xref: /linux/drivers/macintosh/therm_adt746x.c (revision 60b2737de1b1ddfdb90f3ba622634eb49d6f3603)
1 /*
2  * Device driver for the i2c thermostat found on the iBook G4, Albook G4
3  *
4  * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
5  *
6  * Documentation from
7  * http://www.analog.com/UploadedFiles/Data_Sheets/115254175ADT7467_pra.pdf
8  * http://www.analog.com/UploadedFiles/Data_Sheets/3686221171167ADT7460_b.pdf
9  *
10  */
11 
12 #include <linux/config.h>
13 #include <linux/types.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/kernel.h>
17 #include <linux/delay.h>
18 #include <linux/sched.h>
19 #include <linux/i2c.h>
20 #include <linux/slab.h>
21 #include <linux/init.h>
22 #include <linux/spinlock.h>
23 #include <linux/smp_lock.h>
24 #include <linux/wait.h>
25 #include <linux/suspend.h>
26 #include <linux/kthread.h>
27 #include <linux/moduleparam.h>
28 
29 #include <asm/prom.h>
30 #include <asm/machdep.h>
31 #include <asm/io.h>
32 #include <asm/system.h>
33 #include <asm/sections.h>
34 #include <asm/of_device.h>
35 
36 #undef DEBUG
37 
38 #define CONFIG_REG   0x40
39 #define MANUAL_MASK  0xe0
40 #define AUTO_MASK    0x20
41 
42 static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
43 static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
44 static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
45 static u8 REM_CONTROL[2] = {0x00, 0x40};
46 static u8 FAN_SPEED[2]   = {0x28, 0x2a};
47 static u8 FAN_SPD_SET[2] = {0x30, 0x31};
48 
49 static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
50 static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
51 static char *sensor_location[3] = {NULL, NULL, NULL};
52 
53 static int limit_adjust = 0;
54 static int fan_speed = -1;
55 
56 MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
57 MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
58 		   "Powerbook G4 Alu");
59 MODULE_LICENSE("GPL");
60 
61 module_param(limit_adjust, int, 0644);
62 MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
63 		 "by N degrees.");
64 
65 module_param(fan_speed, int, 0644);
66 MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
67 		 "(default 64)");
68 
69 struct thermostat {
70 	struct i2c_client	clt;
71 	u8			temps[3];
72 	u8			cached_temp[3];
73 	u8			initial_limits[3];
74 	u8			limits[3];
75 	int			last_speed[2];
76 	int			last_var[2];
77 };
78 
79 static enum {ADT7460, ADT7467} therm_type;
80 static int therm_bus, therm_address;
81 static struct of_device * of_dev;
82 static struct thermostat* thermostat;
83 static struct task_struct *thread_therm = NULL;
84 
85 static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
86 				 int busno);
87 
88 static void write_both_fan_speed(struct thermostat *th, int speed);
89 static void write_fan_speed(struct thermostat *th, int speed, int fan);
90 
91 static int
92 write_reg(struct thermostat* th, int reg, u8 data)
93 {
94 	u8 tmp[2];
95 	int rc;
96 
97 	tmp[0] = reg;
98 	tmp[1] = data;
99 	rc = i2c_master_send(&th->clt, (const char *)tmp, 2);
100 	if (rc < 0)
101 		return rc;
102 	if (rc != 2)
103 		return -ENODEV;
104 	return 0;
105 }
106 
107 static int
108 read_reg(struct thermostat* th, int reg)
109 {
110 	u8 reg_addr, data;
111 	int rc;
112 
113 	reg_addr = (u8)reg;
114 	rc = i2c_master_send(&th->clt, &reg_addr, 1);
115 	if (rc < 0)
116 		return rc;
117 	if (rc != 1)
118 		return -ENODEV;
119 	rc = i2c_master_recv(&th->clt, (char *)&data, 1);
120 	if (rc < 0)
121 		return rc;
122 	return data;
123 }
124 
125 static int
126 attach_thermostat(struct i2c_adapter *adapter)
127 {
128 	unsigned long bus_no;
129 
130 	if (strncmp(adapter->name, "uni-n", 5))
131 		return -ENODEV;
132 	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
133 	if (bus_no != therm_bus)
134 		return -ENODEV;
135 	return attach_one_thermostat(adapter, therm_address, bus_no);
