xref: /linux/drivers/macintosh/windfarm_pm112.c (revision 18f90d372cf35b387663f1567de701e5393f6eb5)
1 /*
2  * Windfarm PowerMac thermal control.
3  * Control loops for machines with SMU and PPC970MP processors.
4  *
5  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
6  * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
7  *
8  * Use and redistribute under the terms of the GNU GPL v2.
9  */
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/device.h>
14 #include <linux/platform_device.h>
15 #include <linux/reboot.h>
16 #include <asm/prom.h>
17 #include <asm/smu.h>
18 
19 #include "windfarm.h"
20 #include "windfarm_pid.h"
21 
22 #define VERSION "0.2"
23 
24 #define DEBUG
25 #undef LOTSA_DEBUG
26 
27 #ifdef DEBUG
28 #define DBG(args...)	printk(args)
29 #else
30 #define DBG(args...)	do { } while(0)
31 #endif
32 
33 #ifdef LOTSA_DEBUG
34 #define DBG_LOTS(args...)	printk(args)
35 #else
36 #define DBG_LOTS(args...)	do { } while(0)
37 #endif
38 
39 /* define this to force CPU overtemp to 60 degree, useful for testing
40  * the overtemp code
41  */
42 #undef HACKED_OVERTEMP
43 
44 /* We currently only handle 2 chips, 4 cores... */
45 #define NR_CHIPS	2
46 #define NR_CORES	4
47 #define NR_CPU_FANS	3 * NR_CHIPS
48 
49 /* Controls and sensors */
50 static struct wf_sensor *sens_cpu_temp[NR_CORES];
51 static struct wf_sensor *sens_cpu_power[NR_CORES];
52 static struct wf_sensor *hd_temp;
53 static struct wf_sensor *slots_power;
54 static struct wf_sensor *u4_temp;
55 
56 static struct wf_control *cpu_fans[NR_CPU_FANS];
57 static char *cpu_fan_names[NR_CPU_FANS] = {
58 	"cpu-rear-fan-0",
59 	"cpu-rear-fan-1",
60 	"cpu-front-fan-0",
61 	"cpu-front-fan-1",
62 	"cpu-pump-0",
63 	"cpu-pump-1",
64 };
65 static struct wf_control *cpufreq_clamp;
66 
67 /* Second pump isn't required (and isn't actually present) */
68 #define CPU_FANS_REQD		(NR_CPU_FANS - 2)
69 #define FIRST_PUMP		4
70 #define LAST_PUMP		5
71 
72 /* We keep a temperature history for average calculation of 180s */
73 #define CPU_TEMP_HIST_SIZE	180
74 
75 /* Scale factor for fan speed, *100 */
76 static int cpu_fan_scale[NR_CPU_FANS] = {
77 	100,
78 	100,
79 	97,		/* inlet fans run at 97% of exhaust fan */
80 	97,
81 	100,		/* updated later */
82 	100,		/* updated later */
83 };
84 
85 static struct wf_control *backside_fan;
86 static struct wf_control *slots_fan;
87 static struct wf_control *drive_bay_fan;
88 
89 /* PID loop state */
90 static struct wf_cpu_pid_state cpu_pid[NR_CORES];
91 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
92 static int cpu_thist_pt;
93 static s64 cpu_thist_total;
94 static s32 cpu_all_tmax = 100 << 16;
95 static int cpu_last_target;
96 static struct wf_pid_state backside_pid;
97 static int backside_tick;
98 static struct wf_pid_state slots_pid;
99 static bool slots_started;
100 static struct wf_pid_state drive_bay_pid;
101 static int drive_bay_tick;
102 
103 static int nr_cores;
104 static int have_all_controls;
105 static int have_all_sensors;
106 static bool started;
107 
108 static int failure_state;
109 #define FAILURE_SENSOR		1
110 #define FAILURE_FAN		2
111 #define FAILURE_PERM		4
112 #define FAILURE_LOW_OVERTEMP	8
113 #define FAILURE_HIGH_OVERTEMP	16
114 
115 /* Overtemp values */
116 #define LOW_OVER_AVERAGE	0
117 #define LOW_OVER_IMMEDIATE	(10 << 16)
118 #define LOW_OVER_CLEAR		((-10) << 16)
119 #define HIGH_OVER_IMMEDIATE	(14 << 16)
120 #define HIGH_OVER_AVERAGE	(10 << 16)
121 #define HIGH_OVER_IMMEDIATE	(14 << 16)
122 
123 
124 /* Implementation... */
125 static int create_cpu_loop(int cpu)
126 {
127 	int chip = cpu / 2;
128 	int core = cpu & 1;
129 	struct smu_sdbp_header *hdr;
130 	struct smu_sdbp_cpupiddata *piddata;
131 	struct wf_cpu_pid_param pid;
132 	struct wf_control *main_fan = cpu_fans[0];
133 	s32 tmax;
134 	int fmin;
135 
136 	/* Get PID params from the appropriate SAT */
137 	hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
