xref: /linux/drivers/macintosh/windfarm_pm91.c (revision 1fd1dc41724319406b0aff221a352a400b0ddfc5)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops
4  *
5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *                    <benh@kernel.crashing.org>
7  *
8  * The algorithm used is the PID control algorithm, used the same
9  * way the published Darwin code does, using the same values that
10  * are present in the Darwin 8.2 snapshot property lists (note however
11  * that none of the code has been re-used, it's a complete re-implementation
12  *
13  * The various control loops found in Darwin config file are:
14  *
15  * PowerMac9,1
16  * ===========
17  *
18  * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't
19  * try to play with other control loops fans). Drive bay is rather basic PID
20  * with one sensor and one fan. Slots area is a bit different as the Darwin
21  * driver is supposed to be capable of working in a special "AGP" mode which
22  * involves the presence of an AGP sensor and an AGP fan (possibly on the
23  * AGP card itself). I can't deal with that special mode as I don't have
24  * access to those additional sensor/fans for now (though ultimately, it would
25  * be possible to add sensor objects for them) so I'm only implementing the
26  * basic PCI slot control loop
27  */
28 
29 #include <linux/types.h>
30 #include <linux/errno.h>
31 #include <linux/kernel.h>
32 #include <linux/delay.h>
33 #include <linux/slab.h>
34 #include <linux/init.h>
35 #include <linux/spinlock.h>
36 #include <linux/wait.h>
37 #include <linux/kmod.h>
38 #include <linux/device.h>
39 #include <linux/platform_device.h>
40 #include <linux/of.h>
41 
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;
79 static bool wf_smu_started;
80 static bool wf_smu_overtemp;
81 
82 /* Failure handling.. could be nicer */
83 #define FAILURE_FAN		0x01
84 #define FAILURE_SENSOR		0x02
85 #define FAILURE_OVERTEMP	0x04
86 
87 static unsigned int wf_smu_failure_state;
88 static int wf_smu_readjust, wf_smu_skipping;
89 
90 /*
91  * ****** CPU Fans Control Loop ******
92  *
93  */
94 
95 
96 #define WF_SMU_CPU_FANS_INTERVAL	1
97 #define WF_SMU_CPU_FANS_MAX_HISTORY	16
98 
99 /* State data used by the cpu fans control loop
100  */
101 struct wf_smu_cpu_fans_state {
102 	int			ticks;
103 	s32			cpu_setpoint;
104 	struct wf_cpu_pid_state	pid;
105 };
106 
107 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
108 
109 
110 
111 /*
112  * ****** Drive Fan Control Loop ******
113  *
114  */
115 
116 struct wf_smu_drive_fans_state {
117 	int			ticks;
118 	s32			setpoint;
119 	struct wf_pid_state	pid;
120 };
121 
122 static struct wf_smu_drive_fans_state *wf_smu_drive_fans;
123 
124 /*
125  * ****** Slots Fan Control Loop ******
126  *
127  */
128 
129 struct wf_smu_slots_fans_state {
130 	int			ticks;
131 	s32			setpoint;
132 	struct wf_pid_state	pid;
133 };
134 
135 static struct wf_smu_slots_fans_state *wf_smu_slots_fans;
136 
137 /*
138  * ***** Implementation *****
139  *
140  */
141 
142 
143 static void wf_smu_create_cpu_fans(void)
144 {
145 	struct wf_cpu_pid_param pid_param;
146 	const struct smu_sdbp_header *hdr;
147 	struct smu_sdbp_cpupiddata *piddata;
148 	struct smu_sdbp_fvt *fvt;
149 	s32 tmax, tdelta, maxpow, powadj;
