1 /*
2  * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5  *                    <benh@kernel.crashing.org>
6  *
7  * Released under the term of the GNU GPL v2.
8  *
9  * The algorithm used is the PID control algorithm, used the same
10  * way the published Darwin code does, using the same values that
11  * are present in the Darwin 8.2 snapshot property lists (note however
12  * that none of the code has been re-used, it's a complete re-implementation
13  *
14  * The various control loops found in Darwin config file are:
15  *
16  * PowerMac9,1
17  * ===========
18  *
19  * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't
20  * try to play with other control loops fans). Drive bay is rather basic PID
21  * with one sensor and one fan. Slots area is a bit different as the Darwin
22  * driver is supposed to be capable of working in a special "AGP" mode which
23  * involves the presence of an AGP sensor and an AGP fan (possibly on the
24  * AGP card itself). I can't deal with that special mode as I don't have
25  * access to those additional sensor/fans for now (though ultimately, it would
26  * be possible to add sensor objects for them) so I'm only implementing the
27  * basic PCI slot control loop
28  */
29 
30 #include <linux/types.h>
31 #include <linux/errno.h>
32 #include <linux/kernel.h>
33 #include <linux/delay.h>
34 #include <linux/slab.h>
35 #include <linux/init.h>
36 #include <linux/spinlock.h>
37 #include <linux/wait.h>
38 #include <linux/kmod.h>
39 #include <linux/device.h>
40 #include <linux/platform_device.h>
41 #include <asm/prom.h>
42 #include <asm/machdep.h>
43 #include <asm/io.h>
44 #include <asm/sections.h>
45 #include <asm/smu.h>
46 
47 #include "windfarm.h"
48 #include "windfarm_pid.h"
49 
50 #define VERSION "0.4"
51 
52 #undef DEBUG
53 
54 #ifdef DEBUG
55 #define DBG(args...)	printk(args)
56 #else
57 #define DBG(args...)	do { } while(0)
58 #endif
59 
60 /* define this to force CPU overtemp to 74 degree, useful for testing
61  * the overtemp code
62  */
63 #undef HACKED_OVERTEMP
64 
65 /* Controls & sensors */
66 static struct wf_sensor	*sensor_cpu_power;
67 static struct wf_sensor	*sensor_cpu_temp;
68 static struct wf_sensor	*sensor_hd_temp;
69 static struct wf_sensor	*sensor_slots_power;
70 static struct wf_control *fan_cpu_main;
71 static struct wf_control *fan_cpu_second;
72 static struct wf_control *fan_cpu_third;
73 static struct wf_control *fan_hd;
74 static struct wf_control *fan_slots;
75 static struct wf_control *cpufreq_clamp;
76 
77 /* Set to kick the control loop into life */
78 static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok, wf_smu_started;
79 
80 /* Failure handling.. could be nicer */
81 #define FAILURE_FAN		0x01
82 #define FAILURE_SENSOR		0x02
83 #define FAILURE_OVERTEMP	0x04
84 
85 static unsigned int wf_smu_failure_state;
86 static int wf_smu_readjust, wf_smu_skipping;
87 
88 /*
89  * ****** CPU Fans Control Loop ******
90  *
91  */
92 
93 
94 #define WF_SMU_CPU_FANS_INTERVAL	1
95 #define WF_SMU_CPU_FANS_MAX_HISTORY	16
96 
97 /* State data used by the cpu fans control loop
98  */
99 struct wf_smu_cpu_fans_state {
100 	int			ticks;
101 	s32			cpu_setpoint;
102 	struct wf_cpu_pid_state	pid;
103 };
104 
105 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
106 
107 
108 
109 /*
110  * ****** Drive Fan Control Loop ******
111  *
112  */
113 
114 struct wf_smu_drive_fans_state {
115 	int			ticks;
116 	s32			setpoint;
117 	struct wf_pid_state	pid;
118 };
119 
120 static struct wf_smu_drive_fans_state *wf_smu_drive_fans;
121 
122 /*
123  * ****** Slots Fan Control Loop ******