136 }
137 
138 static int
139 detach_thermostat(struct i2c_adapter *adapter)
140 {
141 	struct thermostat* th;
142 	int i;
143 
144 	if (thermostat == NULL)
145 		return 0;
146 
147 	th = thermostat;
148 
149 	if (thread_therm != NULL) {
150 		kthread_stop(thread_therm);
151 	}
152 
153 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
154 			 "%d, %d, %d to %d, %d, %d\n",
155 		th->limits[0], th->limits[1], th->limits[2],
156 		th->initial_limits[0], th->initial_limits[1],
157 		th->initial_limits[2]);
158 
159 	for (i = 0; i < 3; i++)
160 		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
161 
162 	write_both_fan_speed(th, -1);
163 
164 	i2c_detach_client(&th->clt);
165 
166 	thermostat = NULL;
167 
168 	kfree(th);
169 
170 	return 0;
171 }
172 
173 static struct i2c_driver thermostat_driver = {
174 	.owner		= THIS_MODULE,
175 	.name		= "therm_adt746x",
176 	.flags		= I2C_DF_NOTIFY,
177 	.attach_adapter	= attach_thermostat,
178 	.detach_adapter	= detach_thermostat,
179 };
180 
181 static int read_fan_speed(struct thermostat *th, u8 addr)
182 {
183 	u8 tmp[2];
184 	u16 res;
185 
186 	/* should start with low byte */
187 	tmp[1] = read_reg(th, addr);
188 	tmp[0] = read_reg(th, addr + 1);
189 
190 	res = tmp[1] + (tmp[0] << 8);
191 	/* "a value of 0xffff means that the fan has stopped" */
192 	return (res == 0xffff ? 0 : (90000*60)/res);
193 }
194 
195 static void write_both_fan_speed(struct thermostat *th, int speed)
196 {
197 	write_fan_speed(th, speed, 0);
198 	if (therm_type == ADT7460)
199 		write_fan_speed(th, speed, 1);
200 }
201 
202 static void write_fan_speed(struct thermostat *th, int speed, int fan)
203 {
204 	u8 manual;
205 
206 	if (speed > 0xff)
207 		speed = 0xff;
208 	else if (speed < -1)
209 		speed = 0;
210 
211 	if (therm_type == ADT7467 && fan == 1)
212 		return;
213 
214 	if (th->last_speed[fan] != speed) {
215 		if (speed == -1)
216 			printk(KERN_DEBUG "adt746x: Setting speed to automatic "
217 				"for %s fan.\n", sensor_location[fan+1]);
218 		else
219 			printk(KERN_DEBUG "adt746x: Setting speed to %d "
220 				"for %s fan.\n", speed, sensor_location[fan+1]);
221 	} else
222 		return;
223 
224 	if (speed >= 0) {
225 		manual = read_reg(th, MANUAL_MODE[fan]);
226 		write_reg(th, MANUAL_MODE[fan], manual|MANUAL_MASK);
227 		write_reg(th, FAN_SPD_SET[fan], speed);
228 	} else {
229 		/* back to automatic */
230 		if(therm_type == ADT7460) {
231 			manual = read_reg(th,
232 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
233 
234 			write_reg(th,
235 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
236 		} else {
237 			manual = read_reg(th, MANUAL_MODE[fan]);
238 			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
239 		}
240 	}
241 
242 	th->last_speed[fan] = speed;
243 }
244 
245 static void read_sensors(struct thermostat *th)
246 {
247 	int i = 0;
248 
249 	for (i = 0; i < 3; i++)
250 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
251 }
252 
253 #ifdef DEBUG
254 static void display_stats(struct thermostat *th)
255 {
256 	if (th->temps[0] != th->cached_temp[0]
257 	||  th->temps[1] != th->cached_temp[1]
258 	||  th->temps[2] != th->cached_temp[2]) {
259 		printk(KERN_INFO "adt746x: Temperature infos:"
260 				 " thermostats: %d,%d,%d;"
261 				 " limits: %d,%d,%d;"
262 				 " fan speed: %d RPM\n",
263 				 th->temps[0], th->temps[1], th->temps[2],
264 				 th->limits[0],  th->limits[1],  th->limits[2],
265 				 read_fan_speed(th, FAN_SPEED[0]));
266 	}
267 	th->cached_temp[0] = th->temps[0];
268 	th->cached_temp[1] = th->temps[1];
269 	th->cached_temp[2] = th->temps[2];
270 }
271 #endif
272 
273 static void update_fans_speed (struct thermostat *th)
274 {
275 	int lastvar = 0; /* last variation, for iBook */
276 	int i = 0;
277 
278 	/* we don't care about local sensor, so we start at sensor 1 */
279 	for (i = 1; i < 3; i++) {