150 
151 	/* First, locate the PID params in SMU SBD */
152 	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
153 	if (!hdr) {
154 		printk(KERN_WARNING "windfarm: CPU PID fan config not found "
155 		       "max fan speed\n");
156 		goto fail;
157 	}
158 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
159 
160 	/* Get the FVT params for operating point 0 (the only supported one
161 	 * for now) in order to get tmax
162 	 */
163 	hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
164 	if (hdr) {
165 		fvt = (struct smu_sdbp_fvt *)&hdr[1];
166 		tmax = ((s32)fvt->maxtemp) << 16;
167 	} else
168 		tmax = 0x5e0000; /* 94 degree default */
169 
170 	/* Alloc & initialize state */
171 	wf_smu_cpu_fans = kmalloc_obj(struct wf_smu_cpu_fans_state);
172 	if (wf_smu_cpu_fans == NULL)
173 		goto fail;
174        	wf_smu_cpu_fans->ticks = 1;
175 
176 	/* Fill PID params */
177 	pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
178 	pid_param.history_len = piddata->history_len;
179 	if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
180 		printk(KERN_WARNING "windfarm: History size overflow on "
181 		       "CPU control loop (%d)\n", piddata->history_len);
182 		pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
183 	}
184 	pid_param.gd = piddata->gd;
185 	pid_param.gp = piddata->gp;
186 	pid_param.gr = piddata->gr / pid_param.history_len;
187 
188 	tdelta = ((s32)piddata->target_temp_delta) << 16;
189 	maxpow = ((s32)piddata->max_power) << 16;
190 	powadj = ((s32)piddata->power_adj) << 16;
191 
192 	pid_param.tmax = tmax;
193 	pid_param.ttarget = tmax - tdelta;
194 	pid_param.pmaxadj = maxpow - powadj;
195 
196 	pid_param.min = wf_control_get_min(fan_cpu_main);
197 	pid_param.max = wf_control_get_max(fan_cpu_main);
198 
199 	wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
200 
201 	DBG("wf: CPU Fan control initialized.\n");
202 	DBG("    ttarget=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
203 	    FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
204 	    pid_param.min, pid_param.max);
205 
206 	return;
207 
208  fail:
209 	printk(KERN_WARNING "windfarm: CPU fan config not found\n"
210 	       "for this machine model, max fan speed\n");
211 
212 	if (cpufreq_clamp)
213 		wf_control_set_max(cpufreq_clamp);
214 	if (fan_cpu_main)
215 		wf_control_set_max(fan_cpu_main);
216 }
217 
218 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
219 {
220 	s32 new_setpoint, temp, power;
221 	int rc;
222 
223 	if (--st->ticks != 0) {
224 		if (wf_smu_readjust)
225 			goto readjust;
226 		return;
227 	}
228 	st->ticks = WF_SMU_CPU_FANS_INTERVAL;
229 
230 	rc = wf_sensor_get(sensor_cpu_temp, &temp);
231 	if (rc) {
232 		printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
233 		       rc);
234 		wf_smu_failure_state |= FAILURE_SENSOR;
235 		return;
236 	}
237 
238 	rc = wf_sensor_get(sensor_cpu_power, &power);
239 	if (rc) {
240 		printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
241 		       rc);
242 		wf_smu_failure_state |= FAILURE_SENSOR;
243 		return;
244 	}
245 
246 	DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
247 	    FIX32TOPRINT(temp), FIX32TOPRINT(power));
248 
249 #ifdef HACKED_OVERTEMP
250 	if (temp > 0x4a0000)
251 		wf_smu_failure_state |= FAILURE_OVERTEMP;