124  *
125  */
126 
127 struct wf_smu_slots_fans_state {
128 	int			ticks;
129 	s32			setpoint;
130 	struct wf_pid_state	pid;
131 };
132 
133 static struct wf_smu_slots_fans_state *wf_smu_slots_fans;
134 
135 /*
136  * ***** Implementation *****
137  *
138  */
139 
140 
141 static void wf_smu_create_cpu_fans(void)
142 {
143 	struct wf_cpu_pid_param pid_param;
144 	const struct smu_sdbp_header *hdr;
145 	struct smu_sdbp_cpupiddata *piddata;
146 	struct smu_sdbp_fvt *fvt;
147 	s32 tmax, tdelta, maxpow, powadj;
148 
149 	/* First, locate the PID params in SMU SBD */
150 	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
151 	if (hdr == 0) {
152 		printk(KERN_WARNING "windfarm: CPU PID fan config not found "
153 		       "max fan speed\n");
154 		goto fail;
155 	}
156 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
157 
158 	/* Get the FVT params for operating point 0 (the only supported one
159 	 * for now) in order to get tmax
160 	 */
161 	hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
162 	if (hdr) {
163 		fvt = (struct smu_sdbp_fvt *)&hdr[1];
164 		tmax = ((s32)fvt->maxtemp) << 16;
165 	} else
166 		tmax = 0x5e0000; /* 94 degree default */
167 
168 	/* Alloc & initialize state */
169 	wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
170 				  GFP_KERNEL);
171 	if (wf_smu_cpu_fans == NULL)
172 		goto fail;
173        	wf_smu_cpu_fans->ticks = 1;
174 
175 	/* Fill PID params */
176 	pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
177 	pid_param.history_len = piddata->history_len;
178 	if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
179 		printk(KERN_WARNING "windfarm: History size overflow on "
180 		       "CPU control loop (%d)\n", piddata->history_len);
181 		pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
182 	}
183 	pid_param.gd = piddata->gd;
184 	pid_param.gp = piddata->gp;
185 	pid_param.gr = piddata->gr / pid_param.history_len;
186 
187 	tdelta = ((s32)piddata->target_temp_delta) << 16;
188 	maxpow = ((s32)piddata->max_power) << 16;
189 	powadj = ((s32)piddata->power_adj) << 16;
190 
191 	pid_param.tmax = tmax;
192 	pid_param.ttarget = tmax - tdelta;
193 	pid_param.pmaxadj = maxpow - powadj;
194 
195 	pid_param.min = fan_cpu_main->ops->get_min(fan_cpu_main);
196 	pid_param.max = fan_cpu_main->ops->get_max(fan_cpu_main);
197 
198 	wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
199 
200 	DBG("wf: CPU Fan control initialized.\n");
201 	DBG("    ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
202 	    FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
203 	    pid_param.min, pid_param.max);
204 
205 	return;
206 
207  fail:
208 	printk(KERN_WARNING "windfarm: CPU fan config not found\n"
209 	       "for this machine model, max fan speed\n");
210 
211 	if (cpufreq_clamp)
212 		wf_control_set_max(cpufreq_clamp);
213 	if (fan_cpu_main)
214 		wf_control_set_max(fan_cpu_main);
215 }
216 
217 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
218 {
219 	s32 new_setpoint, temp, power;
220 	int rc;
221 
222 	if (--st->ticks != 0) {
223 		if (wf_smu_readjust)
224 			goto readjust;
225 		return;
226 	}
227 	st->ticks = WF_SMU_CPU_FANS_INTERVAL;
228 
229 	rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
230 	if (rc) {
231 		printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
232 		       rc);
233 		wf_smu_failure_state |= FAILURE_SENSOR;
234 		return;
235 	}
236 
237 	rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
238 	if (rc) {
239 		printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
240 		       rc);
