xref: /openbmc/linux/drivers/hwmon/lm78.c (revision ee89bd6b)
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 	return clamp_val((1350000 + rpm * div / 2) / (rpm * div), 1, 254);
98 }
99 
100 static inline int FAN_FROM_REG(u8 val, int div)
101 {
102 	return val == 0 ? -1 : val == 255 ? 0 : 1350000 / (val * div);
103 }
104 
105 /*
106  * TEMP: mC (-128C to +127C)
107  * REG: 1C/bit, two's complement
108  */
109 static inline s8 TEMP_TO_REG(int val)
110 {
111 	int nval = clamp_val(val, -128000, 127000) ;
112 	return nval < 0 ? (nval - 500) / 1000 : (nval + 500) / 1000;
113 }
114 
115 static inline int TEMP_FROM_REG(s8 val)
116 {
117 	return val * 1000;
118 }
119 
120 #define DIV_FROM_REG(val) (1 << (val))
121 
122 struct lm78_data {
123 	struct i2c_client *client;
124 	struct device *hwmon_dev;
125 	struct mutex lock;
126 	enum chips type;
127 
128 	/* For ISA device only */
129 	const char *name;
130 	int isa_addr;
131 
132 	struct mutex update_lock;
133 	char valid;		/* !=0 if following fields are valid */
134 	unsigned long last_updated;	/* In jiffies */
135 
136 	u8 in[7];		/* Register value */
137 	u8 in_max[7];		/* Register value */
138 	u8 in_min[7];		/* Register value */
139 	u8 fan[3];		/* Register value */
140 	u8 fan_min[3];		/* Register value */
141 	s8 temp;		/* Register value */
142 	s8 temp_over;		/* Register value */
143 	s8 temp_hyst;		/* Register value */
144 	u8 fan_div[3];		/* Register encoding, shifted right */
145 	u8 vid;			/* Register encoding, combined */
146 	u16 alarms;		/* Register encoding, combined */
147 };
148 
149 
150 static int lm78_read_value(struct lm78_data *data, u8 reg);
151 static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value);
152 static struct lm78_data *lm78_update_device(struct device *dev);
153 static void lm78_init_device(struct lm78_data *data);
154 
155 
156 /* 7 Voltages */
157 static ssize_t show_in(struct device *dev, struct device_attribute *da,
158 		       char *buf)
159 {
160 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
161 	struct lm78_data *data = lm78_update_device(dev);
162 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in[attr->index]));
163 }
164 
165 static ssize_t show_in_min(struct device *dev, struct device_attribute *da,
166 			   char *buf)
167 {
168 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
169 	struct lm78_data *data = lm78_update_device(dev);
170 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_min[attr->index]));
171 }
172 
173 static ssize_t show_in_max(struct device *dev, struct device_attribute *da,
174 			   char *buf)
175 {
176 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
177 	struct lm78_data *data = lm78_update_device(dev);
178 	return sprintf(buf, "%d\n", IN_FROM_REG(data->in_max[attr->index]));
179 }
180 
181 static ssize_t set_in_min(struct device *dev, struct device_attribute *da,
182 			  const char *buf, size_t count)
183 {
184 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
185 	struct lm78_data *data = dev_get_drvdata(dev);
186 	int nr = attr->index;
187 	unsigned long val;
188 	int err;
189 
190 	err = kstrtoul(buf, 10, &val);
191 	if (err)
192 		return err;
193 
194 	mutex_lock(&data->update_lock);
195 	data->in_min[nr] = IN_TO_REG(val);
196 	lm78_write_value(data, LM78_REG_IN_MIN(nr), data->in_min[nr]);
197 	mutex_unlock(&data->update_lock);
198 	return count;
199 }
200 
201 static ssize_t set_in_max(struct device *dev, struct device_attribute *da,
202 			  const char *buf, size_t count)
203 {
204 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
205 	struct lm78_data *data = dev_get_drvdata(dev);
206 	int nr = attr->index;
207 	unsigned long val;
208 	int err;
209 
210 	err = kstrtoul(buf, 10, &val);
211 	if (err)
212 		return err;
213 
214 	mutex_lock(&data->update_lock);
215 	data->in_max[nr] = IN_TO_REG(val);
216 	lm78_write_value(data, LM78_REG_IN_MAX(nr), data->in_max[nr]);
217 	mutex_unlock(&data->update_lock);
218 	return count;
219 }
220 
221 #define show_in_offset(offset)					\
222 static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
223 		show_in, NULL, offset);				\
224 static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
225 		show_in_min, set_in_min, offset);		\
