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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 */
31static const unsigned short normal_i2c[] = { 0x2E, I2C_CLIENT_END };
32
33static const u8 REG_TEMP[4] = { 0x00, 0x02, 0x04, 0x06 };
34static const u8 REG_TEMP_MIN[4] = { 0x3c, 0x38, 0x39, 0x3a };
35static 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/* 2103-2 and 2103-4's 3rd temperature sensor can be connected to two diodes
52 * in anti-parallel mode, and in this configuration both can be read
53 * independently (so we have 4 temperature inputs).  The device can't
54 * detect if it's connected in this mode, so we have to manually enable
55 * it.  Default is to leave the device in the state it's already in (-1).
56 * This parameter allows APD mode to be optionally forced on or off */
57static int apd = -1;
58module_param(apd, bool, 0);
59MODULE_PARM_DESC(init, "Set to zero to disable anti-parallel diode mode");
60
61struct temperature {
62	s8	degrees;
63	u8	fraction;	/* 0-7 multiples of 0.125 */
64};
65
66struct emc2103_data {
67	struct device		*hwmon_dev;
68	struct mutex		update_lock;
69	bool			valid;		/* registers are valid */
70	bool			fan_rpm_control;
71	int			temp_count;	/* num of temp sensors */
72	unsigned long		last_updated;	/* in jiffies */
73	struct temperature	temp[4];	/* internal + 3 external */
74	s8			temp_min[4];	/* no fractional part */
75	s8			temp_max[4];    /* no fractional part */
76	u8			temp_min_alarm;
77	u8			temp_max_alarm;
78	u8			fan_multiplier;
79	u16			fan_tach;
80	u16			fan_target;
81};
82
83static int read_u8_from_i2c(struct i2c_client *client, u8 i2c_reg, u8 *output)
84{
85	int status = i2c_smbus_read_byte_data(client, i2c_reg);
86	if (status < 0) {
87		dev_warn(&client->dev, "reg 0x%02x, err %d\n",
88			i2c_reg, status);
89	} else {
90		*output = status;
91	}
92	return status;
93}
94
95static void read_temp_from_i2c(struct i2c_client *client, u8 i2c_reg,
96			       struct temperature *temp)
97{
98	u8 degrees, fractional;
99
100	if (read_u8_from_i2c(client, i2c_reg, &degrees) < 0)
101		return;
102
103	if (read_u8_from_i2c(client, i2c_reg + 1, &fractional) < 0)
104		return;
105
106	temp->degrees = degrees;
107	temp->fraction = (fractional & 0xe0) >> 5;
108}
109
110static void read_fan_from_i2c(struct i2c_client *client, u16 *output,
111			      u8 hi_addr, u8 lo_addr)
112{
113	u8 high_byte, lo_byte;
114
115	if (read_u8_from_i2c(client, hi_addr, &high_byte) < 0)
116		return;
117
118	if (read_u8_from_i2c(client, lo_addr, &lo_byte) < 0)
119		return;
120
121	*output = ((u16)high_byte << 5) | (lo_byte >> 3);
122}
123
124static void write_fan_target_to_i2c(struct i2c_client *client, u16 new_target)
125{
126	u8 high_byte = (new_target & 0x1fe0) >> 5;
127	u8 low_byte = (new_target & 0x001f) << 3;
128	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_LO, low_byte);
129	i2c_smbus_write_byte_data(client, REG_FAN_TARGET_HI, high_byte);
130}
131
132static void read_fan_config_from_i2c(struct i2c_client *client)
133
134{
135	struct emc2103_data *data = i2c_get_clientdata(client);
136	u8 conf1;
137
138	if (read_u8_from_i2c(client, REG_FAN_CONF1, &conf1) < 0)
139		return;
140
141	data->fan_multiplier = 1 << ((conf1 & 0x60) >> 5);
142	data->fan_rpm_control = (conf1 & 0x80) != 0;
143}
144
145static struct emc2103_data *emc2103_update_device(struct device *dev)
146{
147	struct i2c_client *client = to_i2c_client(dev);
148	struct emc2103_data *data = i2c_get_clientdata(client);
149
150	mutex_lock(&data->update_lock);
151
152	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
