1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control.
4  * Control loops for machines with SMU and PPC970MP processors.
5  *
6  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
7  * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
8  */
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/device.h>
13 #include <linux/platform_device.h>
14 #include <linux/reboot.h>
15 #include <asm/prom.h>
16 #include <asm/smu.h>
17 
18 #include "windfarm.h"
19 #include "windfarm_pid.h"
20 
21 #define VERSION "0.2"
22 
23 #define DEBUG
24 #undef LOTSA_DEBUG
25 
26 #ifdef DEBUG
27 #define DBG(args...)	printk(args)
28 #else
29 #define DBG(args...)	do { } while(0)
30 #endif
31 
32 #ifdef LOTSA_DEBUG
33 #define DBG_LOTS(args...)	printk(args)
34 #else
35 #define DBG_LOTS(args...)	do { } while(0)
36 #endif
37 
38 /* define this to force CPU overtemp to 60 degree, useful for testing
39  * the overtemp code
40  */
41 #undef HACKED_OVERTEMP
42 
43 /* We currently only handle 2 chips, 4 cores... */
44 #define NR_CHIPS	2
45 #define NR_CORES	4
46 #define NR_CPU_FANS	3 * NR_CHIPS
47 
48 /* Controls and sensors */
49 static struct wf_sensor *sens_cpu_temp[NR_CORES];
50 static struct wf_sensor *sens_cpu_power[NR_CORES];
51 static struct wf_sensor *hd_temp;
52 static struct wf_sensor *slots_power;
53 static struct wf_sensor *u4_temp;
54 
55 static struct wf_control *cpu_fans[NR_CPU_FANS];
56 static char *cpu_fan_names[NR_CPU_FANS] = {
57 	"cpu-rear-fan-0",
58 	"cpu-rear-fan-1",
59 	"cpu-front-fan-0",
60 	"cpu-front-fan-1",
61 	"cpu-pump-0",
62 	"cpu-pump-1",
63 };
64 static struct wf_control *cpufreq_clamp;
65 
66 /* Second pump isn't required (and isn't actually present) */
67 #define CPU_FANS_REQD		(NR_CPU_FANS - 2)
68 #define FIRST_PUMP		4
69 #define LAST_PUMP		5
70 
71 /* We keep a temperature history for average calculation of 180s */
72 #define CPU_TEMP_HIST_SIZE	180
73 
74 /* Scale factor for fan speed, *100 */
75 static int cpu_fan_scale[NR_CPU_FANS] = {
76 	100,
77 	100,
78 	97,		/* inlet fans run at 97% of exhaust fan */
79 	97,
80 	100,		/* updated later */
81 	100,		/* updated later */
82 };
83 
84 static struct wf_control *backside_fan;
85 static struct wf_control *slots_fan;
86 static struct wf_control *drive_bay_fan;
87 
88 /* PID loop state */
89 static struct wf_cpu_pid_state cpu_pid[NR_CORES];
90 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
91 static int cpu_thist_pt;
92 static s64 cpu_thist_total;
93 static s32 cpu_all_tmax = 100 << 16;
94 static int cpu_last_target;
95 static struct wf_pid_state backside_pid;
96 static int backside_tick;
97 static struct wf_pid_state slots_pid;
98 static bool slots_started;
99 static struct wf_pid_state drive_bay_pid;
100 static int drive_bay_tick;
101 
102 static int nr_cores;
103 static int have_all_controls;
104 static int have_all_sensors;
105 static bool started;
106 
107 static int failure_state;
108 #define FAILURE_SENSOR		1
109 #define FAILURE_FAN		2
110 #define FAILURE_PERM		4
111 #define FAILURE_LOW_OVERTEMP	8
112 #define FAILURE_HIGH_OVERTEMP	16
113 
114 /* Overtemp values */
115 #define LOW_OVER_AVERAGE	0
116 #define LOW_OVER_IMMEDIATE	(10 << 16)
117 #define LOW_OVER_CLEAR		((-10) << 16)
118 #define HIGH_OVER_IMMEDIATE	(14 << 16)
119 #define HIGH_OVER_AVERAGE	(10 << 16)
120 #define HIGH_OVER_IMMEDIATE	(14 << 16)
121 
122 
123 /* Implementation... */
124 static int create_cpu_loop(int cpu)
125 {
126 	int chip = cpu / 2;
127 	int core = cpu & 1;
128 	struct smu_sdbp_header *hdr;
129 	struct smu_sdbp_cpupiddata *piddata;
130 	struct wf_cpu_pid_param pid;
131 	struct wf_control *main_fan = cpu_fans[0];
132 	s32 tmax;
133 	int fmin;
134 
135 	/* Get FVT params to get Tmax; if not found, assume default */
136 	hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
137 	if (hdr) {
138 		struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
139 		tmax = fvt->maxtemp << 16;
140 	} else
141 		tmax = 95 << 16;	/* default to 95 degrees C */
142 
143 	/* We keep a global tmax for overtemp calculations */
144 	if (tmax < cpu_all_tmax)
145 		cpu_all_tmax = tmax;
146 
147 	kfree(hdr);
148 
149 	/* Get PID params from the appropriate SAT */
150 	hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
151 	if (hdr == NULL) {
152 		printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
153 		return -EINVAL;
154 	}
155 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
156 
157 	/*
158 	 * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
159 	 * 515 for the 2-way.  That appears to be overkill, so for now,
160 	 * impose a minimum of 750 or 515.