226 static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
227 		show_in_max, set_in_max, offset);
228 
229 show_in_offset(0);
230 show_in_offset(1);
231 show_in_offset(2);
232 show_in_offset(3);
233 show_in_offset(4);
234 show_in_offset(5);
235 show_in_offset(6);
236 
237 /* Temperature */
238 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
239 			 char *buf)
240 {
241 	struct lm78_data *data = lm78_update_device(dev);
242 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
243 }
244 
245 static ssize_t show_temp_over(struct device *dev, struct device_attribute *da,
246 			      char *buf)
247 {
248 	struct lm78_data *data = lm78_update_device(dev);
249 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
250 }
251 
252 static ssize_t set_temp_over(struct device *dev, struct device_attribute *da,
253 			     const char *buf, size_t count)
254 {
255 	struct lm78_data *data = dev_get_drvdata(dev);
256 	long val;
257 	int err;
258 
259 	err = kstrtol(buf, 10, &val);
260 	if (err)
261 		return err;
262 
263 	mutex_lock(&data->update_lock);
264 	data->temp_over = TEMP_TO_REG(val);
265 	lm78_write_value(data, LM78_REG_TEMP_OVER, data->temp_over);
266 	mutex_unlock(&data->update_lock);
267 	return count;
268 }
269 
270 static ssize_t show_temp_hyst(struct device *dev, struct device_attribute *da,
271 			      char *buf)
272 {
273 	struct lm78_data *data = lm78_update_device(dev);
274 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_hyst));
275 }
276 
277 static ssize_t set_temp_hyst(struct device *dev, struct device_attribute *da,
278 			     const char *buf, size_t count)
279 {
280 	struct lm78_data *data = dev_get_drvdata(dev);
281 	long val;
282 	int err;
283 
284 	err = kstrtol(buf, 10, &val);
285 	if (err)
286 		return err;
287 
288 	mutex_lock(&data->update_lock);
289 	data->temp_hyst = TEMP_TO_REG(val);
290 	lm78_write_value(data, LM78_REG_TEMP_HYST, data->temp_hyst);
291 	mutex_unlock(&data->update_lock);
292 	return count;
293 }
294 
295 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
296 static DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
297 		show_temp_over, set_temp_over);
298 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
299 		show_temp_hyst, set_temp_hyst);
300 
301 /* 3 Fans */
302 static ssize_t show_fan(struct device *dev, struct device_attribute *da,
303 			char *buf)
304 {
305 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
306 	struct lm78_data *data = lm78_update_device(dev);
307 	int nr = attr->index;
308 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr],
309 		DIV_FROM_REG(data->fan_div[nr])));
310 }
311 
312 static ssize_t show_fan_min(struct device *dev, struct device_attribute *da,
313 			    char *buf)
314 {
315 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
316 	struct lm78_data *data = lm78_update_device(dev);
317 	int nr = attr->index;
318 	return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr],
319 		DIV_FROM_REG(data->fan_div[nr])));
320 }
321 
322 static ssize_t set_fan_min(struct device *dev, struct device_attribute *da,
323 			   const char *buf, size_t count)
324 {
325 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
326 	struct lm78_data *data = dev_get_drvdata(dev);
327 	int nr = attr->index;
328 	unsigned long val;
329 	int err;
330 
331 	err = kstrtoul(buf, 10, &val);
332 	if (err)
333 		return err;
334 
335 	mutex_lock(&data->update_lock);
336 	data->fan_min[nr] = FAN_TO_REG(val, DIV_FROM_REG(data->fan_div[nr]));
337 	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
338 	mutex_unlock(&data->update_lock);
339 	return count;
340 }
341 
342 static ssize_t show_fan_div(struct device *dev, struct device_attribute *da,
343 			    char *buf)
344 {
345 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
346 	struct lm78_data *data = lm78_update_device(dev);
347 	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fan_div[attr->index]));
348 }
349 
350 /*
351  * Note: we save and restore the fan minimum here, because its value is
352  * determined in part by the fan divisor.  This follows the principle of
353  * least surprise; the user doesn't expect the fan minimum to change just
354  * because the divisor changed.