252 #else
253 	if (temp > st->pid.param.tmax)
254 		wf_smu_failure_state |= FAILURE_OVERTEMP;
255 #endif
256 	new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
257 
258 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
259 
260 	if (st->cpu_setpoint == new_setpoint)
261 		return;
262 	st->cpu_setpoint = new_setpoint;
263  readjust:
264 	if (fan_cpu_main && wf_smu_failure_state == 0) {
265 		rc = wf_control_set(fan_cpu_main, 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 = wf_control_set(fan_cpu_second, st->cpu_setpoint);
274 		if (rc) {
275 			printk(KERN_WARNING "windfarm: CPU second fan"
276 			       " error %d\n", rc);
277 			wf_smu_failure_state |= FAILURE_FAN;
278 		}
279 	}
280 	if (fan_cpu_third && wf_smu_failure_state == 0) {
281 		rc = wf_control_set(fan_cpu_third, st->cpu_setpoint);
282 		if (rc) {
283 			printk(KERN_WARNING "windfarm: CPU third fan"
284 			       " error %d\n", rc);
285 			wf_smu_failure_state |= FAILURE_FAN;
286 		}
287 	}
288 }
289 
290 static void wf_smu_create_drive_fans(void)
291 {
292 	struct wf_pid_param param = {
293 		.interval	= 5,
294 		.history_len	= 2,
295 		.gd		= 0x01e00000,
296 		.gp		= 0x00500000,
297 		.gr		= 0x00000000,
298 		.itarget	= 0x00200000,
299 	};
300 
301 	/* Alloc & initialize state */
302 	wf_smu_drive_fans = kmalloc_obj(struct wf_smu_drive_fans_state);
303 	if (wf_smu_drive_fans == NULL) {
304 		printk(KERN_WARNING "windfarm: Memory allocation error"
305 		       " max fan speed\n");
306 		goto fail;
307 	}
308        	wf_smu_drive_fans->ticks = 1;
309 
310 	/* Fill PID params */
311 	param.additive = (fan_hd->type == WF_CONTROL_RPM_FAN);
312 	param.min = wf_control_get_min(fan_hd);
313 	param.max = wf_control_get_max(fan_hd);
314 	wf_pid_init(&wf_smu_drive_fans->pid, &param);
315 
316 	DBG("wf: Drive Fan control initialized.\n");
317 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
318 	    FIX32TOPRINT(param.itarget), param.min, param.max);
319 	return;
320 
321  fail:
322 	if (fan_hd)
323 		wf_control_set_max(fan_hd);
324 }
325 
326 static void wf_smu_drive_fans_tick(struct wf_smu_drive_fans_state *st)
327 {
328 	s32 new_setpoint, temp;
329 	int rc;
330 
331 	if (--st->ticks != 0) {
332 		if (wf_smu_readjust)
333 			goto readjust;
334 		return;
335 	}
336 	st->ticks = st->pid.param.interval;
337 
338 	rc = wf_sensor_get(sensor_hd_temp, &temp);
339 	if (rc) {
340 		printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
341 		       rc);
342 		wf_smu_failure_state |= FAILURE_SENSOR;
343 		return;
344 	}
345 
346 	DBG("wf_smu: Drive Fans tick ! HD temp: %d.%03d\n",
347 	    FIX32TOPRINT(temp));
348 
349 	if (temp > (st->pid.param.itarget + 0x50000))
350 		wf_smu_failure_state |= FAILURE_OVERTEMP;
351 
352 	new_setpoint = wf_pid_run(&st->pid, temp);
353 
354 	DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
355 
356 	if (st->setpoint == new_setpoint)
357 		return;
358 	st->setpoint = new_setpoint;
359  readjust:
360 	if (fan_hd && wf_smu_failure_state == 0) {
361 		rc = wf_control_set(fan_hd, st->setpoint);
362 		if (rc) {
363 			printk(KERN_WARNING "windfarm: HD fan error %d\n",
364 			       rc);
365 			wf_smu_failure_state |= FAILURE_FAN;
366 		}
367 	}
368 }
369 
370 static void wf_smu_create_slots_fans(void)
