1/*
2 * lm78.c - Part of lm_sensors, Linux kernel modules for hardware
3 *	    monitoring
4 * Copyright (c) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
5 * Copyright (c) 2007, 2011  Jean Delvare <jdelvare@suse.de>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/i2c.h>
29#include <linux/hwmon.h>
30#include <linux/hwmon-vid.h>
31#include <linux/hwmon-sysfs.h>
32#include <linux/err.h>
33#include <linux/mutex.h>
34
35#ifdef CONFIG_ISA
36#include <linux/platform_device.h>
37#include <linux/ioport.h>
38#include <linux/io.h>
39#endif
40
41/* Addresses to scan */
42static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
43						0x2e, 0x2f, I2C_CLIENT_END };
44enum chips { lm78, lm79 };
45
46/* Many LM78 constants specified below */
47
48/* Length of ISA address segment */
49#define LM78_EXTENT 8
50
51/* Where are the ISA address/data registers relative to the base address */
52#define LM78_ADDR_REG_OFFSET 5
53#define LM78_DATA_REG_OFFSET 6
54
55/* The LM78 registers */
56#define LM78_REG_IN_MAX(nr) (0x2b + (nr) * 2)
57#define LM78_REG_IN_MIN(nr) (0x2c + (nr) * 2)
58#define LM78_REG_IN(nr) (0x20 + (nr))
59
60#define LM78_REG_FAN_MIN(nr) (0x3b + (nr))
61#define LM78_REG_FAN(nr) (0x28 + (nr))
62
63#define LM78_REG_TEMP 0x27
64#define LM78_REG_TEMP_OVER 0x39
65#define LM78_REG_TEMP_HYST 0x3a
66
67#define LM78_REG_ALARM1 0x41
68#define LM78_REG_ALARM2 0x42
69
70#define LM78_REG_VID_FANDIV 0x47
71
72#define LM78_REG_CONFIG 0x40
73#define LM78_REG_CHIPID 0x49
74#define LM78_REG_I2C_ADDR 0x48
75
76
77/*
78 * Conversions. Rounding and limit checking is only done on the TO_REG
79 * variants.
80 */
81
82/*
83 * IN: mV (0V to 4.08V)
84 * REG: 16mV/bit
85 */
86static inline u8 IN_TO_REG(unsigned long val)
87{
88	unsigned long nval = clamp_val(val, 0, 4080);
89	return (nval + 8) / 16;
90}
91#define IN_FROM_REG(val) ((val) *  16)
92
93static inline u8 FAN_TO_REG(long rpm, int div)
94{
95	if (rpm <= 0)
96		return 255;
97	if (rpm > 1350000)
98		return 1;
99	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
100}
101
102static inline int FAN_FROM_REG(u8 val, int div)
103{
104	return val == 0 ? -1 : val == 255 ? 0 : 1350000 / (val * div);
105}
106
107/*
108 * TEMP: mC (-128C to +127C)
109 * REG: 1C/bit, two's complement
110 */
111static inline s8 TEMP_TO_REG(long val)
112{
113	int nval = clamp_val(val, -128000, 127000) ;
114	return nval < 0 ? (nval - 500) / 1000 : (nval + 500) / 1000;
115}
116
117static inline int TEMP_FROM_REG(s8 val)
118{
119	return val * 1000;
120}
121
122#define DIV_FROM_REG(val) (1 << (val))
123
124struct lm78_data {
125	struct i2c_client *client;
126	struct mutex lock;
127	enum chips type;
128
129	/* For ISA device only */
130	const char *name;
131	int isa_addr;
132
133	struct mutex update_lock;
134	char valid;		/* !=0 if following fields are valid */
135	unsigned long last_updated;	/* In jiffies */
136
137	u8 in[7];		/* Register value */
138	u8 in_max[7];		/* Register value */
139	u8 in_min[7];		/* Register value */
140	u8 fan[3];		/* Register value */
141	u8 fan_min[3];		/* Register value */
142	s8 temp;		/* Register value */
143	s8 temp_over;		/* Register value */
144	s8 temp_hyst;		/* Register value */
145	u8 fan_div[3];		/* Register encoding, shifted right */
146	u8 vid;			/* Register encoding, combined */
147	u16 alarms;		/* Register encoding, combined */
148};
149
150
151static int lm78_read_value(struct lm78_data *data, u8 reg);
152static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value);
153static struct lm78_data *lm78_update_device(struct device *dev);
154static void lm78_init_device(struct lm78_data *data);
155
156
157/* 7 Voltages */
158static ssize_t show_in(struct device *dev, struct device_attribute *da,
159		       char *buf)
160{
161	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
162	struct lm78_data *data = lm78_update_device(dev);
163	return sprintf(buf, "%d\n", IN_FROM_REG(data->in[attr->index]));
164}
165
166static ssize_t show_in_min(struct device *dev, struct device_attribute *da,