355  */
356 static ssize_t set_fan_div(struct device *dev, struct device_attribute *da,
357 			   const char *buf, size_t count)
358 {
359 	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
360 	struct lm78_data *data = dev_get_drvdata(dev);
361 	int nr = attr->index;
362 	unsigned long min;
363 	u8 reg;
364 	unsigned long val;
365 	int err;
366 
367 	err = kstrtoul(buf, 10, &val);
368 	if (err)
369 		return err;
370 
371 	mutex_lock(&data->update_lock);
372 	min = FAN_FROM_REG(data->fan_min[nr],
373 			   DIV_FROM_REG(data->fan_div[nr]));
374 
375 	switch (val) {
376 	case 1:
377 		data->fan_div[nr] = 0;
378 		break;
379 	case 2:
380 		data->fan_div[nr] = 1;
381 		break;
382 	case 4:
383 		data->fan_div[nr] = 2;
384 		break;
385 	case 8:
386 		data->fan_div[nr] = 3;
387 		break;
388 	default:
389 		dev_err(dev,
390 			"fan_div value %ld not supported. Choose one of 1, 2, 4 or 8!\n",
391 			val);
392 		mutex_unlock(&data->update_lock);
393 		return -EINVAL;
394 	}
395 
396 	reg = lm78_read_value(data, LM78_REG_VID_FANDIV);
397 	switch (nr) {
398 	case 0:
399 		reg = (reg & 0xcf) | (data->fan_div[nr] << 4);
400 		break;
401 	case 1:
402 		reg = (reg & 0x3f) | (data->fan_div[nr] << 6);
403 		break;
404 	}
405 	lm78_write_value(data, LM78_REG_VID_FANDIV, reg);
406 
407 	data->fan_min[nr] =
408 		FAN_TO_REG(min, DIV_FROM_REG(data->fan_div[nr]));
409 	lm78_write_value(data, LM78_REG_FAN_MIN(nr), data->fan_min[nr]);
410 	mutex_unlock(&data->update_lock);
411 
412 	return count;
413 }
414 
415 #define show_fan_offset(offset)				\
416 static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,		\
417 		show_fan, NULL, offset - 1);			\
418 static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,	\
419 		show_fan_min, set_fan_min, offset - 1);
420 
421 show_fan_offset(1);
422 show_fan_offset(2);
423 show_fan_offset(3);
424 
425 /* Fan 3 divisor is locked in H/W */
426 static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
427 		show_fan_div, set_fan_div, 0);
428 static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
429 		show_fan_div, set_fan_div, 1);
430 static SENSOR_DEVICE_ATTR(fan3_div, S_IRUGO, show_fan_div, NULL, 2);
431 
432 /* VID */
433 static ssize_t show_vid(struct device *dev, struct device_attribute *da,
434 			char *buf)
435 {
436 	struct lm78_data *data = lm78_update_device(dev);
437 	return sprintf(buf, "%d\n", vid_from_reg(data->vid, 82));
438 }
439 static DEVICE_ATTR(cpu0_vid, S_IRUGO, show_vid, NULL);
440 
441 /* Alarms */
442 static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
443 			   char *buf)
444 {
445 	struct lm78_data *data = lm78_update_device(dev);
446 	return sprintf(buf, "%u\n", data->alarms);
447 }
448 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
449 
450 static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
451 			  char *buf)
452 {
453 	struct lm78_data *data = lm78_update_device(dev);
454 	int nr = to_sensor_dev_attr(da)->index;
455 	return sprintf(buf, "%u\n", (data->alarms >> nr) & 1);
456 }
457 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
458 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
459 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
460 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
461 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
462 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9);
463 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 10);
464 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
465 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
466 static SENSOR_DEVICE_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 11);
467 static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
468 
469 static struct attribute *lm78_attributes[] = {
470 	&sensor_dev_attr_in0_input.dev_attr.attr,
471 	&sensor_dev_attr_in0_min.dev_attr.attr,
472 	&sensor_dev_attr_in0_max.dev_attr.attr,
473 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
474 	&sensor_dev_attr_in1_input.dev_attr.attr,
475 	&sensor_dev_attr_in1_min.dev_attr.attr,
476 	&sensor_dev_attr_in1_max.dev_attr.attr,
477 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
478 	&sensor_dev_attr_in2_input.dev_attr.attr,
479 	&sensor_dev_attr_in2_min.dev_attr.attr,
480 	&sensor_dev_attr_in2_max.dev_attr.attr,