153	    || !data->valid) {
154		int i;
155
156		for (i = 0; i < data->temp_count; i++) {
157			read_temp_from_i2c(client, REG_TEMP[i], &data->temp[i]);
158			read_u8_from_i2c(client, REG_TEMP_MIN[i],
159				&data->temp_min[i]);
160			read_u8_from_i2c(client, REG_TEMP_MAX[i],
161				&data->temp_max[i]);
162		}
163
164		read_u8_from_i2c(client, REG_TEMP_MIN_ALARM,
165			&data->temp_min_alarm);
166		read_u8_from_i2c(client, REG_TEMP_MAX_ALARM,
167			&data->temp_max_alarm);
168
169		read_fan_from_i2c(client, &data->fan_tach,
170			REG_FAN_TACH_HI, REG_FAN_TACH_LO);
171		read_fan_from_i2c(client, &data->fan_target,
172			REG_FAN_TARGET_HI, REG_FAN_TARGET_LO);
173		read_fan_config_from_i2c(client);
174
175		data->last_updated = jiffies;
176		data->valid = true;
177	}
178
179	mutex_unlock(&data->update_lock);
180
181	return data;
182}
183
184static ssize_t
185show_temp(struct device *dev, struct device_attribute *da, char *buf)
186{
187	int nr = to_sensor_dev_attr(da)->index;
188	struct emc2103_data *data = emc2103_update_device(dev);
189	int millidegrees = data->temp[nr].degrees * 1000
190		+ data->temp[nr].fraction * 125;
191	return sprintf(buf, "%d\n", millidegrees);
192}
193
194static ssize_t
195show_temp_min(struct device *dev, struct device_attribute *da, char *buf)
196{
197	int nr = to_sensor_dev_attr(da)->index;
198	struct emc2103_data *data = emc2103_update_device(dev);
199	int millidegrees = data->temp_min[nr] * 1000;
200	return sprintf(buf, "%d\n", millidegrees);
201}
202
203static ssize_t
204show_temp_max(struct device *dev, struct device_attribute *da, char *buf)
205{
206	int nr = to_sensor_dev_attr(da)->index;
207	struct emc2103_data *data = emc2103_update_device(dev);
208	int millidegrees = data->temp_max[nr] * 1000;
209	return sprintf(buf, "%d\n", millidegrees);
210}
211
212static ssize_t
213show_temp_fault(struct device *dev, struct device_attribute *da, char *buf)
214{
215	int nr = to_sensor_dev_attr(da)->index;
216	struct emc2103_data *data = emc2103_update_device(dev);
217	bool fault = (data->temp[nr].degrees == -128);
218	return sprintf(buf, "%d\n", fault ? 1 : 0);
219}
220
221static ssize_t
222show_temp_min_alarm(struct device *dev, struct device_attribute *da, char *buf)
223{
224	int nr = to_sensor_dev_attr(da)->index;
225	struct emc2103_data *data = emc2103_update_device(dev);
226	bool alarm = data->temp_min_alarm & (1 << nr);
227	return sprintf(buf, "%d\n", alarm ? 1 : 0);
228}
229
230static ssize_t
231show_temp_max_alarm(struct device *dev, struct device_attribute *da, char *buf)
232{
233	int nr = to_sensor_dev_attr(da)->index;
234	struct emc2103_data *data = emc2103_update_device(dev);
235	bool alarm = data->temp_max_alarm & (1 << nr);
236	return sprintf(buf, "%d\n", alarm ? 1 : 0);
237}
238
239static ssize_t set_temp_min(struct device *dev, struct device_attribute *da,
240			    const char *buf, size_t count)
241{
242	int nr = to_sensor_dev_attr(da)->index;
243	struct i2c_client *client = to_i2c_client(dev);
244	struct emc2103_data *data = i2c_get_clientdata(client);
245	long val;
246
247	int result = strict_strtol(buf, 10, &val);
248	if (result < 0)
249		return -EINVAL;
250
251	val = DIV_ROUND_CLOSEST(val, 1000);
252	if ((val < -63) || (val > 127))
253		return -EINVAL;
254
255	mutex_lock(&data->update_lock);
256	data->temp_min[nr] = val;
257	i2c_smbus_write_byte_data(client, REG_TEMP_MIN[nr], val);
258	mutex_unlock(&data->update_lock);
259
260	return count;
261}
262
263static ssize_t set_temp_max(struct device *dev, struct device_attribute *da,
