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 115254175ADT7467_pra.pdf and 3686221171167ADT7460_b.pdf
7  * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
8  * http://www.onsemi.com/PowerSolutions/product.do?id=ADT7460
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 #include <linux/of_platform.h>
28 
29 #include <asm/prom.h>
30 #include <asm/machdep.h>
31 #include <asm/io.h>
32 #include <asm/sections.h>
33 
34 #undef DEBUG
35 
36 #define CONFIG_REG   0x40
37 #define MANUAL_MASK  0xe0
38 #define AUTO_MASK    0x20
39 #define INVERT_MASK  0x10
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 bool 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 	int			pwm_inv[2];
82 };
83 
84 static enum {ADT7460, ADT7467} therm_type;
85 static int therm_bus, therm_address;
86 static struct platform_device * of_dev;
87 static struct thermostat* thermostat;
88 static struct task_struct *thread_therm = NULL;
89 
90 static void write_both_fan_speed(struct thermostat *th, int speed);
91 static void write_fan_speed(struct thermostat *th, int speed, int fan);
92 static void thermostat_create_files(void);
93 static void thermostat_remove_files(void);
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 struct i2c_driver thermostat_driver;
130 
131 static int
132 attach_thermostat(struct i2c_adapter *adapter)
133 {
134 	unsigned long bus_no;
135 	struct i2c_board_info info;
136 	struct i2c_client *client;
137 
138 	if (strncmp(adapter->name, "uni-n", 5))
139 		return -ENODEV;
140 	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
141 	if (bus_no != therm_bus)
142 		return -ENODEV;
143 
144 	memset(&info, 0, sizeof(struct i2c_board_info));
145 	strlcpy(info.type, "therm_adt746x", I2C_NAME_SIZE);
146 	info.addr = therm_address;
147 	client = i2c_new_device(adapter, &info);
148 	if (!client)
149 		return -ENODEV;
150 
151 	/*
152 	 * Let i2c-core delete that device on driver removal.
153 	 * This is safe because i2c-core holds the core_lock mutex for us.
154 	 */
155 	list_add_tail(&client->detected, &thermostat_driver.clients);
156 	return 0;
157 }
158 
159 static int
160 remove_thermostat(struct i2c_client *client)
161 {
162 	struct thermostat *th = i2c_get_clientdata(client);
163 	int i;
164 
165 	thermostat_remove_files();
166 
167 	if (thread_therm != NULL) {
168 		kthread_stop(thread_therm);
169 	}
170 
171 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
172 			 "%d, %d, %d to %d, %d, %d\n",
173 		th->limits[0], th->limits[1], th->limits[2],
174 		th->initial_limits[0], th->initial_limits[1],
175 		th->initial_limits[2]);
176 
177 	for (i = 0; i < 3; i++)
178 		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
179 
180 	write_both_fan_speed(th, -1);
181 
182 	thermostat = NULL;
183 
184 	kfree(th);
185 
186 	return 0;
187 }
188 
189 static int read_fan_speed(struct thermostat *th, u8 addr)
190 {
191 	u8 tmp[2];
192 	u16 res;
193 
194 	/* should start with low byte */
195 	tmp[1] = read_reg(th, addr);
196 	tmp[0] = read_reg(th, addr + 1);
197 
198 	res = tmp[1] + (tmp[0] << 8);
199 	/* "a value of 0xffff means that the fan has stopped" */
200 	return (res == 0xffff ? 0 : (90000*60)/res);
201 }
202 
203 static void write_both_fan_speed(struct thermostat *th, int speed)
204 {
205 	write_fan_speed(th, speed, 0);
206 	if (therm_type == ADT7460)
207 		write_fan_speed(th, speed, 1);
208 }
209 
210 static void write_fan_speed(struct thermostat *th, int speed, int fan)
211 {
212 	u8 manual;
213 
214 	if (speed > 0xff)
215 		speed = 0xff;
216 	else if (speed < -1)
217 		speed = 0;
218 
219 	if (therm_type == ADT7467 && fan == 1)
220 		return;
221 
222 	if (th->last_speed[fan] != speed) {
223 		if (verbose) {
224 			if (speed == -1)
225 				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
226 					"for %s fan.\n", sensor_location[fan+1]);
227 			else
228 				printk(KERN_DEBUG "adt746x: Setting speed to %d "
229 					"for %s fan.\n", speed, sensor_location[fan+1]);
230 		}
231 	} else
232 		return;
233 
234 	if (speed >= 0) {
235 		manual = read_reg(th, MANUAL_MODE[fan]);
236 		manual &= ~INVERT_MASK;
237 		write_reg(th, MANUAL_MODE[fan],
238 			manual | MANUAL_MASK | th->pwm_inv[fan]);
239 		write_reg(th, FAN_SPD_SET[fan], speed);
240 	} else {
241 		/* back to automatic */
242 		if(therm_type == ADT7460) {
243 			manual = read_reg(th,
244 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
245 			manual &= ~INVERT_MASK;
246 			manual |= th->pwm_inv[fan];
247 			write_reg(th,
248 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
