xref: /openbmc/linux/drivers/hwmon/emc2103.c (revision 588b48ca)
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 i2c_client	*client;
70 	const struct		attribute_group *groups[4];
71 	struct mutex		update_lock;
72 	bool			valid;		/* registers are valid */
73 	bool			fan_rpm_control;
74 	int			temp_count;	/* num of temp sensors */
75 	unsigned long		last_updated;	/* in jiffies */
76 	struct temperature	temp[4];	/* internal + 3 external */
77 	s8			temp_min[4];	/* no fractional part */
78 	s8			temp_max[4];    /* no fractional part */
79 	u8			temp_min_alarm;
80 	u8			temp_max_alarm;
81 	u8			fan_multiplier;
82 	u16			fan_tach;
83 	u16			fan_target;
84 };
85 
86 static int read_u8_from_i2c(struct i2c_client *client, u8 i2c_reg, u8 *output)
87 {
88 	int status = i2c_smbus_read_byte_data(client, i2c_reg);
89 	if (status < 0) {
90 		dev_warn(&client->dev, "reg 0x%02x, err %d\n",
91 			i2c_reg, status);
92 	} else {
93 		*output = status;
94 	}
95 	return status;
96 }
97 
98 static void read_temp_from_i2c(struct i2c_client *client, u8 i2c_reg,
99 			       struct temperature *temp)
100 {
101 	u8 degrees, fractional;
102 
103 	if (read_u8_from_i2c(client, i2c_reg, &degrees) < 0)
104 		return;
105 
106 	if (read_u8_from_i2c(client, i2c_reg + 1, &fractional) < 0)
107 		return;
108 
109 	temp->degrees = degrees;
110 	temp->fraction = (fractional & 0xe0) >> 5;
111 }
112 
113 static void read_fan_from_i2c(struct i2c_client *client, u16 *output,
114 			      u8 hi_addr, u8 lo_addr)
115 {
116 	u8 high_byte, lo_byte;
117 
118 	if (read_u8_from_i2c(client, hi_addr, &high_byte) < 0)
119 		return;
120 
121 	if (read_u8_from_i2c(client, lo_addr, &lo_byte) < 0)
122 		return;
123 
124 	*output = ((u16)high_byte << 5) | (lo_byte >> 3);
125 }
126 
127 static void write_fan_target_to_i2c(struct i2c_client *client, u16 new_target)
128 {
129 	u8 high_byte = (new_target & 0x1fe0) >> 5;
130 	u8 low_byte = (new_target & 0x001f) << 3;
131 	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_LO, low_byte);
132 	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_HI, high_byte);
133 }
134 
135 static void read_fan_config_from_i2c(struct i2c_client *client)
136 
137 {
138 	struct emc2103_data *data = i2c_get_clientdata(client);
139 	u8 conf1;
140 
141 	if (read_u8_from_i2c(client, REG_FAN_CONF1, &conf1) < 0)
142 		return;
143 
144 	data->fan_multiplier = 1 << ((conf1 & 0x60) >> 5);
145 	data->fan_rpm_control = (conf1 & 0x80) != 0;
146 }
147 
148 static struct emc2103_data *emc2103_update_device(struct device *dev)
149 {
150 	struct emc2103_data *data = dev_get_drvdata(dev);
151 	struct i2c_client *client = data->client;
152 
153 	mutex_lock(&data->update_lock);
154 
155 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
156 	    || !data->valid) {
157 		int i;
158 
159 		for (i = 0; i < data->temp_count; i++) {
160 			read_temp_from_i2c(client, REG_TEMP[i], &data->temp[i]);
161 			read_u8_from_i2c(client, REG_TEMP_MIN[i],
162 				&data->temp_min[i]);
163 			read_u8_from_i2c(client, REG_TEMP_MAX[i],
164 				&data->temp_max[i]);
165 		}
166 
167 		read_u8_from_i2c(client, REG_TEMP_MIN_ALARM,
168 			&data->temp_min_alarm);
169 		read_u8_from_i2c(client, REG_TEMP_MAX_ALARM,
170 			&data->temp_max_alarm);
171 
172 		read_fan_from_i2c(client, &data->fan_tach,
173 			REG_FAN_TACH_HI, REG_FAN_TACH_LO);
174 		read_fan_from_i2c(client, &data->fan_target,
175 			REG_FAN_TARGET_HI, REG_FAN_TARGET_LO);
176 		read_fan_config_from_i2c(client);
177 
178 		data->last_updated = jiffies;
179 		data->valid = true;
180 	}
181 
182 	mutex_unlock(&data->update_lock);
183 
184 	return data;
185 }
186 
187 static ssize_t
188 show_temp(struct device *dev, struct device_attribute *da, char *buf)
189 {
190 	int nr = to_sensor_dev_attr(da)->index;
191 	struct emc2103_data *data = emc2103_update_device(dev);
192 	int millidegrees = data->temp[nr].degrees * 1000