280 		int started = 0;
281 		int fan_number = (therm_type == ADT7460 && i == 2);
282 		int var = th->temps[i] - th->limits[i];
283 
284 		if (var > -1) {
285 			int step = (255 - fan_speed) / 7;
286 			int new_speed = 0;
287 
288 			/* hysteresis : change fan speed only if variation is
289 			 * more than two degrees */
290 			if (abs(var - th->last_var[fan_number]) < 2)
291 				continue;
292 
293 			started = 1;
294 			new_speed = fan_speed + ((var-1)*step);
295 
296 			if (new_speed < fan_speed)
297 				new_speed = fan_speed;
298 			if (new_speed > 255)
299 				new_speed = 255;
300 
301 			printk(KERN_DEBUG "adt746x: setting fans speed to %d "
302 					 "(limit exceeded by %d on %s) \n",
303 					new_speed, var,
304 					sensor_location[fan_number+1]);
305 			write_both_fan_speed(th, new_speed);
306 			th->last_var[fan_number] = var;
307 		} else if (var < -2) {
308 			/* don't stop fan if sensor2 is cold and sensor1 is not
309 			 * so cold (lastvar >= -1) */
310 			if (i == 2 && lastvar < -1) {
311 				if (th->last_speed[fan_number] != 0)
312 					printk(KERN_DEBUG "adt746x: Stopping "
313 						"fans.\n");
314 				write_both_fan_speed(th, 0);
315 			}
316 		}
317 
318 		lastvar = var;
319 
320 		if (started)
321 			return; /* we don't want to re-stop the fan
322 				* if sensor1 is heating and sensor2 is not */
323 	}
324 }
325 
326 static int monitor_task(void *arg)
327 {
328 	struct thermostat* th = arg;
329 
330 	while(!kthread_should_stop()) {
331 		if (current->flags & PF_FREEZE)
332 			refrigerator(PF_FREEZE);
333 
334 		msleep_interruptible(2000);
335 
336 #ifndef DEBUG
337 		if (fan_speed != -1)
338 			read_sensors(th);
339 #else
340 		read_sensors(th);
341 #endif
342 
343 		if (fan_speed != -1)
344 			update_fans_speed(th);
345 
346 #ifdef DEBUG
347 		display_stats(th);
348 #endif
349 
350 	}
351 
352 	return 0;
353 }
354 
355 static void set_limit(struct thermostat *th, int i)
356 {
357 		/* Set sensor1 limit higher to avoid powerdowns */
358 		th->limits[i] = default_limits_chip[i] + limit_adjust;
359 		write_reg(th, LIMIT_REG[i], th->limits[i]);
360 
361 		/* set our limits to normal */
362 		th->limits[i] = default_limits_local[i] + limit_adjust;
363 }
364 
365 static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
366 				 int busno)
367 {
368 	struct thermostat* th;
369 	int rc;
370 	int i;
371 
372 	if (thermostat)
373 		return 0;
374 
375 	th = (struct thermostat *)
376 		kmalloc(sizeof(struct thermostat), GFP_KERNEL);
377 
378 	if (!th)
379 		return -ENOMEM;
380 
381 	memset(th, 0, sizeof(*th));
382 	th->clt.addr = addr;
383 	th->clt.adapter = adapter;
384 	th->clt.driver = &thermostat_driver;
385 	strcpy(th->clt.name, "thermostat");
386 
387 	rc = read_reg(th, 0);
388 	if (rc < 0) {
389 		printk(KERN_ERR "adt746x: Thermostat failed to read config "
390 				"from bus %d !\n",
391 				busno);
392 		kfree(th);
393 		return -ENODEV;
394 	}
395 
396 	/* force manual control to start the fan quieter */
397 	if (fan_speed == -1)
398 		fan_speed = 64;
399 
400 	if(therm_type == ADT7460) {
401 		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
402 		/* The 7460 needs to be started explicitly */
403 		write_reg(th, CONFIG_REG, 1);
404 	} else
405 		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
406 
407 	for (i = 0; i < 3; i++) {
408 		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
409 		set_limit(th, i);
410 	}
411 
412 	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
413 			 " to %d, %d, %d\n",
414 			 th->initial_limits[0], th->initial_limits[1],
415 			 th->initial_limits[2], th->limits[0], th->limits[1],
416 			 th->limits[2]);
417 
418 	thermostat = th;
419 
420 	if (i2c_attach_client(&th->clt)) {
421 		printk(KERN_INFO "adt746x: Thermostat failed to attach "
422 				 "client !\n");
423 		thermostat = NULL;
424 		kfree(th);