167			   char *buf)
168{
169	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
170	struct lm78_data *data = lm78_update_device(dev);
171	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[attr->index]));
172}
173
174static ssize_t show_in_max(struct device *dev, struct device_attribute *da,
175			   char *buf)
176{
177	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
178	struct lm78_data *data = lm78_update_device(dev);
179	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[attr->index]));
180}
181
182static ssize_t set_in_min(struct device *dev, struct device_attribute *da,
183			  const char *buf, size_t count)
184{
185	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
186	struct lm78_data *data = dev_get_drvdata(dev);
187	int nr = attr->index;
188	unsigned long val;
189	int err;
190
191	err = kstrtoul(buf, 10, &val);
192	if (err)
193		return err;
194
195	mutex_lock(&data->update_lock);
196	data->in_min[nr] = IN_TO_REG(val);
197	lm78_write_value(data, LM78_REG_IN_MIN(nr), data->in_min[nr]);
198	mutex_unlock(&data->update_lock);
199	return count;
200}
201
202static ssize_t set_in_max(struct device *dev, struct device_attribute *da,
203			  const char *buf, size_t count)
204{
205	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
206	struct lm78_data *data = dev_get_drvdata(dev);
207	int nr = attr->index;
208	unsigned long val;
209	int err;
210
211	err = kstrtoul(buf, 10, &val);
212	if (err)
213		return err;
214
215	mutex_lock(&data->update_lock);
216	data->in_max[nr] = IN_TO_REG(val);
217	lm78_write_value(data, LM78_REG_IN_MAX(nr), data->in_max[nr]);
218	mutex_unlock(&data->update_lock);
219	return count;
220}
221
222#define show_in_offset(offset)					\
223static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
224		show_in, NULL, offset);				\
225static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
226		show_in_min, set_in_min, offset);		\
227static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
228		show_in_max, set_in_max, offset);
229
230show_in_offset(0);
231show_in_offset(1);
232show_in_offset(2);
233show_in_offset(3);
234show_in_offset(4);
235show_in_offset(5);
236show_in_offset(6);
237
238/* Temperature */
239static ssize_t show_temp(struct device *dev, struct device_attribute *da,
240			 char *buf)
241{
242	struct lm78_data *data = lm78_update_device(dev);
243	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
244}
245
246static ssize_t show_temp_over(struct device *dev, struct device_attribute *da,
247			      char *buf)
248{
249	struct lm78_data *data = lm78_update_device(dev);
250	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
251}
252
253static ssize_t set_temp_over(struct device *dev, struct device_attribute *da,
254			     const char *buf, size_t count)
255{
256	struct lm78_data *data = dev_get_drvdata(dev);
257	long val;
258	int err;
259
260	err = kstrtol(buf, 10, &val);
261	if (err)
262		return err;
263
264	mutex_lock(&data->update_lock);
265	data->temp_over = TEMP_TO_REG(val);
266	lm78_write_value(data, LM78_REG_TEMP_OVER, data->temp_over);
267	mutex_unlock(&data->update_lock);
268	return count;
269}
270
271static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *da,
272			      char *buf)
273{
274	struct lm78_data *data = lm78_update_device(dev);
275	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
276}
277
278static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *da,
279			     const char *buf, size_t count)
280{
281	struct lm78_data *data = dev_get_drvdata(dev);
282	long val;
283	int err;
284
285	err = kstrtol(buf, 10, &val);
286	if (err)
287		return err;
288
289	mutex_lock(&data->update_lock);
290	data->temp_hyst = TEMP_TO_REG(val);
291	lm78_write_value(data, LM78_REG_TEMP_HYST, data->temp_hyst);
292	mutex_unlock(&data->update_lock);
293	return count;
294}
295
296static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
297static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
298		show_temp_over, set_temp_over);