193 		+ data->temp[nr].fraction * 125;
194 	return sprintf(buf, "%d\n", millidegrees);
195 }
196 
197 static ssize_t
198 show_temp_min(struct device *dev, struct device_attribute *da, char *buf)
199 {
200 	int nr = to_sensor_dev_attr(da)->index;
201 	struct emc2103_data *data = emc2103_update_device(dev);
202 	int millidegrees = data->temp_min[nr] * 1000;
203 	return sprintf(buf, "%d\n", millidegrees);
204 }
205 
206 static ssize_t
207 show_temp_max(struct device *dev, struct device_attribute *da, char *buf)
208 {
209 	int nr = to_sensor_dev_attr(da)->index;
210 	struct emc2103_data *data = emc2103_update_device(dev);
211 	int millidegrees = data->temp_max[nr] * 1000;
212 	return sprintf(buf, "%d\n", millidegrees);
213 }
214 
215 static ssize_t
216 show_temp_fault(struct device *dev, struct device_attribute *da, char *buf)
217 {
218 	int nr = to_sensor_dev_attr(da)->index;
219 	struct emc2103_data *data = emc2103_update_device(dev);
220 	bool fault = (data->temp[nr].degrees == -128);
221 	return sprintf(buf, "%d\n", fault ? 1 : 0);
222 }
223 
224 static ssize_t
225 show_temp_min_alarm(struct device *dev, struct device_attribute *da, char *buf)
226 {
227 	int nr = to_sensor_dev_attr(da)->index;
228 	struct emc2103_data *data = emc2103_update_device(dev);
229 	bool alarm = data->temp_min_alarm & (1 << nr);
230 	return sprintf(buf, "%d\n", alarm ? 1 : 0);
231 }
232 
233 static ssize_t
234 show_temp_max_alarm(struct device *dev, struct device_attribute *da, char *buf)
235 {
236 	int nr = to_sensor_dev_attr(da)->index;
237 	struct emc2103_data *data = emc2103_update_device(dev);
238 	bool alarm = data->temp_max_alarm & (1 << nr);
239 	return sprintf(buf, "%d\n", alarm ? 1 : 0);
240 }
241 
242 static ssize_t set_temp_min(struct device *dev, struct device_attribute *da,
243 			    const char *buf, size_t count)
244 {
245 	int nr = to_sensor_dev_attr(da)->index;
246 	struct emc2103_data *data = dev_get_drvdata(dev);
247 	struct i2c_client *client = data->client;
248 	long val;
249 
250 	int result = kstrtol(buf, 10, &val);
251 	if (result < 0)
252 		return result;
253 
254 	val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -63, 127);
255 
256 	mutex_lock(&data->update_lock);
257 	data->temp_min[nr] = val;
258 	i2c_smbus_write_byte_data(client, REG_TEMP_MIN[nr], val);
259 	mutex_unlock(&data->update_lock);
260 
261 	return count;
262 }
263 
264 static ssize_t set_temp_max(struct device *dev, struct device_attribute *da,
265 			    const char *buf, size_t count)
266 {
267 	int nr = to_sensor_dev_attr(da)->index;
268 	struct emc2103_data *data = dev_get_drvdata(dev);
269 	struct i2c_client *client = data->client;
270 	long val;
271 
272 	int result = kstrtol(buf, 10, &val);
273 	if (result < 0)
274 		return result;
275 
276 	val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -63, 127);
277 
278 	mutex_lock(&data->update_lock);
279 	data->temp_max[nr] = val;
280 	i2c_smbus_write_byte_data(client, REG_TEMP_MAX[nr], val);
281 	mutex_unlock(&data->update_lock);
282 
283 	return count;
284 }
285 
286 static ssize_t
287 show_fan(struct device *dev, struct device_attribute *da, char *buf)
288 {
289 	struct emc2103_data *data = emc2103_update_device(dev);
290 	int rpm = 0;
291 	if (data->fan_tach != 0)
292 		rpm = (FAN_RPM_FACTOR * data->fan_multiplier) / data->fan_tach;
293 	return sprintf(buf, "%d\n", rpm);
294 }
295 
296 static ssize_t
297 show_fan_div(struct device *dev, struct device_attribute *da, char *buf)
298 {
299 	struct emc2103_data *data = emc2103_update_device(dev);
300 	int fan_div = 8 / data->fan_multiplier;
301 	return sprintf(buf, "%d\n", fan_div);
302 }
303 
304 /*
305  * Note: we also update the fan target here, because its value is
306  * determined in part by the fan clock divider.  This follows the principle
307  * of least surprise; the user doesn't expect the fan target to change just
308  * because the divider changed.