138 	if (hdr == NULL) {
139 		printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
140 		return -EINVAL;
141 	}
142 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
143 
144 	/* Get FVT params to get Tmax; if not found, assume default */
145 	hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
146 	if (hdr) {
147 		struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
148 		tmax = fvt->maxtemp << 16;
149 	} else
150 		tmax = 95 << 16;	/* default to 95 degrees C */
151 
152 	/* We keep a global tmax for overtemp calculations */
153 	if (tmax < cpu_all_tmax)
154 		cpu_all_tmax = tmax;
155 
156 	/*
157 	 * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
158 	 * 515 for the 2-way.  That appears to be overkill, so for now,
159 	 * impose a minimum of 750 or 515.
160 	 */
161 	fmin = (nr_cores > 2) ? 750 : 515;
162 
163 	/* Initialize PID loop */
164 	pid.interval = 1;	/* seconds */
165 	pid.history_len = piddata->history_len;
166 	pid.gd = piddata->gd;
167 	pid.gp = piddata->gp;
168 	pid.gr = piddata->gr / piddata->history_len;
169 	pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
170 	pid.ttarget = tmax - (piddata->target_temp_delta << 16);
171 	pid.tmax = tmax;
172 	pid.min = main_fan->ops->get_min(main_fan);
173 	pid.max = main_fan->ops->get_max(main_fan);
174 	if (pid.min < fmin)
175 		pid.min = fmin;
176 
177 	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
178 	return 0;
179 }
180 
181 static void cpu_max_all_fans(void)
182 {
183 	int i;
184 
185 	/* We max all CPU fans in case of a sensor error. We also do the
186 	 * cpufreq clamping now, even if it's supposedly done later by the
187 	 * generic code anyway, we do it earlier here to react faster
188 	 */
189 	if (cpufreq_clamp)
190 		wf_control_set_max(cpufreq_clamp);
191 	for (i = 0; i < NR_CPU_FANS; ++i)
192 		if (cpu_fans[i])
193 			wf_control_set_max(cpu_fans[i]);
194 }
195 
196 static int cpu_check_overtemp(s32 temp)
197 {
198 	int new_state = 0;
199 	s32 t_avg, t_old;
200 
201 	/* First check for immediate overtemps */
202 	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
203 		new_state |= FAILURE_LOW_OVERTEMP;
204 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
205 			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
206 			       " temperature !\n");
207 	}
208 	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
209 		new_state |= FAILURE_HIGH_OVERTEMP;
210 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
211 			printk(KERN_ERR "windfarm: Critical overtemp due to"
212 			       " immediate CPU temperature !\n");
213 	}
214 
215 	/* We calculate a history of max temperatures and use that for the
216 	 * overtemp management
217 	 */
218 	t_old = cpu_thist[cpu_thist_pt];
219 	cpu_thist[cpu_thist_pt] = temp;
220 	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
221 	cpu_thist_total -= t_old;
222 	cpu_thist_total += temp;
223 	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
224 
225 	DBG_LOTS("t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
226 		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
227 
228 	/* Now check for average overtemps */
229 	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
230 		new_state |= FAILURE_LOW_OVERTEMP;
231 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
232 			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
233 			       " temperature !\n");
234 	}
235 	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
236 		new_state |= FAILURE_HIGH_OVERTEMP;
237 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
238 			printk(KERN_ERR "windfarm: Critical overtemp due to"
239 			       " average CPU temperature !\n");
240 	}
241 
242 	/* Now handle overtemp conditions. We don't currently use the windfarm
243 	 * overtemp handling core as it's not fully suited to the needs of those
244 	 * new machine. This will be fixed later.
