xref: /openbmc/linux/drivers/hwmon/lm78.c (revision 930beb5a)
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 <khali@linux-fr.org>
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 */
42 static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
43 						0x2e, 0x2f, I2C_CLIENT_END };
44 enum 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  */
86 static 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 
93 static 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 
102 static 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  */
111 static inline s8 TEMP_TO_REG(int val)
112 {
113 	int nval = clamp_val(val, -128000, 127000) ;
114 	return nval < 0 ? (nval - 500) / 1000 : (nval + 500) / 1000;
115 }
116 
117 static inline int TEMP_FROM_REG(s8 val)
118 {
119 	return val * 1000;
120 }
121 
122 #define DIV_FROM_REG(val) (1 << (val))
123 
124 struct lm78_data {
125 	struct i2c_client *client;
126 	struct device *hwmon_dev;
127 	struct mutex lock;
128 	enum chips type;
129 
130 	/* For ISA device only */
131 	const char *name;
132 	int isa_addr;
133 
134 	struct mutex update_lock;
135 	char valid;		/* !=0 if following fields are valid */
136 	unsigned long last_updated;	/* In jiffies */
137 
138 	u8 in[7];		/* Register value */
139 	u8 in_max[7];		/* Register value */
140 	u8 in_min[7];		/* Register value */
141 	u8 fan[3];		/* Register value */
142 	u8 fan_min[3];		/* Register value */
143 	s8 temp;		/* Register value */
144 	s8 temp_over;		/* Register value */
145 	s8 temp_hyst;		/* Register value */
146 	u8 fan_div[3];		/* Register encoding, shifted right */
147 	u8 vid;			/* Register encoding, combined */
148 	u16 alarms;		/* Register encoding, combined */
149 };
150 
151 
152 static int lm78_read_value(struct lm78_data *data, u8 reg);
153 static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value);
154 static struct lm78_data *lm78_update_device(struct device *dev);
155 static void lm78_init_device(struct lm78_data *data);
156 
157 
158 /* 7 Voltages */
159 static ssize_t show_in(struct device *dev, struct device_attribute *da,
160 		       char *buf)
161 {
162 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
163 	struct lm78_data *data = lm78_update_device(dev);
164 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in[attr->index]));
165 }
166 
167 static ssize_t show_in_min(struct device *dev, struct device_attribute *da,
168 			   char *buf)
169 {
170 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
171 	struct lm78_data *data = lm78_update_device(dev);
172 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[attr->index]));
173 }
174 
175 static ssize_t show_in_max(struct device *dev, struct device_attribute *da,
176 			   char *buf)
177 {
178 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
179 	struct lm78_data *data = lm78_update_device(dev);
180 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[attr->index]));
181 }
182 
183 static ssize_t set_in_min(struct device *dev, struct device_attribute *da,
184 			  const char *buf, size_t count)
185 {
186 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
187 	struct lm78_data *data = dev_get_drvdata(dev);
188 	int nr = attr->index;
189 	unsigned long val;
190 	int err;
191 
192 	err = kstrtoul(buf, 10, &val);
193 	if (err)
194 		return err;
195 
196 	mutex_lock(&data->update_lock);
197 	data->in_min[nr] = IN_TO_REG(val);
198 	lm78_write_value(data, LM78_REG_IN_MIN(nr), data->in_min[nr]);
199 	mutex_unlock(&data->update_lock);
200 	return count;
201 }
202 
203 static ssize_t set_in_max(struct device *dev, struct device_attribute *da,
204 			  const char *buf, size_t count)
205 {
206 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
207 	struct lm78_data *data = dev_get_drvdata(dev);
208 	int nr = attr->index;
209 	unsigned long val;
210 	int err;
211 
212 	err = kstrtoul(buf, 10, &val);
213 	if (err)
214 		return err;
215 
216 	mutex_lock(&data->update_lock);
217 	data->in_max[nr] = IN_TO_REG(val);
218 	lm78_write_value(data, LM78_REG_IN_MAX(nr), data->in_max[nr]);
219 	mutex_unlock(&data->update_lock);
220 	return count;
221 }
222 
223 #define show_in_offset(offset)					\
224 static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
