Linux 2.6.31-rc6
[linux-2.6] / drivers / macintosh / therm_adt746x.c
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 };
83
84 static enum {ADT7460, ADT7467} therm_type;
85 static int therm_bus, therm_address;
86 static struct of_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
93 static int
94 write_reg(struct thermostat* th, int reg, u8 data)
95 {
96         u8 tmp[2];
97         int rc;
98         
99         tmp[0] = reg;
100         tmp[1] = data;
101         rc = i2c_master_send(th->clt, (const char *)tmp, 2);
102         if (rc < 0)
103                 return rc;
104         if (rc != 2)
105                 return -ENODEV;
106         return 0;
107 }
108
109 static int
110 read_reg(struct thermostat* th, int reg)
111 {
112         u8 reg_addr, data;
113         int rc;
114
115         reg_addr = (u8)reg;
116         rc = i2c_master_send(th->clt, &reg_addr, 1);
117         if (rc < 0)
118                 return rc;
119         if (rc != 1)
120                 return -ENODEV;
121         rc = i2c_master_recv(th->clt, (char *)&data, 1);
122         if (rc < 0)
123                 return rc;
124         return data;
125 }
126
127 static int
128 attach_thermostat(struct i2c_adapter *adapter)
129 {
130         unsigned long bus_no;
131         struct i2c_board_info info;
132         struct i2c_client *client;
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
140         memset(&info, 0, sizeof(struct i2c_board_info));
141         strlcpy(info.type, "therm_adt746x", I2C_NAME_SIZE);
142         info.addr = therm_address;
143         client = i2c_new_device(adapter, &info);
144         if (!client)
145                 return -ENODEV;
146
147         /*
148          * Let i2c-core delete that device on driver removal.
149          * This is safe because i2c-core holds the core_lock mutex for us.
150          */
151         list_add_tail(&client->detected, &client->driver->clients);
152         return 0;
153 }
154
155 static int
156 remove_thermostat(struct i2c_client *client)
157 {
158         struct thermostat *th = i2c_get_clientdata(client);
159         int i;
160         
161         if (thread_therm != NULL) {
162                 kthread_stop(thread_therm);
163         }
164
165         printk(KERN_INFO "adt746x: Putting max temperatures back from "
166                          "%d, %d, %d to %d, %d, %d\n",
167                 th->limits[0], th->limits[1], th->limits[2],
168                 th->initial_limits[0], th->initial_limits[1],
169                 th->initial_limits[2]);
170
171         for (i = 0; i < 3; i++)
172                 write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
173
174         write_both_fan_speed(th, -1);
175
176         thermostat = NULL;
177
178         kfree(th);
179
180         return 0;
181 }
182
183 static int read_fan_speed(struct thermostat *th, u8 addr)
184 {
185         u8 tmp[2];
186         u16 res;
187         
188         /* should start with low byte */
189         tmp[1] = read_reg(th, addr);
190         tmp[0] = read_reg(th, addr + 1);
191         
192         res = tmp[1] + (tmp[0] << 8);
193         /* "a value of 0xffff means that the fan has stopped" */
194         return (res == 0xffff ? 0 : (90000*60)/res);
195 }
196
197 static void write_both_fan_speed(struct thermostat *th, int speed)
198 {
199         write_fan_speed(th, speed, 0);
200         if (therm_type == ADT7460)
201                 write_fan_speed(th, speed, 1);
202 }
203
204 static void write_fan_speed(struct thermostat *th, int speed, int fan)
205 {
206         u8 manual;
207         
208         if (speed > 0xff) 
209                 speed = 0xff;
210         else if (speed < -1) 
211                 speed = 0;
212         
213         if (therm_type == ADT7467 && fan == 1)
214                 return;
215         
216         if (th->last_speed[fan] != speed) {
217                 if (verbose) {
218                         if (speed == -1)
219                                 printk(KERN_DEBUG "adt746x: Setting speed to automatic "
220                                         "for %s fan.\n", sensor_location[fan+1]);
221                         else
222                                 printk(KERN_DEBUG "adt746x: Setting speed to %d "
223                                         "for %s fan.\n", speed, sensor_location[fan+1]);
224                 }
225         } else
226                 return;
227         
228         if (speed >= 0) {
229                 manual = read_reg(th, MANUAL_MODE[fan]);
230                 write_reg(th, MANUAL_MODE[fan],
231                         (manual|MANUAL_MASK) & (~INVERT_MASK));
232                 write_reg(th, FAN_SPD_SET[fan], speed);
233         } else {
234                 /* back to automatic */
235                 if(therm_type == ADT7460) {
236                         manual = read_reg(th,
237                                 MANUAL_MODE[fan]) & (~MANUAL_MASK);
238
239                         write_reg(th,
240                                 MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
241                 } else {
242                         manual = read_reg(th, MANUAL_MODE[fan]);
243                         write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
244                 }
245         }
246         
247         th->last_speed[fan] = speed;                    
248 }
249
250 static void read_sensors(struct thermostat *th)
251 {
252         int i = 0;
253
254         for (i = 0; i < 3; i++)
255                 th->temps[i]  = read_reg(th, TEMP_REG[i]);
256 }
257
258 #ifdef DEBUG
259 static void display_stats(struct thermostat *th)
260 {
261         if (th->temps[0] != th->cached_temp[0]
262         ||  th->temps[1] != th->cached_temp[1]