161 	 */
162 	fmin = (nr_cores > 2) ? 750 : 515;
163 
164 	/* Initialize PID loop */
165 	pid.interval = 1;	/* seconds */
166 	pid.history_len = piddata->history_len;
167 	pid.gd = piddata->gd;
168 	pid.gp = piddata->gp;
169 	pid.gr = piddata->gr / piddata->history_len;
170 	pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
171 	pid.ttarget = tmax - (piddata->target_temp_delta << 16);
172 	pid.tmax = tmax;
173 	pid.min = main_fan->ops->get_min(main_fan);
174 	pid.max = main_fan->ops->get_max(main_fan);
175 	if (pid.min < fmin)
176 		pid.min = fmin;
177 
178 	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
179 
180 	kfree(hdr);
181 
182 	return 0;
183 }
184 
185 static void cpu_max_all_fans(void)
186 {
187 	int i;
188 
189 	/* We max all CPU fans in case of a sensor error. We also do the
190 	 * cpufreq clamping now, even if it's supposedly done later by the
191 	 * generic code anyway, we do it earlier here to react faster
192 	 */
193 	if (cpufreq_clamp)
194 		wf_control_set_max(cpufreq_clamp);
195 	for (i = 0; i < NR_CPU_FANS; ++i)
196 		if (cpu_fans[i])
197 			wf_control_set_max(cpu_fans[i]);
198 }
199 
200 static int cpu_check_overtemp(s32 temp)
201 {
202 	int new_state = 0;
203 	s32 t_avg, t_old;
204 
205 	/* First check for immediate overtemps */
206 	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
207 		new_state |= FAILURE_LOW_OVERTEMP;
208 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
209 			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
210 			       " temperature !\n");
211 	}
212 	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
213 		new_state |= FAILURE_HIGH_OVERTEMP;
214 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
215 			printk(KERN_ERR "windfarm: Critical overtemp due to"
216 			       " immediate CPU temperature !\n");
217 	}
218 
219 	/* We calculate a history of max temperatures and use that for the
220 	 * overtemp management
221 	 */
222 	t_old = cpu_thist[cpu_thist_pt];
223 	cpu_thist[cpu_thist_pt] = temp;
224 	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
225 	cpu_thist_total -= t_old;
226 	cpu_thist_total += temp;
227 	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
228 
229 	DBG_LOTS("t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
230 		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
231 
232 	/* Now check for average overtemps */
233 	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
234 		new_state |= FAILURE_LOW_OVERTEMP;
235 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
236 			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
237 			       " temperature !\n");
238 	}
239 	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
240 		new_state |= FAILURE_HIGH_OVERTEMP;
241 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
242 			printk(KERN_ERR "windfarm: Critical overtemp due to"
243 			       " average CPU temperature !\n");
244 	}
245 
246 	/* Now handle overtemp conditions. We don't currently use the windfarm
247 	 * overtemp handling core as it's not fully suited to the needs of those
248 	 * new machine. This will be fixed later.