264			    const char *buf, size_t count)
265{
266	int nr = to_sensor_dev_attr(da)->index;
267	struct i2c_client *client = to_i2c_client(dev);
268	struct emc2103_data *data = i2c_get_clientdata(client);
269	long val;
270
271	int result = strict_strtol(buf, 10, &val);
272	if (result < 0)
273		return -EINVAL;
274
275	val = DIV_ROUND_CLOSEST(val, 1000);
276	if ((val < -63) || (val > 127))
277		return -EINVAL;
278
279	mutex_lock(&data->update_lock);
280	data->temp_max[nr] = val;
281	i2c_smbus_write_byte_data(client, REG_TEMP_MAX[nr], val);
282	mutex_unlock(&data->update_lock);
283
284	return count;
285}
286
287static ssize_t
288show_fan(struct device *dev, struct device_attribute *da, char *buf)
289{
290	struct emc2103_data *data = emc2103_update_device(dev);
291	int rpm = 0;
292	if (data->fan_tach != 0)
293		rpm = (FAN_RPM_FACTOR * data->fan_multiplier) / data->fan_tach;
294	return sprintf(buf, "%d\n", rpm);
295}
296
297static ssize_t
298show_fan_div(struct device *dev, struct device_attribute *da, char *buf)
299{
300	struct emc2103_data *data = emc2103_update_device(dev);
301	int fan_div = 8 / data->fan_multiplier;
302	return sprintf(buf, "%d\n", fan_div);
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. */
309static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
310			   const char *buf, size_t count)
311{
312	struct emc2103_data *data = emc2103_update_device(dev);
313	struct i2c_client *client = to_i2c_client(dev);
314	int new_range_bits, old_div = 8 / data->fan_multiplier;
315	long new_div;
316
317	int status = strict_strtol(buf, 10, &new_div);
318	if (status < 0)
319		return -EINVAL;
320
321	if (new_div == old_div) /* No change */
322		return count;
323
324	switch (new_div) {
325	case 1:
326		new_range_bits = 3;
327		break;
328	case 2:
329		new_range_bits = 2;
330		break;
331	case 4:
332		new_range_bits = 1;
333		break;
334	case 8:
335		new_range_bits = 0;
336		break;
337	default:
338		return -EINVAL;
339	}
340
341	mutex_lock(&data->update_lock);
342
343	status = i2c_smbus_read_byte_data(client, REG_FAN_CONF1);
344	if (status < 0) {
345		dev_dbg(&client->dev, "reg 0x%02x, err %d\n",
346			REG_FAN_CONF1, status);
347		mutex_unlock(&data->update_lock);
348		return -EIO;
349	}
350	status &= 0x9F;
351	status |= (new_range_bits << 5);
352	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, status);
353
354	data->fan_multiplier = 8 / new_div;
355
356	/* update fan target if high byte is not disabled */
357	if ((data->fan_target & 0x1fe0) != 0x1fe0) {
358		u16 new_target = (data->fan_target * old_div) / new_div;
359		data->fan_target = min(new_target, (u16)0x1fff);
360		write_fan_target_to_i2c(client, data->fan_target);
361	}
362
363	/* invalidate data to force re-read from hardware */
364	data->valid = false;
365
366	mutex_unlock(&data->update_lock);
367	return count;
368}
369
370static ssize_t
371show_fan_target(struct device *dev, struct device_attribute *da, char *buf)
372{
373	struct emc2103_data *data = emc2103_update_device(dev);
374	int rpm = 0;
375
376	/* high byte of 0xff indicates disabled so return 0 */
377	if ((data->fan_target != 0) && ((data->fan_target & 0x1fe0) != 0x1fe0))
378		rpm = (FAN_RPM_FACTOR * data->fan_multiplier)
379			/ data->fan_target;
380
381	return sprintf(buf, "%d\n", rpm);
382}
383
384static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
385			      const char *buf, size_t count)
386{
387	struct emc2103_data *data = emc2103_update_device(dev);
388	struct i2c_client *client = to_i2c_client(dev);
389	long rpm_target;
390
391	int result = strict_strtol(buf, 10, &rpm_target);