371 {
372 	struct wf_pid_param param = {
373 		.interval	= 1,
374 		.history_len	= 8,
375 		.gd		= 0x00000000,
376 		.gp		= 0x00000000,
377 		.gr		= 0x00020000,
378 		.itarget	= 0x00000000
379 	};
380 
381 	/* Alloc & initialize state */
382 	wf_smu_slots_fans = kmalloc_obj(struct wf_smu_slots_fans_state);
383 	if (wf_smu_slots_fans == NULL) {
384 		printk(KERN_WARNING "windfarm: Memory allocation error"
385 		       " max fan speed\n");
386 		goto fail;
387 	}
388        	wf_smu_slots_fans->ticks = 1;
389 
390 	/* Fill PID params */
391 	param.additive = (fan_slots->type == WF_CONTROL_RPM_FAN);
392 	param.min = wf_control_get_min(fan_slots);
393 	param.max = wf_control_get_max(fan_slots);
394 	wf_pid_init(&wf_smu_slots_fans->pid, &param);
395 
396 	DBG("wf: Slots Fan control initialized.\n");
397 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
398 	    FIX32TOPRINT(param.itarget), param.min, param.max);
399 	return;
400 
401  fail:
402 	if (fan_slots)
403 		wf_control_set_max(fan_slots);
404 }
405 
406 static void wf_smu_slots_fans_tick(struct wf_smu_slots_fans_state *st)
407 {
408 	s32 new_setpoint, power;
409 	int rc;
410 
411 	if (--st->ticks != 0) {
412 		if (wf_smu_readjust)
413 			goto readjust;
414 		return;
415 	}
416 	st->ticks = st->pid.param.interval;
417 
418 	rc = wf_sensor_get(sensor_slots_power, &power);
419 	if (rc) {
420 		printk(KERN_WARNING "windfarm: Slots power sensor error %d\n",
421 		       rc);
422 		wf_smu_failure_state |= FAILURE_SENSOR;
423 		return;
424 	}
425 
426 	DBG("wf_smu: Slots Fans tick ! Slots power: %d.%03d\n",
427 	    FIX32TOPRINT(power));
428 
429 #if 0 /* Check what makes a good overtemp condition */
430 	if (power > (st->pid.param.itarget + 0x50000))
431 		wf_smu_failure_state |= FAILURE_OVERTEMP;
432 #endif
433 
434 	new_setpoint = wf_pid_run(&st->pid, power);
435 
436 	DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
437 
438 	if (st->setpoint == new_setpoint)
439 		return;
440 	st->setpoint = new_setpoint;
441  readjust:
442 	if (fan_slots && wf_smu_failure_state == 0) {
443 		rc = wf_control_set(fan_slots, st->setpoint);
444 		if (rc) {
445 			printk(KERN_WARNING "windfarm: Slots fan error %d\n",
446 			       rc);
447 			wf_smu_failure_state |= FAILURE_FAN;
448 		}
449 	}
450 }
451 
452 
453 /*
454  * ****** Setup / Init / Misc ... ******
455  *
456  */
457 
458 static void wf_smu_tick(void)
459 {
460 	unsigned int last_failure = wf_smu_failure_state;
461 	unsigned int new_failure;
462 
463 	if (!wf_smu_started) {
464 		DBG("wf: creating control loops !\n");
465 		wf_smu_create_drive_fans();
466 		wf_smu_create_slots_fans();
467 		wf_smu_create_cpu_fans();
468 		wf_smu_started = true;
469 	}
470 
471 	/* Skipping ticks */
472 	if (wf_smu_skipping && --wf_smu_skipping)
473 		return;
474 
475 	wf_smu_failure_state = 0;
476 	if (wf_smu_drive_fans)
477 		wf_smu_drive_fans_tick(wf_smu_drive_fans);
478 	if (wf_smu_slots_fans)
479 		wf_smu_slots_fans_tick(wf_smu_slots_fans);
480 	if (wf_smu_cpu_fans)
481 		wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
482 
483 	wf_smu_readjust = 0;
484 	new_failure = wf_smu_failure_state & ~last_failure;
485 
486 	/* If entering failure mode, clamp cpufreq and ramp all
487 	 * fans to full speed.