225 		show_in, NULL, offset);				\
226 static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
227 		show_in_min, set_in_min, offset);		\
228 static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
229 		show_in_max, set_in_max, offset);
230 
231 show_in_offset(0);
232 show_in_offset(1);
233 show_in_offset(2);
234 show_in_offset(3);
235 show_in_offset(4);
236 show_in_offset(5);
237 show_in_offset(6);
238 
239 /* Temperature */
240 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
241 			 char *buf)
242 {
243 	struct lm78_data *data = lm78_update_device(dev);
244 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
245 }
246 
247 static ssize_t show_temp_over(struct device *dev, struct device_attribute *da,
248 			      char *buf)
249 {
250 	struct lm78_data *data = lm78_update_device(dev);
251 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
252 }
253 
254 static ssize_t set_temp_over(struct device *dev, struct device_attribute *da,
255 			     const char *buf, size_t count)
256 {
257 	struct lm78_data *data = dev_get_drvdata(dev);
258 	long val;
259 	int err;
260 
261 	err = kstrtol(buf, 10, &val);
262 	if (err)
263 		return err;
264 
265 	mutex_lock(&data->update_lock);
266 	data->temp_over = TEMP_TO_REG(val);
267 	lm78_write_value(data, LM78_REG_TEMP_OVER, data->temp_over);
268 	mutex_unlock(&data->update_lock);
269 	return count;
270 }
271 
272 static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *da,
273 			      char *buf)
274 {
275 	struct lm78_data *data = lm78_update_device(dev);
276 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
277 }
278 
279 static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *da,
280 			     const char *buf, size_t count)
281 {
282 	struct lm78_data *data = dev_get_drvdata(dev);
283 	long val;
284 	int err;
285 
286 	err = kstrtol(buf, 10, &val);
287 	if (err)
288 		return err;
289 
290 	mutex_lock(&data->update_lock);
291 	data->temp_hyst = TEMP_TO_REG(val);
292 	lm78_write_value(data, LM78_REG_TEMP_HYST, data->temp_hyst);
293 	mutex_unlock(&data->update_lock);
294 	return count;
295 }
296 
297 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
298 static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
299 		show_temp_over, set_temp_over);
300 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
301 		show_temp_hyst, set_temp_hyst);
302 
303 /* 3 Fans */
304 static ssize_t show_fan(struct device *dev, struct device_attribute *da,
305 			char *buf)
306 {
307 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
308 	struct lm78_data *data = lm78_update_device(dev);
309 	int nr = attr->index;
310 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
311 		DIV_FROM_REG(data->fan_div[nr])));
312 }
313 
314 static ssize_t show_fan_min(struct device *dev, struct device_attribute *da,
315 			    char *buf)
316 {
317 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
318 	struct lm78_data *data = lm78_update_device(dev);
319 	int nr = attr->index;
320 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
321 		DIV_FROM_REG(data->fan_div[nr])));
322 }
323 
324 static ssize_t set_fan_min(struct device *dev, struct device_attribute *da,
325 			   const char *buf, size_t count)
326 {
327 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
328 	struct lm78_data *data = dev_get_drvdata(dev);
329 	int nr = attr->index;
330 	unsigned long val;
331 	int err;
332 
333 	err = kstrtoul(buf, 10, &val);
334 	if (err)
335 		return err;
336 
337 	mutex_lock(&data->update_lock);
338 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
339 	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
340 	mutex_unlock(&data->update_lock);
341 	return count;
342 }
343 
344 static ssize_t show_fan_div(struct device *dev, struct device_attribute *da,
345 			    char *buf)
346 {
347 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
348 	struct lm78_data *data = lm78_update_device(dev);
349 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
350 }
351 
352 /*
353  * Note: we save and restore the fan minimum here, because its value is
354  * determined in part by the fan divisor.  This follows the principle of
355  * least surprise; the user doesn't expect the fan minimum to change just
356  * because the divisor changed.