245 	 */
246 	if (new_state) {
247 		/* High overtemp -> immediate shutdown */
248 		if (new_state & FAILURE_HIGH_OVERTEMP)
249 			machine_power_off();
250 		if ((failure_state & new_state) != new_state)
251 			cpu_max_all_fans();
252 		failure_state |= new_state;
253 	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
254 		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
255 		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
256 		failure_state &= ~FAILURE_LOW_OVERTEMP;
257 	}
258 
259 	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
260 }
261 
262 static void cpu_fans_tick(void)
263 {
264 	int err, cpu;
265 	s32 greatest_delta = 0;
266 	s32 temp, power, t_max = 0;
267 	int i, t, target = 0;
268 	struct wf_sensor *sr;
269 	struct wf_control *ct;
270 	struct wf_cpu_pid_state *sp;
271 
272 	DBG_LOTS(KERN_DEBUG);
273 	for (cpu = 0; cpu < nr_cores; ++cpu) {
274 		/* Get CPU core temperature */
275 		sr = sens_cpu_temp[cpu];
276 		err = sr->ops->get_value(sr, &temp);
277 		if (err) {
278 			DBG("\n");
279 			printk(KERN_WARNING "windfarm: CPU %d temperature "
280 			       "sensor error %d\n", cpu, err);
281 			failure_state |= FAILURE_SENSOR;
282 			cpu_max_all_fans();
283 			return;
284 		}
285 
286 		/* Keep track of highest temp */
287 		t_max = max(t_max, temp);
288 
289 		/* Get CPU power */
290 		sr = sens_cpu_power[cpu];
291 		err = sr->ops->get_value(sr, &power);
292 		if (err) {
293 			DBG("\n");
294 			printk(KERN_WARNING "windfarm: CPU %d power "
295 			       "sensor error %d\n", cpu, err);
296 			failure_state |= FAILURE_SENSOR;
297 			cpu_max_all_fans();
298 			return;
299 		}
300 
301 		/* Run PID */
302 		sp = &cpu_pid[cpu];
303 		t = wf_cpu_pid_run(sp, power, temp);
304 
305 		if (cpu == 0 || sp->last_delta > greatest_delta) {
306 			greatest_delta = sp->last_delta;
307 			target = t;
308 		}
309 		DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
310 		    cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
311 	}
312 	DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
313 
314 	/* Darwin limits decrease to 20 per iteration */
315 	if (target < (cpu_last_target - 20))
316 		target = cpu_last_target - 20;
317 	cpu_last_target = target;
318 	for (cpu = 0; cpu < nr_cores; ++cpu)
319 		cpu_pid[cpu].target = target;
320 
321 	/* Handle possible overtemps */
322 	if (cpu_check_overtemp(t_max))
323 		return;
324 
325 	/* Set fans */
326 	for (i = 0; i < NR_CPU_FANS; ++i) {
327 		ct = cpu_fans[i];
328 		if (ct == NULL)
329 			continue;
330 		err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
331 		if (err) {
332 			printk(KERN_WARNING "windfarm: fan %s reports "
333 			       "error %d\n", ct->name, err);
334 			failure_state |= FAILURE_FAN;
335 			break;
336 		}
337 	}
338 }
339 
340 /* Backside/U4 fan */
341 static struct wf_pid_param backside_param = {
342 	.interval	= 5,
343 	.history_len	= 2,
344 	.gd		= 48 << 20,
345 	.gp		= 5 << 20,
346 	.gr		= 0,
347 	.itarget	= 64 << 16,
348 	.additive	= 1,
349 };
350 
351 static void backside_fan_tick(void)
352 {
353 	s32 temp;
354 	int speed;
355 	int err;
356 
357 	if (!backside_fan || !u4_temp)
358 		return;
359 	if (!backside_tick) {
360 		/* first time; initialize things */
361 		printk(KERN_INFO "windfarm: Backside control loop started.\n");