481 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
482 	&sensor_dev_attr_in3_input.dev_attr.attr,
483 	&sensor_dev_attr_in3_min.dev_attr.attr,
484 	&sensor_dev_attr_in3_max.dev_attr.attr,
485 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
486 	&sensor_dev_attr_in4_input.dev_attr.attr,
487 	&sensor_dev_attr_in4_min.dev_attr.attr,
488 	&sensor_dev_attr_in4_max.dev_attr.attr,
489 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
490 	&sensor_dev_attr_in5_input.dev_attr.attr,
491 	&sensor_dev_attr_in5_min.dev_attr.attr,
492 	&sensor_dev_attr_in5_max.dev_attr.attr,
493 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
494 	&sensor_dev_attr_in6_input.dev_attr.attr,
495 	&sensor_dev_attr_in6_min.dev_attr.attr,
496 	&sensor_dev_attr_in6_max.dev_attr.attr,
497 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
498 	&dev_attr_temp1_input.attr,
499 	&dev_attr_temp1_max.attr,
500 	&dev_attr_temp1_max_hyst.attr,
501 	&sensor_dev_attr_temp1_alarm.dev_attr.attr,
502 	&sensor_dev_attr_fan1_input.dev_attr.attr,
503 	&sensor_dev_attr_fan1_min.dev_attr.attr,
504 	&sensor_dev_attr_fan1_div.dev_attr.attr,
505 	&sensor_dev_attr_fan1_alarm.dev_attr.attr,
506 	&sensor_dev_attr_fan2_input.dev_attr.attr,
507 	&sensor_dev_attr_fan2_min.dev_attr.attr,
508 	&sensor_dev_attr_fan2_div.dev_attr.attr,
509 	&sensor_dev_attr_fan2_alarm.dev_attr.attr,
510 	&sensor_dev_attr_fan3_input.dev_attr.attr,
511 	&sensor_dev_attr_fan3_min.dev_attr.attr,
512 	&sensor_dev_attr_fan3_div.dev_attr.attr,
513 	&sensor_dev_attr_fan3_alarm.dev_attr.attr,
514 	&dev_attr_alarms.attr,
515 	&dev_attr_cpu0_vid.attr,
516 
517 	NULL
518 };
519 
520 static const struct attribute_group lm78_group = {
521 	.attrs = lm78_attributes,
522 };
523 
524 /*
525  * ISA related code
526  */
527 #ifdef CONFIG_ISA
528 
529 /* ISA device, if found */
530 static struct platform_device *pdev;
531 
532 static unsigned short isa_address = 0x290;
533 
534 /*
535  * I2C devices get this name attribute automatically, but for ISA devices
536  * we must create it by ourselves.
537  */
538 static ssize_t show_name(struct device *dev, struct device_attribute
539 			 *devattr, char *buf)
540 {
541 	struct lm78_data *data = dev_get_drvdata(dev);
542 
543 	return sprintf(buf, "%s\n", data->name);
544 }
545 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
546 
547 static struct lm78_data *lm78_data_if_isa(void)
548 {
549 	return pdev ? platform_get_drvdata(pdev) : NULL;
550 }
551 
552 /* Returns 1 if the I2C chip appears to be an alias of the ISA chip */
553 static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
554 {
555 	struct lm78_data *isa;
556 	int i;
557 
558 	if (!pdev)	/* No ISA chip */
559 		return 0;
560 	isa = platform_get_drvdata(pdev);
561 
562 	if (lm78_read_value(isa, LM78_REG_I2C_ADDR) != client->addr)
563 		return 0;	/* Address doesn't match */
564 	if ((lm78_read_value(isa, LM78_REG_CHIPID) & 0xfe) != (chipid & 0xfe))
565 		return 0;	/* Chip type doesn't match */
566 
567 	/*
568 	 * We compare all the limit registers, the config register and the
569 	 * interrupt mask registers
570 	 */
571 	for (i = 0x2b; i <= 0x3d; i++) {
572 		if (lm78_read_value(isa, i) !=
573 		    i2c_smbus_read_byte_data(client, i))
574 			return 0;
575 	}
576 	if (lm78_read_value(isa, LM78_REG_CONFIG) !=
577 	    i2c_smbus_read_byte_data(client, LM78_REG_CONFIG))
578 		return 0;
579 	for (i = 0x43; i <= 0x46; i++) {
580 		if (lm78_read_value(isa, i) !=
581 		    i2c_smbus_read_byte_data(client, i))
582 			return 0;
583 	}
584 
585 	return 1;
586 }
587 #else /* !CONFIG_ISA */
588 
589 static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
590 {
591 	return 0;
592 }
593 
594 static struct lm78_data *lm78_data_if_isa(void)
595 {
596 	return NULL;
597 }
598 #endif /* CONFIG_ISA */
599 
600 static int lm78_i2c_detect(struct i2c_client *client,
601 			   struct i2c_board_info *info)
602 {
603 	int i;
604 	struct lm78_data *isa = lm78_data_if_isa();
605 	const char *client_name;
606 	struct i2c_adapter *adapter = client->adapter;
607 	int address = client->addr;
608 
609 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
610 		return -ENODEV;
611 
612 	/*
613 	 * We block updates of the ISA device to minimize the risk of
614 	 * concurrent access to the same LM78 chip through different
615 	 * interfaces.
