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 #include <linux/of_platform.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 
35 #undef DEBUG
36 
37 #define CONFIG_REG   0x40
38 #define MANUAL_MASK  0xe0
39 #define AUTO_MASK    0x20
40 #define INVERT_MASK  0x10
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 const char *sensor_location[3];
52 
53 static int limit_adjust;
54 static int fan_speed = -1;
55 static int verbose;
56 
57 MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
58 MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
59 		   "Powerbook G4 Alu");
60 MODULE_LICENSE("GPL");
61 
62 module_param(limit_adjust, int, 0644);
63 MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
64 		 "by N degrees.");
65 
66 module_param(fan_speed, int, 0644);
67 MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
68 		 "(default 64)");
69 
70 module_param(verbose, bool, 0);
71 MODULE_PARM_DESC(verbose,"Verbose log operations "
72 		 "(default 0)");
73 
74 struct thermostat {
75 	struct i2c_client	*clt;
76 	u8			temps[3];
77 	u8			cached_temp[3];
78 	u8			initial_limits[3];
79 	u8			limits[3];
80 	int			last_speed[2];
81 	int			last_var[2];
82 	int			pwm_inv[2];
83 };
84 
85 static enum {ADT7460, ADT7467} therm_type;
86 static int therm_bus, therm_address;
87 static struct of_device * of_dev;
88 static struct thermostat* thermostat;
89 static struct task_struct *thread_therm = NULL;
90 
91 static void write_both_fan_speed(struct thermostat *th, int speed);
92 static void write_fan_speed(struct thermostat *th, int speed, int fan);
93 
94 static int
95 write_reg(struct thermostat* th, int reg, u8 data)
96 {
97 	u8 tmp[2];
98 	int rc;
99 
100 	tmp[0] = reg;
101 	tmp[1] = data;
102 	rc = i2c_master_send(th->clt, (const char *)tmp, 2);
103 	if (rc < 0)
104 		return rc;
105 	if (rc != 2)
106 		return -ENODEV;
107 	return 0;
108 }
109 
110 static int
111 read_reg(struct thermostat* th, int reg)
112 {
113 	u8 reg_addr, data;
114 	int rc;
115 
116 	reg_addr = (u8)reg;
117 	rc = i2c_master_send(th->clt, &reg_addr, 1);
118 	if (rc < 0)
119 		return rc;
120 	if (rc != 1)
121 		return -ENODEV;
122 	rc = i2c_master_recv(th->clt, (char *)&data, 1);
123 	if (rc < 0)
124 		return rc;
125 	return data;
126 }
127 
128 static struct i2c_driver thermostat_driver;
129 
130 static int
131 attach_thermostat(struct i2c_adapter *adapter)
132 {
133 	unsigned long bus_no;
134 	struct i2c_board_info info;
135 	struct i2c_client *client;
136 
137 	if (strncmp(adapter->name, "uni-n", 5))
138 		return -ENODEV;
139 	bus_no = simple_strtoul(adapter->name + 6, NULL, 10);
140 	if (bus_no != therm_bus)
141 		return -ENODEV;
142 
143 	memset(&info, 0, sizeof(struct i2c_board_info));
144 	strlcpy(info.type, "therm_adt746x", I2C_NAME_SIZE);
145 	info.addr = therm_address;
146 	client = i2c_new_device(adapter, &info);
147 	if (!client)
148 		return -ENODEV;
149 
150 	/*
151 	 * Let i2c-core delete that device on driver removal.
152 	 * This is safe because i2c-core holds the core_lock mutex for us.