263         ||  th->temps[2] != th->cached_temp[2]) {
264                 printk(KERN_INFO "adt746x: Temperature infos:"
265                                  " thermostats: %d,%d,%d;"
266                                  " limits: %d,%d,%d;"
267                                  " fan speed: %d RPM\n",
268                                  th->temps[0], th->temps[1], th->temps[2],
269                                  th->limits[0],  th->limits[1],  th->limits[2],
270                                  read_fan_speed(th, FAN_SPEED[0]));
271         }
272         th->cached_temp[0] = th->temps[0];
273         th->cached_temp[1] = th->temps[1];
274         th->cached_temp[2] = th->temps[2];
275 }
276 #endif
277
278 static void update_fans_speed (struct thermostat *th)
279 {
280         int lastvar = 0; /* last variation, for iBook */
281         int i = 0;
282
283         /* we don't care about local sensor, so we start at sensor 1 */
284         for (i = 1; i < 3; i++) {
285                 int started = 0;
286                 int fan_number = (therm_type == ADT7460 && i == 2);
287                 int var = th->temps[i] - th->limits[i];
288
289                 if (var > -1) {
290                         int step = (255 - fan_speed) / 7;
291                         int new_speed = 0;
292
293                         /* hysteresis : change fan speed only if variation is
294                          * more than two degrees */
295                         if (abs(var - th->last_var[fan_number]) < 2)
296                                 continue;
297
298                         started = 1;
299                         new_speed = fan_speed + ((var-1)*step);
300
301                         if (new_speed < fan_speed)
302                                 new_speed = fan_speed;
303                         if (new_speed > 255)
304                                 new_speed = 255;
305
306                         if (verbose)
307                                 printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
308                                                  "(limit exceeded by %d on %s) \n",
309                                                 new_speed, var,
310                                                 sensor_location[fan_number+1]);
311                         write_both_fan_speed(th, new_speed);
312                         th->last_var[fan_number] = var;
313                 } else if (var < -2) {
314                         /* don't stop fan if sensor2 is cold and sensor1 is not
315                          * so cold (lastvar >= -1) */
316                         if (i == 2 && lastvar < -1) {
317                                 if (th->last_speed[fan_number] != 0)
318                                         if (verbose)
319                                                 printk(KERN_DEBUG "adt746x: Stopping "
320                                                         "fans.\n");
321                                 write_both_fan_speed(th, 0);
322                         }
323                 }
324
325                 lastvar = var;
326
327                 if (started)
328                         return; /* we don't want to re-stop the fan
329                                 * if sensor1 is heating and sensor2 is not */
330         }
331 }
332
333 static int monitor_task(void *arg)
334 {
335         struct thermostat* th = arg;
336
337         set_freezable();
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 probe_thermostat(struct i2c_client *client,
372                             const struct i2c_device_id *id)
373 {
374         struct thermostat* th;
375         int rc;
376         int i;
377
378         if (thermostat)
379                 return 0;
380
381         th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
382         if (!th)
383                 return -ENOMEM;
384
385         i2c_set_clientdata(client, th);
386         th->clt = client;
387
388         rc = read_reg(th, 0);
389         if (rc < 0) {
390                 dev_err(&client->dev, "Thermostat failed to read config!\n");
391                 kfree(th);
392                 return -ENODEV;
393         }
394
395         /* force manual control to start the fan quieter */
396         if (fan_speed == -1)
397                 fan_speed = 64;
398         
399         if(therm_type == ADT7460) {
400                 printk(KERN_INFO "adt746x: ADT7460 initializing\n");
401                 /* The 7460 needs to be started explicitly */
402                 write_reg(th, CONFIG_REG, 1);
403         } else
404                 printk(KERN_INFO "adt746x: ADT7467 initializing\n");
405
406         for (i = 0; i < 3; i++) {
407                 th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
408                 set_limit(th, i);
409         }
410
411         printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
412                          " to %d, %d, %d\n",
413                          th->initial_limits[0], th->initial_limits[1],
414                          th->initial_limits[2], th->limits[0], th->limits[1],
415                          th->limits[2]);
416
417         thermostat = th;
418
419         /* be sure to really write fan speed the first time */
420         th->last_speed[0] = -2;
421         th->last_speed[1] = -2;
422         th->last_var[0] = -80;
423         th->last_var[1] = -80;
424
425         if (fan_speed != -1) {
426                 /* manual mode, stop fans */
427                 write_both_fan_speed(th, 0);
428         } else {
429                 /* automatic mode */
430                 write_both_fan_speed(th, -1);
431         }
432         
433         thread_therm = kthread_run(monitor_task, th, "kfand");