309  */
310 static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
311 			   const char *buf, size_t count)
312 {
313 	struct emc2103_data *data = emc2103_update_device(dev);
314 	struct i2c_client *client = data->client;
315 	int new_range_bits, old_div = 8 / data->fan_multiplier;
316 	long new_div;
317 
318 	int status = kstrtol(buf, 10, &new_div);
319 	if (status < 0)
320 		return status;
321 
322 	if (new_div == old_div) /* No change */
323 		return count;
324 
325 	switch (new_div) {
326 	case 1:
327 		new_range_bits = 3;
328 		break;
329 	case 2:
330 		new_range_bits = 2;
331 		break;
332 	case 4:
333 		new_range_bits = 1;
334 		break;
335 	case 8:
336 		new_range_bits = 0;
337 		break;
338 	default:
339 		return -EINVAL;
340 	}
341 
342 	mutex_lock(&data->update_lock);
343 
344 	status = i2c_smbus_read_byte_data(client, REG_FAN_CONF1);
345 	if (status < 0) {
346 		dev_dbg(&client->dev, "reg 0x%02x, err %d\n",
347 			REG_FAN_CONF1, status);
348 		mutex_unlock(&data->update_lock);
349 		return status;
350 	}
351 	status &= 0x9F;
352 	status |= (new_range_bits << 5);
353 	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, status);
354 
355 	data->fan_multiplier = 8 / new_div;
356 
357 	/* update fan target if high byte is not disabled */
358 	if ((data->fan_target & 0x1fe0) != 0x1fe0) {
359 		u16 new_target = (data->fan_target * old_div) / new_div;
360 		data->fan_target = min(new_target, (u16)0x1fff);
361 		write_fan_target_to_i2c(client, data->fan_target);
362 	}
363 
364 	/* invalidate data to force re-read from hardware */
365 	data->valid = false;
366 
367 	mutex_unlock(&data->update_lock);
368 	return count;
369 }
370 
371 static ssize_t
372 show_fan_target(struct device *dev, struct device_attribute *da, char *buf)
373 {
374 	struct emc2103_data *data = emc2103_update_device(dev);
375 	int rpm = 0;
376 
377 	/* high byte of 0xff indicates disabled so return 0 */
378 	if ((data->fan_target != 0) && ((data->fan_target & 0x1fe0) != 0x1fe0))
379 		rpm = (FAN_RPM_FACTOR * data->fan_multiplier)
380 			/ data->fan_target;
381 
382 	return sprintf(buf, "%d\n", rpm);
383 }
384 
385 static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
386 			      const char *buf, size_t count)
387 {
388 	struct emc2103_data *data = emc2103_update_device(dev);
389 	struct i2c_client *client = data->client;
390 	unsigned long rpm_target;
391 
392 	int result = kstrtoul(buf, 10, &rpm_target);
393 	if (result < 0)
394 		return result;
395 
396 	/* Datasheet states 16384 as maximum RPM target (table 3.2) */
397 	rpm_target = clamp_val(rpm_target, 0, 16384);
398 
399 	mutex_lock(&data->update_lock);
400 
401 	if (rpm_target == 0)
402 		data->fan_target = 0x1fff;
403 	else
404 		data->fan_target = clamp_val(
405 			(FAN_RPM_FACTOR * data->fan_multiplier) / rpm_target,
406 			0, 0x1fff);
407 
408 	write_fan_target_to_i2c(client, data->fan_target);
409 
410 	mutex_unlock(&data->update_lock);
411 	return count;
412 }
413 
414 static ssize_t
415 show_fan_fault(struct device *dev, struct device_attribute *da, char *buf)
416 {
417 	struct emc2103_data *data = emc2103_update_device(dev);
418 	bool fault = ((data->fan_tach & 0x1fe0) == 0x1fe0);
419 	return sprintf(buf, "%d\n", fault ? 1 : 0);
420 }
421 
422 static ssize_t
423 show_pwm_enable(struct device *dev, struct device_attribute *da, char *buf)
424 {
425 	struct emc2103_data *data = emc2103_update_device(dev);
426 	return sprintf(buf, "%d\n", data->fan_rpm_control ? 3 : 0);
427 }
428 
429 static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
430 			      const char *buf, size_t count)
431 {
432 	struct emc2103_data *data = dev_get_drvdata(dev);
433 	struct i2c_client *client = data->client;
434 	long new_value;
435 	u8 conf_reg;
436 
437 	int result = kstrtol(buf, 10, &new_value);
438 	if (result < 0)
439 		return result;
440 
441 	mutex_lock(&data->update_lock);
442 	switch (new_value) {
443 	case 0:
444 		data->fan_rpm_control = false;
445 		break;
446 	case 3:
447 		data->fan_rpm_control = true;
448 		break;
449 	default:
450 		count = -EINVAL;
451 		goto err;
452 	}
453 
454 	result = read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
455 	if (result) {