153 	 */
154 	list_add_tail(&client->detected, &thermostat_driver.clients);
155 	return 0;
156 }
157 
158 static int
159 remove_thermostat(struct i2c_client *client)
160 {
161 	struct thermostat *th = i2c_get_clientdata(client);
162 	int i;
163 
164 	if (thread_therm != NULL) {
165 		kthread_stop(thread_therm);
166 	}
167 
168 	printk(KERN_INFO "adt746x: Putting max temperatures back from "
169 			 "%d, %d, %d to %d, %d, %d\n",
170 		th->limits[0], th->limits[1], th->limits[2],
171 		th->initial_limits[0], th->initial_limits[1],
172 		th->initial_limits[2]);
173 
174 	for (i = 0; i < 3; i++)
175 		write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
176 
177 	write_both_fan_speed(th, -1);
178 
179 	thermostat = NULL;
180 
181 	kfree(th);
182 
183 	return 0;
184 }
185 
186 static int read_fan_speed(struct thermostat *th, u8 addr)
187 {
188 	u8 tmp[2];
189 	u16 res;
190 
191 	/* should start with low byte */
192 	tmp[1] = read_reg(th, addr);
193 	tmp[0] = read_reg(th, addr + 1);
194 
195 	res = tmp[1] + (tmp[0] << 8);
196 	/* "a value of 0xffff means that the fan has stopped" */
197 	return (res == 0xffff ? 0 : (90000*60)/res);
198 }
199 
200 static void write_both_fan_speed(struct thermostat *th, int speed)
201 {
202 	write_fan_speed(th, speed, 0);
203 	if (therm_type == ADT7460)
204 		write_fan_speed(th, speed, 1);
205 }
206 
207 static void write_fan_speed(struct thermostat *th, int speed, int fan)
208 {
209 	u8 manual;
210 
211 	if (speed > 0xff)
212 		speed = 0xff;
213 	else if (speed < -1)
214 		speed = 0;
215 
216 	if (therm_type == ADT7467 && fan == 1)
217 		return;
218 
219 	if (th->last_speed[fan] != speed) {
220 		if (verbose) {
221 			if (speed == -1)
222 				printk(KERN_DEBUG "adt746x: Setting speed to automatic "
223 					"for %s fan.\n", sensor_location[fan+1]);
224 			else
225 				printk(KERN_DEBUG "adt746x: Setting speed to %d "
226 					"for %s fan.\n", speed, sensor_location[fan+1]);
227 		}
228 	} else
229 		return;
230 
231 	if (speed >= 0) {
232 		manual = read_reg(th, MANUAL_MODE[fan]);
233 		manual &= ~INVERT_MASK;
234 		write_reg(th, MANUAL_MODE[fan],
235 			manual | MANUAL_MASK | th->pwm_inv[fan]);
236 		write_reg(th, FAN_SPD_SET[fan], speed);
237 	} else {
238 		/* back to automatic */
239 		if(therm_type == ADT7460) {
240 			manual = read_reg(th,
241 				MANUAL_MODE[fan]) & (~MANUAL_MASK);
242 			manual &= ~INVERT_MASK;
243 			manual |= th->pwm_inv[fan];
244 			write_reg(th,
245 				MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
246 		} else {
247 			manual = read_reg(th, MANUAL_MODE[fan]);
248 			manual &= ~INVERT_MASK;
249 			manual |= th->pwm_inv[fan];
250 			write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
251 		}
252 	}
253 
254 	th->last_speed[fan] = speed;
255 }
256 
257 static void read_sensors(struct thermostat *th)
258 {
259 	int i = 0;
260 
261 	for (i = 0; i < 3; i++)
262 		th->temps[i]  = read_reg(th, TEMP_REG[i]);
263 }
264 
265 #ifdef DEBUG
266 static void display_stats(struct thermostat *th)
267 {
268 	if (th->temps[0] != th->cached_temp[0]
269 	||  th->temps[1] != th->cached_temp[1]
270 	||  th->temps[2] != th->cached_temp[2]) {
271 		printk(KERN_INFO "adt746x: Temperature infos:"
272 				 " thermostats: %d,%d,%d;"
273 				 " limits: %d,%d,%d;"
274 				 " fan speed: %d RPM\n",
275 				 th->temps[0], th->temps[1], th->temps[2],
276 				 th->limits[0],  th->limits[1],  th->limits[2],
277 				 read_fan_speed(th, FAN_SPEED[0]));
278 	}
279 	th->cached_temp[0] = th->temps[0];
280 	th->cached_temp[1] = th->temps[1];
281 	th->cached_temp[2] = th->temps[2];
282 }
283 #endif
284 
285 static void update_fans_speed (struct thermostat *th)
286 {
287 	int lastvar = 0; /* last variation, for iBook */
288 	int i = 0;
289 
290 	/* we don't care about local sensor, so we start at sensor 1 */
291 	for (i = 1; i < 3; i++) {
292 		int started = 0;
293 		int fan_number = (therm_type == ADT7460 && i == 2);
294 		int var = th->temps[i] - th->limits[i];
295 
296 		if (var > -1) {