392	if (result < 0)
393		return -EINVAL;
394
395	/* Datasheet states 16384 as maximum RPM target (table 3.2) */
396	if ((rpm_target < 0) || (rpm_target > 16384))
397		return -EINVAL;
398
399	mutex_lock(&data->update_lock);
400
401	if (rpm_target == 0)
402		data->fan_target = 0x1fff;
403	else
404		data->fan_target = SENSORS_LIMIT(
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
414static ssize_t
415show_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
422static ssize_t
423show_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
429static ssize_t set_pwm_enable(struct device *dev, struct device_attribute *da,
430			      const char *buf, size_t count)
431{
432	struct i2c_client *client = to_i2c_client(dev);
433	struct emc2103_data *data = i2c_get_clientdata(client);
434	long new_value;
435	u8 conf_reg;
436
437	int result = strict_strtol(buf, 10, &new_value);
438	if (result < 0)
439		return -EINVAL;
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		mutex_unlock(&data->update_lock);
451		return -EINVAL;
452	}
453
454	read_u8_from_i2c(client, REG_FAN_CONF1, &conf_reg);
455
456	if (data->fan_rpm_control)
457		conf_reg |= 0x80;
458	else
459		conf_reg &= ~0x80;
460
461	i2c_smbus_write_byte_data(client, REG_FAN_CONF1, conf_reg);
462
463	mutex_unlock(&data->update_lock);
464	return count;
465}
466
467static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
468static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR, show_temp_min,
469	set_temp_min, 0);
470static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR, show_temp_max,
471	set_temp_max, 0);
472static SENSOR_DEVICE_ATTR(temp1_fault, S_IRUGO, show_temp_fault, NULL, 0);
473static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_temp_min_alarm,
474	NULL, 0);
475static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_temp_max_alarm,
476	NULL, 0);
477
478static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
479static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO | S_IWUSR, show_temp_min,
480	set_temp_min, 1);
481static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO | S_IWUSR, show_temp_max,
482	set_temp_max, 1);
483static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_temp_fault, NULL, 1);
484static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_temp_min_alarm,
485	NULL, 1);
486static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_temp_max_alarm,
487	NULL, 1);
488
489static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
490static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO | S_IWUSR, show_temp_min,
491	set_temp_min, 2);
492static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO | S_IWUSR, show_temp_max,
493	set_temp_max, 2);
494static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_temp_fault, NULL, 2);
495static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_temp_min_alarm,
496	NULL, 2);
497static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_temp_max_alarm,
498	NULL, 2);
499
500static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
501static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO | S_IWUSR, show_temp_min,
502	set_temp_min, 3);
503static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO | S_IWUSR, show_temp_max,
504	set_temp_max, 3);
505static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_temp_fault, NULL, 3);
506static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_temp_min_alarm,
507	NULL, 3);
508static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_temp_max_alarm,