616 	 */
617 	if (isa)
618 		mutex_lock(&isa->update_lock);
619 
620 	if ((i2c_smbus_read_byte_data(client, LM78_REG_CONFIG) & 0x80)
621 	 || i2c_smbus_read_byte_data(client, LM78_REG_I2C_ADDR) != address)
622 		goto err_nodev;
623 
624 	/* Explicitly prevent the misdetection of Winbond chips */
625 	i = i2c_smbus_read_byte_data(client, 0x4f);
626 	if (i == 0xa3 || i == 0x5c)
627 		goto err_nodev;
628 
629 	/* Determine the chip type. */
630 	i = i2c_smbus_read_byte_data(client, LM78_REG_CHIPID);
631 	if (i == 0x00 || i == 0x20	/* LM78 */
632 	 || i == 0x40)			/* LM78-J */
633 		client_name = "lm78";
634 	else if ((i & 0xfe) == 0xc0)
635 		client_name = "lm79";
636 	else
637 		goto err_nodev;
638 
639 	if (lm78_alias_detect(client, i)) {
640 		dev_dbg(&adapter->dev,
641 			"Device at 0x%02x appears to be the same as ISA device\n",
642 			address);
643 		goto err_nodev;
644 	}
645 
646 	if (isa)
647 		mutex_unlock(&isa->update_lock);
648 
649 	strlcpy(info->type, client_name, I2C_NAME_SIZE);
650 
651 	return 0;
652 
653  err_nodev:
654 	if (isa)
655 		mutex_unlock(&isa->update_lock);
656 	return -ENODEV;
657 }
658 
659 static int lm78_i2c_probe(struct i2c_client *client,
660 			  const struct i2c_device_id *id)
661 {
662 	struct lm78_data *data;
663 	int err;
664 
665 	data = devm_kzalloc(&client->dev, sizeof(struct lm78_data), GFP_KERNEL);
666 	if (!data)
667 		return -ENOMEM;
668 
669 	i2c_set_clientdata(client, data);
670 	data->client = client;
671 	data->type = id->driver_data;
672 
673 	/* Initialize the LM78 chip */
674 	lm78_init_device(data);
675 
676 	/* Register sysfs hooks */
677 	err = sysfs_create_group(&client->dev.kobj, &lm78_group);
678 	if (err)
679 		return err;
680 
681 	data->hwmon_dev = hwmon_device_register(&client->dev);
682 	if (IS_ERR(data->hwmon_dev)) {
683 		err = PTR_ERR(data->hwmon_dev);
684 		goto error;
685 	}
686 
687 	return 0;
688 
689 error:
690 	sysfs_remove_group(&client->dev.kobj, &lm78_group);
691 	return err;
692 }
693 
694 static int lm78_i2c_remove(struct i2c_client *client)
695 {
696 	struct lm78_data *data = i2c_get_clientdata(client);
697 
698 	hwmon_device_unregister(data->hwmon_dev);
699 	sysfs_remove_group(&client->dev.kobj, &lm78_group);
700 
701 	return 0;
702 }
703 
704 static const struct i2c_device_id lm78_i2c_id[] = {
705 	{ "lm78", lm78 },
706 	{ "lm79", lm79 },
707 	{ }
708 };
709 MODULE_DEVICE_TABLE(i2c, lm78_i2c_id);
710 
711 static struct i2c_driver lm78_driver = {
712 	.class		= I2C_CLASS_HWMON,
713 	.driver = {
714 		.name	= "lm78",
715 	},
716 	.probe		= lm78_i2c_probe,
717 	.remove		= lm78_i2c_remove,
718 	.id_table	= lm78_i2c_id,
719 	.detect		= lm78_i2c_detect,
720 	.address_list	= normal_i2c,
721 };
722 
723 /*
724  * The SMBus locks itself, but ISA access must be locked explicitly!
725  * We don't want to lock the whole ISA bus, so we lock each client
726  * separately.
727  * We ignore the LM78 BUSY flag at this moment - it could lead to deadlocks,
728  * would slow down the LM78 access and should not be necessary.