299static DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
300		show_temp_hyst, set_temp_hyst);
301
302/* 3 Fans */
303static ssize_t show_fan(struct device *dev, struct device_attribute *da,
304			char *buf)
305{
306	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
307	struct lm78_data *data = lm78_update_device(dev);
308	int nr = attr->index;
309	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
310		DIV_FROM_REG(data->fan_div[nr])));
311}
312
313static ssize_t show_fan_min(struct device *dev, struct device_attribute *da,
314			    char *buf)
315{
316	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
317	struct lm78_data *data = lm78_update_device(dev);
318	int nr = attr->index;
319	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
320		DIV_FROM_REG(data->fan_div[nr])));
321}
322
323static ssize_t set_fan_min(struct device *dev, struct device_attribute *da,
324			   const char *buf, size_t count)
325{
326	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
327	struct lm78_data *data = dev_get_drvdata(dev);
328	int nr = attr->index;
329	unsigned long val;
330	int err;
331
332	err = kstrtoul(buf, 10, &val);
333	if (err)
334		return err;
335
336	mutex_lock(&data->update_lock);
337	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
338	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
339	mutex_unlock(&data->update_lock);
340	return count;
341}
342
343static ssize_t show_fan_div(struct device *dev, struct device_attribute *da,
344			    char *buf)
345{
346	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
347	struct lm78_data *data = lm78_update_device(dev);
348	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
349}
350
351/*
352 * Note: we save and restore the fan minimum here, because its value is
353 * determined in part by the fan divisor.  This follows the principle of
354 * least surprise; the user doesn't expect the fan minimum to change just
355 * because the divisor changed.
356 */
357static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
358			   const char *buf, size_t count)
359{
360	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
361	struct lm78_data *data = dev_get_drvdata(dev);
362	int nr = attr->index;
363	unsigned long min;
364	u8 reg;
365	unsigned long val;
366	int err;
367
368	err = kstrtoul(buf, 10, &val);
369	if (err)
370		return err;
371
372	mutex_lock(&data->update_lock);
373	min = FAN_FROM_REG(data->fan_min[nr],
374			   DIV_FROM_REG(data->fan_div[nr]));
375
376	switch (val) {
377	case 1:
378		data->fan_div[nr] = 0;
379		break;
380	case 2:
381		data->fan_div[nr] = 1;
382		break;
383	case 4:
384		data->fan_div[nr] = 2;
385		break;
386	case 8:
387		data->fan_div[nr] = 3;
388		break;
389	default:
390		dev_err(dev,
391			"fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
392			val);
393		mutex_unlock(&data->update_lock);
394		return -EINVAL;
395	}
396
397	reg = lm78_read_value(data, LM78_REG_VID_FANDIV);
398	switch (nr) {
399	case 0:
400		reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
401		break;
402	case 1:
403		reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
404		break;
405	}
406	lm78_write_value(data, LM78_REG_VID_FANDIV, reg);
407
408	data->fan_min[nr] =
409		FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
410	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
411	mutex_unlock(&data->update_lock);
412
413	return count;
414}
415
416#define show_fan_offset(offset)				\
417static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,		\
418		show_fan, NULL, offset - 1);			\
419static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,	\
420		show_fan_min, set_fan_min, offset - 1);
421
422show_fan_offset(1);
423show_fan_offset(2);
424show_fan_offset(3);
425
426/* Fan 3 divisor is locked in H/W */
427static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
428		show_fan_div, set_fan_div, 0);
429static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
430		show_fan_div, set_fan_div, 1);
431static SENSOR_DEVICE_ATTR(fan3_div, S_IRUGO, show_fan_div, NULL, 2);