249 		} else {
250 			manual = read_reg(th, MANUAL_MODE[fan]);
251 			manual &= ~INVERT_MASK;
252 			manual |= th->pwm_inv[fan];
253 			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
254 		}
255 	}
256 
257 	th->last_speed[fan] = speed;
258 }
259 
260 static void read_sensors(struct thermostat *th)
261 {
262 	int i = 0;
263 
264 	for (i = 0; i < 3; i++)
265 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
266 }
267 
268 #ifdef DEBUG
269 static void display_stats(struct thermostat *th)
270 {
271 	if (th->temps[0] != th->cached_temp[0]
272 	||  th->temps[1] != th->cached_temp[1]
273 	||  th->temps[2] != th->cached_temp[2]) {
274 		printk(KERN_INFO "adt746x: Temperature infos:"
275 				 " thermostats: %d,%d,%d;"
276 				 " limits: %d,%d,%d;"
277 				 " fan speed: %d RPM\n",
278 				 th->temps[0], th->temps[1], th->temps[2],
279 				 th->limits[0],  th->limits[1],  th->limits[2],
280 				 read_fan_speed(th, FAN_SPEED[0]));
281 	}
282 	th->cached_temp[0] = th->temps[0];
283 	th->cached_temp[1] = th->temps[1];
284 	th->cached_temp[2] = th->temps[2];
285 }
286 #endif
287 
288 static void update_fans_speed (struct thermostat *th)
289 {
290 	int lastvar = 0; /* last variation, for iBook */
291 	int i = 0;
292 
293 	/* we don't care about local sensor, so we start at sensor 1 */
294 	for (i = 1; i < 3; i++) {
295 		int started = 0;
296 		int fan_number = (therm_type == ADT7460 && i == 2);
297 		int var = th->temps[i] - th->limits[i];
298 
299 		if (var > -1) {
300 			int step = (255 - fan_speed) / 7;
301 			int new_speed = 0;
302 
303 			/* hysteresis : change fan speed only if variation is
304 			 * more than two degrees */
305 			if (abs(var - th->last_var[fan_number]) < 2)
306 				continue;
307 
308 			started = 1;
309 			new_speed = fan_speed + ((var-1)*step);
310 
311 			if (new_speed < fan_speed)
312 				new_speed = fan_speed;
313 			if (new_speed > 255)
314 				new_speed = 255;
315 
316 			if (verbose)
317 				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
318 						 "(limit exceeded by %d on %s)\n",
319 						new_speed, var,
320 						sensor_location[fan_number+1]);
321 			write_both_fan_speed(th, new_speed);
322 			th->last_var[fan_number] = var;
323 		} else if (var < -2) {
324 			/* don't stop fan if sensor2 is cold and sensor1 is not
325 			 * so cold (lastvar >= -1) */
326 			if (i == 2 && lastvar < -1) {
327 				if (th->last_speed[fan_number] != 0)
328 					if (verbose)
329 						printk(KERN_DEBUG "adt746x: Stopping "
330 							"fans.\n");
331 				write_both_fan_speed(th, 0);
332 			}
333 		}
334 
335 		lastvar = var;
336 
337 		if (started)
338 			return; /* we don't want to re-stop the fan
339 				* if sensor1 is heating and sensor2 is not */
340 	}
341 }
342 
343 static int monitor_task(void *arg)
344 {
345 	struct thermostat* th = arg;
346 
347 	set_freezable();
348 	while(!kthread_should_stop()) {
349 		try_to_freeze();
350 		msleep_interruptible(2000);
351 
352 #ifndef DEBUG
353 		if (fan_speed != -1)
354 			read_sensors(th);
355 #else
356 		read_sensors(th);
357 #endif
358 
359 		if (fan_speed != -1)
360 			update_fans_speed(th);
361 
362 #ifdef DEBUG
363 		display_stats(th);
364 #endif
365 
366 	}
367 
368 	return 0;
369 }
370 
371 static void set_limit(struct thermostat *th, int i)
372 {
373 		/* Set sensor1 limit higher to avoid powerdowns */
374 		th->limits[i] = default_limits_chip[i] + limit_adjust;
375 		write_reg(th, LIMIT_REG[i], th->limits[i]);
376 
377 		/* set our limits to normal */
378 		th->limits[i] = default_limits_local[i] + limit_adjust;
379 }
380 
381 static int probe_thermostat(struct i2c_client *client,
382 			    const struct i2c_device_id *id)
383 {
384 	struct thermostat* th;
385 	int rc;
386 	int i;
387 
388 	if (thermostat)
389 		return 0;
390 
391 	th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
392 	if (!th)
393 		return -ENOMEM;
394 
395 	i2c_set_clientdata(client, th);
396 	th->clt = client;
397 
398 	rc = read_reg(th, CONFIG_REG);
399 	if (rc < 0) {
400 		dev_err(&client->dev, "Thermostat failed to read config!\n");
401 		kfree(th);
402 		return -ENODEV;
403 	}
404 
405 	/* force manual control to start the fan quieter */
406 	if (fan_speed == -1)
407 		fan_speed = 64;
408 
409 	if(therm_type == ADT7460) {
410 		printk(KERN_INFO "adt746x: ADT7460 initializing\n");
411 		/* The 7460 needs to be started explicitly */
412 		write_reg(th, CONFIG_REG, 1);
413 	} else
414 		printk(KERN_INFO "adt746x: ADT7467 initializing\n");
415 