729  */
730 static int lm78_read_value(struct lm78_data *data, u8 reg)
731 {
732 	struct i2c_client *client = data->client;
733 
734 #ifdef CONFIG_ISA
735 	if (!client) { /* ISA device */
736 		int res;
737 		mutex_lock(&data->lock);
738 		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
739 		res = inb_p(data->isa_addr + LM78_DATA_REG_OFFSET);
740 		mutex_unlock(&data->lock);
741 		return res;
742 	} else
743 #endif
744 		return i2c_smbus_read_byte_data(client, reg);
745 }
746 
747 static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value)
748 {
749 	struct i2c_client *client = data->client;
750 
751 #ifdef CONFIG_ISA
752 	if (!client) { /* ISA device */
753 		mutex_lock(&data->lock);
754 		outb_p(reg, data->isa_addr + LM78_ADDR_REG_OFFSET);
755 		outb_p(value, data->isa_addr + LM78_DATA_REG_OFFSET);
756 		mutex_unlock(&data->lock);
757 		return 0;
758 	} else
759 #endif
760 		return i2c_smbus_write_byte_data(client, reg, value);
761 }
762 
763 static void lm78_init_device(struct lm78_data *data)
764 {
765 	u8 config;
766 	int i;
767 
768 	/* Start monitoring */
769 	config = lm78_read_value(data, LM78_REG_CONFIG);
770 	if ((config & 0x09) != 0x01)
771 		lm78_write_value(data, LM78_REG_CONFIG,
772 				 (config & 0xf7) | 0x01);
773 
774 	/* A few vars need to be filled upon startup */
775 	for (i = 0; i < 3; i++) {
776 		data->fan_min[i] = lm78_read_value(data,
777 					LM78_REG_FAN_MIN(i));
778 	}
779 
780 	mutex_init(&data->update_lock);
781 }
782 
783 static struct lm78_data *lm78_update_device(struct device *dev)
784 {
785 	struct lm78_data *data = dev_get_drvdata(dev);
786 	int i;
787 
788 	mutex_lock(&data->update_lock);
789 
790 	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
791 	    || !data->valid) {
792 
793 		dev_dbg(dev, "Starting lm78 update\n");
794 
795 		for (i = 0; i <= 6; i++) {
796 			data->in[i] =
797 			    lm78_read_value(data, LM78_REG_IN(i));
798 			data->in_min[i] =
799 			    lm78_read_value(data, LM78_REG_IN_MIN(i));
800 			data->in_max[i] =
801 			    lm78_read_value(data, LM78_REG_IN_MAX(i));
802 		}
803 		for (i = 0; i < 3; i++) {
804 			data->fan[i] =
805 			    lm78_read_value(data, LM78_REG_FAN(i));
806 			data->fan_min[i] =
807 			    lm78_read_value(data, LM78_REG_FAN_MIN(i));
808 		}
809 		data->temp = lm78_read_value(data, LM78_REG_TEMP);
810 		data->temp_over =
811 		    lm78_read_value(data, LM78_REG_TEMP_OVER);
812 		data->temp_hyst =
813 		    lm78_read_value(data, LM78_REG_TEMP_HYST);
814 		i = lm78_read_value(data, LM78_REG_VID_FANDIV);
815 		data->vid = i & 0x0f;
816 		if (data->type == lm79)
817 			data->vid |=
818 			    (lm78_read_value(data, LM78_REG_CHIPID) &
819 			     0x01) << 4;
820 		else
821 			data->vid |= 0x10;
822 		data->fan_div[0] = (i >> 4) & 0x03;
823 		data->fan_div[1] = i >> 6;
824 		data->alarms = lm78_read_value(data, LM78_REG_ALARM1) +
825 		    (lm78_read_value(data, LM78_REG_ALARM2) << 8);
826 		data->last_updated = jiffies;
827 		data->valid = 1;
828 
829 		data->fan_div[2] = 1;
830 	}
831 
832 	mutex_unlock(&data->update_lock);
833 
834 	return data;
835 }
836 
837 #ifdef CONFIG_ISA
838 static int lm78_isa_probe(struct platform_device *pdev)
839 {
840 	int err;
841 	struct lm78_data *data;
842 	struct resource *res;
843 
844 	/* Reserve the ISA region */
845 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
846 	if (!devm_request_region(&pdev->dev, res->start + LM78_ADDR_REG_OFFSET,
847 				 2, "lm78"))
848 		return -EBUSY;
849 
850 	data = devm_kzalloc(&pdev->dev, sizeof(struct lm78_data), GFP_KERNEL);