357  */
358 static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
359 			   const char *buf, size_t count)
360 {
361 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
362 	struct lm78_data *data = dev_get_drvdata(dev);
363 	int nr = attr->index;
364 	unsigned long min;
365 	u8 reg;
366 	unsigned long val;
367 	int err;
368 
369 	err = kstrtoul(buf, 10, &val);
370 	if (err)
371 		return err;
372 
373 	mutex_lock(&data->update_lock);
374 	min = FAN_FROM_REG(data->fan_min[nr],
375 			   DIV_FROM_REG(data->fan_div[nr]));
376 
377 	switch (val) {
378 	case 1:
379 		data->fan_div[nr] = 0;
380 		break;
381 	case 2:
382 		data->fan_div[nr] = 1;
383 		break;
384 	case 4:
385 		data->fan_div[nr] = 2;
386 		break;
387 	case 8:
388 		data->fan_div[nr] = 3;
389 		break;
390 	default:
391 		dev_err(dev,
392 			"fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
393 			val);
394 		mutex_unlock(&data->update_lock);
395 		return -EINVAL;
396 	}
397 
398 	reg = lm78_read_value(data, LM78_REG_VID_FANDIV);
399 	switch (nr) {
400 	case 0:
401 		reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
402 		break;
403 	case 1:
404 		reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
405 		break;
406 	}
407 	lm78_write_value(data, LM78_REG_VID_FANDIV, reg);
408 
409 	data->fan_min[nr] =
410 		FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
411 	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
412 	mutex_unlock(&data->update_lock);
413 
414 	return count;
415 }
416 
417 #define show_fan_offset(offset)				\
418 static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,		\
419 		show_fan, NULL, offset - 1);			\
420 static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,	\
421 		show_fan_min, set_fan_min, offset - 1);
422 
423 show_fan_offset(1);
424 show_fan_offset(2);
425 show_fan_offset(3);
426 
427 /* Fan 3 divisor is locked in H/W */
428 static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
429 		show_fan_div, set_fan_div, 0);
430 static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
431 		show_fan_div, set_fan_div, 1);
432 static SENSOR_DEVICE_ATTR(fan3_div, S_IRUGO, show_fan_div, NULL, 2);
433 
434 /* VID */
435 static ssize_t show_vid(struct device *dev, struct device_attribute *da,
436 			char *buf)
437 {
438 	struct lm78_data *data = lm78_update_device(dev);
439 	return sprintf(buf, "%d\n", vid_from_reg(data->vid, 82));
440 }
441 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
442 
443 /* Alarms */
444 static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
445 			   char *buf)
446 {
447 	struct lm78_data *data = lm78_update_device(dev);
448 	return sprintf(buf, "%u\n", data->alarms);
449 }
450 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
451 
452 static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
453 			  char *buf)
454 {
455 	struct lm78_data *data = lm78_update_device(dev);
456 	int nr = to_sensor_dev_attr(da)->index;
457 	return sprintf(buf, "%u\n", (data->alarms >> nr) & 1);
458 }
459 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
460 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
461 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
462 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
463 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
464 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9);
465 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 10);
466 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
467 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
468 static SENSOR_DEVICE_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 11);
469 static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
470 
471 static struct attribute *lm78_attributes[] = {
472 	&sensor_dev_attr_in0_input.dev_attr.attr,
473 	&sensor_dev_attr_in0_min.dev_attr.attr,
474 	&sensor_dev_attr_in0_max.dev_attr.attr,
475 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
476 	&sensor_dev_attr_in1_input.dev_attr.attr,
477 	&sensor_dev_attr_in1_min.dev_attr.attr,
478 	&sensor_dev_attr_in1_max.dev_attr.attr,
479 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
480 	&sensor_dev_attr_in2_input.dev_attr.attr,
481 	&sensor_dev_attr_in2_min.dev_attr.attr,
482 	&sensor_dev_attr_in2_max.dev_attr.attr,
483 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
484 	&sensor_dev_attr_in3_input.dev_attr.attr,
485 	&sensor_dev_attr_in3_min.dev_attr.attr,
486 	&sensor_dev_attr_in3_max.dev_attr.attr,
487 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
488 	&sensor_dev_attr_in4_input.dev_attr.attr,
489 	&sensor_dev_attr_in4_min.dev_attr.attr,
490 	&sensor_dev_attr_in4_max.dev_attr.attr,
491 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
492 	&sensor_dev_attr_in5_input.dev_attr.attr,
493 	&sensor_dev_attr_in5_min.dev_attr.attr,
494 	&sensor_dev_attr_in5_max.dev_attr.attr,
495 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
496 	&sensor_dev_attr_in6_input.dev_attr.attr,
497 	&sensor_dev_attr_in6_min.dev_attr.attr,
498 	&sensor_dev_attr_in6_max.dev_attr.attr,
499 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
500 	&dev_attr_temp1_input.attr,
501 	&dev_attr_temp1_max.attr,
502 	&dev_attr_temp1_max_hyst.attr,
503 	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
504 	&sensor_dev_attr_fan1_input.dev_attr.attr,
505 	&sensor_dev_attr_fan1_min.dev_attr.attr,
506 	&sensor_dev_attr_fan1_div.dev_attr.attr,
507 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
508 	&sensor_dev_attr_fan2_input.dev_attr.attr,
509 	&sensor_dev_attr_fan2_min.dev_attr.attr,
510 	&sensor_dev_attr_fan2_div.dev_attr.attr,
511 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
512 	&sensor_dev_attr_fan3_input.dev_attr.attr,
513 	&sensor_dev_attr_fan3_min.dev_attr.attr,
514 	&sensor_dev_attr_fan3_div.dev_attr.attr,
515 	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
516 	&dev_attr_alarms.attr,
517 	&dev_attr_cpu0_vid.attr,
518 
519 	NULL
520 };
521 
522 static const struct attribute_group lm78_group = {
523 	.attrs = lm78_attributes,
524 };
525 
526 /*
527  * ISA related code
528  */
529 #ifdef CONFIG_ISA
530 
531 /* ISA device, if found */
532 static struct platform_device *pdev;
533 
534 static unsigned short isa_address = 0x290;
535 
536 /*
537  * I2C devices get this name attribute automatically, but for ISA devices
538  * we must create it by ourselves.