432
433/* VID */
434static ssize_t show_vid(struct device *dev, struct device_attribute *da,
435			char *buf)
436{
437	struct lm78_data *data = lm78_update_device(dev);
438	return sprintf(buf, "%d\n", vid_from_reg(data->vid, 82));
439}
440static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
441
442/* Alarms */
443static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
444			   char *buf)
445{
446	struct lm78_data *data = lm78_update_device(dev);
447	return sprintf(buf, "%u\n", data->alarms);
448}
449static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
450
451static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
452			  char *buf)
453{
454	struct lm78_data *data = lm78_update_device(dev);
455	int nr = to_sensor_dev_attr(da)->index;
456	return sprintf(buf, "%u\n", (data->alarms >> nr) & 1);
457}
458static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
459static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
460static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
461static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
462static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
463static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9);
464static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 10);
465static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
466static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
467static SENSOR_DEVICE_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 11);
468static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
469
470static struct attribute *lm78_attrs[] = {
471	&sensor_dev_attr_in0_input.dev_attr.attr,
472	&sensor_dev_attr_in0_min.dev_attr.attr,
473	&sensor_dev_attr_in0_max.dev_attr.attr,
474	&sensor_dev_attr_in0_alarm.dev_attr.attr,
475	&sensor_dev_attr_in1_input.dev_attr.attr,
476	&sensor_dev_attr_in1_min.dev_attr.attr,
477	&sensor_dev_attr_in1_max.dev_attr.attr,
478	&sensor_dev_attr_in1_alarm.dev_attr.attr,
479	&sensor_dev_attr_in2_input.dev_attr.attr,
480	&sensor_dev_attr_in2_min.dev_attr.attr,
481	&sensor_dev_attr_in2_max.dev_attr.attr,
482	&sensor_dev_attr_in2_alarm.dev_attr.attr,
483	&sensor_dev_attr_in3_input.dev_attr.attr,
484	&sensor_dev_attr_in3_min.dev_attr.attr,
485	&sensor_dev_attr_in3_max.dev_attr.attr,
486	&sensor_dev_attr_in3_alarm.dev_attr.attr,
487	&sensor_dev_attr_in4_input.dev_attr.attr,
488	&sensor_dev_attr_in4_min.dev_attr.attr,
489	&sensor_dev_attr_in4_max.dev_attr.attr,
490	&sensor_dev_attr_in4_alarm.dev_attr.attr,
491	&sensor_dev_attr_in5_input.dev_attr.attr,
492	&sensor_dev_attr_in5_min.dev_attr.attr,
493	&sensor_dev_attr_in5_max.dev_attr.attr,
494	&sensor_dev_attr_in5_alarm.dev_attr.attr,
495	&sensor_dev_attr_in6_input.dev_attr.attr,
496	&sensor_dev_attr_in6_min.dev_attr.attr,
497	&sensor_dev_attr_in6_max.dev_attr.attr,
498	&sensor_dev_attr_in6_alarm.dev_attr.attr,
499	&dev_attr_temp1_input.attr,
500	&dev_attr_temp1_max.attr,
501	&dev_attr_temp1_max_hyst.attr,
502	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
503	&sensor_dev_attr_fan1_input.dev_attr.attr,
504	&sensor_dev_attr_fan1_min.dev_attr.attr,
505	&sensor_dev_attr_fan1_div.dev_attr.attr,
506	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
507	&sensor_dev_attr_fan2_input.dev_attr.attr,
508	&sensor_dev_attr_fan2_min.dev_attr.attr,
509	&sensor_dev_attr_fan2_div.dev_attr.attr,
510	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
511	&sensor_dev_attr_fan3_input.dev_attr.attr,
512	&sensor_dev_attr_fan3_min.dev_attr.attr,
513	&sensor_dev_attr_fan3_div.dev_attr.attr,
514	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
515	&dev_attr_alarms.attr,
516	&dev_attr_cpu0_vid.attr,
517
518	NULL
519};
520
521ATTRIBUTE_GROUPS(lm78);
522
523/*
524 * ISA related code
525 */
526#ifdef CONFIG_ISA
527
528/* ISA device, if found */
529static struct platform_device *pdev;
530
531static unsigned short isa_address = 0x290;
532
533static struct lm78_data *lm78_data_if_isa(void)
534{