434
435         if (thread_therm == ERR_PTR(-ENOMEM)) {
436                 printk(KERN_INFO "adt746x: Kthread creation failed\n");
437                 thread_therm = NULL;
438                 return -ENOMEM;
439         }
440
441         return 0;
442 }
443
444 static const struct i2c_device_id therm_adt746x_id[] = {
445         { "therm_adt746x", 0 },
446         { }
447 };
448
449 static struct i2c_driver thermostat_driver = {
450         .driver = {
451                 .name   = "therm_adt746x",
452         },
453         .attach_adapter = attach_thermostat,
454         .probe = probe_thermostat,
455         .remove = remove_thermostat,
456         .id_table = therm_adt746x_id,
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         int val;                                                \
504         val = simple_strtol(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         int err;
559
560         np = of_find_node_by_name(NULL, "fan");
561         if (!np)
562                 return -ENODEV;
563         if (of_device_is_compatible(np, "adt7460"))
564                 therm_type = ADT7460;
565         else if (of_device_is_compatible(np, "adt7467"))
566                 therm_type = ADT7467;
567         else {
568                 of_node_put(np);
569                 return -ENODEV;
570         }
571
572         prop = of_get_property(np, "hwsensor-params-version", NULL);
573         printk(KERN_INFO "adt746x: version %d (%ssupported)\n", *prop,
574                          (*prop == 1)?"":"un");
575         if (*prop != 1) {
576                 of_node_put(np);
577                 return -ENODEV;
578         }
579
580         prop = of_get_property(np, "reg", NULL);
581         if (!prop) {
582                 of_node_put(np);
583                 return -ENODEV;
584         }
585
586         /* look for bus either by path or using "reg" */
587         if (strstr(np->full_name, "/i2c-bus@") != NULL) {
588                 const char *tmp_bus = (strstr(np->full_name, "/i2c-bus@") + 9);
589                 therm_bus = tmp_bus[0]-'0';
590         } else {
591                 therm_bus = ((*prop) >> 8) & 0x0f;
592         }
593
594         therm_address = ((*prop) & 0xff) >> 1;
595
596         printk(KERN_INFO "adt746x: Thermostat bus: %d, address: 0x%02x, "
597                          "limit_adjust: %d, fan_speed: %d\n",
598                          therm_bus, therm_address, limit_adjust, fan_speed);
599
600         if (of_get_property(np, "hwsensor-location", NULL)) {
601                 for (i = 0; i < 3; i++) {
602                         sensor_location[i] = of_get_property(np,
603                                         "hwsensor-location", NULL) + offset;
604
605                         if (sensor_location[i] == NULL)
606                                 sensor_location[i] = "";
607
608                         printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
609                         offset += strlen(sensor_location[i]) + 1;
610                 }
611         } else {
612                 sensor_location[0] = "?";
613                 sensor_location[1] = "?";
614                 sensor_location[2] = "?";
615         }
616
617         of_dev = of_platform_device_create(np, "temperatures", NULL);
618         of_node_put(np);
619
620         if (of_dev == NULL) {
621                 printk(KERN_ERR "Can't register temperatures device !\n");
622                 return -ENODEV;
623         }
624
625         err = device_create_file(&of_dev->dev, &dev_attr_sensor1_temperature);
626         err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_temperature);
627         err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_limit);
628         err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_limit);
629         err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_location);
630         err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_location);
631         err |= device_create_file(&of_dev->dev, &dev_attr_limit_adjust);
632         err |= device_create_file(&of_dev->dev, &dev_attr_specified_fan_speed);
633         err |= device_create_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
634         if(therm_type == ADT7460)
635                 err |= device_create_file(&of_dev->dev, &dev_attr_sensor2_fan_speed);
636         if (err)
637                 printk(KERN_WARNING
638                         "Failed to create tempertaure attribute file(s).\n");
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 __exit
648 thermostat_exit(void)
649 {
650         if (of_dev) {
651                 device_remove_file(&of_dev->dev, &dev_attr_sensor1_temperature);
652                 device_remove_file(&of_dev->dev, &dev_attr_sensor2_temperature);
653                 device_remove_file(&of_dev->dev, &dev_attr_sensor1_limit);
654                 device_remove_file(&of_dev->dev, &dev_attr_sensor2_limit);
655                 device_remove_file(&of_dev->dev, &dev_attr_sensor1_location);
656                 device_remove_file(&of_dev->dev, &dev_attr_sensor2_location);
657                 device_remove_file(&of_dev->dev, &dev_attr_limit_adjust);
658                 device_remove_file(&of_dev->dev, &dev_attr_specified_fan_speed);
659                 device_remove_file(&of_dev->dev, &dev_attr_sensor1_fan_speed);
660
661                 if(therm_type == ADT7460)
662                         device_remove_file(&of_dev->dev,
663                                            &dev_attr_sensor2_fan_speed);
664
665                 of_device_unregister(of_dev);
666         }
667         i2c_del_driver(&thermostat_driver);
668 }
669
670 module_init(thermostat_init);
671 module_exit(thermostat_exit);