539  */
540 static ssize_t show_name(struct device *dev, struct device_attribute
541 			 *devattr, char *buf)
542 {
543 	struct lm78_data *data = dev_get_drvdata(dev);
544 
545 	return sprintf(buf, "%s\n", data->name);
546 }
547 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
548 
549 static struct lm78_data *lm78_data_if_isa(void)
550 {
551 	return pdev ? platform_get_drvdata(pdev) : NULL;
552 }
553 
554 /* Returns 1 if the I2C chip appears to be an alias of the ISA chip */
555 static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
556 {
557 	struct lm78_data *isa;
558 	int i;
559 
560 	if (!pdev)	/* No ISA chip */
561 		return 0;
562 	isa = platform_get_drvdata(pdev);
563 
564 	if (lm78_read_value(isa, LM78_REG_I2C_ADDR) != client->addr)
565 		return 0;	/* Address doesn't match */
566 	if ((lm78_read_value(isa, LM78_REG_CHIPID) & 0xfe) != (chipid & 0xfe))
567 		return 0;	/* Chip type doesn't match */
568 
569 	/*
570 	 * We compare all the limit registers, the config register and the
571 	 * interrupt mask registers
572 	 */
573 	for (i = 0x2b; i <= 0x3d; i++) {
574 		if (lm78_read_value(isa, i) !=
575 		    i2c_smbus_read_byte_data(client, i))
576 			return 0;
577 	}
578 	if (lm78_read_value(isa, LM78_REG_CONFIG) !=
579 	    i2c_smbus_read_byte_data(client, LM78_REG_CONFIG))
580 		return 0;
581 	for (i = 0x43; i <= 0x46; i++) {
582 		if (lm78_read_value(isa, i) !=
583 		    i2c_smbus_read_byte_data(client, i))
584 			return 0;
585 	}
586 
587 	return 1;
588 }
589 #else /* !CONFIG_ISA */
590 
591 static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
592 {
593 	return 0;
594 }
595 
596 static struct lm78_data *lm78_data_if_isa(void)
597 {
598 	return NULL;
599 }
600 #endif /* CONFIG_ISA */
601 
602 static int lm78_i2c_detect(struct i2c_client *client,
603 			   struct i2c_board_info *info)
604 {
605 	int i;
606 	struct lm78_data *isa = lm78_data_if_isa();
607 	const char *client_name;
608 	struct i2c_adapter *adapter = client->adapter;
609 	int address = client->addr;
610 
611 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
612 		return -ENODEV;
613 
614 	/*
615 	 * We block updates of the ISA device to minimize the risk of
616 	 * concurrent access to the same LM78 chip through different
617 	 * interfaces.
