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/types.h>
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/delay.h>
17 #include <linux/sched.h>
18 #include <linux/i2c.h>
19 #include <linux/slab.h>
20 #include <linux/init.h>
21 #include <linux/spinlock.h>
22 #include <linux/wait.h>
23 #include <linux/suspend.h>
24 #include <linux/kthread.h>
25 #include <linux/moduleparam.h>
26 #include <linux/freezer.h>
27 
28 #include <asm/prom.h>
29 #include <asm/machdep.h>
30 #include <asm/io.h>
31 #include <asm/system.h>
32 #include <asm/sections.h>
33 #include <asm/of_platform.h>
34 
35 #undef DEBUG
36 
37 #define CONFIG_REG   0x40
38 #define MANUAL_MASK  0xe0
39 #define AUTO_MASK    0x20
40 
41 static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
42 static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
43 static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
44 static u8 REM_CONTROL[2] = {0x00, 0x40};
45 static u8 FAN_SPEED[2]   = {0x28, 0x2a};
46 static u8 FAN_SPD_SET[2] = {0x30, 0x31};
47 
48 static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
49 static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
50 static const char *sensor_location[3];
51 
52 static int limit_adjust;
53 static int fan_speed = -1;
54 static int verbose;
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 module_param(verbose, bool, 0);
70 MODULE_PARM_DESC(verbose,"Verbose log operations "
71 		 "(default 0)");
72 
73 struct thermostat {
74 	struct i2c_client	clt;
75 	u8			temps[3];
76 	u8			cached_temp[3];
77 	u8			initial_limits[3];
78 	u8			limits[3];
79 	int			last_speed[2];
80 	int			last_var[2];
81 };
82 
83 static enum {ADT7460, ADT7467} therm_type;
84 static int therm_bus, therm_address;
85 static struct of_device * of_dev;
86 static struct thermostat* thermostat;
87 static struct task_struct *thread_therm = NULL;
88 
89 static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
90 				 int busno);
91 
92 static void write_both_fan_speed(struct thermostat *th, int speed);
93 static void write_fan_speed(struct thermostat *th, int speed, int fan);
94 
95 static int
96 write_reg(struct thermostat* th, int reg, u8 data)
97 {
98 	u8 tmp[2];
99 	int rc;
100 
101 	tmp[0] = reg;
102 	tmp[1] = data;
103 	rc = i2c_master_send(&th->clt, (const char *)tmp, 2);
104 	if (rc < 0)
105 		return rc;
106 	if (rc != 2)
107 		return -ENODEV;
108 	return 0;
109 }
110 
111 static int
112 read_reg(struct thermostat* th, int reg)
113 {
114 	u8 reg_addr, data;
115 	int rc;
116 
117 	reg_addr = (u8)reg;
118 	rc = i2c_master_send(&th->clt, &reg_addr, 1);
119 	if (rc < 0)
120 		return rc;
121 	if (rc != 1)
122 		return -ENODEV;
123 	rc = i2c_master_recv(&th->clt, (char *)&data, 1);
124 	if (rc < 0)
125 		return rc;
126 	return data;
127 }
128 
129 static int
130 attach_thermostat(struct i2c_adapter *adapter)
131 {
132 	unsigned long bus_no;
133 
134 	if (strncmp(adapter->name, "uni-n", 5))
135 		return -ENODEV;
136 	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
137 	if (bus_no != therm_bus)
138 		return -ENODEV;
139 	return attach_one_thermostat(adapter, therm_address, bus_no);
140 }
141 
142 static int
143 detach_thermostat(struct i2c_adapter *adapter)
144 {
145 	struct thermostat* th;
146 	int i;
147 
148 	if (thermostat == NULL)
149 		return 0;
150 
151 	th = thermostat;
152 
153 	if (thread_therm != NULL) {
154 		kthread_stop(thread_therm);
155 	}
156 
157 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
158 			 "%d, %d, %d to %d, %d, %d\n",
159 		th->limits[0], th->limits[1], th->limits[2],
160 		th->initial_limits[0], th->initial_limits[1],
161 		th->initial_limits[2]);
162 
163 	for (i = 0; i < 3; i++)
164 		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
