xref: /linux/drivers/hwmon/emc2103.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
1 /*
2  * emc2103.c - Support for SMSC EMC2103
3  * Copyright (c) 2010 SMSC
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 /* Addresses scanned */
31 static const unsigned short normal_i2c[] = { 0x2E, I2C_CLIENT_END };
32 
33 static const u8 REG_TEMP[4] = { 0x00, 0x02, 0x04, 0x06 };
34 static const u8 REG_TEMP_MIN[4] = { 0x3c, 0x38, 0x39, 0x3a };
35 static const u8 REG_TEMP_MAX[4] = { 0x34, 0x30, 0x31, 0x32 };
36 
37 #define REG_CONF1		0x20
38 #define REG_TEMP_MAX_ALARM	0x24
39 #define REG_TEMP_MIN_ALARM	0x25
40 #define REG_FAN_CONF1		0x42
41 #define REG_FAN_TARGET_LO	0x4c
42 #define REG_FAN_TARGET_HI	0x4d
43 #define REG_FAN_TACH_HI		0x4e
44 #define REG_FAN_TACH_LO		0x4f
45 #define REG_PRODUCT_ID		0xfd
46 #define REG_MFG_ID		0xfe
47 
48 /* equation 4 from datasheet: rpm = (3932160 * multipler) / count */
49 #define FAN_RPM_FACTOR		3932160
50 
51 /*
52  * 2103-2 and 2103-4's 3rd temperature sensor can be connected to two diodes
53  * in anti-parallel mode, and in this configuration both can be read
54  * independently (so we have 4 temperature inputs).  The device can't
55  * detect if it's connected in this mode, so we have to manually enable
56  * it.  Default is to leave the device in the state it's already in (-1).
57  * This parameter allows APD mode to be optionally forced on or off
58  */
59 static int apd = -1;
60 module_param(apd, bint, 0);
61 MODULE_PARM_DESC(init, "Set to zero to disable anti-parallel diode mode");
62 
63 struct temperature {
64 	s8	degrees;
65 	u8	fraction;	/* 0-7 multiples of 0.125 */
66 };
67 
68 struct emc2103_data {
69 	struct device		*hwmon_dev;
70 	struct mutex		update_lock;
71 	bool			valid;		/* registers are valid */
72 	bool			fan_rpm_control;
73 	int			temp_count;	/* num of temp sensors */
74 	unsigned long		last_updated;	/* in jiffies */
75 	struct temperature	temp[4];	/* internal + 3 external */
76 	s8			temp_min[4];	/* no fractional part */
77 	s8			temp_max[4];    /* no fractional part */
78 	u8			temp_min_alarm;
79 	u8			temp_max_alarm;
80 	u8			fan_multiplier;
81 	u16			fan_tach;
82 	u16			fan_target;
83 };
84 
85 static int read_u8_from_i2c(struct i2c_client *client, u8 i2c_reg, u8 *output)
86 {
87 	int status = i2c_smbus_read_byte_data(client, i2c_reg);
88 	if (status < 0) {
89 		dev_warn(&client->dev, "reg 0x%02x, err %d\n",
90 			i2c_reg, status);
91 	} else {
92 		*output = status;
93 	}
94 	return status;
95 }
96 
97 static void read_temp_from_i2c(struct i2c_client *client, u8 i2c_reg,
98 			       struct temperature *temp)
99 {
100 	u8 degrees, fractional;
101 
102 	if (read_u8_from_i2c(client, i2c_reg, &degrees) < 0)
103 		return;
104 
105 	if (read_u8_from_i2c(client, i2c_reg + 1, &fractional) < 0)
106 		return;
107 
108 	temp->degrees = degrees;
109 	temp->fraction = (fractional & 0xe0) >> 5;
110 }
111 
112 static void read_fan_from_i2c(struct i2c_client *client, u16 *output,
113 			      u8 hi_addr, u8 lo_addr)
114 {
115 	u8 high_byte, lo_byte;
116 
117 	if (read_u8_from_i2c(client, hi_addr, &high_byte) < 0)
118 		return;
119 
120 	if (read_u8_from_i2c(client, lo_addr, &lo_byte) < 0)
121 		return;
122 
123 	*output = ((u16)high_byte << 5) | (lo_byte >> 3);
124 }
125 
126 static void write_fan_target_to_i2c(struct i2c_client *client, u16 new_target)
127 {
128 	u8 high_byte = (new_target & 0x1fe0) >> 5;
129 	u8 low_byte = (new_target & 0x001f) << 3;
130 	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_LO, low_byte);
131 	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_HI, high_byte);
132 }
133 
134 static void read_fan_config_from_i2c(struct i2c_client *client)
135 
136 {
137 	struct emc2103_data *data = i2c_get_clientdata(client);
138 	u8 conf1;
139 
140 	if (read_u8_from_i2c(client, REG_FAN_CONF1, &conf1) < 0)