618 	 */
619 	if (isa)
620 		mutex_lock(&isa->update_lock);
621 
622 	if ((i2c_smbus_read_byte_data(client, LM78_REG_CONFIG) & 0x80)
623 	 || i2c_smbus_read_byte_data(client, LM78_REG_I2C_ADDR) != address)
624 		goto err_nodev;
625 
626 	/* Explicitly prevent the misdetection of Winbond chips */
627 	i = i2c_smbus_read_byte_data(client, 0x4f);
628 	if (i == 0xa3 || i == 0x5c)
629 		goto err_nodev;
630 
631 	/* Determine the chip type. */
632 	i = i2c_smbus_read_byte_data(client, LM78_REG_CHIPID);
633 	if (i == 0x00 || i == 0x20	/* LM78 */
634 	 || i == 0x40)			/* LM78-J */
635 		client_name = "lm78";
636 	else if ((i & 0xfe) == 0xc0)
637 		client_name = "lm79";
638 	else
639 		goto err_nodev;
640 
641 	if (lm78_alias_detect(client, i)) {
642 		dev_dbg(&adapter->dev,
643 			"Device at 0x%02x appears to be the same as ISA device\n",
644 			address);
645 		goto err_nodev;
646 	}
647 
648 	if (isa)
649 		mutex_unlock(&isa->update_lock);
650 
651 	strlcpy(info->type, client_name, I2C_NAME_SIZE);
652 
653 	return 0;
654 
655  err_nodev:
656 	if (isa)
657 		mutex_unlock(&isa->update_lock);
658 	return -ENODEV;
659 }
660 
661 static int lm78_i2c_probe(struct i2c_client *client,
662 			  const struct i2c_device_id *id)
663 {
664 	struct lm78_data *data;
665 	int err;
666 
667 	data = devm_kzalloc(&client->dev, sizeof(struct lm78_data), GFP_KERNEL);
668 	if (!data)
669 		return -ENOMEM;
670 
671 	i2c_set_clientdata(client, data);
672 	data->client = client;
673 	data->type = id->driver_data;
674 
675 	/* Initialize the LM78 chip */
676 	lm78_init_device(data);
677 
678 	/* Register sysfs hooks */
679 	err = sysfs_create_group(&client->dev.kobj, &lm78_group);
680 	if (err)
681 		return err;
682 
683 	data->hwmon_dev = hwmon_device_register(&client->dev);
684 	if (IS_ERR(data->hwmon_dev)) {
685 		err = PTR_ERR(data->hwmon_dev);
686 		goto error;
687 	}
688 
689 	return 0;
690 
691 error:
692 	sysfs_remove_group(&client->dev.kobj, &lm78_group);
693 	return err;
694 }
695 
696 static int lm78_i2c_remove(struct i2c_client *client)
697 {
698 	struct lm78_data *data = i2c_get_clientdata(client);
699 
700 	hwmon_device_unregister(data->hwmon_dev);
701 	sysfs_remove_group(&client->dev.kobj, &lm78_group);
702 
703 	return 0;
704 }
705 
706 static const struct i2c_device_id lm78_i2c_id[] = {
707 	{ "lm78", lm78 },
708 	{ "lm79", lm79 },
709 	{ }
710 };
711 MODULE_DEVICE_TABLE(i2c, lm78_i2c_id);
712 
713 static struct i2c_driver lm78_driver = {
714 	.class		= I2C_CLASS_HWMON,
715 	.driver = {
716 		.name	= "lm78",
717 	},
718 	.probe		= lm78_i2c_probe,
719 	.remove		= lm78_i2c_remove,
720 	.id_table	= lm78_i2c_id,
721 	.detect		= lm78_i2c_detect,
722 	.address_list	= normal_i2c,
723 };
724 
725 /*
726  * The SMBus locks itself, but ISA access must be locked explicitly!
727  * We don't want to lock the whole ISA bus, so we lock each client
728  * separately.
729  * We ignore the LM78 BUSY flag at this moment - it could lead to deadlocks,
730  * would slow down the LM78 access and should not be necessary.