165 
166 	write_both_fan_speed(th, -1);
167 
168 	i2c_detach_client(&th->clt);
169 
170 	thermostat = NULL;
171 
172 	kfree(th);
173 
174 	return 0;
175 }
176 
177 static struct i2c_driver thermostat_driver = {
178 	.driver = {
179 		.name	= "therm_adt746x",
180 	},
181 	.attach_adapter	= attach_thermostat,
182 	.detach_adapter	= detach_thermostat,
183 };
184 
185 static int read_fan_speed(struct thermostat *th, u8 addr)
186 {
187 	u8 tmp[2];
188 	u16 res;
189 
190 	/* should start with low byte */
191 	tmp[1] = read_reg(th, addr);
192 	tmp[0] = read_reg(th, addr + 1);
193 
194 	res = tmp[1] + (tmp[0] << 8);
195 	/* "a value of 0xffff means that the fan has stopped" */
196 	return (res == 0xffff ? 0 : (90000*60)/res);
197 }
198 
199 static void write_both_fan_speed(struct thermostat *th, int speed)
200 {
201 	write_fan_speed(th, speed, 0);
202 	if (therm_type == ADT7460)
203 		write_fan_speed(th, speed, 1);
204 }
205 
206 static void write_fan_speed(struct thermostat *th, int speed, int fan)
207 {
208 	u8 manual;
209 
210 	if (speed > 0xff)
211 		speed = 0xff;
212 	else if (speed < -1)
213 		speed = 0;
214 
215 	if (therm_type == ADT7467 && fan == 1)
216 		return;
217 
218 	if (th->last_speed[fan] != speed) {
219 		if (verbose) {
220 			if (speed == -1)
221 				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
222 					"for %s fan.\n", sensor_location[fan+1]);
223 			else
224 				printk(KERN_DEBUG "adt746x: Setting speed to %d "
225 					"for %s fan.\n", speed, sensor_location[fan+1]);
226 		}
227 	} else
228 		return;
229 
230 	if (speed >= 0) {
231 		manual = read_reg(th, MANUAL_MODE[fan]);
232 		write_reg(th, MANUAL_MODE[fan], manual|MANUAL_MASK);
233 		write_reg(th, FAN_SPD_SET[fan], speed);
234 	} else {
235 		/* back to automatic */
236 		if(therm_type == ADT7460) {
237 			manual = read_reg(th,
238 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
239 
240 			write_reg(th,
241 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
242 		} else {
243 			manual = read_reg(th, MANUAL_MODE[fan]);
244 			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
245 		}
246 	}
247 
248 	th->last_speed[fan] = speed;
249 }
250 
251 static void read_sensors(struct thermostat *th)
252 {
253 	int i = 0;
254 
255 	for (i = 0; i < 3; i++)
256 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
257 }
258 
259 #ifdef DEBUG
260 static void display_stats(struct thermostat *th)
261 {
262 	if (th->temps[0] != th->cached_temp[0]
263 	||  th->temps[1] != th->cached_temp[1]
264 	||  th->temps[2] != th->cached_temp[2]) {
265 		printk(KERN_INFO "adt746x: Temperature infos:"
266 				 " thermostats: %d,%d,%d;"
267 				 " limits: %d,%d,%d;"
268 				 " fan speed: %d RPM\n",
269 				 th->temps[0], th->temps[1], th->temps[2],
270 				 th->limits[0],  th->limits[1],  th->limits[2],
271 				 read_fan_speed(th, FAN_SPEED[0]));
272 	}
273 	th->cached_temp[0] = th->temps[0];
274 	th->cached_temp[1] = th->temps[1];
275 	th->cached_temp[2] = th->temps[2];
276 }
277 #endif
278 
279 static void update_fans_speed (struct thermostat *th)
280 {
281 	int lastvar = 0; /* last variation, for iBook */
282 	int i = 0;
283 
284 	/* we don't care about local sensor, so we start at sensor 1 */
285 	for (i = 1; i < 3; i++) {
286 		int started = 0;
287 		int fan_number = (therm_type == ADT7460 && i == 2);
288 		int var = th->temps[i] - th->limits[i];
289 
290 		if (var > -1) {
291 			int step = (255 - fan_speed) / 7;
292 			int new_speed = 0;
293 
294 			/* hysteresis : change fan speed only if variation is
295 			 * more than two degrees */
296 			if (abs(var - th->last_var[fan_number]) < 2)
297 				continue;
298 
299 			started = 1;