249 	 */
250 	if (new_state) {
251 		/* High overtemp -> immediate shutdown */
252 		if (new_state & FAILURE_HIGH_OVERTEMP)
253 			machine_power_off();
254 		if ((failure_state & new_state) != new_state)
255 			cpu_max_all_fans();
256 		failure_state |= new_state;
257 	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
258 		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
259 		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
260 		failure_state &= ~FAILURE_LOW_OVERTEMP;
261 	}
262 
263 	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
264 }
265 
266 static void cpu_fans_tick(void)
267 {
268 	int err, cpu;
269 	s32 greatest_delta = 0;
270 	s32 temp, power, t_max = 0;
271 	int i, t, target = 0;
272 	struct wf_sensor *sr;
273 	struct wf_control *ct;
274 	struct wf_cpu_pid_state *sp;
275 
276 	DBG_LOTS(KERN_DEBUG);
277 	for (cpu = 0; cpu < nr_cores; ++cpu) {
278 		/* Get CPU core temperature */
279 		sr = sens_cpu_temp[cpu];
280 		err = sr->ops->get_value(sr, &temp);
281 		if (err) {
282 			DBG("\n");
283 			printk(KERN_WARNING "windfarm: CPU %d temperature "
284 			       "sensor error %d\n", cpu, err);
285 			failure_state |= FAILURE_SENSOR;
286 			cpu_max_all_fans();
287 			return;
288 		}
289 
290 		/* Keep track of highest temp */
291 		t_max = max(t_max, temp);
292 
293 		/* Get CPU power */
294 		sr = sens_cpu_power[cpu];
295 		err = sr->ops->get_value(sr, &power);
296 		if (err) {
297 			DBG("\n");
298 			printk(KERN_WARNING "windfarm: CPU %d power "
299 			       "sensor error %d\n", cpu, err);
300 			failure_state |= FAILURE_SENSOR;
301 			cpu_max_all_fans();
302 			return;
303 		}
304 
305 		/* Run PID */
306 		sp = &cpu_pid[cpu];
307 		t = wf_cpu_pid_run(sp, power, temp);
308 
309 		if (cpu == 0 || sp->last_delta > greatest_delta) {
310 			greatest_delta = sp->last_delta;
311 			target = t;
312 		}
313 		DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
314 		    cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
315 	}
316 	DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
317 
318 	/* Darwin limits decrease to 20 per iteration */
319 	if (target < (cpu_last_target - 20))
320 		target = cpu_last_target - 20;
321 	cpu_last_target = target;
322 	for (cpu = 0; cpu < nr_cores; ++cpu)
323 		cpu_pid[cpu].target = target;
324 
325 	/* Handle possible overtemps */
326 	if (cpu_check_overtemp(t_max))
327 		return;
328 
329 	/* Set fans */
330 	for (i = 0; i < NR_CPU_FANS; ++i) {
331 		ct = cpu_fans[i];
332 		if (ct == NULL)
333 			continue;
334 		err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
335 		if (err) {
336 			printk(KERN_WARNING "windfarm: fan %s reports "
337 			       "error %d\n", ct->name, err);
338 			failure_state |= FAILURE_FAN;
339 			break;
340 		}
341 	}
342 }
343 
344 /* Backside/U4 fan */
345 static struct wf_pid_param backside_param = {
346 	.interval	= 5,
347 	.history_len	= 2,
348 	.gd		= 48 << 20,
349 	.gp		= 5 << 20,
350 	.gr		= 0,
351 	.itarget	= 64 << 16,
352 	.additive	= 1,
353 };
354 
355 static void backside_fan_tick(void)
356 {
357 	s32 temp;
358 	int speed;
359 	int err;
360 
361 	if (!backside_fan || !u4_temp)
362 		return;
363 	if (!backside_tick) {
364 		/* first time; initialize things */
365 		printk(KERN_INFO "windfarm: Backside control loop started.\n");
366 		backside_param.min = backside_fan->ops->get_min(backside_fan);
367 		backside_param.max = backside_fan->ops->get_max(backside_fan);
368 		wf_pid_init(&backside_pid, &backside_param);
369 		backside_tick = 1;
370 	}
371 	if (--backside_tick > 0)
372 		return;
373 	backside_tick = backside_pid.param.interval;
374 
375 	err = u4_temp->ops->get_value(u4_temp, &temp);
376 	if (err) {