731  */
732 static int lm78_read_value(struct lm78_data *data, u8 reg)
733 {
734 	struct i2c_client *client = data->client;
735 
736 #ifdef CONFIG_ISA
737 	if (!client) { /* ISA device */
738 		int res;
739 		mutex_lock(&data->lock);
740 		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
741 		res = inb_p(data->isa_addr + LM78_DATA_REG_OFFSET);
742 		mutex_unlock(&data->lock);
743 		return res;
744 	} else
745 #endif
746 		return i2c_smbus_read_byte_data(client, reg);
747 }
748 
749 static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value)
750 {
751 	struct i2c_client *client = data->client;
752 
753 #ifdef CONFIG_ISA
754 	if (!client) { /* ISA device */
755 		mutex_lock(&data->lock);
756 		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
757 		outb_p(value, data->isa_addr + LM78_DATA_REG_OFFSET);
758 		mutex_unlock(&data->lock);
759 		return 0;
760 	} else
761 #endif
762 		return i2c_smbus_write_byte_data(client, reg, value);
763 }
764 
765 static void lm78_init_device(struct lm78_data *data)
766 {
767 	u8 config;
768 	int i;
769 
770 	/* Start monitoring */
771 	config = lm78_read_value(data, LM78_REG_CONFIG);
772 	if ((config & 0x09) != 0x01)
773 		lm78_write_value(data, LM78_REG_CONFIG,
774 				 (config & 0xf7) | 0x01);
775 
776 	/* A few vars need to be filled upon startup */
777 	for (i = 0; i < 3; i++) {
778 		data->fan_min[i] = lm78_read_value(data,
779 					LM78_REG_FAN_MIN(i));
780 	}
781 
782 	mutex_init(&data->update_lock);
783 }
784 
785 static struct lm78_data *lm78_update_device(struct device *dev)
786 {
787 	struct lm78_data *data = dev_get_drvdata(dev);
788 	int i;
789 
790 	mutex_lock(&data->update_lock);
791 
792 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
793 	    || !data->valid) {
794 
795 		dev_dbg(dev, "Starting lm78 update\n");
796 
797 		for (i = 0; i <= 6; i++) {
798 			data->in[i] =
799 			    lm78_read_value(data, LM78_REG_IN(i));
800 			data->in_min[i] =
801 			    lm78_read_value(data, LM78_REG_IN_MIN(i));
802 			data->in_max[i] =
803 			    lm78_read_value(data, LM78_REG_IN_MAX(i));
804 		}
805 		for (i = 0; i < 3; i++) {
806 			data->fan[i] =
807 			    lm78_read_value(data, LM78_REG_FAN(i));
808 			data->fan_min[i] =
809 			    lm78_read_value(data, LM78_REG_FAN_MIN(i));
810 		}
811 		data->temp = lm78_read_value(data, LM78_REG_TEMP);
812 		data->temp_over =
813 		    lm78_read_value(data, LM78_REG_TEMP_OVER);
814 		data->temp_hyst =
815 		    lm78_read_value(data, LM78_REG_TEMP_HYST);
816 		i = lm78_read_value(data, LM78_REG_VID_FANDIV);
817 		data->vid = i & 0x0f;
818 		if (data->type == lm79)
819 			data->vid |=
820 			    (lm78_read_value(data, LM78_REG_CHIPID) &
821 			     0x01) << 4;
822 		else
823 			data->vid |= 0x10;
824 		data->fan_div[0] = (i >> 4) & 0x03;
825 		data->fan_div[1] = i >> 6;
826 		data->alarms = lm78_read_value(data, LM78_REG_ALARM1) +
827 		    (lm78_read_value(data, LM78_REG_ALARM2) << 8);
828 		data->last_updated = jiffies;
829 		data->valid = 1;
830 
831 		data->fan_div[2] = 1;
832 	}
833 
834 	mutex_unlock(&data->update_lock);
835 
836 	return data;
837 }
838 
839 #ifdef CONFIG_ISA
840 static int lm78_isa_probe(struct platform_device *pdev)
841 {
842 	int err;
843 	struct lm78_data *data;
844 	struct resource *res;
845 
846 	/* Reserve the ISA region */
847 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
848 	if (!devm_request_region(&pdev->dev, res->start + LM78_ADDR_REG_OFFSET,
849 				 2, "lm78"))
850 		return -EBUSY;
851 
852 	data = devm_kzalloc(&pdev->dev, sizeof(struct lm78_data), GFP_KERNEL);
