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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 	char valid;		/* !=0 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 
max6639_update_device(struct device * dev)92 static struct max6639_data *max6639_update_device(struct device *dev)
93 {
94 	struct max6639_data *data = dev_get_drvdata(dev);
95 	struct i2c_client *client = data->client;
96 	struct max6639_data *ret = data;
97 	int i;
98 	int status_reg;
99 
100 	mutex_lock(&data->update_lock);
101 
102 	if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
103 		int res;
104 
105 		dev_dbg(&client->dev, "Starting max6639 update\n");
106 
107 		status_reg = i2c_smbus_read_byte_data(client,
108 						      MAX6639_REG_STATUS);
109 		if (status_reg < 0) {
110 			ret = ERR_PTR(status_reg);
111 			goto abort;
112 		}
113 
114 		data->status = status_reg;
115 
116 		for (i = 0; i < 2; i++) {
117 			res = i2c_smbus_read_byte_data(client,
118 					MAX6639_REG_FAN_CNT(i));
119 			if (res < 0) {
120 				ret = ERR_PTR(res);
121 				goto abort;
122 			}
123 			data->fan[i] = res;
124 
125 			res = i2c_smbus_read_byte_data(client,
126 					MAX6639_REG_TEMP_EXT(i));
127 			if (res < 0) {
128 				ret = ERR_PTR(res);
129 				goto abort;
130 			}
131 			data->temp[i] = res >> 5;
132 			data->temp_fault[i] = res & 0x01;
133 
134 			res = i2c_smbus_read_byte_data(client,
135 					MAX6639_REG_TEMP(i));
136 			if (res < 0) {
137 				ret = ERR_PTR(res);
138 				goto abort;
139 			}
140 			data->temp[i] |= res << 3;
141 		}
142 
143 		data->last_updated = jiffies;
144 		data->valid = 1;
145 	}
146 abort:
147 	mutex_unlock(&data->update_lock);
148 
149 	return ret;
150 }
151 
temp_input_show(struct device * dev,struct device_attribute * dev_attr,char * buf)152 static ssize_t temp_input_show(struct device *dev,
153 			       struct device_attribute *dev_attr, char *buf)
154 {
155 	long temp;
156 	struct max6639_data *data = max6639_update_device(dev);
157 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
158 
159 	if (IS_ERR(data))
160 		return PTR_ERR(data);
161 
162 	temp = data->temp[attr->index] * 125;
163 	return sprintf(buf, "%ld\n", temp);
164 }
165 
temp_fault_show(struct device * dev,struct device_attribute * dev_attr,char * buf)166 static ssize_t temp_fault_show(struct device *dev,
167 			       struct device_attribute *dev_attr, char *buf)
168 {
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 	return sprintf(buf, "%d\n", data->temp_fault[attr->index]);
176 }
177 
temp_max_show(struct device * dev,struct device_attribute * dev_attr,char * buf)178 static ssize_t temp_max_show(struct device *dev,
179 			     struct device_attribute *dev_attr, char *buf)
180 {
181 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
182 	struct max6639_data *data = dev_get_drvdata(dev);
183 
184 	return sprintf(buf, "%d\n", (data->temp_therm[attr->index] * 1000));
185 }
186 
temp_max_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)187 static ssize_t temp_max_store(struct device *dev,
188 			      struct device_attribute *dev_attr,
189 			      const char *buf, size_t count)
190 {
191 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
192 	struct max6639_data *data = dev_get_drvdata(dev);
193 	struct i2c_client *client = data->client;
194 	unsigned long val;
195 	int res;
196 
197 	res = kstrtoul(buf, 10, &val);
198 	if (res)
199 		return res;
200 
201 	mutex_lock(&data->update_lock);
202 	data->temp_therm[attr->index] = TEMP_LIMIT_TO_REG(val);
203 	i2c_smbus_write_byte_data(client,
204 				  MAX6639_REG_THERM_LIMIT(attr->index),
205 				  data->temp_therm[attr->index]);
206 	mutex_unlock(&data->update_lock);
207 	return count;
208 }
209 
temp_crit_show(struct device * dev,struct device_attribute * dev_attr,char * buf)210 static ssize_t temp_crit_show(struct device *dev,
211 			      struct device_attribute *dev_attr, char *buf)
212 {
213 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
214 	struct max6639_data *data = dev_get_drvdata(dev);
215 
216 	return sprintf(buf, "%d\n", (data->temp_alert[attr->index] * 1000));
217 }
218 
temp_crit_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)219 static ssize_t temp_crit_store(struct device *dev,
220 			       struct device_attribute *dev_attr,
