1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * max6639.c - Support for Maxim MAX6639
4 *
5 * 2-Channel Temperature Monitor with Dual PWM Fan-Speed Controller
6 *
7 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
8 *
9 * based on the initial MAX6639 support from semptian.net
10 * by He Changqing <hechangqing@semptian.com>
11 */
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/jiffies.h>
17 #include <linux/i2c.h>
18 #include <linux/hwmon.h>
19 #include <linux/hwmon-sysfs.h>
20 #include <linux/err.h>
21 #include <linux/mutex.h>
22 #include <linux/platform_data/max6639.h>
23
24 /* Addresses to scan */
25 static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };
26
27 /* The MAX6639 registers, valid channel numbers: 0, 1 */
28 #define MAX6639_REG_TEMP(ch) (0x00 + (ch))
29 #define MAX6639_REG_STATUS 0x02
30 #define MAX6639_REG_OUTPUT_MASK 0x03
31 #define MAX6639_REG_GCONFIG 0x04
32 #define MAX6639_REG_TEMP_EXT(ch) (0x05 + (ch))
33 #define MAX6639_REG_ALERT_LIMIT(ch) (0x08 + (ch))
34 #define MAX6639_REG_OT_LIMIT(ch) (0x0A + (ch))
35 #define MAX6639_REG_THERM_LIMIT(ch) (0x0C + (ch))
36 #define MAX6639_REG_FAN_CONFIG1(ch) (0x10 + (ch) * 4)
37 #define MAX6639_REG_FAN_CONFIG2a(ch) (0x11 + (ch) * 4)
38 #define MAX6639_REG_FAN_CONFIG2b(ch) (0x12 + (ch) * 4)
39 #define MAX6639_REG_FAN_CONFIG3(ch) (0x13 + (ch) * 4)
40 #define MAX6639_REG_FAN_CNT(ch) (0x20 + (ch))
41 #define MAX6639_REG_TARGET_CNT(ch) (0x22 + (ch))
42 #define MAX6639_REG_FAN_PPR(ch) (0x24 + (ch))
43 #define MAX6639_REG_TARGTDUTY(ch) (0x26 + (ch))
44 #define MAX6639_REG_FAN_START_TEMP(ch) (0x28 + (ch))
45 #define MAX6639_REG_DEVID 0x3D
46 #define MAX6639_REG_MANUID 0x3E
47 #define MAX6639_REG_DEVREV 0x3F
48
49 /* Register bits */
50 #define MAX6639_GCONFIG_STANDBY 0x80
51 #define MAX6639_GCONFIG_POR 0x40
52 #define MAX6639_GCONFIG_DISABLE_TIMEOUT 0x20
53 #define MAX6639_GCONFIG_CH2_LOCAL 0x10
54 #define MAX6639_GCONFIG_PWM_FREQ_HI 0x08
55
56 #define MAX6639_FAN_CONFIG1_PWM 0x80
57
58 #define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED 0x40
59
60 static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
61
62 #define FAN_FROM_REG(val, rpm_range) ((val) == 0 || (val) == 255 ? \
63 0 : (rpm_ranges[rpm_range] * 30) / (val))
64 #define TEMP_LIMIT_TO_REG(val) clamp_val((val) / 1000, 0, 255)
65
66 /*
67 * Client data (each client gets its own)
68 */
69 struct max6639_data {
70 struct i2c_client *client;
71 struct mutex update_lock;
72 bool valid; /* true if following fields are valid */
73 unsigned long last_updated; /* In jiffies */
74
75 /* Register values sampled regularly */
76 u16 temp[2]; /* Temperature, in 1/8 C, 0..255 C */
77 bool temp_fault[2]; /* Detected temperature diode failure */
78 u8 fan[2]; /* Register value: TACH count for fans >=30 */
79 u8 status; /* Detected channel alarms and fan failures */
80
81 /* Register values only written to */
82 u8 pwm[2]; /* Register value: Duty cycle 0..120 */
83 u8 temp_therm[2]; /* THERM Temperature, 0..255 C (->_max) */
84 u8 temp_alert[2]; /* ALERT Temperature, 0..255 C (->_crit) */
85 u8 temp_ot[2]; /* OT Temperature, 0..255 C (->_emergency) */
86
87 /* Register values initialized only once */
88 u8 ppr; /* Pulses per rotation 0..3 for 1..4 ppr */
89 u8 rpm_range; /* Index in above rpm_ranges table */
90
91 /* Optional regulator for FAN supply */
92 struct regulator *reg;
93 };
94
max6639_update_device(struct device * dev)95 static struct max6639_data *max6639_update_device(struct device *dev)
96 {
97 struct max6639_data *data = dev_get_drvdata(dev);
98 struct i2c_client *client = data->client;
99 struct max6639_data *ret = data;
100 int i;
101 int status_reg;
102
103 mutex_lock(&data->update_lock);
104
105 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
106 int res;
107
108 dev_dbg(&client->dev, "Starting max6639 update\n");
109
110 status_reg = i2c_smbus_read_byte_data(client,
111 MAX6639_REG_STATUS);
112 if (status_reg < 0) {
113 ret = ERR_PTR(status_reg);
114 goto abort;
115 }
116
117 data->status = status_reg;
118
119 for (i = 0; i < 2; i++) {
120 res = i2c_smbus_read_byte_data(client,
121 MAX6639_REG_FAN_CNT(i));