535	return pdev ? platform_get_drvdata(pdev) : NULL;
536}
537
538/* Returns 1 if the I2C chip appears to be an alias of the ISA chip */
539static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
540{
541	struct lm78_data *isa;
542	int i;
543
544	if (!pdev)	/* No ISA chip */
545		return 0;
546	isa = platform_get_drvdata(pdev);
547
548	if (lm78_read_value(isa, LM78_REG_I2C_ADDR) != client->addr)
549		return 0;	/* Address doesn't match */
550	if ((lm78_read_value(isa, LM78_REG_CHIPID) & 0xfe) != (chipid & 0xfe))
551		return 0;	/* Chip type doesn't match */
552
553	/*
554	 * We compare all the limit registers, the config register and the
555	 * interrupt mask registers
556	 */
557	for (i = 0x2b; i <= 0x3d; i++) {
558		if (lm78_read_value(isa, i) !=
559		    i2c_smbus_read_byte_data(client, i))
560			return 0;
561	}
562	if (lm78_read_value(isa, LM78_REG_CONFIG) !=
563	    i2c_smbus_read_byte_data(client, LM78_REG_CONFIG))
564		return 0;
565	for (i = 0x43; i <= 0x46; i++) {
566		if (lm78_read_value(isa, i) !=
567		    i2c_smbus_read_byte_data(client, i))
568			return 0;
569	}
570
571	return 1;
572}
573#else /* !CONFIG_ISA */
574
575static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
576{
577	return 0;
578}
579
580static struct lm78_data *lm78_data_if_isa(void)
581{
582	return NULL;
583}
584#endif /* CONFIG_ISA */
585
586static int lm78_i2c_detect(struct i2c_client *client,
587			   struct i2c_board_info *info)
588{
589	int i;
590	struct lm78_data *isa = lm78_data_if_isa();
591	const char *client_name;
592	struct i2c_adapter *adapter = client->adapter;
593	int address = client->addr;
594
595	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
596		return -ENODEV;
597
598	/*
599	 * We block updates of the ISA device to minimize the risk of
600	 * concurrent access to the same LM78 chip through different
601	 * interfaces.
602	 */
603	if (isa)
604		mutex_lock(&isa->update_lock);
605
606	if ((i2c_smbus_read_byte_data(client, LM78_REG_CONFIG) & 0x80)
607	 || i2c_smbus_read_byte_data(client, LM78_REG_I2C_ADDR) != address)
608		goto err_nodev;
609
610	/* Explicitly prevent the misdetection of Winbond chips */
611	i = i2c_smbus_read_byte_data(client, 0x4f);
612	if (i == 0xa3 || i == 0x5c)
613		goto err_nodev;
614
615	/* Determine the chip type. */
616	i = i2c_smbus_read_byte_data(client, LM78_REG_CHIPID);
617	if (i == 0x00 || i == 0x20	/* LM78 */
618	 || i == 0x40)			/* LM78-J */
619		client_name = "lm78";
620	else if ((i & 0xfe) == 0xc0)
621		client_name = "lm79";
622	else
623		goto err_nodev;
624
625	if (lm78_alias_detect(client, i)) {
626		dev_dbg(&adapter->dev,
627			"Device at 0x%02x appears to be the same as ISA device\n",
628			address);
629		goto err_nodev;
630	}
631
632	if (isa)
633		mutex_unlock(&isa->update_lock);
634
635	strlcpy(info->type, client_name, I2C_NAME_SIZE);
636
637	return 0;
638
639 err_nodev:
640	if (isa)
641		mutex_unlock(&isa->update_lock);
642	return -ENODEV;
643}
644
645static int lm78_i2c_probe(struct i2c_client *client,
646			  const struct i2c_device_id *id)
647{
648	struct device *dev = &client->dev;
649	struct device *hwmon_dev;
650	struct lm78_data *data;
651
652	data = devm_kzalloc(dev, sizeof(struct lm78_data), GFP_KERNEL);
653	if (!data)
654		return -ENOMEM;
655
656	data->client = client;
657	data->type = id->driver_data;
658
659	/* Initialize the LM78 chip */
660	lm78_init_device(data);
661
662	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
663							   data, lm78_groups);
664	return PTR_ERR_OR_ZERO(hwmon_dev);
665}
666
667static const struct i2c_device_id lm78_i2c_id[] = {
668	{ "lm78", lm78 },
669	{ "lm79", lm79 },
670	{ }
671};
672MODULE_DEVICE_TABLE(i2c, lm78_i2c_id);
673
674static struct i2c_driver lm78_driver = {
675	.class		= I2C_CLASS_HWMON,
676	.driver = {
677		.name	= "lm78",
678	},
679	.probe		= lm78_i2c_probe,
680	.id_table	= lm78_i2c_id,
681	.detect		= lm78_i2c_detect,
682	.address_list	= normal_i2c,
683};
684
685/*
686 * The SMBus locks itself, but ISA access must be locked explicitly!