362 		backside_param.min = backside_fan->ops->get_min(backside_fan);
363 		backside_param.max = backside_fan->ops->get_max(backside_fan);
364 		wf_pid_init(&backside_pid, &backside_param);
365 		backside_tick = 1;
366 	}
367 	if (--backside_tick > 0)
368 		return;
369 	backside_tick = backside_pid.param.interval;
370 
371 	err = u4_temp->ops->get_value(u4_temp, &temp);
372 	if (err) {
373 		printk(KERN_WARNING "windfarm: U4 temp sensor error %d\n",
374 		       err);
375 		failure_state |= FAILURE_SENSOR;
376 		wf_control_set_max(backside_fan);
377 		return;
378 	}
379 	speed = wf_pid_run(&backside_pid, temp);
380 	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
381 		 FIX32TOPRINT(temp), speed);
382 
383 	err = backside_fan->ops->set_value(backside_fan, speed);
384 	if (err) {
385 		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
386 		failure_state |= FAILURE_FAN;
387 	}
388 }
389 
390 /* Drive bay fan */
391 static struct wf_pid_param drive_bay_prm = {
392 	.interval	= 5,
393 	.history_len	= 2,
394 	.gd		= 30 << 20,
395 	.gp		= 5 << 20,
396 	.gr		= 0,
397 	.itarget	= 40 << 16,
398 	.additive	= 1,
399 };
400 
401 static void drive_bay_fan_tick(void)
402 {
403 	s32 temp;
404 	int speed;
405 	int err;
406 
407 	if (!drive_bay_fan || !hd_temp)
408 		return;
409 	if (!drive_bay_tick) {
410 		/* first time; initialize things */
411 		printk(KERN_INFO "windfarm: Drive bay control loop started.\n");
412 		drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
413 		drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
414 		wf_pid_init(&drive_bay_pid, &drive_bay_prm);
415 		drive_bay_tick = 1;
416 	}
417 	if (--drive_bay_tick > 0)
418 		return;
419 	drive_bay_tick = drive_bay_pid.param.interval;
420 
421 	err = hd_temp->ops->get_value(hd_temp, &temp);
422 	if (err) {
423 		printk(KERN_WARNING "windfarm: drive bay temp sensor "
424 		       "error %d\n", err);
425 		failure_state |= FAILURE_SENSOR;
426 		wf_control_set_max(drive_bay_fan);
427 		return;
428 	}
429 	speed = wf_pid_run(&drive_bay_pid, temp);
430 	DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
431 		 FIX32TOPRINT(temp), speed);
432 
433 	err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
434 	if (err) {
435 		printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
436 		failure_state |= FAILURE_FAN;
437 	}
438 }
439 
440 /* PCI slots area fan */
441 /* This makes the fan speed proportional to the power consumed */
442 static struct wf_pid_param slots_param = {
443 	.interval	= 1,
444 	.history_len	= 2,
445 	.gd		= 0,
446 	.gp		= 0,
447 	.gr		= 0x1277952,
448 	.itarget	= 0,
449 	.min		= 1560,
450 	.max		= 3510,
451 };
452 
453 static void slots_fan_tick(void)
454 {
455 	s32 power;
456 	int speed;
457 	int err;
458 
459 	if (!slots_fan || !slots_power)
460 		return;
461 	if (!slots_started) {
462 		/* first time; initialize things */
463 		printk(KERN_INFO "windfarm: Slots control loop started.\n");
464 		wf_pid_init(&slots_pid, &slots_param);
465 		slots_started = true;
466 	}
467 
468 	err = slots_power->ops->get_value(slots_power, &power);
469 	if (err) {
470 		printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
471 		       err);
472 		failure_state |= FAILURE_SENSOR;
473 		wf_control_set_max(slots_fan);
474 		return;
475 	}
476 	speed = wf_pid_run(&slots_pid, power);