141 		return;
142 
143 	data->fan_multiplier = 1 << ((conf1 & 0x60) >> 5);
144 	data->fan_rpm_control = (conf1 & 0x80) != 0;
145 }
146 
147 static struct emc2103_data *emc2103_update_device(struct device *dev)
148 {
149 	struct i2c_client *client = to_i2c_client(dev);
150 	struct emc2103_data *data = i2c_get_clientdata(client);
151 
152 	mutex_lock(&data->update_lock);
153 
154 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
155 	    || !data->valid) {
156 		int i;
157 
158 		for (i = 0; i < data->temp_count; i++) {
159 			read_temp_from_i2c(client, REG_TEMP[i], &data->temp[i]);
160 			read_u8_from_i2c(client, REG_TEMP_MIN[i],
161 				&data->temp_min[i]);
162 			read_u8_from_i2c(client, REG_TEMP_MAX[i],
163 				&data->temp_max[i]);
164 		}
165 
166 		read_u8_from_i2c(client, REG_TEMP_MIN_ALARM,
167 			&data->temp_min_alarm);
168 		read_u8_from_i2c(client, REG_TEMP_MAX_ALARM,
169 			&data->temp_max_alarm);
170 
171 		read_fan_from_i2c(client, &data->fan_tach,
172 			REG_FAN_TACH_HI, REG_FAN_TACH_LO);
173 		read_fan_from_i2c(client, &data->fan_target,
174 			REG_FAN_TARGET_HI, REG_FAN_TARGET_LO);
175 		read_fan_config_from_i2c(client);
176 
177 		data->last_updated = jiffies;
178 		data->valid = true;
179 	}
180 
181 	mutex_unlock(&data->update_lock);
182 
183 	return data;
184 }
185 
186 static ssize_t
187 show_temp(struct device *dev, struct device_attribute *da, char *buf)
188 {
189 	int nr = to_sensor_dev_attr(da)->index;
190 	struct emc2103_data *data = emc2103_update_device(dev);
191 	int millidegrees = data->temp[nr].degrees * 1000
192 		+ data->temp[nr].fraction * 125;
193 	return sprintf(buf, "%d\n", millidegrees);
194 }
195 
196 static ssize_t
197 show_temp_min(struct device *dev, struct device_attribute *da, char *buf)
198 {
199 	int nr = to_sensor_dev_attr(da)->index;
200 	struct emc2103_data *data = emc2103_update_device(dev);
201 	int millidegrees = data->temp_min[nr] * 1000;
202 	return sprintf(buf, "%d\n", millidegrees);
203 }
204 
205 static ssize_t
206 show_temp_max(struct device *dev, struct device_attribute *da, char *buf)
207 {
208 	int nr = to_sensor_dev_attr(da)->index;
209 	struct emc2103_data *data = emc2103_update_device(dev);
210 	int millidegrees = data->temp_max[nr] * 1000;
211 	return sprintf(buf, "%d\n", millidegrees);
212 }
213 
214 static ssize_t
215 show_temp_fault(struct device *dev, struct device_attribute *da, char *buf)
216 {
217 	int nr = to_sensor_dev_attr(da)->index;
218 	struct emc2103_data *data = emc2103_update_device(dev);
219 	bool fault = (data->temp[nr].degrees == -128);
220 	return sprintf(buf, "%d\n", fault ? 1 : 0);
221 }
222 
223 static ssize_t
224 show_temp_min_alarm(struct device *dev, struct device_attribute *da, char *buf)
225 {
226 	int nr = to_sensor_dev_attr(da)->index;
227 	struct emc2103_data *data = emc2103_update_device(dev);
228 	bool alarm = data->temp_min_alarm & (1 << nr);
229 	return sprintf(buf, "%d\n", alarm ? 1 : 0);
230 }
231 
232 static ssize_t
233 show_temp_max_alarm(struct device *dev, struct device_attribute *da, char *buf)
234 {
235 	int nr = to_sensor_dev_attr(da)->index;
236 	struct emc2103_data *data = emc2103_update_device(dev);
237 	bool alarm = data->temp_max_alarm & (1 << nr);
238 	return sprintf(buf, "%d\n", alarm ? 1 : 0);
239 }
240 
241 static ssize_t set_temp_min(struct device *dev, struct device_attribute *da,
242 			    const char *buf, size_t count)
243 {
244 	int nr = to_sensor_dev_attr(da)->index;
245 	struct i2c_client *client = to_i2c_client(dev);
246 	struct emc2103_data *data = i2c_get_clientdata(client);
247 	long val;
248 
249 	int result = kstrtol(buf, 10, &val);
250 	if (result < 0)
251 		return -EINVAL;
252 
253 	val = DIV_ROUND_CLOSEST(val, 1000);
254 	if ((val < -63) || (val > 127))
255 		return -EINVAL;
256 
257 	mutex_lock(&data->update_lock);
258 	data->temp_min[nr] = val;