509	NULL, 3);
510
511static DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL);
512static DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR, show_fan_div, set_fan_div);
513static DEVICE_ATTR(fan1_target, S_IRUGO | S_IWUSR, show_fan_target,
514	set_fan_target);
515static DEVICE_ATTR(fan1_fault, S_IRUGO, show_fan_fault, NULL);
516
517static DEVICE_ATTR(pwm1_enable, S_IRUGO | S_IWUSR, show_pwm_enable,
518	set_pwm_enable);
519
520/* sensors present on all models */
521static struct attribute *emc2103_attributes[] = {
522	&sensor_dev_attr_temp1_input.dev_attr.attr,
523	&sensor_dev_attr_temp1_min.dev_attr.attr,
524	&sensor_dev_attr_temp1_max.dev_attr.attr,
525	&sensor_dev_attr_temp1_fault.dev_attr.attr,
526	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
527	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
528	&sensor_dev_attr_temp2_input.dev_attr.attr,
529	&sensor_dev_attr_temp2_min.dev_attr.attr,
530	&sensor_dev_attr_temp2_max.dev_attr.attr,
531	&sensor_dev_attr_temp2_fault.dev_attr.attr,
532	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
533	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
534	&dev_attr_fan1_input.attr,
535	&dev_attr_fan1_div.attr,
536	&dev_attr_fan1_target.attr,
537	&dev_attr_fan1_fault.attr,
538	&dev_attr_pwm1_enable.attr,
539	NULL
540};
541
542/* extra temperature sensors only present on 2103-2 and 2103-4 */
543static struct attribute *emc2103_attributes_temp3[] = {
544	&sensor_dev_attr_temp3_input.dev_attr.attr,
545	&sensor_dev_attr_temp3_min.dev_attr.attr,
546	&sensor_dev_attr_temp3_max.dev_attr.attr,
547	&sensor_dev_attr_temp3_fault.dev_attr.attr,
548	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
549	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
550	NULL
551};
552
553/* extra temperature sensors only present on 2103-2 and 2103-4 in APD mode */
554static struct attribute *emc2103_attributes_temp4[] = {
555	&sensor_dev_attr_temp4_input.dev_attr.attr,
556	&sensor_dev_attr_temp4_min.dev_attr.attr,
557	&sensor_dev_attr_temp4_max.dev_attr.attr,
558	&sensor_dev_attr_temp4_fault.dev_attr.attr,
559	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
560	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
561	NULL
562};
563
564static const struct attribute_group emc2103_group = {
565	.attrs = emc2103_attributes,
566};
567
568static const struct attribute_group emc2103_temp3_group = {
569	.attrs = emc2103_attributes_temp3,
570};
571
572static const struct attribute_group emc2103_temp4_group = {
573	.attrs = emc2103_attributes_temp4,
574};
575
576static int
577emc2103_probe(struct i2c_client *client, const struct i2c_device_id *id)
578{
579	struct emc2103_data *data;
580	int status;
581
582	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
583		return -EIO;
584
585	data = kzalloc(sizeof(struct emc2103_data), GFP_KERNEL);
586	if (!data)
587		return -ENOMEM;
588
589	i2c_set_clientdata(client, data);
590	mutex_init(&data->update_lock);
591
592	/* 2103-2 and 2103-4 have 3 external diodes, 2103-1 has 1 */
593	status = i2c_smbus_read_byte_data(client, REG_PRODUCT_ID);
594	if (status == 0x24) {
595		/* 2103-1 only has 1 external diode */
596		data->temp_count = 2;
597	} else {
598		/* 2103-2 and 2103-4 have 3 or 4 external diodes */
599		status = i2c_smbus_read_byte_data(client, REG_CONF1);
600		if (status < 0) {
601			dev_dbg(&client->dev, "reg 0x%02x, err %d\n", REG_CONF1,
602				status);
603			goto exit_free;
604		}
605
606		/* detect current state of hardware */
607		data->temp_count = (status & 0x01) ? 4 : 3;
608