221 			       const char *buf, size_t count)
222 {
223 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
224 	struct max6639_data *data = dev_get_drvdata(dev);
225 	struct i2c_client *client = data->client;
226 	unsigned long val;
227 	int res;
228 
229 	res = kstrtoul(buf, 10, &val);
230 	if (res)
231 		return res;
232 
233 	mutex_lock(&data->update_lock);
234 	data->temp_alert[attr->index] = TEMP_LIMIT_TO_REG(val);
235 	i2c_smbus_write_byte_data(client,
236 				  MAX6639_REG_ALERT_LIMIT(attr->index),
237 				  data->temp_alert[attr->index]);
238 	mutex_unlock(&data->update_lock);
239 	return count;
240 }
241 
temp_emergency_show(struct device * dev,struct device_attribute * dev_attr,char * buf)242 static ssize_t temp_emergency_show(struct device *dev,
243 				   struct device_attribute *dev_attr,
244 				   char *buf)
245 {
246 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
247 	struct max6639_data *data = dev_get_drvdata(dev);
248 
249 	return sprintf(buf, "%d\n", (data->temp_ot[attr->index] * 1000));
250 }
251 
temp_emergency_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)252 static ssize_t temp_emergency_store(struct device *dev,
253 				    struct device_attribute *dev_attr,
254 				    const char *buf, size_t count)
255 {
256 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
257 	struct max6639_data *data = dev_get_drvdata(dev);
258 	struct i2c_client *client = data->client;
259 	unsigned long val;
260 	int res;
261 
262 	res = kstrtoul(buf, 10, &val);
263 	if (res)
264 		return res;
265 
266 	mutex_lock(&data->update_lock);
267 	data->temp_ot[attr->index] = TEMP_LIMIT_TO_REG(val);
268 	i2c_smbus_write_byte_data(client,
269 				  MAX6639_REG_OT_LIMIT(attr->index),
270 				  data->temp_ot[attr->index]);
271 	mutex_unlock(&data->update_lock);
272 	return count;
273 }
274 
pwm_show(struct device * dev,struct device_attribute * dev_attr,char * buf)275 static ssize_t pwm_show(struct device *dev, struct device_attribute *dev_attr,
276 			char *buf)
277 {
278 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
279 	struct max6639_data *data = dev_get_drvdata(dev);
280 
281 	return sprintf(buf, "%d\n", data->pwm[attr->index] * 255 / 120);
282 }
283 
pwm_store(struct device * dev,struct device_attribute * dev_attr,const char * buf,size_t count)284 static ssize_t pwm_store(struct device *dev,
285 			 struct device_attribute *dev_attr, const char *buf,
286 			 size_t count)
287 {
288 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
289 	struct max6639_data *data = dev_get_drvdata(dev);
290 	struct i2c_client *client = data->client;
291 	unsigned long val;
292 	int res;
293 
294 	res = kstrtoul(buf, 10, &val);
295 	if (res)
296 		return res;
297 
298 	val = clamp_val(val, 0, 255);
299 
300 	mutex_lock(&data->update_lock);
301 	data->pwm[attr->index] = (u8)(val * 120 / 255);
302 	i2c_smbus_write_byte_data(client,
303 				  MAX6639_REG_TARGTDUTY(attr->index),
304 				  data->pwm[attr->index]);
305 	mutex_unlock(&data->update_lock);
306 	return count;
307 }
308 
fan_input_show(struct device * dev,struct device_attribute * dev_attr,char * buf)309 static ssize_t fan_input_show(struct device *dev,
310 			      struct device_attribute *dev_attr, char *buf)
311 {
312 	struct max6639_data *data = max6639_update_device(dev);
313 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
314 
315 	if (IS_ERR(data))
316 		return PTR_ERR(data);
317 
318 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
319 		       data->rpm_range));
320 }
321 
alarm_show(struct device * dev,struct device_attribute * dev_attr,char * buf)322 static ssize_t alarm_show(struct device *dev,
323 			  struct device_attribute *dev_attr, char *buf)
324 {
325 	struct max6639_data *data = max6639_update_device(dev);
326 	struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr);
327 
328 	if (IS_ERR(data))
329 		return PTR_ERR(data);
330 
331 	return sprintf(buf, "%d\n", !!(data->status & (1 << attr->index)));
332 }
333 
334 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp_input, 0);
335 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp_input, 1);
336 static SENSOR_DEVICE_ATTR_RO(temp1_fault, temp_fault, 0);
337 static SENSOR_DEVICE_ATTR_RO(temp2_fault, temp_fault, 1);
338 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp_max, 0);