259 	i2c_smbus_write_byte_data(client, REG_TEMP_MIN[nr], val);
260 	mutex_unlock(&data->update_lock);
261 
262 	return count;
263 }
264 
265 static ssize_t set_temp_max(struct device *dev, struct device_attribute *da,
266 			    const char *buf, size_t count)
267 {
268 	int nr = to_sensor_dev_attr(da)->index;
269 	struct i2c_client *client = to_i2c_client(dev);
270 	struct emc2103_data *data = i2c_get_clientdata(client);
271 	long val;
272 
273 	int result = kstrtol(buf, 10, &val);
274 	if (result < 0)
275 		return -EINVAL;
276 
277 	val = DIV_ROUND_CLOSEST(val, 1000);
278 	if ((val < -63) || (val > 127))
279 		return -EINVAL;
280 
281 	mutex_lock(&data->update_lock);
282 	data->temp_max[nr] = val;
283 	i2c_smbus_write_byte_data(client, REG_TEMP_MAX[nr], val);
284 	mutex_unlock(&data->update_lock);
285 
286 	return count;
287 }
288 
289 static ssize_t
290 show_fan(struct device *dev, struct device_attribute *da, char *buf)
291 {
292 	struct emc2103_data *data = emc2103_update_device(dev);
293 	int rpm = 0;
294 	if (data->fan_tach != 0)
295 		rpm = (FAN_RPM_FACTOR * data->fan_multiplier) / data->fan_tach;
296 	return sprintf(buf, "%d\n", rpm);
297 }
298 
299 static ssize_t
300 show_fan_div(struct device *dev, struct device_attribute *da, char *buf)
301 {
302 	struct emc2103_data *data = emc2103_update_device(dev);
303 	int fan_div = 8 / data->fan_multiplier;
304 	return sprintf(buf, "%d\n", fan_div);
305 }
306 
307 /*
308  * Note: we also update the fan target here, because its value is
309  * determined in part by the fan clock divider.  This follows the principle
310  * of least surprise; the user doesn't expect the fan target to change just
311  * because the divider changed.
312  */
313 static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
314 			   const char *buf, size_t count)
315 {
316 	struct emc2103_data *data = emc2103_update_device(dev);
317 	struct i2c_client *client = to_i2c_client(dev);
318 	int new_range_bits, old_div = 8 / data->fan_multiplier;
319 	long new_div;
320 
321 	int status = kstrtol(buf, 10, &new_div);
322 	if (status < 0)
323 		return -EINVAL;
324 
325 	if (new_div == old_div) /* No change */
326 		return count;
327 
328 	switch (new_div) {
329 	case 1:
330 		new_range_bits = 3;
331 		break;
332 	case 2:
333 		new_range_bits = 2;
334 		break;
335 	case 4:
336 		new_range_bits = 1;
337 		break;
338 	case 8:
339 		new_range_bits = 0;
340 		break;
341 	default:
342 		return -EINVAL;
343 	}
344 
345 	mutex_lock(&data->update_lock);
346 
347 	status = i2c_smbus_read_byte_data(client, REG_FAN_CONF1);
348 	if (status < 0) {
349 		dev_dbg(&client->dev, "reg 0x%02x, err %d\n",
350 			REG_FAN_CONF1, status);
351 		mutex_unlock(&data->update_lock);
352 		return -EIO;
353 	}
354 	status &= 0x9F;
355 	status |= (new_range_bits << 5);
356 	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, status);
357 
358 	data->fan_multiplier = 8 / new_div;
359 
360 	/* update fan target if high byte is not disabled */
361 	if ((data->fan_target & 0x1fe0) != 0x1fe0) {
362 		u16 new_target = (data->fan_target * old_div) / new_div;
363 		data->fan_target = min(new_target, (u16)0x1fff);
364 		write_fan_target_to_i2c(client, data->fan_target);
365 	}
366 
367 	/* invalidate data to force re-read from hardware */
368 	data->valid = false;
369 
370 	mutex_unlock(&data->update_lock);
371 	return count;
372 }
373 
374 static ssize_t
375 show_fan_target(struct device *dev, struct device_attribute *da, char *buf)
376 {
377 	struct emc2103_data *data = emc2103_update_device(dev);
378 	int rpm = 0;
379 
380 	/* high byte of 0xff indicates disabled so return 0 */
381 	if ((data->fan_target != 0) && ((data->fan_target & 0x1fe0) != 0x1fe0))
382 		rpm = (FAN_RPM_FACTOR * data->fan_multiplier)
383 			/ data->fan_target;
384 
385 	return sprintf(buf, "%d\n", rpm);
386 }
387 
