwmon_dev);
 572                 goto error_remove;
 573         }
 574
 575         dev_info(&client->dev, "temperature sensor and fan control found\n");
 576
 577         return 0;
 578
 579 error_remove:
 580         sysfs_remove_group(&client->dev.kobj, &max6639_group);
 581         return err;
 582 }
 583
 584 static int max6639_remove(struct i2c_client *client)
 585 {
 586         struct max6639_data *data = i2c_get_clientdata(client);
 587
 588         hwmon_device_unregister(data->hwmon_dev);
 589         sysfs_remove_group(&client->dev.kobj, &max6639_group);
 590
 591         return 0;
 592 }
 593
 594 #ifdef CONFIG_PM_SLEEP
 595 static int max6639_suspend(struct device *dev)
 596 {
 597         struct i2c_client *client = to_i2c_client(dev);
 598         int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 599         if (data < 0)
 600                 return data;
 601
 602         return i2c_smbus_write_byte_data(client,
 603                         MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
 604 }
 605
 606 static int max6639_resume(struct device *dev)
 607 {
 608         struct i2c_client *client = to_i2c_client(dev);
 609         int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
 610         if (data < 0)
 611                 return data;
 612
 613         return i2c_smbus_write_byte_data(client,
 614                         MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
 615 }
 616 #endif /* CONFIG_PM_SLEEP */
 617
 618 static const struct i2c_device_id max6639_id[] = {
 619         {"max6639", 0},
 620         { }
 621 };
 622
 623 MODULE_DEVICE_TABLE(i2c, max6639_id);
 624
 625 static const struct dev_pm_ops max6639_pm_ops = {
 626         SET_SYSTEM_SLEEP_PM_OPS(max6639_suspend, max6639_resume)
 627 };
 628
 629 static struct i2c_driver max6639_driver = {
 630         .class = I2C_CLASS_HWMON,
 631         .driver = {
 632                    .name = "max6639",
 633                    .pm = &max6639_pm_ops,
 634                    },
 635         .probe = max6639_probe,
 636         .remove = max6639_remove,
 637         .id_table = max6639_id,
 638         .detect = max6639_detect,
 639         .address_list = normal_i2c,
 640 };
 641
 642 module_i2c_driver(max6639_driver);
 643
 644 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
 645 MODULE_DESCRIPTION("max6639 driver");
 646 MODULE_LICENSE("GPL");