297 			int step = (255 - fan_speed) / 7;
298 			int new_speed = 0;
299 
300 			/* hysteresis : change fan speed only if variation is
301 			 * more than two degrees */
302 			if (abs(var - th->last_var[fan_number]) < 2)
303 				continue;
304 
305 			started = 1;
306 			new_speed = fan_speed + ((var-1)*step);
307 
308 			if (new_speed < fan_speed)
309 				new_speed = fan_speed;
310 			if (new_speed > 255)
311 				new_speed = 255;
312 
313 			if (verbose)
314 				printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
315 						 "(limit exceeded by %d on %s) \n",
316 						new_speed, var,
317 						sensor_location[fan_number+1]);
318 			write_both_fan_speed(th, new_speed);
319 			th->last_var[fan_number] = var;
320 		} else if (var < -2) {
321 			/* don't stop fan if sensor2 is cold and sensor1 is not
322 			 * so cold (lastvar >= -1) */
323 			if (i == 2 && lastvar < -1) {
324 				if (th->last_speed[fan_number] != 0)
325 					if (verbose)
326 						printk(KERN_DEBUG "adt746x: Stopping "
327 							"fans.\n");
328 				write_both_fan_speed(th, 0);
329 			}
330 		}
331 
332 		lastvar = var;
333 
334 		if (started)
335 			return; /* we don't want to re-stop the fan
336 				* if sensor1 is heating and sensor2 is not */
337 	}
338 }
339 
340 static int monitor_task(void *arg)
341 {
342 	struct thermostat* th = arg;
343 
344 	set_freezable();
345 	while(!kthread_should_stop()) {
346 		try_to_freeze();
347 		msleep_interruptible(2000);
348 
349 #ifndef DEBUG
350 		if (fan_speed != -1)
351 			read_sensors(th);
352 #else
353 		read_sensors(th);
354 #endif
355 
356 		if (fan_speed != -1)
357 			update_fans_speed(th);
358 
359 #ifdef DEBUG
360 		display_stats(th);
361 #endif
362 
363 	}
364 
365 	return 0;
366 }
367 
368 static void set_limit(struct thermostat *th, int i)
369 {
370 		/* Set sensor1 limit higher to avoid powerdowns */
371 		th->limits[i] = default_limits_chip[i] + limit_adjust;
372 		write_reg(th, LIMIT_REG[i], th->limits[i]);
373 
374 		/* set our limits to normal */
375 		th->limits[i] = default_limits_local[i] + limit_adjust;
376 }
377 
378 static int probe_thermostat(struct i2c_client *client,
379 			    const struct i2c_device_id *id)
380 {
381 	struct thermostat* th;
382 	int rc;
383 	int i;
384 
385 	if (thermostat)
386 		return 0;
387 
388 	th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
389 	if (!th)
390 		return -ENOMEM;
391 
392 	i2c_set_clientdata(client, th);
393 	th->clt = client;
394 
395 	rc = read_reg(th, CONFIG_REG);
396 	if (rc < 0) {
397 		dev_err(&client->dev, "Thermostat failed to read config!\n");
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 	/* record invert bit status because fw can corrupt it after suspend */
427 	th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
428 	th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
429 
430 	/* be sure to really write fan speed the first time */
431 	th->last_speed[0] = -2;
432 	th->last_speed[1] = -2;
433 	th->last_var[0] = -80;
434 	th->last_var[1] = -80;
435 
436 	if (fan_speed != -1) {
437 		/* manual mode, stop fans */
438 		write_both_fan_speed(th, 0);
439 	} else {
440 		/* automatic mode */
441 		write_both_fan_speed(th, -1);
442 	}
443 
444 	thread_therm = kthread_run(monitor_task, th, "kfand");
445 
446 	if (thread_therm == ERR_PTR(-ENOMEM)) {
447 		printk(KERN_INFO "adt746x: Kthread creation failed\n");
448 		thread_therm = NULL;
449 		return -ENOMEM;
450 	}
451 
452 	return 0;
453 }
454 
455 static const struct i2c_device_id therm_adt746x_id[] = {
456 	{ "therm_adt746x", 0 },
457 	{ }
458 };
459 
460 static struct i2c_driver thermostat_driver = {
461 	.driver = {
462 		.name	= "therm_adt746x",
463 	},
464 	.attach_adapter	= attach_thermostat,
465 	.probe = probe_thermostat,
466 	.remove = remove_thermostat,
467 	.id_table = therm_adt746x_id,
468 };
469 
470 /*
471  * Now, unfortunately, sysfs doesn't give us a nice void * we could
472  * pass around to the attribute functions, so we don't really have
473  * choice but implement a bunch of them...