122 if (res < 0) {
123 ret = ERR_PTR(res);
124 goto abort;
125 }
126 data->fan[i] = res;
127
128 res = i2c_smbus_read_byte_data(client,
129 MAX6639_REG_TEMP_EXT(i));
130 if (res < 0) {
131 ret = ERR_PTR(res);
132 goto abort;
133 }
134 data->temp[i] = res >> 5;
135 data->temp_fault[i] = res & 0x01;
136
137 res = i2c_smbus_read_byte_data(client,
138 MAX6639_REG_TEMP(i));
139 if (res < 0) {
140 ret = ERR_PTR(res);
141 goto abort;
142 }
143 data->temp[i] |= res << 3;
144 }
145
146 data->last_updated = jiffies;
147 data->valid = true;
148 }
149 abort:
150 mutex_unlock(&data->update_lock);
151
152 return ret;
153 }
154
temp_input_show(struct device * dev,struct device_attribute * dev_attr,char * buf)155 static ssize_t temp_input_show(struct device *dev,
156 struct device_attribute *dev_attr, char *buf)
157 {
158 long temp;
159 struct max6639_data *data = max6639_update_device(dev);
160 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
161
162 if (IS_ERR(data))
163 return PTR_ERR(data);
164
165 temp = data->temp[attr->index] * 125;
166 return sprintf(buf, "%ld\n", temp);
167 }
168
temp_fault_show(struct device * dev,struct device_attribute * dev_attr,char * buf)169 static ssize_t temp_fault_show(struct device *dev,
170 struct device_attribute *dev_attr, char *buf)
171 {
172 struct max6639_data *data = max6639_update_device(dev);
173 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
174
175 if (IS_ERR(data))
176 return PTR_ERR(data);
177
178 return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
179 }
180
temp_max_show(struct device * dev,struct device_attribute * dev_attr,char * buf)181 static ssize_t temp_max_show(struct device *dev,
182 struct device_attribute *dev_attr, char *buf)
183 {
184 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
185 struct max6639_data *data = dev_get_drvdata(dev);
186
187 return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
188 }
189
temp_max_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)190 static ssize_t temp_max_store(struct device *dev,
191 struct device_attribute *dev_attr,
192 const char *buf, size_t count)
193 {
194 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
195 struct max6639_data *data = dev_get_drvdata(dev);
196 struct i2c_client *client = data->client;
197 unsigned long val;
198 int res;
199
200 res = kstrtoul(buf, 10, &val);
201 if (res)
202 return res;
203
204 mutex_lock(&data->update_lock);
205 data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
206 i2c_smbus_write_byte_data(client,
207 MAX6639_REG_THERM_LIMIT(attr->index),
208 data->temp_therm[attr->index]);
209 mutex_unlock(&data->update_lock);
210 return count;
211 }
212
temp_crit_show(struct device * dev,struct device_attribute * dev_attr,char * buf)213 static ssize_t temp_crit_show(struct device *dev,
214 struct device_attribute *dev_attr, char *buf)
215 {
216 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
217 struct max6639_data *data = dev_get_drvdata(dev);
218
219 return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
220 }
221
temp_crit_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)222 static ssize_t temp_crit_store(struct device *dev,
223 struct device_attribute *dev_attr,
224 const char *buf, size_t count)
225 {
226 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
227 struct max6639_data *data = dev_get_drvdata(dev);
228 struct i2c_client *client = data->client;
229 unsigned long val;
230 int res;
231
232 res = kstrtoul(buf, 10, &val);
233 if (res)
234 return res;
235
236 mutex_lock(&data->update_lock);
237 data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
238 i2c_smbus_write_byte_data(client,
239 MAX6639_REG_ALERT_LIMIT(attr->index),
240 data->temp_alert[attr->index]);
241 mutex_unlock(&data->update_lock);
242 return count;
243 }
244
temp_emergency_show(struct device * dev,struct device_attribute * dev_attr,char * buf)245 static ssize_t temp_emergency_show(struct device *dev,
246 struct device_attribute *dev_attr,
247 char *buf)
248 {
249 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
250 struct max6639_data *data = dev_get_drvdata(dev);
251
252 return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