416 	for (i = 0; i < 3; i++) {
417 		th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
418 		set_limit(th, i);
419 	}
420 
421 	printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
422 			 " to %d, %d, %d\n",
423 			 th->initial_limits[0], th->initial_limits[1],
424 			 th->initial_limits[2], th->limits[0], th->limits[1],
425 			 th->limits[2]);
426 
427 	thermostat = th;
428 
429 	/* record invert bit status because fw can corrupt it after suspend */
430 	th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
431 	th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
432 
433 	/* be sure to really write fan speed the first time */
434 	th->last_speed[0] = -2;
435 	th->last_speed[1] = -2;
436 	th->last_var[0] = -80;
437 	th->last_var[1] = -80;
438 
439 	if (fan_speed != -1) {
440 		/* manual mode, stop fans */
441 		write_both_fan_speed(th, 0);
442 	} else {
443 		/* automatic mode */
444 		write_both_fan_speed(th, -1);
445 	}
446 
447 	thread_therm = kthread_run(monitor_task, th, "kfand");
448 
449 	if (thread_therm == ERR_PTR(-ENOMEM)) {
450 		printk(KERN_INFO "adt746x: Kthread creation failed\n");
451 		thread_therm = NULL;
452 		return -ENOMEM;
453 	}
454 
455 	thermostat_create_files();
456 
457 	return 0;
458 }
459 
460 static const struct i2c_device_id therm_adt746x_id[] = {
461 	{ "therm_adt746x", 0 },
462 	{ }
463 };
464 
465 static struct i2c_driver thermostat_driver = {
466 	.driver = {
467 		.name	= "therm_adt746x",
468 	},
469 	.attach_adapter	= attach_thermostat,
470 	.probe = probe_thermostat,
471 	.remove = remove_thermostat,
472 	.id_table = therm_adt746x_id,
473 };
474 
475 /*
476  * Now, unfortunately, sysfs doesn't give us a nice void * we could
477  * pass around to the attribute functions, so we don't really have
478  * choice but implement a bunch of them...
479  *
480  * FIXME, it does now...
481  */
482 #define BUILD_SHOW_FUNC_INT(name, data)				\
483 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
484 {								\
485 	return sprintf(buf, "%d\n", data);			\
486 }
487 
488 #define BUILD_SHOW_FUNC_STR(name, data)				\
489 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
490 {								\
491 	return sprintf(buf, "%s\n", data);			\
492 }
493 
494 #define BUILD_SHOW_FUNC_FAN(name, data)				\
495 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
496 {								\
497 	return sprintf(buf, "%d (%d rpm)\n", 			\
498 		thermostat->last_speed[data],			\
499 		read_fan_speed(thermostat, FAN_SPEED[data])	\
500 		);						\
501 }
502 
503 #define BUILD_STORE_FUNC_DEG(name, data)			\
504 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
505 {								\
506 	int val;						\
507 	int i;							\
508 	val = simple_strtol(buf, NULL, 10);			\
509 	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
510 	limit_adjust = val;					\
511 	for (i=0; i < 3; i++)					\
512 		set_limit(thermostat, i);			\
513 	return n;						\
514 }
515 
516 #define BUILD_STORE_FUNC_INT(name, data)			\
517 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
518 {								\
519 	int val;						\
520 	val = simple_strtol(buf, NULL, 10);			\
521 	if (val < 0 || val > 255)				\
522 		return -EINVAL;					\
523 	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
524 	data = val;						\
525 	return n;						\
526 }
527 
528 BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
529 BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
530 BUILD_SHOW_FUNC_INT(sensor1_limit,		 thermostat->limits[1])
531 BUILD_SHOW_FUNC_INT(sensor2_limit,		 thermostat->limits[2])
532 BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
533 BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
534 
535 BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
536 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
537 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
538 
539 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
540 BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
541 BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
542 
543 static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
544 		   show_sensor1_temperature,NULL);
545 static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
546 		   show_sensor2_temperature,NULL);
547 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
548 		   show_sensor1_limit,	NULL);
549 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
550 		   show_sensor2_limit,	NULL);
551 static DEVICE_ATTR(sensor1_location, S_IRUGO,
552 		   show_sensor1_location, NULL);