474  *
475  * FIXME, it does now...
476  */
477 #define BUILD_SHOW_FUNC_INT(name, data)				\
478 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)	\
479 {								\
480 	return sprintf(buf, "%d\n", data);			\
481 }
482 
483 #define BUILD_SHOW_FUNC_STR(name, data)				\
484 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
485 {								\
486 	return sprintf(buf, "%s\n", data);			\
487 }
488 
489 #define BUILD_SHOW_FUNC_FAN(name, data)				\
490 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
491 {								\
492 	return sprintf(buf, "%d (%d rpm)\n", 			\
493 		thermostat->last_speed[data],			\
494 		read_fan_speed(thermostat, FAN_SPEED[data])	\
495 		);						\
496 }
497 
498 #define BUILD_STORE_FUNC_DEG(name, data)			\
499 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
500 {								\
501 	int val;						\
502 	int i;							\
503 	val = simple_strtol(buf, NULL, 10);			\
504 	printk(KERN_INFO "Adjusting limits by %d degrees\n", val);	\
505 	limit_adjust = val;					\
506 	for (i=0; i < 3; i++)					\
507 		set_limit(thermostat, i);			\
508 	return n;						\
509 }
510 
511 #define BUILD_STORE_FUNC_INT(name, data)			\
512 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
513 {								\
514 	int val;						\
515 	val = simple_strtol(buf, NULL, 10);			\
516 	if (val < 0 || val > 255)				\
517 		return -EINVAL;					\
518 	printk(KERN_INFO "Setting specified fan speed to %d\n", val);	\
519 	data = val;						\
520 	return n;						\
521 }
522 
523 BUILD_SHOW_FUNC_INT(sensor1_temperature,	 (read_reg(thermostat, TEMP_REG[1])))
524 BUILD_SHOW_FUNC_INT(sensor2_temperature,	 (read_reg(thermostat, TEMP_REG[2])))
525 BUILD_SHOW_FUNC_INT(sensor1_limit,		 thermostat->limits[1])
526 BUILD_SHOW_FUNC_INT(sensor2_limit,		 thermostat->limits[2])
527 BUILD_SHOW_FUNC_STR(sensor1_location,		 sensor_location[1])
528 BUILD_SHOW_FUNC_STR(sensor2_location,		 sensor_location[2])
529 
530 BUILD_SHOW_FUNC_INT(specified_fan_speed, fan_speed)
531 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,	 0)
532 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,	 1)
533 
534 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
535 BUILD_SHOW_FUNC_INT(limit_adjust,	 limit_adjust)
536 BUILD_STORE_FUNC_DEG(limit_adjust,	 thermostat)
537 
538 static DEVICE_ATTR(sensor1_temperature,	S_IRUGO,
539 		   show_sensor1_temperature,NULL);
540 static DEVICE_ATTR(sensor2_temperature,	S_IRUGO,
541 		   show_sensor2_temperature,NULL);
542 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
543 		   show_sensor1_limit,	NULL);
544 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
545 		   show_sensor2_limit,	NULL);
546 static DEVICE_ATTR(sensor1_location, S_IRUGO,
547 		   show_sensor1_location, NULL);
548 static DEVICE_ATTR(sensor2_location, S_IRUGO,
549 		   show_sensor2_location, NULL);
550 
551 static DEVICE_ATTR(specified_fan_speed,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
552 		   show_specified_fan_speed,store_specified_fan_speed);
553 
554 static DEVICE_ATTR(sensor1_fan_speed,	S_IRUGO,
555 		   show_sensor1_fan_speed,	NULL);
556 static DEVICE_ATTR(sensor2_fan_speed,	S_IRUGO,
557 		   show_sensor2_fan_speed,	NULL);
558 
559 static DEVICE_ATTR(limit_adjust,	S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
560 		   show_limit_adjust,	store_limit_adjust);
561 
562 
563 static int __init
564 thermostat_init(void)
565 {
566 	struct device_node* np;
567 	const u32 *prop;
568 	int i = 0, offset = 0;
569 	int err;
570 
571 	np = of_find_node_by_name(NULL, "fan");
572 	if (!np)
573 		return -ENODEV;
574 	if (of_device_is_compatible(np, "adt7460"))