851 	if (!data)
852 		return -ENOMEM;
853 
854 	mutex_init(&data->lock);
855 	data->isa_addr = res->start;
856 	platform_set_drvdata(pdev, data);
857 
858 	if (lm78_read_value(data, LM78_REG_CHIPID) & 0x80) {
859 		data->type = lm79;
860 		data->name = "lm79";
861 	} else {
862 		data->type = lm78;
863 		data->name = "lm78";
864 	}
865 
866 	/* Initialize the LM78 chip */
867 	lm78_init_device(data);
868 
869 	/* Register sysfs hooks */
870 	err = sysfs_create_group(&pdev->dev.kobj, &lm78_group);
871 	if (err)
872 		goto exit_remove_files;
873 	err = device_create_file(&pdev->dev, &dev_attr_name);
874 	if (err)
875 		goto exit_remove_files;
876 
877 	data->hwmon_dev = hwmon_device_register(&pdev->dev);
878 	if (IS_ERR(data->hwmon_dev)) {
879 		err = PTR_ERR(data->hwmon_dev);
880 		goto exit_remove_files;
881 	}
882 
883 	return 0;
884 
885  exit_remove_files:
886 	sysfs_remove_group(&pdev->dev.kobj, &lm78_group);
887 	device_remove_file(&pdev->dev, &dev_attr_name);
888 	return err;
889 }
890 
891 static int lm78_isa_remove(struct platform_device *pdev)
892 {
893 	struct lm78_data *data = platform_get_drvdata(pdev);
894 
895 	hwmon_device_unregister(data->hwmon_dev);
896 	sysfs_remove_group(&pdev->dev.kobj, &lm78_group);
897 	device_remove_file(&pdev->dev, &dev_attr_name);
898 
899 	return 0;
900 }
901 
902 static struct platform_driver lm78_isa_driver = {
903 	.driver = {
904 		.owner	= THIS_MODULE,
905 		.name	= "lm78",
906 	},
907 	.probe		= lm78_isa_probe,
908 	.remove		= lm78_isa_remove,
909 };
910 
911 /* return 1 if a supported chip is found, 0 otherwise */
912 static int __init lm78_isa_found(unsigned short address)
913 {
914 	int val, save, found = 0;
915 	int port;
916 
917 	/*
918 	 * Some boards declare base+0 to base+7 as a PNP device, some base+4
919 	 * to base+7 and some base+5 to base+6. So we better request each port
920 	 * individually for the probing phase.
921 	 */
922 	for (port = address; port < address + LM78_EXTENT; port++) {
923 		if (!request_region(port, 1, "lm78")) {
924 			pr_debug("Failed to request port 0x%x\n", port);
925 			goto release;
926 		}
927 	}
928 
929 #define REALLY_SLOW_IO
930 	/*
931 	 * We need the timeouts for at least some LM78-like
932 	 * chips. But only if we read 'undefined' registers.
933 	 */
934 	val = inb_p(address + 1);
935 	if (inb_p(address + 2) != val
936 	 || inb_p(address + 3) != val
937 	 || inb_p(address + 7) != val)
938 		goto release;
939 #undef REALLY_SLOW_IO
940 
941 	/*
942 	 * We should be able to change the 7 LSB of the address port. The
943 	 * MSB (busy flag) should be clear initially, set after the write.
944 	 */
945 	save = inb_p(address + LM78_ADDR_REG_OFFSET);
946 	if (save & 0x80)
947 		goto release;
948 	val = ~save & 0x7f;
949 	outb_p(val, address + LM78_ADDR_REG_OFFSET);
950 	if (inb_p(address + LM78_ADDR_REG_OFFSET) != (val | 0x80)) {
951 		outb_p(save, address + LM78_ADDR_REG_OFFSET);
952 		goto release;
953 	}
954 
955 	/* We found a device, now see if it could be an LM78 */
956 	outb_p(LM78_REG_CONFIG, address + LM78_ADDR_REG_OFFSET);
957 	val = inb_p(address + LM78_DATA_REG_OFFSET);
958 	if (val & 0x80)
959 		goto release;
960 	outb_p(LM78_REG_I2C_ADDR, address + LM78_ADDR_REG_OFFSET);
961 	val = inb_p(address + LM78_DATA_REG_OFFSET);
962 	if (val < 0x03 || val > 0x77)	/* Not a valid I2C address */
963 		goto release;
964 
965 	/* The busy flag should be clear again */
966 	if (inb_p(address + LM78_ADDR_REG_OFFSET) & 0x80)
967 		goto release;
968 
969 	/* Explicitly prevent the misdetection of Winbond chips */