241 		wf_smu_failure_state |= FAILURE_SENSOR;
242 		return;
243 	}
244 
245 	DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
246 	    FIX32TOPRINT(temp), FIX32TOPRINT(power));
247 
248 #ifdef HACKED_OVERTEMP
249 	if (temp > 0x4a0000)
250 		wf_smu_failure_state |= FAILURE_OVERTEMP;
251 #else
252 	if (temp > st->pid.param.tmax)
253 		wf_smu_failure_state |= FAILURE_OVERTEMP;
254 #endif
255 	new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
256 
257 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
258 
259 	if (st->cpu_setpoint == new_setpoint)
260 		return;
261 	st->cpu_setpoint = new_setpoint;
262  readjust:
263 	if (fan_cpu_main && wf_smu_failure_state == 0) {
264 		rc = fan_cpu_main->ops->set_value(fan_cpu_main,
265 						  st->cpu_setpoint);
266 		if (rc) {
267 			printk(KERN_WARNING "windfarm: CPU main fan"
268 			       " error %d\n", rc);
269 			wf_smu_failure_state |= FAILURE_FAN;
270 		}
271 	}
272 	if (fan_cpu_second && wf_smu_failure_state == 0) {
273 		rc = fan_cpu_second->ops->set_value(fan_cpu_second,
274 						    st->cpu_setpoint);
275 		if (rc) {
276 			printk(KERN_WARNING "windfarm: CPU second fan"
277 			       " error %d\n", rc);
278 			wf_smu_failure_state |= FAILURE_FAN;
279 		}
280 	}
281 	if (fan_cpu_third && wf_smu_failure_state == 0) {
282 		rc = fan_cpu_main->ops->set_value(fan_cpu_third,
283 						  st->cpu_setpoint);
284 		if (rc) {
285 			printk(KERN_WARNING "windfarm: CPU third fan"
286 			       " error %d\n", rc);
287 			wf_smu_failure_state |= FAILURE_FAN;
288 		}
289 	}
290 }
291 
292 static void wf_smu_create_drive_fans(void)
293 {
294 	struct wf_pid_param param = {
295 		.interval	= 5,
296 		.history_len	= 2,
297 		.gd		= 0x01e00000,
298 		.gp		= 0x00500000,
299 		.gr		= 0x00000000,
300 		.itarget	= 0x00200000,
301 	};
302 
303 	/* Alloc & initialize state */
304 	wf_smu_drive_fans = kmalloc(sizeof(struct wf_smu_drive_fans_state),
305 					GFP_KERNEL);
306 	if (wf_smu_drive_fans == NULL) {
307 		printk(KERN_WARNING "windfarm: Memory allocation error"
308 		       " max fan speed\n");
309 		goto fail;
310 	}
311        	wf_smu_drive_fans->ticks = 1;
312 
313 	/* Fill PID params */
314 	param.additive = (fan_hd->type == WF_CONTROL_RPM_FAN);
315 	param.min = fan_hd->ops->get_min(fan_hd);
316 	param.max = fan_hd->ops->get_max(fan_hd);
317 	wf_pid_init(&wf_smu_drive_fans->pid, &param);
318 
319 	DBG("wf: Drive Fan control initialized.\n");
320 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
321 	    FIX32TOPRINT(param.itarget), param.min, param.max);
322 	return;
323 
324  fail:
325 	if (fan_hd)
326 		wf_control_set_max(fan_hd);
327 }
328 
329 static void wf_smu_drive_fans_tick(struct wf_smu_drive_fans_state *st)
330 {
331 	s32 new_setpoint, temp;
332 	int rc;
333 
334 	if (--st->ticks != 0) {
335 		if (wf_smu_readjust)
336 			goto readjust;
337 		return;
338 	}
339 	st->ticks = st->pid.param.interval;
340 
341 	rc = sensor_hd_temp->ops->get_value(sensor_hd_temp, &temp);
342 	if (rc) {
343 		printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
344 		       rc);
345 		wf_smu_failure_state |= FAILURE_SENSOR;
346 		return;
347 	}
348 
349 	DBG("wf_smu: Drive Fans tick ! HD temp: %d.%03d\n",
350 	    FIX32TOPRINT(temp));
351 
352 	if (temp > (st->pid.param.itarget + 0x50000))
353 		wf_smu_failure_state |= FAILURE_OVERTEMP;
354 
355 	new_setpoint = wf_pid_run(&st->pid, temp);
356 
357 	DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
358 
359 	if (st->setpoint == new_setpoint)
360 		return;
361 	st->setpoint = new_setpoint;
362  readjust:
363 	if (fan_hd && wf_smu_failure_state == 0) {