253 }
254
temp_emergency_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)255 static ssize_t temp_emergency_store(struct device *dev,
256 struct device_attribute *dev_attr,
257 const char *buf, size_t count)
258 {
259 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
260 struct max6639_data *data = dev_get_drvdata(dev);
261 struct i2c_client *client = data->client;
262 unsigned long val;
263 int res;
264
265 res = kstrtoul(buf, 10, &val);
266 if (res)
267 return res;
268
269 mutex_lock(&data->update_lock);
270 data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
271 i2c_smbus_write_byte_data(client,
272 MAX6639_REG_OT_LIMIT(attr->index),
273 data->temp_ot[attr->index]);
274 mutex_unlock(&data->update_lock);
275 return count;
276 }
277
pwm_show(struct device * dev,struct device_attribute * dev_attr,char * buf)278 static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
279 char *buf)
280 {
281 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
282 struct max6639_data *data = dev_get_drvdata(dev);
283
284 return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
285 }
286
pwm_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)287 static ssize_t pwm_store(struct device *dev,
288 struct device_attribute *dev_attr, const char *buf,
289 size_t count)
290 {
291 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
292 struct max6639_data *data = dev_get_drvdata(dev);
293 struct i2c_client *client = data->client;
294 unsigned long val;
295 int res;
296
297 res = kstrtoul(buf, 10, &val);
298 if (res)
299 return res;
300
301 val = clamp_val(val, 0, 255);
302
303 mutex_lock(&data->update_lock);
304 data->pwm[attr->index] = (u8)(val * 120 / 255);
305 i2c_smbus_write_byte_data(client,
306 MAX6639_REG_TARGTDUTY(attr->index),
307 data->pwm[attr->index]);
308 mutex_unlock(&data->update_lock);
309 return count;
310 }
311
fan_input_show(struct device * dev,struct device_attribute * dev_attr,char * buf)312 static ssize_t fan_input_show(struct device *dev,
313 struct device_attribute *dev_attr, char *buf)
314 {
315 struct max6639_data *data = max6639_update_device(dev);
316 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
317
318 if (IS_ERR(data))
319 return PTR_ERR(data);
320
321 return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
322 data->rpm_range));
323 }
324
alarm_show(struct device * dev,struct device_attribute * dev_attr,char * buf)325 static ssize_t alarm_show(struct device *dev,
326 struct device_attribute *dev_attr, char *buf)
327 {
328 struct max6639_data *data = max6639_update_device(dev);
329 struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
330
331 if (IS_ERR(data))
332 return PTR_ERR(data);
333
334 return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
335 }
336
337 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
338 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_input, 1);
339 static SENSOR_DEVICE_ATTR_RO(temp1_fault, temp_fault, 0);
340 static SENSOR_DEVICE_ATTR_RO(temp2_fault, temp_fault, 1);
341 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
342 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
343 static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
344 static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
345 static SENSOR_DEVICE_ATTR_RW(temp1_emergency, temp_emergency, 0);
346 static SENSOR_DEVICE_ATTR_RW(temp2_emergency, temp_emergency, 1);
347 static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
348 static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
349 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
350 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan_input, 1);
351 static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
352 static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 0);
353 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 3);
354 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
355 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 7);
356 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 6);
357 static SENSOR_DEVICE_ATTR_RO(temp1_emergency_alarm, alarm, 5);