477 	DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
478 		 FIX32TOPRINT(power), speed);
479 
480 	err = slots_fan->ops->set_value(slots_fan, speed);
481 	if (err) {
482 		printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
483 		failure_state |= FAILURE_FAN;
484 	}
485 }
486 
487 static void set_fail_state(void)
488 {
489 	int i;
490 
491 	if (cpufreq_clamp)
492 		wf_control_set_max(cpufreq_clamp);
493 	for (i = 0; i < NR_CPU_FANS; ++i)
494 		if (cpu_fans[i])
495 			wf_control_set_max(cpu_fans[i]);
496 	if (backside_fan)
497 		wf_control_set_max(backside_fan);
498 	if (slots_fan)
499 		wf_control_set_max(slots_fan);
500 	if (drive_bay_fan)
501 		wf_control_set_max(drive_bay_fan);
502 }
503 
504 static void pm112_tick(void)
505 {
506 	int i, last_failure;
507 
508 	if (!started) {
509 		started = true;
510 		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
511 		for (i = 0; i < nr_cores; ++i) {
512 			if (create_cpu_loop(i) < 0) {
513 				failure_state = FAILURE_PERM;
514 				set_fail_state();
515 				break;
516 			}
517 		}
518 		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
519 
520 #ifdef HACKED_OVERTEMP
521 		cpu_all_tmax = 60 << 16;
522 #endif
523 	}
524 
525 	/* Permanent failure, bail out */
526 	if (failure_state & FAILURE_PERM)
527 		return;
528 	/* Clear all failure bits except low overtemp which will be eventually
529 	 * cleared by the control loop itself
530 	 */
531 	last_failure = failure_state;
532 	failure_state &= FAILURE_LOW_OVERTEMP;
533 	cpu_fans_tick();
534 	backside_fan_tick();
535 	slots_fan_tick();
536 	drive_bay_fan_tick();
537 
538 	DBG_LOTS("last_failure: 0x%x, failure_state: %x\n",
539 		 last_failure, failure_state);
540 
541 	/* Check for failures. Any failure causes cpufreq clamping */
542 	if (failure_state && last_failure == 0 && cpufreq_clamp)
543 		wf_control_set_max(cpufreq_clamp);
544 	if (failure_state == 0 && last_failure && cpufreq_clamp)
545 		wf_control_set_min(cpufreq_clamp);
546 
547 	/* That's it for now, we might want to deal with other failures
548 	 * differently in the future though
549 	 */
550 }
551 
552 static void pm112_new_control(struct wf_control *ct)
553 {
554 	int i, max_exhaust;
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 	for (i = 0; i < NR_CPU_FANS; ++i) {
562 		if (!strcmp(ct->name, cpu_fan_names[i])) {
563 			if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
564 				cpu_fans[i] = ct;
565 			break;
566 		}
567 	}
568 	if (i >= NR_CPU_FANS) {
569 		/* not a CPU fan, try the others */
570 		if (!strcmp(ct->name, "backside-fan")) {
571 			if (backside_fan == NULL && wf_get_control(ct) == 0)
572 				backside_fan = ct;
573 		} else if (!strcmp(ct->name, "slots-fan")) {
574 			if (slots_fan == NULL && wf_get_control(ct) == 0)
575 				slots_fan = ct;
576 		} else if (!strcmp(ct->name, "drive-bay-fan")) {
577 			if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
578 				drive_bay_fan = ct;
579 		}
580 		return;
581 	}
582 
583 	for (i = 0; i < CPU_FANS_REQD; ++i)
584 		if (cpu_fans[i] == NULL)
585 			return;
586 
587 	/* work out pump scaling factors */
588 	max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
589 	for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
590 		if ((ct = cpu_fans[i]) != NULL)
591 			cpu_fan_scale[i] =
592 				ct->ops->get_max(ct) * 100 / max_exhaust;
593 