364 		rc = fan_hd->ops->set_value(fan_hd, st->setpoint);
365 		if (rc) {
366 			printk(KERN_WARNING "windfarm: HD fan error %d\n",
367 			       rc);
368 			wf_smu_failure_state |= FAILURE_FAN;
369 		}
370 	}
371 }
372 
373 static void wf_smu_create_slots_fans(void)
374 {
375 	struct wf_pid_param param = {
376 		.interval	= 1,
377 		.history_len	= 8,
378 		.gd		= 0x00000000,
379 		.gp		= 0x00000000,
380 		.gr		= 0x00020000,
381 		.itarget	= 0x00000000
382 	};
383 
384 	/* Alloc & initialize state */
385 	wf_smu_slots_fans = kmalloc(sizeof(struct wf_smu_slots_fans_state),
386 					GFP_KERNEL);
387 	if (wf_smu_slots_fans == NULL) {
388 		printk(KERN_WARNING "windfarm: Memory allocation error"
389 		       " max fan speed\n");
390 		goto fail;
391 	}
392        	wf_smu_slots_fans->ticks = 1;
393 
394 	/* Fill PID params */
395 	param.additive = (fan_slots->type == WF_CONTROL_RPM_FAN);
396 	param.min = fan_slots->ops->get_min(fan_slots);
397 	param.max = fan_slots->ops->get_max(fan_slots);
398 	wf_pid_init(&wf_smu_slots_fans->pid, &param);
399 
400 	DBG("wf: Slots Fan control initialized.\n");
401 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
402 	    FIX32TOPRINT(param.itarget), param.min, param.max);
403 	return;
404 
405  fail:
406 	if (fan_slots)
407 		wf_control_set_max(fan_slots);
408 }
409 
410 static void wf_smu_slots_fans_tick(struct wf_smu_slots_fans_state *st)
411 {
412 	s32 new_setpoint, power;
413 	int rc;
414 
415 	if (--st->ticks != 0) {
416 		if (wf_smu_readjust)
417 			goto readjust;
418 		return;
419 	}
420 	st->ticks = st->pid.param.interval;
421 
422 	rc = sensor_slots_power->ops->get_value(sensor_slots_power, &power);
423 	if (rc) {
424 		printk(KERN_WARNING "windfarm: Slots power sensor error %d\n",
425 		       rc);
426 		wf_smu_failure_state |= FAILURE_SENSOR;
427 		return;
428 	}
429 
430 	DBG("wf_smu: Slots Fans tick ! Slots power: %d.%03d\n",
431 	    FIX32TOPRINT(power));
432 
433 #if 0 /* Check what makes a good overtemp condition */
434 	if (power > (st->pid.param.itarget + 0x50000))
435 		wf_smu_failure_state |= FAILURE_OVERTEMP;
436 #endif
437 
438 	new_setpoint = wf_pid_run(&st->pid, power);
439 
440 	DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
441 
442 	if (st->setpoint == new_setpoint)
443 		return;
444 	st->setpoint = new_setpoint;
445  readjust:
446 	if (fan_slots && wf_smu_failure_state == 0) {
447 		rc = fan_slots->ops->set_value(fan_slots, st->setpoint);
448 		if (rc) {
449 			printk(KERN_WARNING "windfarm: Slots fan error %d\n",
450 			       rc);
451 			wf_smu_failure_state |= FAILURE_FAN;
452 		}
453 	}
454 }
455 
456 
457 /*
458  * ****** Setup / Init / Misc ... ******
459  *
460  */
461 
462 static void wf_smu_tick(void)
463 {
464 	unsigned int last_failure = wf_smu_failure_state;
465 	unsigned int new_failure;
466 
467 	if (!wf_smu_started) {
468 		DBG("wf: creating control loops !\n");
469 		wf_smu_create_drive_fans();
470 		wf_smu_create_slots_fans();
471 		wf_smu_create_cpu_fans();
472 		wf_smu_started = 1;
473 	}
474 
475 	/* Skipping ticks */
476 	if (wf_smu_skipping && --wf_smu_skipping)
477 		return;
478 
479 	wf_smu_failure_state = 0;
480 	if (wf_smu_drive_fans)
481 		wf_smu_drive_fans_tick(wf_smu_drive_fans);
482 	if (wf_smu_slots_fans)
483 		wf_smu_slots_fans_tick(wf_smu_slots_fans);
484 	if (wf_smu_cpu_fans)
485 		wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
486 
487 	wf_smu_readjust = 0;
488 	new_failure = wf_smu_failure_state & ~last_failure;
489 
490 	/* If entering failure mode, clamp cpufreq and ramp all
491 	 * fans to full speed.