456 		count = result;
457 		goto err;
458 	}
459 
460 	if (data->fan_rpm_control)
461 		conf_reg |= 0x80;
462 	else
463 		conf_reg &= ~0x80;
464 
465 	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, conf_reg);
466 err:
467 	mutex_unlock(&data->update_lock);
468 	return count;
469 }
470 
471 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
472 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, show_temp_min,
473 	set_temp_min, 0);
474 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, show_temp_max,
475 	set_temp_max, 0);
476 static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
477 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_temp_min_alarm,
478 	NULL, 0);
479 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_temp_max_alarm,
480 	NULL, 0);
481 
482 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
483 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, show_temp_min,
484 	set_temp_min, 1);
485 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR, show_temp_max,
486 	set_temp_max, 1);
487 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
488 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_temp_min_alarm,
489 	NULL, 1);
490 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_temp_max_alarm,
491 	NULL, 1);
492 
493 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
494 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR, show_temp_min,
495 	set_temp_min, 2);
496 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR, show_temp_max,
497 	set_temp_max, 2);
498 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_temp_fault, NULL, 2);
499 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_temp_min_alarm,
500 	NULL, 2);
501 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_temp_max_alarm,
502 	NULL, 2);
503 
504 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
505 static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO | S_IWUSR, show_temp_min,
506 	set_temp_min, 3);
507 static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO | S_IWUSR, show_temp_max,
508 	set_temp_max, 3);
509 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_temp_fault, NULL, 3);
510 static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_temp_min_alarm,
511 	NULL, 3);
512 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_temp_max_alarm,
513 	NULL, 3);
514 
515 static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
516 static DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR, show_fan_div, set_fan_div);
517 static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_fan_target,
518 	set_fan_target);
519 static DEVICE_ATTR(fan1_fault, S_IRUGO, show_fan_fault, NULL);
520 
521 static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR, show_pwm_enable,
522 	set_pwm_enable);
523 
524 /* sensors present on all models */
525 static struct attribute *emc2103_attributes[] = {
526 	&sensor_dev_attr_temp1_input.dev_attr.attr,
527 	&sensor_dev_attr_temp1_min.dev_attr.attr,
528 	&sensor_dev_attr_temp1_max.dev_attr.attr,
529 	&sensor_dev_attr_temp1_fault.dev_attr.attr,
530 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
531 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
532 	&sensor_dev_attr_temp2_input.dev_attr.attr,
533 	&sensor_dev_attr_temp2_min.dev_attr.attr,
534 	&sensor_dev_attr_temp2_max.dev_attr.attr,
535 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
536 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
537 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
538 	&dev_attr_fan1_input.attr,
539 	&dev_attr_fan1_div.attr,
540 	&dev_attr_fan1_target.attr,
541 	&dev_attr_fan1_fault.attr,
542 	&dev_attr_pwm1_enable.attr,
543 	NULL
544 };
545 
546 /* extra temperature sensors only present on 2103-2 and 2103-4 */
547 static struct attribute *emc2103_attributes_temp3[] = {
548 	&sensor_dev_attr_temp3_input.dev_attr.attr,
549 	&sensor_dev_attr_temp3_min.dev_attr.attr,
550 	&sensor_dev_attr_temp3_max.dev_attr.attr,
551 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
552 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
553 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
554 	NULL
555 };
556 