687 * We don't want to lock the whole ISA bus, so we lock each client
688 * separately.
689 * We ignore the LM78 BUSY flag at this moment - it could lead to deadlocks,
690 * would slow down the LM78 access and should not be necessary.
691 */
692static int lm78_read_value(struct lm78_data *data, u8 reg)
693{
694	struct i2c_client *client = data->client;
695
696#ifdef CONFIG_ISA
697	if (!client) { /* ISA device */
698		int res;
699		mutex_lock(&data->lock);
700		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
701		res = inb_p(data->isa_addr + LM78_DATA_REG_OFFSET);
702		mutex_unlock(&data->lock);
703		return res;
704	} else
705#endif
706		return i2c_smbus_read_byte_data(client, reg);
707}
708
709static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value)
710{
711	struct i2c_client *client = data->client;
712
713#ifdef CONFIG_ISA
714	if (!client) { /* ISA device */
715		mutex_lock(&data->lock);
716		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
717		outb_p(value, data->isa_addr + LM78_DATA_REG_OFFSET);
718		mutex_unlock(&data->lock);
719		return 0;
720	} else
721#endif
722		return i2c_smbus_write_byte_data(client, reg, value);
723}
724
725static void lm78_init_device(struct lm78_data *data)
726{
727	u8 config;
728	int i;
729
730	/* Start monitoring */
731	config = lm78_read_value(data, LM78_REG_CONFIG);
732	if ((config & 0x09) != 0x01)
733		lm78_write_value(data, LM78_REG_CONFIG,
734				 (config & 0xf7) | 0x01);
735
736	/* A few vars need to be filled upon startup */
737	for (i = 0; i < 3; i++) {
738		data->fan_min[i] = lm78_read_value(data,
739					LM78_REG_FAN_MIN(i));
740	}
741
742	mutex_init(&data->update_lock);
743}
744
745static struct lm78_data *lm78_update_device(struct device *dev)
746{
747	struct lm78_data *data = dev_get_drvdata(dev);
748	int i;
749
750	mutex_lock(&data->update_lock);
751
752	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
753	    || !data->valid) {
754
755		dev_dbg(dev, "Starting lm78 update\n");
756
757		for (i = 0; i <= 6; i++) {
758			data->in[i] =
759			    lm78_read_value(data, LM78_REG_IN(i));
760			data->in_min[i] =
761			    lm78_read_value(data, LM78_REG_IN_MIN(i));
762			data->in_max[i] =
763			    lm78_read_value(data, LM78_REG_IN_MAX(i));
764		}
765		for (i = 0; i < 3; i++) {
766			data->fan[i] =
767			    lm78_read_value(data, LM78_REG_FAN(i));
768			data->fan_min[i] =
769			    lm78_read_value(data, LM78_REG_FAN_MIN(i));
770		}
771		data->temp = lm78_read_value(data, LM78_REG_TEMP);
772		data->temp_over =
773		    lm78_read_value(data, LM78_REG_TEMP_OVER);
774		data->temp_hyst =
775		    lm78_read_value(data, LM78_REG_TEMP_HYST);
776		i = lm78_read_value(data, LM78_REG_VID_FANDIV);
777		data->vid = i & 0x0f;
778		if (data->type == lm79)
779			data->vid |=
780			    (lm78_read_value(data, LM78_REG_CHIPID) &
781			     0x01) << 4;
782		else
783			data->vid |= 0x10;
784		data->fan_div[0] = (i >> 4) & 0x03;
785		data->fan_div[1] = i >> 6;
786		data->alarms = lm78_read_value(data, LM78_REG_ALARM1) +
787		    (lm78_read_value(data, LM78_REG_ALARM2) << 8);
788		data->last_updated = jiffies;
789		data->valid = 1;
790
791		data->fan_div[2] = 1;
792	}
793
794	mutex_unlock(&data->update_lock);
795
796	return data;
797}
798