300 			new_speed = fan_speed + ((var-1)*step);
301 
302 			if (new_speed < fan_speed)
303 				new_speed = fan_speed;
304 			if (new_speed > 255)
305 				new_speed = 255;
306 
307 			if (verbose)
308 				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
309 						 "(limit exceeded by %d on %s) \n",
310 						new_speed, var,
311 						sensor_location[fan_number+1]);
312 			write_both_fan_speed(th, new_speed);
313 			th->last_var[fan_number] = var;
314 		} else if (var < -2) {
315 			/* don't stop fan if sensor2 is cold and sensor1 is not
316 			 * so cold (lastvar >= -1) */
317 			if (i == 2 && lastvar < -1) {
318 				if (th->last_speed[fan_number] != 0)
319 					if (verbose)
320 						printk(KERN_DEBUG "adt746x: Stopping "
321 							"fans.\n");
322 				write_both_fan_speed(th, 0);
323 			}
324 		}
325 
326 		lastvar = var;
327 
328 		if (started)
329 			return; /* we don't want to re-stop the fan
330 				* if sensor1 is heating and sensor2 is not */
331 	}
332 }
333 
334 static int monitor_task(void *arg)
335 {
336 	struct thermostat* th = arg;
337 
338 	while(!kthread_should_stop()) {
339 		try_to_freeze();
340 		msleep_interruptible(2000);
341 
342 #ifndef DEBUG
343 		if (fan_speed != -1)
344 			read_sensors(th);
345 #else
346 		read_sensors(th);
347 #endif
348 
349 		if (fan_speed != -1)
350 			update_fans_speed(th);
351 
352 #ifdef DEBUG
353 		display_stats(th);
354 #endif
355 
356 	}
357 
358 	return 0;
359 }
360 
361 static void set_limit(struct thermostat *th, int i)
362 {
363 		/* Set sensor1 limit higher to avoid powerdowns */
364 		th->limits[i] = default_limits_chip[i] + limit_adjust;
365 		write_reg(th, LIMIT_REG[i], th->limits[i]);
366 
367 		/* set our limits to normal */
368 		th->limits[i] = default_limits_local[i] + limit_adjust;
369 }
370 
371 static int attach_one_thermostat(struct i2c_adapter *adapter, int addr,
372 				 int busno)
373 {
374 	struct thermostat* th;
375 	int rc;
376 	int i;
377 
378 	if (thermostat)
379 		return 0;
380 
381 	th = (struct thermostat *)
382 		kmalloc(sizeof(struct thermostat), GFP_KERNEL);
383 
384 	if (!th)
385 		return -ENOMEM;
386 
387 	memset(th, 0, sizeof(*th));
388 	th->clt.addr = addr;
389 	th->clt.adapter = adapter;
390 	th->clt.driver = &thermostat_driver;
391 	strcpy(th->clt.name, "thermostat");
392 
393 	rc = read_reg(th, 0);
394 	if (rc < 0) {
395 		printk(KERN_ERR "adt746x: Thermostat failed to read config "
396 				"from bus %d !\n",
397 				busno);
398 		kfree(th);
399 		return -ENODEV;
400 	}
401 
402 	/* force manual control to start the fan quieter */
403 	if (fan_speed == -1)
404 		fan_speed = 64;
405 
406 	if(therm_type == ADT7460) {
407 		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
408 		/* The 7460 needs to be started explicitly */
409 		write_reg(th, CONFIG_REG, 1);
410 	} else
411 		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
412 
413 	for (i = 0; i < 3; i++) {
414 		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
415 		set_limit(th, i);
416 	}
417 
418 	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
419 			 " to %d, %d, %d\n",
420 			 th->initial_limits[0], th->initial_limits[1],
421 			 th->initial_limits[2], th->limits[0], th->limits[1],
422 			 th->limits[2]);
423 
424 	thermostat = th;
425 
426 	if (i2c_attach_client(&th->clt)) {
427 		printk(KERN_INFO "adt746x: Thermostat failed to attach "
428 				 "client !\n");
429 		thermostat = NULL;
430 		kfree(th);
431 		return -ENODEV;
432 	}
433 
434 	/* be sure to really write fan speed the first time */
435 	th->last_speed[0] = -2;
436 	th->last_speed[1] = -2;
437 	th->last_var[0] = -80;
438 	th->last_var[1] = -80;
439 
440 	if (fan_speed != -1) {
441 		/* manual mode, stop fans */
442 		write_both_fan_speed(th, 0);