388 static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
389 			      const char *buf, size_t count)
390 {
391 	struct emc2103_data *data = emc2103_update_device(dev);
392 	struct i2c_client *client = to_i2c_client(dev);
393 	long rpm_target;
394 
395 	int result = kstrtol(buf, 10, &rpm_target);
396 	if (result < 0)
397 		return -EINVAL;
398 
399 	/* Datasheet states 16384 as maximum RPM target (table 3.2) */
400 	if ((rpm_target < 0) || (rpm_target > 16384))
401 		return -EINVAL;
402 
403 	mutex_lock(&data->update_lock);
404 
405 	if (rpm_target == 0)
406 		data->fan_target = 0x1fff;
407 	else
408 		data->fan_target = clamp_val(
409 			(FAN_RPM_FACTOR * data->fan_multiplier) / rpm_target,
410 			0, 0x1fff);
411 
412 	write_fan_target_to_i2c(client, data->fan_target);
413 
414 	mutex_unlock(&data->update_lock);
415 	return count;
416 }
417 
418 static ssize_t
419 show_fan_fault(struct device *dev, struct device_attribute *da, char *buf)
420 {
421 	struct emc2103_data *data = emc2103_update_device(dev);
422 	bool fault = ((data->fan_tach & 0x1fe0) == 0x1fe0);
423 	return sprintf(buf, "%d\n", fault ? 1 : 0);
424 }
425 
426 static ssize_t
427 show_pwm_enable(struct device *dev, struct device_attribute *da, char *buf)
428 {
429 	struct emc2103_data *data = emc2103_update_device(dev);
430 	return sprintf(buf, "%d\n", data->fan_rpm_control ? 3 : 0);
431 }
432 
433 static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
434 			      const char *buf, size_t count)
435 {
436 	struct i2c_client *client = to_i2c_client(dev);
437 	struct emc2103_data *data = i2c_get_clientdata(client);
438 	long new_value;
439 	u8 conf_reg;
440 
441 	int result = kstrtol(buf, 10, &new_value);
442 	if (result < 0)
443 		return -EINVAL;
444 
445 	mutex_lock(&data->update_lock);
446 	switch (new_value) {
447 	case 0:
448 		data->fan_rpm_control = false;
449 		break;
450 	case 3:
451 		data->fan_rpm_control = true;
452 		break;
453 	default:
454 		count = -EINVAL;
455 		goto err;
456 	}
457 
458 	result = read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
459 	if (result) {
460 		count = result;
461 		goto err;
462 	}
463 
464 	if (data->fan_rpm_control)
465 		conf_reg |= 0x80;
466 	else
467 		conf_reg &= ~0x80;
468 
469 	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, conf_reg);
470 err:
471 	mutex_unlock(&data->update_lock);
472 	return count;
473 }
474 
475 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
476 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, show_temp_min,
477 	set_temp_min, 0);
478 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, show_temp_max,
479 	set_temp_max, 0);
480 static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
481 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_temp_min_alarm,
482 	NULL, 0);
483 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_temp_max_alarm,
484 	NULL, 0);
485 
486 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
487 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, show_temp_min,
488 	set_temp_min, 1);
489 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR, show_temp_max,
490 	set_temp_max, 1);
491 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
492 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_temp_min_alarm,
493 	NULL, 1);
494 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_temp_max_alarm,
495 	NULL, 1);
496 
497 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
498 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR, show_temp_min,
499 	set_temp_min, 2);
500 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR, show_temp_max,
501 	set_temp_max, 2);
502 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_temp_fault, NULL, 2);
503 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_temp_min_alarm,
504 	NULL, 2);