557 /* extra temperature sensors only present on 2103-2 and 2103-4 in APD mode */
558 static struct attribute *emc2103_attributes_temp4[] = {
559 	&sensor_dev_attr_temp4_input.dev_attr.attr,
560 	&sensor_dev_attr_temp4_min.dev_attr.attr,
561 	&sensor_dev_attr_temp4_max.dev_attr.attr,
562 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
563 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
564 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
565 	NULL
566 };
567 
568 static const struct attribute_group emc2103_group = {
569 	.attrs = emc2103_attributes,
570 };
571 
572 static const struct attribute_group emc2103_temp3_group = {
573 	.attrs = emc2103_attributes_temp3,
574 };
575 
576 static const struct attribute_group emc2103_temp4_group = {
577 	.attrs = emc2103_attributes_temp4,
578 };
579 
580 static int
581 emc2103_probe(struct i2c_client *client, const struct i2c_device_id *id)
582 {
583 	struct emc2103_data *data;
584 	struct device *hwmon_dev;
585 	int status, idx = 0;
586 
587 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
588 		return -EIO;
589 
590 	data = devm_kzalloc(&client->dev, sizeof(struct emc2103_data),
591 			    GFP_KERNEL);
592 	if (!data)
593 		return -ENOMEM;
594 
595 	i2c_set_clientdata(client, data);
596 	data->client = client;
597 	mutex_init(&data->update_lock);
598 
599 	/* 2103-2 and 2103-4 have 3 external diodes, 2103-1 has 1 */
600 	status = i2c_smbus_read_byte_data(client, REG_PRODUCT_ID);
601 	if (status == 0x24) {
602 		/* 2103-1 only has 1 external diode */
603 		data->temp_count = 2;
604 	} else {
605 		/* 2103-2 and 2103-4 have 3 or 4 external diodes */
606 		status = i2c_smbus_read_byte_data(client, REG_CONF1);
607 		if (status < 0) {
608 			dev_dbg(&client->dev, "reg 0x%02x, err %d\n", REG_CONF1,
609 				status);
610 			return status;
611 		}
612 
613 		/* detect current state of hardware */
614 		data->temp_count = (status & 0x01) ? 4 : 3;
615 
616 		/* force APD state if module parameter is set */
617 		if (apd == 0) {
618 			/* force APD mode off */
619 			data->temp_count = 3;
620 			status &= ~(0x01);
621 			i2c_smbus_write_byte_data(client, REG_CONF1, status);
622 		} else if (apd == 1) {
623 			/* force APD mode on */
624 			data->temp_count = 4;
625 			status |= 0x01;
626 			i2c_smbus_write_byte_data(client, REG_CONF1, status);
627 		}
628 	}
629 
630 	/* sysfs hooks */
631 	data->groups[idx++] = &emc2103_group;
632 	if (data->temp_count >= 3)
633 		data->groups[idx++] = &emc2103_temp3_group;
634 	if (data->temp_count == 4)
635 		data->groups[idx++] = &emc2103_temp4_group;
636 
637 	hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev,
638 							   client->name, data,
639 							   data->groups);
640 	if (IS_ERR(hwmon_dev))
641 		return PTR_ERR(hwmon_dev);
642 
643 	dev_info(&client->dev, "%s: sensor '%s'\n",
644 		 dev_name(hwmon_dev), client->name);
645 
646 	return 0;
647 }
648 
649 static const struct i2c_device_id emc2103_ids[] = {
650 	{ "emc2103", 0, },
651 	{ /* LIST END */ }
652 };
653 MODULE_DEVICE_TABLE(i2c, emc2103_ids);
654 
655 /* Return 0 if detection is successful, -ENODEV otherwise */
656 static int
657 emc2103_detect(struct i2c_client *new_client, struct i2c_board_info *info)
658 {
659 	struct i2c_adapter *adapter = new_client->adapter;
660 	int manufacturer, product;
661 
662 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
663 		return -ENODEV;
664 
665 	manufacturer = i2c_smbus_read_byte_data(new_client, REG_MFG_ID);
666 	if (manufacturer != 0x5D)
667 		return -ENODEV;
668 
669 	product = i2c_smbus_read_byte_data(new_client, REG_PRODUCT_ID);
670 	if ((product != 0x24) && (product != 0x26))
671 		return -ENODEV;
672 
673 	strlcpy(info->type, "emc2103", I2C_NAME_SIZE);
674 
675 	return 0;
676 }
677 
678 static struct i2c_driver emc2103_driver = {
679 	.class		= I2C_CLASS_HWMON,
680 	.driver = {
681 		.name	= "emc2103",
682 	},
683 	.probe		= emc2103_probe,
684 	.id_table	= emc2103_ids,
685 	.detect		= emc2103_detect,
686 	.address_list	= normal_i2c,
687 };
688 
689 module_i2c_driver(emc2103_driver);
690 
691 MODULE_AUTHOR("Steve Glendinning <steve.glendinning@shawell.net>");
692 MODULE_DESCRIPTION("SMSC EMC2103 hwmon driver");
693 MODULE_LICENSE("GPL");
694