443 	} else {
444 		/* automatic mode */
445 		write_both_fan_speed(th, -1);
446 	}
447 
448 	thread_therm = kthread_run(monitor_task, th, "kfand");
449 
450 	if (thread_therm == ERR_PTR(-ENOMEM)) {
451 		printk(KERN_INFO "adt746x: Kthread creation failed\n");
452 		thread_therm = NULL;
453 		return -ENOMEM;
454 	}
455 
456 	return 0;
457 }
458 
459 /*
460  * Now, unfortunately, sysfs doesn't give us a nice void * we could
461  * pass around to the attribute functions, so we don't really have
462  * choice but implement a bunch of them...
463  *
464  * FIXME, it does now...
465  */
466 #define BUILD_SHOW_FUNC_INT(name, data)				\
467 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
468 {								\
469 	return sprintf(buf, "%d\n", data);			\
470 }
471 
472 #define BUILD_SHOW_FUNC_STR(name, data)				\
473 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
474 {								\
475 	return sprintf(buf, "%s\n", data);			\
476 }
477 
478 #define BUILD_SHOW_FUNC_FAN(name, data)				\
479 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
480 {								\
481 	return sprintf(buf, "%d (%d rpm)\n", 			\
482 		thermostat->last_speed[data],			\
483 		read_fan_speed(thermostat, FAN_SPEED[data])	\
484 		);						\
485 }
486 
487 #define BUILD_STORE_FUNC_DEG(name, data)			\
488 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
489 {								\
490 	int val;						\
491 	int i;							\
492 	val = simple_strtol(buf, NULL, 10);			\
493 	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
494 	limit_adjust = val;					\
495 	for (i=0; i < 3; i++)					\
496 		set_limit(thermostat, i);			\
497 	return n;						\
498 }
499 
500 #define BUILD_STORE_FUNC_INT(name, data)			\
501 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
502 {								\
503 	u32 val;						\
504 	val = simple_strtoul(buf, NULL, 10);			\
505 	if (val < 0 || val > 255)				\
506 		return -EINVAL;					\
507 	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
508 	data = val;						\
509 	return n;						\
510 }
511 
512 BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
513 BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
514 BUILD_SHOW_FUNC_INT(sensor1_limit,		 thermostat->limits[1])
515 BUILD_SHOW_FUNC_INT(sensor2_limit,		 thermostat->limits[2])
516 BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
517 BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
518 
519 BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
520 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
521 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
522 
523 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
524 BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
525 BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
526 
527 static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
528 		   show_sensor1_temperature,NULL);
529 static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
530 		   show_sensor2_temperature,NULL);
531 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
532 		   show_sensor1_limit,	NULL);
533 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
534 		   show_sensor2_limit,	NULL);
535 static DEVICE_ATTR(sensor1_location, S_IRUGO,
536 		   show_sensor1_location, NULL);
537 static DEVICE_ATTR(sensor2_location, S_IRUGO,
538 		   show_sensor2_location, NULL);
539 
540 static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
541 		   show_specified_fan_speed,store_specified_fan_speed);
542 
543 static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
544 		   show_sensor1_fan_speed,	NULL);
545 static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
546 		   show_sensor2_fan_speed,	NULL);
547 
548 static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