853 	if (!data)
854 		return -ENOMEM;
855 
856 	mutex_init(&data->lock);
857 	data->isa_addr = res->start;
858 	platform_set_drvdata(pdev, data);
859 
860 	if (lm78_read_value(data, LM78_REG_CHIPID) & 0x80) {
861 		data->type = lm79;
862 		data->name = "lm79";
863 	} else {
864 		data->type = lm78;
865 		data->name = "lm78";
866 	}
867 
868 	/* Initialize the LM78 chip */
869 	lm78_init_device(data);
870 
871 	/* Register sysfs hooks */
872 	err = sysfs_create_group(&pdev->dev.kobj, &lm78_group);
873 	if (err)
874 		goto exit_remove_files;
875 	err = device_create_file(&pdev->dev, &dev_attr_name);
876 	if (err)
877 		goto exit_remove_files;
878 
879 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
880 	if (IS_ERR(data->hwmon_dev)) {
881 		err = PTR_ERR(data->hwmon_dev);
882 		goto exit_remove_files;
883 	}
884 
885 	return 0;
886 
887  exit_remove_files:
888 	sysfs_remove_group(&pdev->dev.kobj, &lm78_group);
889 	device_remove_file(&pdev->dev, &dev_attr_name);
890 	return err;
891 }
892 
893 static int lm78_isa_remove(struct platform_device *pdev)
894 {
895 	struct lm78_data *data = platform_get_drvdata(pdev);
896 
897 	hwmon_device_unregister(data->hwmon_dev);
898 	sysfs_remove_group(&pdev->dev.kobj, &lm78_group);
899 	device_remove_file(&pdev->dev, &dev_attr_name);
900 
901 	return 0;
902 }
903 
904 static struct platform_driver lm78_isa_driver = {
905 	.driver = {
906 		.owner	= THIS_MODULE,
907 		.name	= "lm78",
908 	},
909 	.probe		= lm78_isa_probe,
910 	.remove		= lm78_isa_remove,
911 };
912 
913 /* return 1 if a supported chip is found, 0 otherwise */
914 static int __init lm78_isa_found(unsigned short address)
915 {
916 	int val, save, found = 0;
917 	int port;
918 
919 	/*
920 	 * Some boards declare base+0 to base+7 as a PNP device, some base+4
921 	 * to base+7 and some base+5 to base+6. So we better request each port
922 	 * individually for the probing phase.
923 	 */
924 	for (port = address; port < address + LM78_EXTENT; port++) {
925 		if (!request_region(port, 1, "lm78")) {
926 			pr_debug("Failed to request port 0x%x\n", port);
927 			goto release;
928 		}
929 	}
930 
931 #define REALLY_SLOW_IO
932 	/*
933 	 * We need the timeouts for at least some LM78-like
934 	 * chips. But only if we read 'undefined' registers.
935 	 */
936 	val = inb_p(address + 1);
937 	if (inb_p(address + 2) != val
938 	 || inb_p(address + 3) != val
939 	 || inb_p(address + 7) != val)
940 		goto release;
941 #undef REALLY_SLOW_IO
942 
943 	/*
944 	 * We should be able to change the 7 LSB of the address port. The
945 	 * MSB (busy flag) should be clear initially, set after the write.
946 	 */
947 	save = inb_p(address + LM78_ADDR_REG_OFFSET);
948 	if (save & 0x80)
949 		goto release;
950 	val = ~save & 0x7f;
951 	outb_p(val, address + LM78_ADDR_REG_OFFSET);
952 	if (inb_p(address + LM78_ADDR_REG_OFFSET) != (val | 0x80)) {
953 		outb_p(save, address + LM78_ADDR_REG_OFFSET);
954 		goto release;
955 	}
956 
957 	/* We found a device, now see if it could be an LM78 */
958 	outb_p(LM78_REG_CONFIG, address + LM78_ADDR_REG_OFFSET);
959 	val = inb_p(address + LM78_DATA_REG_OFFSET);
960 	if (val & 0x80)
961 		goto release;
962 	outb_p(LM78_REG_I2C_ADDR, address + LM78_ADDR_REG_OFFSET);
963 	val = inb_p(address + LM78_DATA_REG_OFFSET);
964 	if (val < 0x03 || val > 0x77)	/* Not a valid I2C address */
965 		goto release;
966 
967 	/* The busy flag should be clear again */
968 	if (inb_p(address + LM78_ADDR_REG_OFFSET) & 0x80)
969 		goto release;
970 
971 	/* Explicitly prevent the misdetection of Winbond chips */