339 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp_max, 1);
340 static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp_crit, 0);
341 static SENSOR_DEVICE_ATTR_RW(temp2_crit, temp_crit, 1);
342 static SENSOR_DEVICE_ATTR_RW(temp1_emergency, temp_emergency, 0);
343 static SENSOR_DEVICE_ATTR_RW(temp2_emergency, temp_emergency, 1);
344 static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
345 static SENSOR_DEVICE_ATTR_RW(pwm2, pwm, 1);
346 static SENSOR_DEVICE_ATTR_RO(fan1_input, fan_input, 0);
347 static SENSOR_DEVICE_ATTR_RO(fan2_input, fan_input, 1);
348 static SENSOR_DEVICE_ATTR_RO(fan1_fault, alarm, 1);
349 static SENSOR_DEVICE_ATTR_RO(fan2_fault, alarm, 0);
350 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 3);
351 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 2);
352 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 7);
353 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 6);
354 static SENSOR_DEVICE_ATTR_RO(temp1_emergency_alarm, alarm, 5);
355 static SENSOR_DEVICE_ATTR_RO(temp2_emergency_alarm, alarm, 4);
356 
357 
358 static struct attribute *max6639_attrs[] = {
359 	&sensor_dev_attr_temp1_input.dev_attr.attr,
360 	&sensor_dev_attr_temp2_input.dev_attr.attr,
361 	&sensor_dev_attr_temp1_fault.dev_attr.attr,
362 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
363 	&sensor_dev_attr_temp1_max.dev_attr.attr,
364 	&sensor_dev_attr_temp2_max.dev_attr.attr,
365 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
366 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
367 	&sensor_dev_attr_temp1_emergency.dev_attr.attr,
368 	&sensor_dev_attr_temp2_emergency.dev_attr.attr,
369 	&sensor_dev_attr_pwm1.dev_attr.attr,
370 	&sensor_dev_attr_pwm2.dev_attr.attr,
371 	&sensor_dev_attr_fan1_input.dev_attr.attr,
372 	&sensor_dev_attr_fan2_input.dev_attr.attr,
373 	&sensor_dev_attr_fan1_fault.dev_attr.attr,
374 	&sensor_dev_attr_fan2_fault.dev_attr.attr,
375 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
376 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
377 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
378 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
379 	&sensor_dev_attr_temp1_emergency_alarm.dev_attr.attr,
380 	&sensor_dev_attr_temp2_emergency_alarm.dev_attr.attr,
381 	NULL
382 };
383 ATTRIBUTE_GROUPS(max6639);
384 
385 /*
386  *  returns respective index in rpm_ranges table
387  *  1 by default on invalid range
388  */
rpm_range_to_reg(int range)389 static int rpm_range_to_reg(int range)
390 {
391 	int i;
392 
393 	for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
394 		if (rpm_ranges[i] == range)
395 			return i;
396 	}
397 
398 	return 1; /* default: 4000 RPM */
399 }
400 
max6639_init_client(struct i2c_client * client,struct max6639_data * data)401 static int max6639_init_client(struct i2c_client *client,
402 			       struct max6639_data *data)
403 {
404 	struct max6639_platform_data *max6639_info =
405 		dev_get_platdata(&client->dev);
406 	int i;
407 	int rpm_range = 1; /* default: 4000 RPM */
408 	int err;
409 
410 	/* Reset chip to default values, see below for GCONFIG setup */
411 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
412 				  MAX6639_GCONFIG_POR);
413 	if (err)
414 		goto exit;
415 
416 	/* Fans pulse per revolution is 2 by default */
417 	if (max6639_info && max6639_info->ppr > 0 &&
418 			max6639_info->ppr < 5)
419 		data->ppr = max6639_info->ppr;
420 	else
421 		data->ppr = 2;
422 	data->ppr -= 1;
423 
424 	if (max6639_info)
425 		rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
426 	data->rpm_range = rpm_range;
427 
428 	for (i = 0; i < 2; i++) {
429 
430 		/* Set Fan pulse per revolution */
431 		err = i2c_smbus_write_byte_data(client,
432 				MAX6639_REG_FAN_PPR(i),
433 				data->ppr << 6);
434 		if (err)
435 			goto exit;
436 
437 		/* Fans config PWM, RPM */
438 		err = i2c_smbus_write_byte_data(client,
439 			MAX6639_REG_FAN_CONFIG1(i),
440 			MAX6639_FAN_CONFIG1_PWM | rpm_range);
441 		if (err)
442 			goto exit;
443 
444 		/* Fans PWM polarity high by default */
445 		if (max6639_info && max6639_info->pwm_polarity == 0)
446 			err = i2c_smbus_write_byte_data(client,
447 				MAX6639_REG_FAN_CONFIG2a(i), 0x00);
448 		else
449 			err = i2c_smbus_write_byte_data(client,