609		/* force APD state if module parameter is set */
610		if (apd == 0) {
611			/* force APD mode off */
612			data->temp_count = 3;
613			status &= ~(0x01);
614			i2c_smbus_write_byte_data(client, REG_CONF1, status);
615		} else if (apd == 1) {
616			/* force APD mode on */
617			data->temp_count = 4;
618			status |= 0x01;
619			i2c_smbus_write_byte_data(client, REG_CONF1, status);
620		}
621	}
622
623	/* Register sysfs hooks */
624	status = sysfs_create_group(&client->dev.kobj, &emc2103_group);
625	if (status)
626		goto exit_free;
627
628	if (data->temp_count >= 3) {
629		status = sysfs_create_group(&client->dev.kobj,
630			&emc2103_temp3_group);
631		if (status)
632			goto exit_remove;
633	}
634
635	if (data->temp_count == 4) {
636		status = sysfs_create_group(&client->dev.kobj,
637			&emc2103_temp4_group);
638		if (status)
639			goto exit_remove_temp3;
640	}
641
642	data->hwmon_dev = hwmon_device_register(&client->dev);
643	if (IS_ERR(data->hwmon_dev)) {
644		status = PTR_ERR(data->hwmon_dev);
645		goto exit_remove_temp4;
646	}
647
648	dev_info(&client->dev, "%s: sensor '%s'\n",
649		 dev_name(data->hwmon_dev), client->name);
650
651	return 0;
652
653exit_remove_temp4:
654	if (data->temp_count == 4)
655		sysfs_remove_group(&client->dev.kobj, &emc2103_temp4_group);
656exit_remove_temp3:
657	if (data->temp_count >= 3)
658		sysfs_remove_group(&client->dev.kobj, &emc2103_temp3_group);
659exit_remove:
660	sysfs_remove_group(&client->dev.kobj, &emc2103_group);
661exit_free:
662	kfree(data);
663	return status;
664}
665
666static int emc2103_remove(struct i2c_client *client)
667{
668	struct emc2103_data *data = i2c_get_clientdata(client);
669
670	hwmon_device_unregister(data->hwmon_dev);
671
672	if (data->temp_count == 4)
673		sysfs_remove_group(&client->dev.kobj, &emc2103_temp4_group);
674
675	if (data->temp_count >= 3)
676		sysfs_remove_group(&client->dev.kobj, &emc2103_temp3_group);
677
678	sysfs_remove_group(&client->dev.kobj, &emc2103_group);
679
680	kfree(data);
681	return 0;
682}
683
684static const struct i2c_device_id emc2103_ids[] = {
685	{ "emc2103", 0, },
686	{ /* LIST END */ }
687};
688MODULE_DEVICE_TABLE(i2c, emc2103_ids);
689
690/* Return 0 if detection is successful, -ENODEV otherwise */
691static int
692emc2103_detect(struct i2c_client *new_client, struct i2c_board_info *info)
693{
694	struct i2c_adapter *adapter = new_client->adapter;
695	int manufacturer, product;
696
697	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
698		return -ENODEV;
699
700	manufacturer = i2c_smbus_read_byte_data(new_client, REG_MFG_ID);
701	if (manufacturer != 0x5D)
702		return -ENODEV;
703
704	product = i2c_smbus_read_byte_data(new_client, REG_PRODUCT_ID);
705	if ((product != 0x24) && (product != 0x26))
706		return -ENODEV;
707
708	strlcpy(info->type, "emc2103", I2C_NAME_SIZE);
709
710	return 0;
711}
712
713static struct i2c_driver emc2103_driver = {
714	.class		= I2C_CLASS_HWMON,
715	.driver = {
716		.name	= "emc2103",
717	},
718	.probe		= emc2103_probe,
719	.remove		= emc2103_remove,
720	.id_table	= emc2103_ids,
721	.detect		= emc2103_detect,
722	.address_list	= normal_i2c,
723};
724
725static int __init sensors_emc2103_init(void)
726{
727	return i2c_add_driver(&emc2103_driver);
728}
729
730static void __exit sensors_emc2103_exit(void)
731{
732	i2c_del_driver(&emc2103_driver);
733}
734
735MODULE_AUTHOR("Steve Glendinning <steve.glendinning@smsc.com>");
736MODULE_DESCRIPTION("SMSC EMC2103 hwmon driver");
737MODULE_LICENSE("GPL");
738
739module_init(sensors_emc2103_init);
740module_exit(sensors_emc2103_exit);
741