425 		return -ENODEV;
426 	}
427 
428 	/* be sure to really write fan speed the first time */
429 	th->last_speed[0] = -2;
430 	th->last_speed[1] = -2;
431 	th->last_var[0] = -80;
432 	th->last_var[1] = -80;
433 
434 	if (fan_speed != -1) {
435 		/* manual mode, stop fans */
436 		write_both_fan_speed(th, 0);
437 	} else {
438 		/* automatic mode */
439 		write_both_fan_speed(th, -1);
440 	}
441 
442 	thread_therm = kthread_run(monitor_task, th, "kfand");
443 
444 	if (thread_therm == ERR_PTR(-ENOMEM)) {
445 		printk(KERN_INFO "adt746x: Kthread creation failed\n");
446 		thread_therm = NULL;
447 		return -ENOMEM;
448 	}
449 
450 	return 0;
451 }
452 
453 /*
454  * Now, unfortunately, sysfs doesn't give us a nice void * we could
455  * pass around to the attribute functions, so we don't really have
456  * choice but implement a bunch of them...
457  *
458  * FIXME, it does now...
459  */
460 #define BUILD_SHOW_FUNC_INT(name, data)				\
461 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
462 {								\
463 	return sprintf(buf, "%d\n", data);			\
464 }
465 
466 #define BUILD_SHOW_FUNC_STR(name, data)				\
467 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
468 {								\
469 	return sprintf(buf, "%s\n", data);			\
470 }
471 
472 #define BUILD_SHOW_FUNC_FAN(name, data)				\
473 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
474 {								\
475 	return sprintf(buf, "%d (%d rpm)\n", 			\
476 		thermostat->last_speed[data],			\
477 		read_fan_speed(thermostat, FAN_SPEED[data])	\
478 		);						\
479 }
480 
481 #define BUILD_STORE_FUNC_DEG(name, data)			\
482 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
483 {								\
484 	int val;						\
485 	int i;							\
486 	val = simple_strtol(buf, NULL, 10);			\
487 	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
488 	limit_adjust = val;					\
489 	for (i=0; i < 3; i++)					\
490 		set_limit(thermostat, i);			\
491 	return n;						\
492 }
493 
494 #define BUILD_STORE_FUNC_INT(name, data)			\
495 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
496 {								\
497 	u32 val;						\
498 	val = simple_strtoul(buf, NULL, 10);			\
499 	if (val < 0 || val > 255)				\
500 		return -EINVAL;					\
501 	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
502 	data = val;						\
503 	return n;						\
504 }
505 
506 BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
507 BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
508 BUILD_SHOW_FUNC_INT(sensor1_limit,		 thermostat->limits[1])
509 BUILD_SHOW_FUNC_INT(sensor2_limit,		 thermostat->limits[2])
510 BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
511 BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
512 
513 BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
514 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
515 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
516 
517 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
518 BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
519 BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
520 
521 static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
522 		   show_sensor1_temperature,NULL);
523 static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
524 		   show_sensor2_temperature,NULL);
525 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
526 		   show_sensor1_limit,	NULL);
527 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
528 		   show_sensor2_limit,	NULL);
529 static DEVICE_ATTR(sensor1_location, S_IRUGO,
530 		   show_sensor1_location, NULL);
531 static DEVICE_ATTR(sensor2_location, S_IRUGO,
532 		   show_sensor2_location, NULL);
533 
534 static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
535 		   show_specified_fan_speed,store_specified_fan_speed);
536 
537 static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
538 		   show_sensor1_fan_speed,	NULL);