450 				MAX6639_REG_FAN_CONFIG2a(i), 0x02);
451 		if (err)
452 			goto exit;
453 
454 		/*
455 		 * /THERM full speed enable,
456 		 * PWM frequency 25kHz, see also GCONFIG below
457 		 */
458 		err = i2c_smbus_write_byte_data(client,
459 			MAX6639_REG_FAN_CONFIG3(i),
460 			MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
461 		if (err)
462 			goto exit;
463 
464 		/* Max. temp. 80C/90C/100C */
465 		data->temp_therm[i] = 80;
466 		data->temp_alert[i] = 90;
467 		data->temp_ot[i] = 100;
468 		err = i2c_smbus_write_byte_data(client,
469 				MAX6639_REG_THERM_LIMIT(i),
470 				data->temp_therm[i]);
471 		if (err)
472 			goto exit;
473 		err = i2c_smbus_write_byte_data(client,
474 				MAX6639_REG_ALERT_LIMIT(i),
475 				data->temp_alert[i]);
476 		if (err)
477 			goto exit;
478 		err = i2c_smbus_write_byte_data(client,
479 				MAX6639_REG_OT_LIMIT(i), data->temp_ot[i]);
480 		if (err)
481 			goto exit;
482 
483 		/* PWM 120/120 (i.e. 100%) */
484 		data->pwm[i] = 120;
485 		err = i2c_smbus_write_byte_data(client,
486 				MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
487 		if (err)
488 			goto exit;
489 	}
490 	/* Start monitoring */
491 	err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
492 		MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
493 		MAX6639_GCONFIG_PWM_FREQ_HI);
494 exit:
495 	return err;
496 }
497 
498 /* Return 0 if detection is successful, -ENODEV otherwise */
max6639_detect(struct i2c_client * client,struct i2c_board_info * info)499 static int max6639_detect(struct i2c_client *client,
500 			  struct i2c_board_info *info)
501 {
502 	struct i2c_adapter *adapter = client->adapter;
503 	int dev_id, manu_id;
504 
505 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
506 		return -ENODEV;
507 
508 	/* Actual detection via device and manufacturer ID */
509 	dev_id = i2c_smbus_read_byte_data(client, MAX6639_REG_DEVID);
510 	manu_id = i2c_smbus_read_byte_data(client, MAX6639_REG_MANUID);
511 	if (dev_id != 0x58 || manu_id != 0x4D)
512 		return -ENODEV;
513 
514 	strlcpy(info->type, "max6639", I2C_NAME_SIZE);
515 
516 	return 0;
517 }
518 
max6639_probe(struct i2c_client * client)519 static int max6639_probe(struct i2c_client *client)
520 {
521 	struct device *dev = &client->dev;
522 	struct max6639_data *data;
523 	struct device *hwmon_dev;
524 	int err;
525 
526 	data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
527 	if (!data)
528 		return -ENOMEM;
529 
530 	data->client = client;
531 	mutex_init(&data->update_lock);
532 
533 	/* Initialize the max6639 chip */
534 	err = max6639_init_client(client, data);
535 	if (err < 0)
536 		return err;
537 
538 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
539 							   data,
540 							   max6639_groups);
541 	return PTR_ERR_OR_ZERO(hwmon_dev);
542 }
543 
544 #ifdef CONFIG_PM_SLEEP
max6639_suspend(struct device * dev)545 static int max6639_suspend(struct device *dev)
546 {
547 	struct i2c_client *client = to_i2c_client(dev);
548 	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
549 	if (data < 0)
550 		return data;
551 
552 	return i2c_smbus_write_byte_data(client,
553 			MAX6639_REG_GCONFIG, data | MAX6639_GCONFIG_STANDBY);
554 }
555 
max6639_resume(struct device * dev)556 static int max6639_resume(struct device *dev)
557 {
558 	struct i2c_client *client = to_i2c_client(dev);
559 	int data = i2c_smbus_read_byte_data(client, MAX6639_REG_GCONFIG);
560 	if (data < 0)
561 		return data;
562 
563 	return i2c_smbus_write_byte_data(client,
564 			MAX6639_REG_GCONFIG, data & ~MAX6639_GCONFIG_STANDBY);
565 }
566 #endif /* CONFIG_PM_SLEEP */
567 
568 static const struct i2c_device_id max6639_id[] = {
569 	{"max6639", 0},
570 	{ }
571 };
572 
573 MODULE_DEVICE_TABLE(i2c, max6639_id);
574 
575 static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
576 
577 static struct i2c_driver max6639_driver = {
578 	.class = I2C_CLASS_HWMON,
579 	.driver = {
580 		   .name = "max6639",
581 		   .pm = &max6639_pm_ops,
582 		   },
583 	.probe_new = max6639_probe,
584 	.id_table = max6639_id,
585 	.detect = max6639_detect,
586 	.address_list = normal_i2c,
587 };
588 
589 module_i2c_driver(max6639_driver);
590 
591 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
592 MODULE_DESCRIPTION("max6639 driver");
593 MODULE_LICENSE("GPL");
594