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max6639.c
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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 <[email protected]>
7  *
8  * based on the initial MAX6639 support from semptian.net
9  * by He Changqing <[email protected]>
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) SENSORS_LIMIT((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 = SENSORS_LIMIT(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  client->dev.platform_data;
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 <[email protected]>");
645 MODULE_DESCRIPTION("max6639 driver");
646 MODULE_LICENSE("GPL");
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