539 static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
540 		   show_sensor2_fan_speed,	NULL);
541 
542 static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
543 		   show_limit_adjust,	store_limit_adjust);
544 
545 
546 static int __init
547 thermostat_init(void)
548 {
549 	struct device_node* np;
550 	u32 *prop;
551 	int i = 0, offset = 0;
552 
553 	np = of_find_node_by_name(NULL, "fan");
554 	if (!np)
555 		return -ENODEV;
556 	if (device_is_compatible(np, "adt7460"))
557 		therm_type = ADT7460;
558 	else if (device_is_compatible(np, "adt7467"))
559 		therm_type = ADT7467;
560 	else
561 		return -ENODEV;
562 
563 	prop = (u32 *)get_property(np, "hwsensor-params-version", NULL);
564 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
565 			 (*prop == 1)?"":"un");
566 	if (*prop != 1)
567 		return -ENODEV;
568 
569 	prop = (u32 *)get_property(np, "reg", NULL);
570 	if (!prop)
571 		return -ENODEV;
572 
573 	/* look for bus either by path or using "reg" */
574 	if (strstr(np->full_name, "/i2c-bus@") != NULL) {
575 		const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
576 		therm_bus = tmp_bus[0]-'0';
577 	} else {
578 		therm_bus = ((*prop) >> 8) & 0x0f;
579 	}
580 
581 	therm_address = ((*prop) & 0xff) >> 1;
582 
583 	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
584 			 "limit_adjust: %d, fan_speed: %d\n",
585 			 therm_bus, therm_address, limit_adjust, fan_speed);
586 
587 	if (get_property(np, "hwsensor-location", NULL)) {
588 		for (i = 0; i < 3; i++) {
589 			sensor_location[i] = get_property(np,
590 					"hwsensor-location", NULL) + offset;
591 
592 			if (sensor_location[i] == NULL)
593 				sensor_location[i] = "";
594 
595 			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
596 			offset += strlen(sensor_location[i]) + 1;
597 		}
598 	} else {
599 		sensor_location[0] = "?";
600 		sensor_location[1] = "?";
601 		sensor_location[2] = "?";
602 	}
603 
604 	of_dev = of_platform_device_create(np, "temperatures");
605 
606 	if (of_dev == NULL) {
607 		printk(KERN_ERR "Can't register temperatures device !\n");
608 		return -ENODEV;
609 	}
610 
611 	device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
612 	device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
613 	device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
614 	device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
615 	device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
616 	device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
617 	device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
618 	device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
619 	device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
620 	if(therm_type == ADT7460)
621 		device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
622 
623 #ifndef CONFIG_I2C_KEYWEST
624 	request_module("i2c-keywest");
625 #endif
626 
627 	return i2c_add_driver(&thermostat_driver);
628 }
629 
630 static void __exit
631 thermostat_exit(void)
632 {
633 	if (of_dev) {
634 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
635 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
636 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
637 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
638 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
639 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
640 		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
641 		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
642 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
643 
644 		if(therm_type == ADT7460)
645 			device_remove_file(&of_dev->dev,
646 					   &dev_attr_sensor2_fan_speed);
647 
648 		of_device_unregister(of_dev);
649 	}
650 	i2c_del_driver(&thermostat_driver);
651 }
652 
653 module_init(thermostat_init);
654 module_exit(thermostat_exit);
655