799#ifdef CONFIG_ISA
800static int lm78_isa_probe(struct platform_device *pdev)
801{
802	struct device *dev = &pdev->dev;
803	struct device *hwmon_dev;
804	struct lm78_data *data;
805	struct resource *res;
806
807	/* Reserve the ISA region */
808	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
809	if (!devm_request_region(dev, res->start + LM78_ADDR_REG_OFFSET,
810				 2, "lm78"))
811		return -EBUSY;
812
813	data = devm_kzalloc(dev, sizeof(struct lm78_data), GFP_KERNEL);
814	if (!data)
815		return -ENOMEM;
816
817	mutex_init(&data->lock);
818	data->isa_addr = res->start;
819	platform_set_drvdata(pdev, data);
820
821	if (lm78_read_value(data, LM78_REG_CHIPID) & 0x80) {
822		data->type = lm79;
823		data->name = "lm79";
824	} else {
825		data->type = lm78;
826		data->name = "lm78";
827	}
828
829	/* Initialize the LM78 chip */
830	lm78_init_device(data);
831
832	hwmon_dev = devm_hwmon_device_register_with_groups(dev, data->name,
833							   data, lm78_groups);
834	return PTR_ERR_OR_ZERO(hwmon_dev);
835}
836
837static struct platform_driver lm78_isa_driver = {
838	.driver = {
839		.name	= "lm78",
840	},
841	.probe		= lm78_isa_probe,
842};
843
844/* return 1 if a supported chip is found, 0 otherwise */
845static int __init lm78_isa_found(unsigned short address)
846{
847	int val, save, found = 0;
848	int port;
849
850	/*
851	 * Some boards declare base+0 to base+7 as a PNP device, some base+4
852	 * to base+7 and some base+5 to base+6. So we better request each port
853	 * individually for the probing phase.
854	 */
855	for (port = address; port < address + LM78_EXTENT; port++) {
856		if (!request_region(port, 1, "lm78")) {
857			pr_debug("Failed to request port 0x%x\n", port);
858			goto release;
859		}
860	}
861
862#define REALLY_SLOW_IO
863	/*
864	 * We need the timeouts for at least some LM78-like
865	 * chips. But only if we read 'undefined' registers.
866	 */
867	val = inb_p(address + 1);
868	if (inb_p(address + 2) != val
869	 || inb_p(address + 3) != val
870	 || inb_p(address + 7) != val)
871		goto release;
872#undef REALLY_SLOW_IO
873
874	/*
875	 * We should be able to change the 7 LSB of the address port. The
876	 * MSB (busy flag) should be clear initially, set after the write.
877	 */
878	save = inb_p(address + LM78_ADDR_REG_OFFSET);
879	if (save & 0x80)
880		goto release;
881	val = ~save & 0x7f;
882	outb_p(val, address + LM78_ADDR_REG_OFFSET);
883	if (inb_p(address + LM78_ADDR_REG_OFFSET) != (val | 0x80)) {
884		outb_p(save, address + LM78_ADDR_REG_OFFSET);
885		goto release;
886	}
887
888	/* We found a device, now see if it could be an LM78 */
889	outb_p(LM78_REG_CONFIG, address + LM78_ADDR_REG_OFFSET);
890	val = inb_p(address + LM78_DATA_REG_OFFSET);
891	if (val & 0x80)
892		goto release;
893	outb_p(LM78_REG_I2C_ADDR, address + LM78_ADDR_REG_OFFSET);
894	val = inb_p(address + LM78_DATA_REG_OFFSET);
895	if (val < 0x03 || val > 0x77)	/* Not a valid I2C address */
896		goto release;
897
898	/* The busy flag should be clear again */
899	if (inb_p(address + LM78_ADDR_REG_OFFSET) & 0x80)
900		goto release;
901
902	/* Explicitly prevent the misdetection of Winbond chips */
903	outb_p(0x4f, address + LM78_ADDR_REG_OFFSET);
904	val = inb_p(address + LM78_DATA_REG_OFFSET);