488 	 */
489 	if (wf_smu_failure_state && !last_failure) {
490 		if (cpufreq_clamp)
491 			wf_control_set_max(cpufreq_clamp);
492 		if (fan_cpu_main)
493 			wf_control_set_max(fan_cpu_main);
494 		if (fan_cpu_second)
495 			wf_control_set_max(fan_cpu_second);
496 		if (fan_cpu_third)
497 			wf_control_set_max(fan_cpu_third);
498 		if (fan_hd)
499 			wf_control_set_max(fan_hd);
500 		if (fan_slots)
501 			wf_control_set_max(fan_slots);
502 	}
503 
504 	/* If leaving failure mode, unclamp cpufreq and readjust
505 	 * all fans on next iteration
506 	 */
507 	if (!wf_smu_failure_state && last_failure) {
508 		if (cpufreq_clamp)
509 			wf_control_set_min(cpufreq_clamp);
510 		wf_smu_readjust = 1;
511 	}
512 
513 	/* Overtemp condition detected, notify and start skipping a couple
514 	 * ticks to let the temperature go down
515 	 */
516 	if (new_failure & FAILURE_OVERTEMP) {
517 		wf_set_overtemp();
518 		wf_smu_skipping = 2;
519 		wf_smu_overtemp = true;
520 	}
521 
522 	/* We only clear the overtemp condition if overtemp is cleared
523 	 * _and_ no other failure is present. Since a sensor error will
524 	 * clear the overtemp condition (can't measure temperature) at
525 	 * the control loop levels, but we don't want to keep it clear
526 	 * here in this case
527 	 */
528 	if (!wf_smu_failure_state && wf_smu_overtemp) {
529 		wf_clear_overtemp();
530 		wf_smu_overtemp = false;
531 	}
532 }
533 
534 
535 static void wf_smu_new_control(struct wf_control *ct)
536 {
537 	if (wf_smu_all_controls_ok)
538 		return;
539 
540 	if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-rear-fan-0")) {
541 		if (wf_get_control(ct) == 0)
542 			fan_cpu_main = ct;
543 	}
544 
545 	if (fan_cpu_second == NULL && !strcmp(ct->name, "cpu-rear-fan-1")) {
546 		if (wf_get_control(ct) == 0)
547 			fan_cpu_second = ct;
548 	}
549 
550 	if (fan_cpu_third == NULL && !strcmp(ct->name, "cpu-front-fan-0")) {
551 		if (wf_get_control(ct) == 0)
552 			fan_cpu_third = ct;
553 	}
554 
555 	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
556 		if (wf_get_control(ct) == 0)
557 			cpufreq_clamp = ct;
558 	}
559 
560 	if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
561 		if (wf_get_control(ct) == 0)
562 			fan_hd = ct;
563 	}
564 
565 	if (fan_slots == NULL && !strcmp(ct->name, "slots-fan")) {
566 		if (wf_get_control(ct) == 0)
567 			fan_slots = ct;
568 	}
569 
570 	if (fan_cpu_main && (fan_cpu_second || fan_cpu_third) && fan_hd &&
571 	    fan_slots && cpufreq_clamp)
572 		wf_smu_all_controls_ok = 1;
573 }
574 
575 static void wf_smu_new_sensor(struct wf_sensor *sr)
576 {
577 	if (wf_smu_all_sensors_ok)
578 		return;
579 
580 	if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
581 		if (wf_get_sensor(sr) == 0)
582 			sensor_cpu_power = sr;
583 	}
584 
585 	if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
586 		if (wf_get_sensor(sr) == 0)
587 			sensor_cpu_temp = sr;
588 	}
589 
590 	if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
591 		if (wf_get_sensor(sr) == 0)
592 			sensor_hd_temp = sr;
593 	}
594 
595 	if (sensor_slots_power == NULL && !strcmp(sr->name, "slots-power")) {
596 		if (wf_get_sensor(sr) == 0)
597 			sensor_slots_power = sr;
598 	}
599 
600 	if (sensor_cpu_power && sensor_cpu_temp &&
601 	    sensor_hd_temp && sensor_slots_power)
602 		wf_smu_all_sensors_ok = 1;
603 }
604 
605 
606 static int wf_smu_notify(struct notifier_block *self,
607 			       unsigned long event, void *data)
608 {