505 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_temp_max_alarm,
506 	NULL, 2);
507 
508 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
509 static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO | S_IWUSR, show_temp_min,
510 	set_temp_min, 3);
511 static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO | S_IWUSR, show_temp_max,
512 	set_temp_max, 3);
513 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_temp_fault, NULL, 3);
514 static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_temp_min_alarm,
515 	NULL, 3);
516 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_temp_max_alarm,
517 	NULL, 3);
518 
519 static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
520 static DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR, show_fan_div, set_fan_div);
521 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_fan_target,
522 	set_fan_target);
523 static DEVICE_ATTR(fan1_fault, S_IRUGO, show_fan_fault, NULL);
524 
525 static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR, show_pwm_enable,
526 	set_pwm_enable);
527 
528 /* sensors present on all models */
529 static struct attribute *emc2103_attributes[] = {
530 	&sensor_dev_attr_temp1_input.dev_attr.attr,
531 	&sensor_dev_attr_temp1_min.dev_attr.attr,
532 	&sensor_dev_attr_temp1_max.dev_attr.attr,
533 	&sensor_dev_attr_temp1_fault.dev_attr.attr,
534 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
535 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
536 	&sensor_dev_attr_temp2_input.dev_attr.attr,
537 	&sensor_dev_attr_temp2_min.dev_attr.attr,
538 	&sensor_dev_attr_temp2_max.dev_attr.attr,
539 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
540 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
541 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
542 	&dev_attr_fan1_input.attr,
543 	&dev_attr_fan1_div.attr,
544 	&dev_attr_fan1_target.attr,
545 	&dev_attr_fan1_fault.attr,
546 	&dev_attr_pwm1_enable.attr,
547 	NULL
548 };
549 
550 /* extra temperature sensors only present on 2103-2 and 2103-4 */
551 static struct attribute *emc2103_attributes_temp3[] = {
552 	&sensor_dev_attr_temp3_input.dev_attr.attr,
553 	&sensor_dev_attr_temp3_min.dev_attr.attr,
554 	&sensor_dev_attr_temp3_max.dev_attr.attr,
555 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
556 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
557 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
558 	NULL
559 };
560 
561 /* extra temperature sensors only present on 2103-2 and 2103-4 in APD mode */
562 static struct attribute *emc2103_attributes_temp4[] = {
563 	&sensor_dev_attr_temp4_input.dev_attr.attr,
564 	&sensor_dev_attr_temp4_min.dev_attr.attr,
565 	&sensor_dev_attr_temp4_max.dev_attr.attr,
566 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
567 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
568 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
569 	NULL
570 };
571 
572 static const struct attribute_group emc2103_group = {
573 	.attrs = emc2103_attributes,
574 };
575 
576 static const struct attribute_group emc2103_temp3_group = {
577 	.attrs = emc2103_attributes_temp3,
578 };
579 
580 static const struct attribute_group emc2103_temp4_group = {
581 	.attrs = emc2103_attributes_temp4,
582 };
583 
584 static int
585 emc2103_probe(struct i2c_client *client, const struct i2c_device_id *id)
586 {
587 	struct emc2103_data *data;
588 	int status;
589 
590 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
591 		return -EIO;
592 
593 	data = devm_kzalloc(&client->dev, sizeof(struct emc2103_data),
594 			    GFP_KERNEL);
595 	if (!data)
596 		return -ENOMEM;
597 
598 	i2c_set_clientdata(client, data);
599 	mutex_init(&data->update_lock);
600 
601 	/* 2103-2 and 2103-4 have 3 external diodes, 2103-1 has 1 */
602 	status = i2c_smbus_read_byte_data(client, REG_PRODUCT_ID);
603 	if (status == 0x24) {