594 	have_all_controls = 1;
595 }
596 
597 static void pm112_new_sensor(struct wf_sensor *sr)
598 {
599 	unsigned int i;
600 
601 	if (!strncmp(sr->name, "cpu-temp-", 9)) {
602 		i = sr->name[9] - '0';
603 		if (sr->name[10] == 0 && i < NR_CORES &&
604 		    sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
605 			sens_cpu_temp[i] = sr;
606 
607 	} else if (!strncmp(sr->name, "cpu-power-", 10)) {
608 		i = sr->name[10] - '0';
609 		if (sr->name[11] == 0 && i < NR_CORES &&
610 		    sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
611 			sens_cpu_power[i] = sr;
612 	} else if (!strcmp(sr->name, "hd-temp")) {
613 		if (hd_temp == NULL && wf_get_sensor(sr) == 0)
614 			hd_temp = sr;
615 	} else if (!strcmp(sr->name, "slots-power")) {
616 		if (slots_power == NULL && wf_get_sensor(sr) == 0)
617 			slots_power = sr;
618 	} else if (!strcmp(sr->name, "backside-temp")) {
619 		if (u4_temp == NULL && wf_get_sensor(sr) == 0)
620 			u4_temp = sr;
621 	} else
622 		return;
623 
624 	/* check if we have all the sensors we need */
625 	for (i = 0; i < nr_cores; ++i)
626 		if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
627 			return;
628 
629 	have_all_sensors = 1;
630 }
631 
632 static int pm112_wf_notify(struct notifier_block *self,
633 			   unsigned long event, void *data)
634 {
635 	switch (event) {
636 	case WF_EVENT_NEW_SENSOR:
637 		pm112_new_sensor(data);
638 		break;
639 	case WF_EVENT_NEW_CONTROL:
640 		pm112_new_control(data);
641 		break;
642 	case WF_EVENT_TICK:
643 		if (have_all_controls && have_all_sensors)
644 			pm112_tick();
645 	}
646 	return 0;
647 }
648 
649 static struct notifier_block pm112_events = {
650 	.notifier_call = pm112_wf_notify,
651 };
652 
653 static int wf_pm112_probe(struct platform_device *dev)
654 {
655 	wf_register_client(&pm112_events);
656 	return 0;
657 }
658 
659 static int wf_pm112_remove(struct platform_device *dev)
660 {
661 	wf_unregister_client(&pm112_events);
662 	/* should release all sensors and controls */
663 	return 0;
664 }
665 
666 static struct platform_driver wf_pm112_driver = {
667 	.probe = wf_pm112_probe,
668 	.remove = wf_pm112_remove,
669 	.driver = {
670 		.name = "windfarm",
671 	},
672 };
673 
674 static int __init wf_pm112_init(void)
675 {
676 	struct device_node *cpu;
677 
678 	if (!of_machine_is_compatible("PowerMac11,2"))
679 		return -ENODEV;
680 
681 	/* Count the number of CPU cores */
682 	nr_cores = 0;
683 	for_each_node_by_type(cpu, "cpu")
684 		++nr_cores;
685 
686 	printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
687 
688 #ifdef MODULE
689 	request_module("windfarm_smu_controls");
690 	request_module("windfarm_smu_sensors");
691 	request_module("windfarm_smu_sat");
692 	request_module("windfarm_lm75_sensor");
693 	request_module("windfarm_max6690_sensor");
694 	request_module("windfarm_cpufreq_clamp");
695 
696 #endif /* MODULE */
697 
698 	platform_driver_register(&wf_pm112_driver);
699 	return 0;
700 }
701 
702 static void __exit wf_pm112_exit(void)
703 {
704 	platform_driver_unregister(&wf_pm112_driver);
705 }
706 
707 module_init(wf_pm112_init);
708 module_exit(wf_pm112_exit);
709 
710 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
711 MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
712 MODULE_LICENSE("GPL");
713 MODULE_ALIAS("platform:windfarm");
714