609 	switch(event) {
610 	case WF_EVENT_NEW_CONTROL:
611 		DBG("wf: new control %s detected\n",
612 		    ((struct wf_control *)data)->name);
613 		wf_smu_new_control(data);
614 		wf_smu_readjust = 1;
615 		break;
616 	case WF_EVENT_NEW_SENSOR:
617 		DBG("wf: new sensor %s detected\n",
618 		    ((struct wf_sensor *)data)->name);
619 		wf_smu_new_sensor(data);
620 		break;
621 	case WF_EVENT_TICK:
622 		if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
623 			wf_smu_tick();
624 	}
625 
626 	return 0;
627 }
628 
629 static struct notifier_block wf_smu_events = {
630 	.notifier_call	= wf_smu_notify,
631 };
632 
633 static int wf_init_pm(void)
634 {
635 	printk(KERN_INFO "windfarm: Initializing for Desktop G5 model\n");
636 
637 	return 0;
638 }
639 
640 static int wf_smu_probe(struct platform_device *ddev)
641 {
642 	wf_register_client(&wf_smu_events);
643 
644 	return 0;
645 }
646 
647 static void wf_smu_remove(struct platform_device *ddev)
648 {
649 	wf_unregister_client(&wf_smu_events);
650 
651 	/* XXX We don't have yet a guarantee that our callback isn't
652 	 * in progress when returning from wf_unregister_client, so
653 	 * we add an arbitrary delay. I'll have to fix that in the core
654 	 */
655 	msleep(1000);
656 
657 	/* Release all sensors */
658 	/* One more crappy race: I don't think we have any guarantee here
659 	 * that the attribute callback won't race with the sensor beeing
660 	 * disposed of, and I'm not 100% certain what best way to deal
661 	 * with that except by adding locks all over... I'll do that
662 	 * eventually but heh, who ever rmmod this module anyway ?
663 	 */
664 	if (sensor_cpu_power)
665 		wf_put_sensor(sensor_cpu_power);
666 	if (sensor_cpu_temp)
667 		wf_put_sensor(sensor_cpu_temp);
668 	if (sensor_hd_temp)
669 		wf_put_sensor(sensor_hd_temp);
670 	if (sensor_slots_power)
671 		wf_put_sensor(sensor_slots_power);
672 
673 	/* Release all controls */
674 	if (fan_cpu_main)
675 		wf_put_control(fan_cpu_main);
676 	if (fan_cpu_second)
677 		wf_put_control(fan_cpu_second);
678 	if (fan_cpu_third)
679 		wf_put_control(fan_cpu_third);
680 	if (fan_hd)
681 		wf_put_control(fan_hd);
682 	if (fan_slots)
683 		wf_put_control(fan_slots);
684 	if (cpufreq_clamp)
685 		wf_put_control(cpufreq_clamp);
686 
687 	/* Destroy control loops state structures */
688 	kfree(wf_smu_slots_fans);
689 	kfree(wf_smu_drive_fans);
690 	kfree(wf_smu_cpu_fans);
691 }
692 
693 static struct platform_driver wf_smu_driver = {
694 	.probe = wf_smu_probe,
695 	.remove = wf_smu_remove,
696 	.driver = {
697 		.name = "windfarm",
698 	},
699 };
700 
701 
702 static int __init wf_smu_init(void)
703 {
704 	int rc = -ENODEV;
705 
706 	if (of_machine_is_compatible("PowerMac9,1"))
707 		rc = wf_init_pm();
708 
709 	if (rc == 0) {
710 #ifdef MODULE
711 		request_module("windfarm_smu_controls");
712 		request_module("windfarm_smu_sensors");
713 		request_module("windfarm_lm75_sensor");
714 		request_module("windfarm_cpufreq_clamp");
715 
716 #endif /* MODULE */
717 		platform_driver_register(&wf_smu_driver);
718 	}
719 
720 	return rc;
721 }
722 
723 static void __exit wf_smu_exit(void)
724 {
725 
726 	platform_driver_unregister(&wf_smu_driver);
727 }
728 
729 
730 module_init(wf_smu_init);
731 module_exit(wf_smu_exit);
732 
733 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
734 MODULE_DESCRIPTION("Thermal control logic for PowerMac9,1");
735 MODULE_LICENSE("GPL");
736 
737 MODULE_ALIAS("platform:windfarm");
738