5ba190ce14a07dbc8a17607d5dce10bc919f8b29
[linux-2.6.git] / 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/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);