972 	outb_p(0x4f, address + LM78_ADDR_REG_OFFSET);
973 	val = inb_p(address + LM78_DATA_REG_OFFSET);
974 	if (val == 0xa3 || val == 0x5c)
975 		goto release;
976 
977 	/* Explicitly prevent the misdetection of ITE chips */
978 	outb_p(0x58, address + LM78_ADDR_REG_OFFSET);
979 	val = inb_p(address + LM78_DATA_REG_OFFSET);
980 	if (val == 0x90)
981 		goto release;
982 
983 	/* Determine the chip type */
984 	outb_p(LM78_REG_CHIPID, address + LM78_ADDR_REG_OFFSET);
985 	val = inb_p(address + LM78_DATA_REG_OFFSET);
986 	if (val == 0x00 || val == 0x20	/* LM78 */
987 	 || val == 0x40			/* LM78-J */
988 	 || (val & 0xfe) == 0xc0)	/* LM79 */
989 		found = 1;
990 
991 	if (found)
992 		pr_info("Found an %s chip at %#x\n",
993 			val & 0x80 ? "LM79" : "LM78", (int)address);
994 
995  release:
996 	for (port--; port >= address; port--)
997 		release_region(port, 1);
998 	return found;
999 }
1000 
1001 static int __init lm78_isa_device_add(unsigned short address)
1002 {
1003 	struct resource res = {
1004 		.start	= address,
1005 		.end	= address + LM78_EXTENT - 1,
1006 		.name	= "lm78",
1007 		.flags	= IORESOURCE_IO,
1008 	};
1009 	int err;
1010 
1011 	pdev = platform_device_alloc("lm78", address);
1012 	if (!pdev) {
1013 		err = -ENOMEM;
1014 		pr_err("Device allocation failed\n");
1015 		goto exit;
1016 	}
1017 
1018 	err = platform_device_add_resources(pdev, &res, 1);
1019 	if (err) {
1020 		pr_err("Device resource addition failed (%d)\n", err);
1021 		goto exit_device_put;
1022 	}
1023 
1024 	err = platform_device_add(pdev);
1025 	if (err) {
1026 		pr_err("Device addition failed (%d)\n", err);
1027 		goto exit_device_put;
1028 	}
1029 
1030 	return 0;
1031 
1032  exit_device_put:
1033 	platform_device_put(pdev);
1034  exit:
1035 	pdev = NULL;
1036 	return err;
1037 }
1038 
1039 static int __init lm78_isa_register(void)
1040 {
1041 	int res;
1042 
1043 	if (lm78_isa_found(isa_address)) {
1044 		res = platform_driver_register(&lm78_isa_driver);
1045 		if (res)
1046 			goto exit;
1047 
1048 		/* Sets global pdev as a side effect */
1049 		res = lm78_isa_device_add(isa_address);
1050 		if (res)
1051 			goto exit_unreg_isa_driver;
1052 	}
1053 
1054 	return 0;
1055 
1056  exit_unreg_isa_driver:
1057 	platform_driver_unregister(&lm78_isa_driver);
1058  exit:
1059 	return res;
1060 }
1061 
1062 static void lm78_isa_unregister(void)
1063 {
1064 	if (pdev) {
1065 		platform_device_unregister(pdev);
1066 		platform_driver_unregister(&lm78_isa_driver);
1067 	}
1068 }
1069 #else /* !CONFIG_ISA */
1070 
1071 static int __init lm78_isa_register(void)
1072 {
1073 	return 0;
1074 }
1075 
1076 static void lm78_isa_unregister(void)
1077 {
1078 }
1079 #endif /* CONFIG_ISA */
1080 
1081 static int __init sm_lm78_init(void)
1082 {
1083 	int res;
1084 
1085 	/*
1086 	 * We register the ISA device first, so that we can skip the
1087 	 * registration of an I2C interface to the same device.
1088 	 */
1089 	res = lm78_isa_register();
1090 	if (res)
1091 		goto exit;
1092 
1093 	res = i2c_add_driver(&lm78_driver);
1094 	if (res)
1095 		goto exit_unreg_isa_device;
1096 
1097 	return 0;
1098 
1099  exit_unreg_isa_device:
1100 	lm78_isa_unregister();
1101  exit:
1102 	return res;
1103 }
1104 
1105 static void __exit sm_lm78_exit(void)
1106 {
1107 	lm78_isa_unregister();
1108 	i2c_del_driver(&lm78_driver);
1109 }
1110 
1111 MODULE_AUTHOR("Frodo Looijaard, Jean Delvare <khali@linux-fr.org>");
1112 MODULE_DESCRIPTION("LM78/LM79 driver");
1113 MODULE_LICENSE("GPL");
1114 
1115 module_init(sm_lm78_init);
1116 module_exit(sm_lm78_exit);
1117