970 	outb_p(0x4f, address + LM78_ADDR_REG_OFFSET);
971 	val = inb_p(address + LM78_DATA_REG_OFFSET);
972 	if (val == 0xa3 || val == 0x5c)
973 		goto release;
974 
975 	/* Explicitly prevent the misdetection of ITE chips */
976 	outb_p(0x58, address + LM78_ADDR_REG_OFFSET);
977 	val = inb_p(address + LM78_DATA_REG_OFFSET);
978 	if (val == 0x90)
979 		goto release;
980 
981 	/* Determine the chip type */
982 	outb_p(LM78_REG_CHIPID, address + LM78_ADDR_REG_OFFSET);
983 	val = inb_p(address + LM78_DATA_REG_OFFSET);
984 	if (val == 0x00 || val == 0x20	/* LM78 */
985 	 || val == 0x40			/* LM78-J */
986 	 || (val & 0xfe) == 0xc0)	/* LM79 */
987 		found = 1;
988 
989 	if (found)
990 		pr_info("Found an %s chip at %#x\n",
991 			val & 0x80 ? "LM79" : "LM78", (int)address);
992 
993  release:
994 	for (port--; port >= address; port--)
995 		release_region(port, 1);
996 	return found;
997 }
998 
999 static int __init lm78_isa_device_add(unsigned short address)
1000 {
1001 	struct resource res = {
1002 		.start	= address,
1003 		.end	= address + LM78_EXTENT - 1,
1004 		.name	= "lm78",
1005 		.flags	= IORESOURCE_IO,
1006 	};
1007 	int err;
1008 
1009 	pdev = platform_device_alloc("lm78", address);
1010 	if (!pdev) {
1011 		err = -ENOMEM;
1012 		pr_err("Device allocation failed\n");
1013 		goto exit;
1014 	}
1015 
1016 	err = platform_device_add_resources(pdev, &res, 1);
1017 	if (err) {
1018 		pr_err("Device resource addition failed (%d)\n", err);
1019 		goto exit_device_put;
1020 	}
1021 
1022 	err = platform_device_add(pdev);
1023 	if (err) {
1024 		pr_err("Device addition failed (%d)\n", err);
1025 		goto exit_device_put;
1026 	}
1027 
1028 	return 0;
1029 
1030  exit_device_put:
1031 	platform_device_put(pdev);
1032  exit:
1033 	pdev = NULL;
1034 	return err;
1035 }
1036 
1037 static int __init lm78_isa_register(void)
1038 {
1039 	int res;
1040 
1041 	if (lm78_isa_found(isa_address)) {
1042 		res = platform_driver_register(&lm78_isa_driver);
1043 		if (res)
1044 			goto exit;
1045 
1046 		/* Sets global pdev as a side effect */
1047 		res = lm78_isa_device_add(isa_address);
1048 		if (res)
1049 			goto exit_unreg_isa_driver;
1050 	}
1051 
1052 	return 0;
1053 
1054  exit_unreg_isa_driver:
1055 	platform_driver_unregister(&lm78_isa_driver);
1056  exit:
1057 	return res;
1058 }
1059 
1060 static void lm78_isa_unregister(void)
1061 {
1062 	if (pdev) {
1063 		platform_device_unregister(pdev);
1064 		platform_driver_unregister(&lm78_isa_driver);
1065 	}
1066 }
1067 #else /* !CONFIG_ISA */
1068 
1069 static int __init lm78_isa_register(void)
1070 {
1071 	return 0;
1072 }
1073 
1074 static void lm78_isa_unregister(void)
1075 {
1076 }
1077 #endif /* CONFIG_ISA */
1078 
1079 static int __init sm_lm78_init(void)
1080 {
1081 	int res;
1082 
1083 	/*
1084 	 * We register the ISA device first, so that we can skip the
1085 	 * registration of an I2C interface to the same device.
1086 	 */
1087 	res = lm78_isa_register();
1088 	if (res)
1089 		goto exit;
1090 
1091 	res = i2c_add_driver(&lm78_driver);
1092 	if (res)
1093 		goto exit_unreg_isa_device;
1094 
1095 	return 0;
1096 
1097  exit_unreg_isa_device:
1098 	lm78_isa_unregister();
1099  exit:
1100 	return res;
1101 }
1102 
1103 static void __exit sm_lm78_exit(void)
1104 {
1105 	lm78_isa_unregister();
1106 	i2c_del_driver(&lm78_driver);
1107 }
1108 
1109 MODULE_AUTHOR("Frodo Looijaard, Jean Delvare <khali@linux-fr.org>");
1110 MODULE_DESCRIPTION("LM78/LM79 driver");
1111 MODULE_LICENSE("GPL");
1112 
1113 module_init(sm_lm78_init);
1114 module_exit(sm_lm78_exit);
1115