xref: /openbmc/linux/drivers/hwmon/lm78.c (revision d0e22329)
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 */
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(long 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 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 
151 static int lm78_read_value(struct lm78_data *data, u8 reg);
152 static int lm78_write_value(struct lm78_data *data, u8 reg, u8 value);
153 static struct lm78_data *lm78_update_device(struct device *dev);
154 static void lm78_init_device(struct lm78_data *data);
155 
156 
157 /* 7 Voltages */
158 static 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 
166 static 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 
174 static 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 
182 static 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 
202 static 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)					\
223 static SENSOR_DEVICE_ATTR(in##offset##_input, S_IRUGO,		\
224 		show_in, NULL, offset);				\
225 static SENSOR_DEVICE_ATTR(in##offset##_min, S_IRUGO | S_IWUSR,	\
226 		show_in_min, set_in_min, offset);		\
227 static SENSOR_DEVICE_ATTR(in##offset##_max, S_IRUGO | S_IWUSR,	\
228 		show_in_max, set_in_max, offset);
229 
230 show_in_offset(0);
231 show_in_offset(1);
232 show_in_offset(2);
233 show_in_offset(3);
234 show_in_offset(4);
235 show_in_offset(5);
236 show_in_offset(6);
237 
238 /* Temperature */
239 static ssize_t temp1_input_show(struct device *dev,
240 				struct device_attribute *da, 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 
246 static ssize_t temp1_max_show(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 
253 static ssize_t temp1_max_store(struct device *dev,
254 			       struct device_attribute *da, const char *buf,
255 			       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 temp1_max_hyst_show(struct device *dev,
273 				   struct device_attribute *da, 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 temp1_max_hyst_store(struct device *dev,
280 				    struct device_attribute *da,
281 				    const char *buf, size_t count)
282 {
283 	struct lm78_data *data = dev_get_drvdata(dev);
284 	long val;
285 	int err;
286 
287 	err = kstrtol(buf, 10, &val);
288 	if (err)
289 		return err;
290 
291 	mutex_lock(&data->update_lock);
292 	data->temp_hyst = TEMP_TO_REG(val);
293 	lm78_write_value(data, LM78_REG_TEMP_HYST, data->temp_hyst);
294 	mutex_unlock(&data->update_lock);
295 	return count;
296 }
297 
298 static DEVICE_ATTR_RO(temp1_input);
299 static DEVICE_ATTR_RW(temp1_max);
300 static DEVICE_ATTR_RW(temp1_max_hyst);
301 
302 /* 3 Fans */
303 static 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 
313 static 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 
323 static 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 
343 static 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  */
357 static 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)				\
417 static SENSOR_DEVICE_ATTR(fan##offset##_input, S_IRUGO,		\
418 		show_fan, NULL, offset - 1);			\
419 static SENSOR_DEVICE_ATTR(fan##offset##_min, S_IRUGO | S_IWUSR,	\
420 		show_fan_min, set_fan_min, offset - 1);
421 
422 show_fan_offset(1);
423 show_fan_offset(2);
424 show_fan_offset(3);
425 
426 /* Fan 3 divisor is locked in H/W */
427 static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
428 		show_fan_div, set_fan_div, 0);
429 static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
430 		show_fan_div, set_fan_div, 1);
431 static SENSOR_DEVICE_ATTR(fan3_div, S_IRUGO, show_fan_div, NULL, 2);
432 
433 /* VID */
434 static ssize_t cpu0_vid_show(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 }
440 static DEVICE_ATTR_RO(cpu0_vid);
441 
442 /* Alarms */
443 static ssize_t alarms_show(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 }
449 static DEVICE_ATTR_RO(alarms);
450 
451 static 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 }
458 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, show_alarm, NULL, 0);
459 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, show_alarm, NULL, 1);
460 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, show_alarm, NULL, 2);
461 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, show_alarm, NULL, 3);
462 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, show_alarm, NULL, 8);
463 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, show_alarm, NULL, 9);
464 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, show_alarm, NULL, 10);
465 static SENSOR_DEVICE_ATTR(fan1_alarm, S_IRUGO, show_alarm, NULL, 6);
466 static SENSOR_DEVICE_ATTR(fan2_alarm, S_IRUGO, show_alarm, NULL, 7);
467 static SENSOR_DEVICE_ATTR(fan3_alarm, S_IRUGO, show_alarm, NULL, 11);
468 static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, show_alarm, NULL, 4);
469 
470 static 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 
521 ATTRIBUTE_GROUPS(lm78);
522 
523 /*
524  * ISA related code
525  */
526 #ifdef CONFIG_ISA
527 
528 /* ISA device, if found */
529 static struct platform_device *pdev;
530 
531 static unsigned short isa_address = 0x290;
532 
533 static 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 */
539 static 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 
575 static int lm78_alias_detect(struct i2c_client *client, u8 chipid)
576 {
577 	return 0;
578 }
579 
580 static struct lm78_data *lm78_data_if_isa(void)
581 {
582 	return NULL;
583 }
584 #endif /* CONFIG_ISA */
585 
586 static 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 
645 static 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 
667 static const struct i2c_device_id lm78_i2c_id[] = {
668 	{ "lm78", lm78 },
669 	{ "lm79", lm79 },
670 	{ }
671 };
672 MODULE_DEVICE_TABLE(i2c, lm78_i2c_id);
673 
674 static 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  */
692 static 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 
709 static 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 
725 static 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 
745 static 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
800 static 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 
837 static 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 */
845 static 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 
932 static 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 
970 static 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 
993 static 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 
1002 static int __init lm78_isa_register(void)
1003 {
1004 	return 0;
1005 }
1006 
1007 static void lm78_isa_unregister(void)
1008 {
1009 }
1010 #endif /* CONFIG_ISA */
1011 
1012 static 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 
1036 static void __exit sm_lm78_exit(void)
1037 {
1038 	lm78_isa_unregister();
1039 	i2c_del_driver(&lm78_driver);
1040 }
1041 
1042 MODULE_AUTHOR("Frodo Looijaard, Jean Delvare <jdelvare@suse.de>");
1043 MODULE_DESCRIPTION("LM78/LM79 driver");
1044 MODULE_LICENSE("GPL");
1045 
1046 module_init(sm_lm78_init);
1047 module_exit(sm_lm78_exit);
1048