492 	 */
493 	if (wf_smu_failure_state && !last_failure) {
494 		if (cpufreq_clamp)
495 			wf_control_set_max(cpufreq_clamp);
496 		if (fan_cpu_main)
497 			wf_control_set_max(fan_cpu_main);
498 		if (fan_cpu_second)
499 			wf_control_set_max(fan_cpu_second);
500 		if (fan_cpu_third)
501 			wf_control_set_max(fan_cpu_third);
502 		if (fan_hd)
503 			wf_control_set_max(fan_hd);
504 		if (fan_slots)
505 			wf_control_set_max(fan_slots);
506 	}
507 
508 	/* If leaving failure mode, unclamp cpufreq and readjust
509 	 * all fans on next iteration
510 	 */
511 	if (!wf_smu_failure_state && last_failure) {
512 		if (cpufreq_clamp)
513 			wf_control_set_min(cpufreq_clamp);
514 		wf_smu_readjust = 1;
515 	}
516 
517 	/* Overtemp condition detected, notify and start skipping a couple
518 	 * ticks to let the temperature go down
519 	 */
520 	if (new_failure & FAILURE_OVERTEMP) {
521 		wf_set_overtemp();
522 		wf_smu_skipping = 2;
523 	}
524 
525 	/* We only clear the overtemp condition if overtemp is cleared
526 	 * _and_ no other failure is present. Since a sensor error will
527 	 * clear the overtemp condition (can't measure temperature) at
528 	 * the control loop levels, but we don't want to keep it clear
529 	 * here in this case
530 	 */
531 	if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
532 		wf_clear_overtemp();
533 }
534 
535 
536 static void wf_smu_new_control(struct wf_control *ct)
537 {
538 	if (wf_smu_all_controls_ok)
539 		return;
540 
541 	if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-rear-fan-0")) {
542 		if (wf_get_control(ct) == 0)
543 			fan_cpu_main = ct;
544 	}
545 
546 	if (fan_cpu_second == NULL && !strcmp(ct->name, "cpu-rear-fan-1")) {
547 		if (wf_get_control(ct) == 0)
548 			fan_cpu_second = ct;
549 	}
550 
551 	if (fan_cpu_third == NULL && !strcmp(ct->name, "cpu-front-fan-0")) {
552 		if (wf_get_control(ct) == 0)
553 			fan_cpu_third = ct;
554 	}
555 
556 	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
557 		if (wf_get_control(ct) == 0)
558 			cpufreq_clamp = ct;
559 	}
560 
561 	if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
562 		if (wf_get_control(ct) == 0)
563 			fan_hd = ct;
564 	}
565 
566 	if (fan_slots == NULL && !strcmp(ct->name, "slots-fan")) {
567 		if (wf_get_control(ct) == 0)
568 			fan_slots = ct;
569 	}
570 
571 	if (fan_cpu_main && (fan_cpu_second || fan_cpu_third) && fan_hd &&
572 	    fan_slots && cpufreq_clamp)
573 		wf_smu_all_controls_ok = 1;
574 }
575 
576 static void wf_smu_new_sensor(struct wf_sensor *sr)
577 {
578 	if (wf_smu_all_sensors_ok)
579 		return;
580 
581 	if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
582 		if (wf_get_sensor(sr) == 0)
583 			sensor_cpu_power = sr;
584 	}
585 
586 	if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
587 		if (wf_get_sensor(sr) == 0)
588 			sensor_cpu_temp = sr;
589 	}
590 
591 	if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
592 		if (wf_get_sensor(sr) == 0)
593 			sensor_hd_temp = sr;
594 	}
595 
596 	if (sensor_slots_power == NULL && !strcmp(sr->name, "slots-power")) {
597 		if (wf_get_sensor(sr) == 0)
598 			sensor_slots_power = sr;
599 	}
600 
601 	if (sensor_cpu_power && sensor_cpu_temp &&
602 	    sensor_hd_temp && sensor_slots_power)
603 		wf_smu_all_sensors_ok = 1;
604 }
605 
606 
607 static int wf_smu_notify(struct notifier_block *self,
608 			       unsigned long event, void *data)
609 {
610 	switch(event) {
611 	case WF_EVENT_NEW_CONTROL:
612 		DBG("wf: new control %s detected\n",