905	if (val == 0xa3 || val == 0x5c)
906		goto release;
907
908	/* Explicitly prevent the misdetection of ITE chips */
909	outb_p(0x58, address + LM78_ADDR_REG_OFFSET);
910	val = inb_p(address + LM78_DATA_REG_OFFSET);
911	if (val == 0x90)
912		goto release;
913
914	/* Determine the chip type */
915	outb_p(LM78_REG_CHIPID, address + LM78_ADDR_REG_OFFSET);
916	val = inb_p(address + LM78_DATA_REG_OFFSET);
917	if (val == 0x00 || val == 0x20	/* LM78 */
918	 || val == 0x40			/* LM78-J */
919	 || (val & 0xfe) == 0xc0)	/* LM79 */
920		found = 1;
921
922	if (found)
923		pr_info("Found an %s chip at %#x\n",
924			val & 0x80 ? "LM79" : "LM78", (int)address);
925
926 release:
927	for (port--; port >= address; port--)
928		release_region(port, 1);
929	return found;
930}
931
932static int __init lm78_isa_device_add(unsigned short address)
933{
934	struct resource res = {
935		.start	= address,
936		.end	= address + LM78_EXTENT - 1,
937		.name	= "lm78",
938		.flags	= IORESOURCE_IO,
939	};
940	int err;
941
942	pdev = platform_device_alloc("lm78", address);
943	if (!pdev) {
944		err = -ENOMEM;
945		pr_err("Device allocation failed\n");
946		goto exit;
947	}
948
949	err = platform_device_add_resources(pdev, &res, 1);
950	if (err) {
951		pr_err("Device resource addition failed (%d)\n", err);
952		goto exit_device_put;
953	}
954
955	err = platform_device_add(pdev);
956	if (err) {
957		pr_err("Device addition failed (%d)\n", err);
958		goto exit_device_put;
959	}
960
961	return 0;
962
963 exit_device_put:
964	platform_device_put(pdev);
965 exit:
966	pdev = NULL;
967	return err;
968}
969
970static int __init lm78_isa_register(void)
971{
972	int res;
973
974	if (lm78_isa_found(isa_address)) {
975		res = platform_driver_register(&lm78_isa_driver);
976		if (res)
977			goto exit;
978
979		/* Sets global pdev as a side effect */
980		res = lm78_isa_device_add(isa_address);
981		if (res)
982			goto exit_unreg_isa_driver;
983	}
984
985	return 0;
986
987 exit_unreg_isa_driver:
988	platform_driver_unregister(&lm78_isa_driver);
989 exit:
990	return res;
991}
992
993static void lm78_isa_unregister(void)
994{
995	if (pdev) {
996		platform_device_unregister(pdev);
997		platform_driver_unregister(&lm78_isa_driver);
998	}
999}
1000#else /* !CONFIG_ISA */
1001
1002static int __init lm78_isa_register(void)
1003{
1004	return 0;
1005}
1006
1007static void lm78_isa_unregister(void)
1008{
1009}
1010#endif /* CONFIG_ISA */
1011
1012static int __init sm_lm78_init(void)
1013{
1014	int res;
1015
1016	/*
1017	 * We register the ISA device first, so that we can skip the
1018	 * registration of an I2C interface to the same device.
1019	 */
1020	res = lm78_isa_register();
1021	if (res)
1022		goto exit;
1023
1024	res = i2c_add_driver(&lm78_driver);
1025	if (res)
1026		goto exit_unreg_isa_device;
1027
1028	return 0;
1029
1030 exit_unreg_isa_device:
1031	lm78_isa_unregister();
1032 exit:
1033	return res;
1034}
1035
1036static void __exit sm_lm78_exit(void)
1037{
1038	lm78_isa_unregister();
1039	i2c_del_driver(&lm78_driver);
1040}
1041
1042MODULE_AUTHOR("Frodo Looijaard, Jean Delvare <jdelvare@suse.de>");
1043MODULE_DESCRIPTION("LM78/LM79 driver");
1044MODULE_LICENSE("GPL");
1045
1046module_init(sm_lm78_init);
1047module_exit(sm_lm78_exit);
1048