575 		therm_type = ADT7460;
576 	else if (of_device_is_compatible(np, "adt7467"))
577 		therm_type = ADT7467;
578 	else {
579 		of_node_put(np);
580 		return -ENODEV;
581 	}
582 
583 	prop = of_get_property(np, "hwsensor-params-version", NULL);
584 	printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
585 			 (*prop == 1)?"":"un");
586 	if (*prop != 1) {
587 		of_node_put(np);
588 		return -ENODEV;
589 	}
590 
591 	prop = of_get_property(np, "reg", NULL);
592 	if (!prop) {
593 		of_node_put(np);
594 		return -ENODEV;
595 	}
596 
597 	/* look for bus either by path or using "reg" */
598 	if (strstr(np->full_name, "/i2c-bus@") != NULL) {
599 		const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
600 		therm_bus = tmp_bus[0]-'0';
601 	} else {
602 		therm_bus = ((*prop) >> 8) & 0x0f;
603 	}
604 
605 	therm_address = ((*prop) & 0xff) >> 1;
606 
607 	printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
608 			 "limit_adjust: %d, fan_speed: %d\n",
609 			 therm_bus, therm_address, limit_adjust, fan_speed);
610 
611 	if (of_get_property(np, "hwsensor-location", NULL)) {
612 		for (i = 0; i < 3; i++) {
613 			sensor_location[i] = of_get_property(np,
614 					"hwsensor-location", NULL) + offset;
615 
616 			if (sensor_location[i] == NULL)
617 				sensor_location[i] = "";
618 
619 			printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
620 			offset += strlen(sensor_location[i]) + 1;
621 		}
622 	} else {
623 		sensor_location[0] = "?";
624 		sensor_location[1] = "?";
625 		sensor_location[2] = "?";
626 	}
627 
628 	of_dev = of_platform_device_create(np, "temperatures", NULL);
629 	of_node_put(np);
630 
631 	if (of_dev == NULL) {
632 		printk(KERN_ERR "Can't register temperatures device !\n");
633 		return -ENODEV;
634 	}
635 
636 	err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
637 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
638 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
639 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
640 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
641 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
642 	err |= device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
643 	err |= device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
644 	err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
645 	if(therm_type == ADT7460)
646 		err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
647 	if (err)
648 		printk(KERN_WARNING
649 			"Failed to create tempertaure attribute file(s).\n");
650 
651 #ifndef CONFIG_I2C_POWERMAC
652 	request_module("i2c-powermac");
653 #endif
654 
655 	return i2c_add_driver(&thermostat_driver);
656 }
657 
658 static void __exit
659 thermostat_exit(void)
660 {
661 	if (of_dev) {
662 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
663 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
664 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
665 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
666 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
667 		device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
668 		device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
669 		device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
670 		device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
671 
672 		if(therm_type == ADT7460)
673 			device_remove_file(&of_dev->dev,
674 					   &dev_attr_sensor2_fan_speed);
675 
676 		of_device_unregister(of_dev);
677 	}
678 	i2c_del_driver(&thermostat_driver);
679 }
680 
681 module_init(thermostat_init);
682 module_exit(thermostat_exit);
683