613 		    ((struct wf_control *)data)->name);
614 		wf_smu_new_control(data);
615 		wf_smu_readjust = 1;
616 		break;
617 	case WF_EVENT_NEW_SENSOR:
618 		DBG("wf: new sensor %s detected\n",
619 		    ((struct wf_sensor *)data)->name);
620 		wf_smu_new_sensor(data);
621 		break;
622 	case WF_EVENT_TICK:
623 		if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
624 			wf_smu_tick();
625 	}
626 
627 	return 0;
628 }
629 
630 static struct notifier_block wf_smu_events = {
631 	.notifier_call	= wf_smu_notify,
632 };
633 
634 static int wf_init_pm(void)
635 {
636 	printk(KERN_INFO "windfarm: Initializing for Desktop G5 model\n");
637 
638 	return 0;
639 }
640 
641 static int wf_smu_probe(struct platform_device *ddev)
642 {
643 	wf_register_client(&wf_smu_events);
644 
645 	return 0;
646 }
647 
648 static int __devexit wf_smu_remove(struct platform_device *ddev)
649 {
650 	wf_unregister_client(&wf_smu_events);
651 
652 	/* XXX We don't have yet a guarantee that our callback isn't
653 	 * in progress when returning from wf_unregister_client, so
654 	 * we add an arbitrary delay. I'll have to fix that in the core
655 	 */
656 	msleep(1000);
657 
658 	/* Release all sensors */
659 	/* One more crappy race: I don't think we have any guarantee here
660 	 * that the attribute callback won't race with the sensor beeing
661 	 * disposed of, and I'm not 100% certain what best way to deal
662 	 * with that except by adding locks all over... I'll do that
663 	 * eventually but heh, who ever rmmod this module anyway ?
664 	 */
665 	if (sensor_cpu_power)
666 		wf_put_sensor(sensor_cpu_power);
667 	if (sensor_cpu_temp)
668 		wf_put_sensor(sensor_cpu_temp);
669 	if (sensor_hd_temp)
670 		wf_put_sensor(sensor_hd_temp);
671 	if (sensor_slots_power)
672 		wf_put_sensor(sensor_slots_power);
673 
674 	/* Release all controls */
675 	if (fan_cpu_main)
676 		wf_put_control(fan_cpu_main);
677 	if (fan_cpu_second)
678 		wf_put_control(fan_cpu_second);
679 	if (fan_cpu_third)
680 		wf_put_control(fan_cpu_third);
681 	if (fan_hd)
682 		wf_put_control(fan_hd);
683 	if (fan_slots)
684 		wf_put_control(fan_slots);
685 	if (cpufreq_clamp)
686 		wf_put_control(cpufreq_clamp);
687 
688 	/* Destroy control loops state structures */
689 	kfree(wf_smu_slots_fans);
690 	kfree(wf_smu_drive_fans);
691 	kfree(wf_smu_cpu_fans);
692 
693 	return 0;
694 }
695 
696 static struct platform_driver wf_smu_driver = {
697         .probe = wf_smu_probe,
698         .remove = __devexit_p(wf_smu_remove),
699 	.driver = {
700 		.name = "windfarm",
701 		.owner	= THIS_MODULE,
702 	},
703 };
704 
705 
706 static int __init wf_smu_init(void)
707 {
708 	int rc = -ENODEV;
709 
710 	if (of_machine_is_compatible("PowerMac9,1"))
711 		rc = wf_init_pm();
712 
713 	if (rc == 0) {
714 #ifdef MODULE
715 		request_module("windfarm_smu_controls");
716 		request_module("windfarm_smu_sensors");
717 		request_module("windfarm_lm75_sensor");
718 		request_module("windfarm_cpufreq_clamp");
719 
720 #endif /* MODULE */
721 		platform_driver_register(&wf_smu_driver);
722 	}
723 
724 	return rc;
725 }
726 
727 static void __exit wf_smu_exit(void)
728 {
729 
730 	platform_driver_unregister(&wf_smu_driver);
731 }
732 
733 
734 module_init(wf_smu_init);
735 module_exit(wf_smu_exit);
736 
737 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
738 MODULE_DESCRIPTION("Thermal control logic for PowerMac9,1");
739 MODULE_LICENSE("GPL");
740 
741 MODULE_ALIAS("platform:windfarm");
742