358 static SENSOR_DEVICE_ATTR_RO(temp2_emergency_alarm, alarm, 4);
359
360
361 static struct attribute *max6639_attrs[] = {
362 &sensor_dev_attr_temp1_input.dev_attr.attr,
363 &sensor_dev_attr_temp2_input.dev_attr.attr,
364 &sensor_dev_attr_temp1_fault.dev_attr.attr,
365 &sensor_dev_attr_temp2_fault.dev_attr.attr,
366 &sensor_dev_attr_temp1_max.dev_attr.attr,
367 &sensor_dev_attr_temp2_max.dev_attr.attr,
368 &sensor_dev_attr_temp1_crit.dev_attr.attr,
369 &sensor_dev_attr_temp2_crit.dev_attr.attr,
370 &sensor_dev_attr_temp1_emergency.dev_attr.attr,
371 &sensor_dev_attr_temp2_emergency.dev_attr.attr,
372 &sensor_dev_attr_pwm1.dev_attr.attr,
373 &sensor_dev_attr_pwm2.dev_attr.attr,
374 &sensor_dev_attr_fan1_input.dev_attr.attr,
375 &sensor_dev_attr_fan2_input.dev_attr.attr,
376 &sensor_dev_attr_fan1_fault.dev_attr.attr,
377 &sensor_dev_attr_fan2_fault.dev_attr.attr,
378 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
379 &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
380 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
381 &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
382 &sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
383 &sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
384 NULL
385 };
386 ATTRIBUTE_GROUPS(max6639);
387
388 /*
389 * returns respective index in rpm_ranges table
390 * 1 by default on invalid range
391 */
rpm_range_to_reg(int range)392 static int rpm_range_to_reg(int range)
393 {
394 int i;
395
396 for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
397 if (rpm_ranges[i] == range)
398 return i;
399 }
400
401 return 1; /* default: 4000 RPM */
402 }
403
max6639_init_client(struct i2c_client * client,struct max6639_data * data)404 static int max6639_init_client(struct i2c_client *client,
405 struct max6639_data *data)
406 {
407 struct max6639_platform_data *max6639_info =
408 dev_get_platdata(&client->dev);
409 int i;
410 int rpm_range = 1; /* default: 4000 RPM */
411 int err;
412
413 /* Reset chip to default values, see below for GCONFIG setup */
414 err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
415 MAX6639_GCONFIG_POR);
416 if (err)
417 goto exit;
418
419 /* Fans pulse per revolution is 2 by default */
420 if (max6639_info && max6639_info->ppr > 0 &&
421 max6639_info->ppr < 5)
422 data->ppr = max6639_info->ppr;
423 else
424 data->ppr = 2;
425 data->ppr -= 1;
426
427 if (max6639_info)
428 rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
429 data->rpm_range = rpm_range;
430
431 for (i = 0; i < 2; i++) {
432
433 /* Set Fan pulse per revolution */
434 err = i2c_smbus_write_byte_data(client,
435 MAX6639_REG_FAN_PPR(i),
436 data->ppr << 6);
437 if (err)
438 goto exit;
439
440 /* Fans config PWM, RPM */
441 err = i2c_smbus_write_byte_data(client,
442 MAX6639_REG_FAN_CONFIG1(i),
443 MAX6639_FAN_CONFIG1_PWM | rpm_range);
444 if (err)
445 goto exit;
446
447 /* Fans PWM polarity high by default */
448 if (max6639_info && max6639_info->pwm_polarity == 0)
449 err = i2c_smbus_write_byte_data(client,
450 MAX6639_REG_FAN_CONFIG2a(i), 0x00);
451 else
452 err = i2c_smbus_write_byte_data(client,
453 MAX6639_REG_FAN_CONFIG2a(i), 0x02);
454 if (err)
455 goto exit;
456
457 /*
458 * /THERM full speed enable,
459 * PWM frequency 25kHz, see also GCONFIG below
460 */
461 err = i2c_smbus_write_byte_data(client,
462 MAX6639_REG_FAN_CONFIG3(i),
463 MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
464 if (err)
465 goto exit;
466
467 /* Max. temp. 80C/90C/100C */
468 data->temp_therm[i] = 80;
469 data->temp_alert[i] = 90;
470 data->temp_ot[i] = 100;
471 err = i2c_smbus_write_byte_data(client,
472 MAX6639_REG_THERM_LIMIT(i),
473 data->temp_therm[i]);
474 if (err)
475 goto exit;
476 err = i2c_smbus_write_byte_data(client,
477 MAX6639_REG_ALERT_LIMIT(i),
478 data->temp_alert[i]);
479 if (err)
480 goto exit;
481 err = i2c_smbus_write_byte_data(client,
482 MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
483 if (err)
484 goto exit;
485
486 /* PWM 120/120 (i.e. 100%) */
487 data->pwm[i] = 120;
488 err = i2c_smbus_write_byte_data(client,
489 MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
490 if (err)
491 goto exit;
492 }
493 /* Start monitoring */