604 		/* 2103-1 only has 1 external diode */
605 		data->temp_count = 2;
606 	} else {
607 		/* 2103-2 and 2103-4 have 3 or 4 external diodes */
608 		status = i2c_smbus_read_byte_data(client, REG_CONF1);
609 		if (status < 0) {
610 			dev_dbg(&client->dev, "reg 0x%02x, err %d\n", REG_CONF1,
611 				status);
612 			return status;
613 		}
614 
615 		/* detect current state of hardware */
616 		data->temp_count = (status & 0x01) ? 4 : 3;
617 
618 		/* force APD state if module parameter is set */
619 		if (apd == 0) {
620 			/* force APD mode off */
621 			data->temp_count = 3;
622 			status &= ~(0x01);
623 			i2c_smbus_write_byte_data(client, REG_CONF1, status);
624 		} else if (apd == 1) {
625 			/* force APD mode on */
626 			data->temp_count = 4;
627 			status |= 0x01;
628 			i2c_smbus_write_byte_data(client, REG_CONF1, status);
629 		}
630 	}
631 
632 	/* Register sysfs hooks */
633 	status = sysfs_create_group(&client->dev.kobj, &emc2103_group);
634 	if (status)
635 		return status;
636 
637 	if (data->temp_count >= 3) {
638 		status = sysfs_create_group(&client->dev.kobj,
639 			&emc2103_temp3_group);
640 		if (status)
641 			goto exit_remove;
642 	}
643 
644 	if (data->temp_count == 4) {
645 		status = sysfs_create_group(&client->dev.kobj,
646 			&emc2103_temp4_group);
647 		if (status)
648 			goto exit_remove_temp3;
649 	}
650 
651 	data->hwmon_dev = hwmon_device_register(&client->dev);
652 	if (IS_ERR(data->hwmon_dev)) {
653 		status = PTR_ERR(data->hwmon_dev);
654 		goto exit_remove_temp4;
655 	}
656 
657 	dev_info(&client->dev, "%s: sensor '%s'\n",
658 		 dev_name(data->hwmon_dev), client->name);
659 
660 	return 0;
661 
662 exit_remove_temp4:
663 	if (data->temp_count == 4)
664 		sysfs_remove_group(&client->dev.kobj, &emc2103_temp4_group);
665 exit_remove_temp3:
666 	if (data->temp_count >= 3)
667 		sysfs_remove_group(&client->dev.kobj, &emc2103_temp3_group);
668 exit_remove:
669 	sysfs_remove_group(&client->dev.kobj, &emc2103_group);
670 	return status;
671 }
672 
673 static int emc2103_remove(struct i2c_client *client)
674 {
675 	struct emc2103_data *data = i2c_get_clientdata(client);
676 
677 	hwmon_device_unregister(data->hwmon_dev);
678 
679 	if (data->temp_count == 4)
680 		sysfs_remove_group(&client->dev.kobj, &emc2103_temp4_group);
681 
682 	if (data->temp_count >= 3)
683 		sysfs_remove_group(&client->dev.kobj, &emc2103_temp3_group);
684 
685 	sysfs_remove_group(&client->dev.kobj, &emc2103_group);
686 
687 	return 0;
688 }
689 
690 static const struct i2c_device_id emc2103_ids[] = {
691 	{ "emc2103", 0, },
692 	{ /* LIST END */ }
693 };
694 MODULE_DEVICE_TABLE(i2c, emc2103_ids);
695 
696 /* Return 0 if detection is successful, -ENODEV otherwise */
697 static int
698 emc2103_detect(struct i2c_client *new_client, struct i2c_board_info *info)
699 {
700 	struct i2c_adapter *adapter = new_client->adapter;
701 	int manufacturer, product;
702 
703 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
704 		return -ENODEV;
705 
706 	manufacturer = i2c_smbus_read_byte_data(new_client, REG_MFG_ID);
707 	if (manufacturer != 0x5D)
708 		return -ENODEV;
709 
710 	product = i2c_smbus_read_byte_data(new_client, REG_PRODUCT_ID);
711 	if ((product != 0x24) && (product != 0x26))
712 		return -ENODEV;
713 
714 	strlcpy(info->type, "emc2103", I2C_NAME_SIZE);
715 
716 	return 0;
717 }
718 
719 static struct i2c_driver emc2103_driver = {
720 	.class		= I2C_CLASS_HWMON,
721 	.driver = {
722 		.name	= "emc2103",
723 	},
724 	.probe		= emc2103_probe,
725 	.remove		= emc2103_remove,
726 	.id_table	= emc2103_ids,
727 	.detect		= emc2103_detect,
728 	.address_list	= normal_i2c,
729 };
730 
731 module_i2c_driver(emc2103_driver);
732 
733 MODULE_AUTHOR("Steve Glendinning <steve.glendinning@shawell.net>");
734 MODULE_DESCRIPTION("SMSC EMC2103 hwmon driver");
735 MODULE_LICENSE("GPL");
736