549 		   show_limit_adjust,	store_limit_adjust);
550 
551 
552 static int __init
553 thermostat_init(void)
554 {
555 	struct device_node* np;
556 	const u32 *prop;
557 	int i = 0, offset = 0;
558 
559 	np = of_find_node_by_name(NULL, "fan");
560 	if (!np)
561 		return -ENODEV;
562 	if (of_device_is_compatible(np, "adt7460"))
563 		therm_type = ADT7460;
564 	else if (of_device_is_compatible(np, "adt7467"))
565 		therm_type = ADT7467;
566 	else
567 		return -ENODEV;
568 
569 	prop = of_get_property(np, "hwsensor-params-version", NULL);
570 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
571 			 (*prop == 1)?"":"un");
572 	if (*prop != 1)
573 		return -ENODEV;
574 
575 	prop = of_get_property(np, "reg", NULL);
576 	if (!prop)
577 		return -ENODEV;
578 
579 	/* look for bus either by path or using "reg" */
580 	if (strstr(np->full_name, "/i2c-bus@") != NULL) {
581 		const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
582 		therm_bus = tmp_bus[0]-'0';
583 	} else {
584 		therm_bus = ((*prop) >> 8) & 0x0f;
585 	}
586 
587 	therm_address = ((*prop) & 0xff) >> 1;
588 
589 	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
590 			 "limit_adjust: %d, fan_speed: %d\n",
591 			 therm_bus, therm_address, limit_adjust, fan_speed);
592 
593 	if (of_get_property(np, "hwsensor-location", NULL)) {
594 		for (i = 0; i < 3; i++) {
595 			sensor_location[i] = of_get_property(np,
596 					"hwsensor-location", NULL) + offset;
597 
598 			if (sensor_location[i] == NULL)
599 				sensor_location[i] = "";
600 
601 			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
602 			offset += strlen(sensor_location[i]) + 1;
603 		}
604 	} else {
605 		sensor_location[0] = "?";
606 		sensor_location[1] = "?";
607 		sensor_location[2] = "?";
608 	}
609 
610 	of_dev = of_platform_device_create(np, "temperatures", NULL);
611 
612 	if (of_dev == NULL) {
613 		printk(KERN_ERR "Can't register temperatures device !\n");
614 		return -ENODEV;
615 	}
616 
617 	device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
618 	device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
619 	device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
620 	device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
621 	device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
622 	device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
623 	device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
624 	device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
625 	device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
626 	if(therm_type == ADT7460)
627 		device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
628 
629 #ifndef CONFIG_I2C_POWERMAC
630 	request_module("i2c-powermac");
631 #endif
632 
633 	return i2c_add_driver(&thermostat_driver);
634 }
635 
636 static void __exit
637 thermostat_exit(void)
638 {
639 	if (of_dev) {
640 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
641 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
642 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
643 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
644 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
645 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
646 		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
647 		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
648 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
649 
650 		if(therm_type == ADT7460)
651 			device_remove_file(&of_dev->dev,
652 					   &dev_attr_sensor2_fan_speed);
653 
654 		of_device_unregister(of_dev);
655 	}
656 	i2c_del_driver(&thermostat_driver);
657 }
658 
659 module_init(thermostat_init);
660 module_exit(thermostat_exit);
661