494 err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
495 MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
496 MAX6639_GCONFIG_PWM_FREQ_HI);
497 exit:
498 return err;
499 }
500
501 /* Return 0 if detection is successful, -ENODEV otherwise */
max6639_detect(struct i2c_client * client,struct i2c_board_info * info)502 static int max6639_detect(struct i2c_client *client,
503 struct i2c_board_info *info)
504 {
505 struct i2c_adapter *adapter = client->adapter;
506 int dev_id, manu_id;
507
508 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
509 return -ENODEV;
510
511 /* Actual detection via device and manufacturer ID */
512 dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
513 manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
514 if (dev_id != 0x58 || manu_id != 0x4D)
515 return -ENODEV;
516
517 strscpy(info->type, "max6639", I2C_NAME_SIZE);
518
519 return 0;
520 }
521
max6639_regulator_disable(void * data)522 static void max6639_regulator_disable(void *data)
523 {
524 regulator_disable(data);
525 }
526
max6639_probe(struct i2c_client * client)527 static int max6639_probe(struct i2c_client *client)
528 {
529 struct device *dev = &client->dev;
530 struct max6639_data *data;
531 struct device *hwmon_dev;
532 int err;
533
534 data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
535 if (!data)
536 return -ENOMEM;
537
538 data->client = client;
539
540 data->reg = devm_regulator_get_optional(dev, "fan");
541 if (IS_ERR(data->reg)) {
542 if (PTR_ERR(data->reg) != -ENODEV)
543 return PTR_ERR(data->reg);
544
545 data->reg = NULL;
546 } else {
547 /* Spin up fans */
548 err = regulator_enable(data->reg);
549 if (err) {
550 dev_err(dev, "Failed to enable fan supply: %d\n", err);
551 return err;
552 }
553 err = devm_add_action_or_reset(dev, max6639_regulator_disable,
554 data->reg);
555 if (err) {
556 dev_err(dev, "Failed to register action: %d\n", err);
557 return err;
558 }
559 }
560
561 mutex_init(&data->update_lock);
562
563 /* Initialize the max6639 chip */
564 err = max6639_init_client(client, data);
565 if (err < 0)
566 return err;
567
568 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
569 data,
570 max6639_groups);
571 return PTR_ERR_OR_ZERO(hwmon_dev);
572 }
573
max6639_suspend(struct device * dev)574 static int max6639_suspend(struct device *dev)
575 {
576 struct i2c_client *client = to_i2c_client(dev);
577 struct max6639_data *data = dev_get_drvdata(dev);
578 int ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
579
580 if (ret < 0)
581 return ret;
582
583 if (data->reg)
584 regulator_disable(data->reg);
585
586 return i2c_smbus_write_byte_data(client,
587 MAX6639_REG_GCONFIG, ret | MAX6639_GCONFIG_STANDBY);
588 }
589
max6639_resume(struct device * dev)590 static int max6639_resume(struct device *dev)
591 {
592 struct i2c_client *client = to_i2c_client(dev);
593 struct max6639_data *data = dev_get_drvdata(dev);
594 int ret;
595
596 if (data->reg) {
597 ret = regulator_enable(data->reg);
598 if (ret) {
599 dev_err(dev, "Failed to enable fan supply: %d\n", ret);
600 return ret;
601 }
602 }
603
604 ret = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
605 if (ret < 0)
606 return ret;
607
608 return i2c_smbus_write_byte_data(client,
609 MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
610 }
611
612 static const struct i2c_device_id max6639_id[] = {
613 {"max6639", 0},
614 { }
615 };
616
617 MODULE_DEVICE_TABLE(i2c, max6639_id);
618
619 static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
620
621 static const struct of_device_id max6639_of_match[] = {
622 { .compatible = "maxim,max6639", },
623 { },
624 };
625
626 static struct i2c_driver max6639_driver = {
627 .class = I2C_CLASS_HWMON,
628 .driver = {
629 .name = "max6639",
630 .pm = pm_sleep_ptr(&max6639_pm_ops),
631 .of_match_table = max6639_of_match,
632 },
633 .probe = max6639_probe,
634 .id_table = max6639_id,
635 .detect = max6639_detect,
636 .address_list = normal_i2c,
637 };
638
639 module_i2c_driver(max6639_driver);
640
641 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
642 MODULE_DESCRIPTION("max6639 driver");
643 MODULE_LICENSE("GPL");
644