553 static DEVICE_ATTR(sensor2_location, S_IRUGO,
554 		   show_sensor2_location, NULL);
555 
556 static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
557 		   show_specified_fan_speed,store_specified_fan_speed);
558 
559 static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
560 		   show_sensor1_fan_speed,	NULL);
561 static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
562 		   show_sensor2_fan_speed,	NULL);
563 
564 static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
565 		   show_limit_adjust,	store_limit_adjust);
566 
567 
568 static int __init
569 thermostat_init(void)
570 {
571 	struct device_node* np;
572 	const u32 *prop;
573 	int i = 0, offset = 0;
574 
575 	np = of_find_node_by_name(NULL, "fan");
576 	if (!np)
577 		return -ENODEV;
578 	if (of_device_is_compatible(np, "adt7460"))
579 		therm_type = ADT7460;
580 	else if (of_device_is_compatible(np, "adt7467"))
581 		therm_type = ADT7467;
582 	else {
583 		of_node_put(np);
584 		return -ENODEV;
585 	}
586 
587 	prop = of_get_property(np, "hwsensor-params-version", NULL);
588 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
589 			 (*prop == 1)?"":"un");
590 	if (*prop != 1) {
591 		of_node_put(np);
592 		return -ENODEV;
593 	}
594 
595 	prop = of_get_property(np, "reg", NULL);
596 	if (!prop) {
597 		of_node_put(np);
598 		return -ENODEV;
599 	}
600 
601 	/* look for bus either by path or using "reg" */
602 	if (strstr(np->full_name, "/i2c-bus@") != NULL) {
603 		const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
604 		therm_bus = tmp_bus[0]-'0';
605 	} else {
606 		therm_bus = ((*prop) >> 8) & 0x0f;
607 	}
608 
609 	therm_address = ((*prop) & 0xff) >> 1;
610 
611 	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
612 			 "limit_adjust: %d, fan_speed: %d\n",
613 			 therm_bus, therm_address, limit_adjust, fan_speed);
614 
615 	if (of_get_property(np, "hwsensor-location", NULL)) {
616 		for (i = 0; i < 3; i++) {
617 			sensor_location[i] = of_get_property(np,
618 					"hwsensor-location", NULL) + offset;
619 
620 			if (sensor_location[i] == NULL)
621 				sensor_location[i] = "";
622 
623 			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
624 			offset += strlen(sensor_location[i]) + 1;
625 		}
626 	} else {
627 		sensor_location[0] = "?";
628 		sensor_location[1] = "?";
629 		sensor_location[2] = "?";
630 	}
631 
632 	of_dev = of_platform_device_create(np, "temperatures", NULL);
633 	of_node_put(np);
634 
635 	if (of_dev == NULL) {
636 		printk(KERN_ERR "Can't register temperatures device !\n");
637 		return -ENODEV;
638 	}
639 
640 #ifndef CONFIG_I2C_POWERMAC
641 	request_module("i2c-powermac");
642 #endif
643 
644 	return i2c_add_driver(&thermostat_driver);
645 }
646 
647 static void thermostat_create_files(void)
648 {
649 	int err;
650 
651 	err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
652 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
653 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
654 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
655 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
656 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
657 	err |= device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
658 	err |= device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
659 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
660 	if(therm_type == ADT7460)
661 		err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
662 	if (err)
663 		printk(KERN_WARNING
664 			"Failed to create temperature attribute file(s).\n");
665 }
666 
667 static void thermostat_remove_files(void)
668 {
669 	if (of_dev) {
670 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
671 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
672 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
673 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
674 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
675 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
676 		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
677 		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
678 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
679 
680 		if(therm_type == ADT7460)
681 			device_remove_file(&of_dev->dev,
682 					   &dev_attr_sensor2_fan_speed);
683 
684 	}
685 }
686 
687 static void __exit
688 thermostat_exit(void)
689 {
690 	i2c_del_driver(&thermostat_driver);
691 	of_device_unregister(of_dev);
692 }
693 
694 module_init(thermostat_init);
695 module_exit(thermostat_exit);
696