377 		printk(KERN_WARNING "windfarm: U4 temp sensor error %d\n",
378 		       err);
379 		failure_state |= FAILURE_SENSOR;
380 		wf_control_set_max(backside_fan);
381 		return;
382 	}
383 	speed = wf_pid_run(&backside_pid, temp);
384 	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
385 		 FIX32TOPRINT(temp), speed);
386 
387 	err = backside_fan->ops->set_value(backside_fan, speed);
388 	if (err) {
389 		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
390 		failure_state |= FAILURE_FAN;
391 	}
392 }
393 
394 /* Drive bay fan */
395 static struct wf_pid_param drive_bay_prm = {
396 	.interval	= 5,
397 	.history_len	= 2,
398 	.gd		= 30 << 20,
399 	.gp		= 5 << 20,
400 	.gr		= 0,
401 	.itarget	= 40 << 16,
402 	.additive	= 1,
403 };
404 
405 static void drive_bay_fan_tick(void)
406 {
407 	s32 temp;
408 	int speed;
409 	int err;
410 
411 	if (!drive_bay_fan || !hd_temp)
412 		return;
413 	if (!drive_bay_tick) {
414 		/* first time; initialize things */
415 		printk(KERN_INFO "windfarm: Drive bay control loop started.\n");
416 		drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
417 		drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
418 		wf_pid_init(&drive_bay_pid, &drive_bay_prm);
419 		drive_bay_tick = 1;
420 	}
421 	if (--drive_bay_tick > 0)
422 		return;
423 	drive_bay_tick = drive_bay_pid.param.interval;
424 
425 	err = hd_temp->ops->get_value(hd_temp, &temp);
426 	if (err) {
427 		printk(KERN_WARNING "windfarm: drive bay temp sensor "
428 		       "error %d\n", err);
429 		failure_state |= FAILURE_SENSOR;
430 		wf_control_set_max(drive_bay_fan);
431 		return;
432 	}
433 	speed = wf_pid_run(&drive_bay_pid, temp);
434 	DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
435 		 FIX32TOPRINT(temp), speed);
436 
437 	err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
438 	if (err) {
439 		printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
440 		failure_state |= FAILURE_FAN;
441 	}
442 }
443 
444 /* PCI slots area fan */
445 /* This makes the fan speed proportional to the power consumed */
446 static struct wf_pid_param slots_param = {
447 	.interval	= 1,
448 	.history_len	= 2,
449 	.gd		= 0,
450 	.gp		= 0,
451 	.gr		= 0x1277952,
452 	.itarget	= 0,
453 	.min		= 1560,
454 	.max		= 3510,
455 };
456 
457 static void slots_fan_tick(void)
458 {
459 	s32 power;
460 	int speed;
461 	int err;
462 
463 	if (!slots_fan || !slots_power)
464 		return;
465 	if (!slots_started) {
466 		/* first time; initialize things */
467 		printk(KERN_INFO "windfarm: Slots control loop started.\n");
468 		wf_pid_init(&slots_pid, &slots_param);
469 		slots_started = true;
470 	}
471 
472 	err = slots_power->ops->get_value(slots_power, &power);
473 	if (err) {
474 		printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
475 		       err);
476 		failure_state |= FAILURE_SENSOR;
477 		wf_control_set_max(slots_fan);
478 		return;
479 	}
480 	speed = wf_pid_run(&slots_pid, power);
481 	DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
482 		 FIX32TOPRINT(power), speed);
483 
484 	err = slots_fan->ops->set_value(slots_fan, speed);
485 	if (err) {
486 		printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
487 		failure_state |= FAILURE_FAN;
488 	}
489 }
490 
491 static void set_fail_state(void)
492 {
493 	int i;
494 
495 	if (cpufreq_clamp)
496 		wf_control_set_max(cpufreq_clamp);
497 	for (i = 0; i < NR_CPU_FANS; ++i)
498 		if (cpu_fans[i])
499 			wf_control_set_max(cpu_fans[i]);
500 	if (backside_fan)
501 		wf_control_set_max(backside_fan);
502 	if (slots_fan)
503 		wf_control_set_max(slots_fan);
504 	if (drive_bay_fan)
505 		wf_control_set_max(drive_bay_fan);
506 }
507 
508 static void pm112_tick(void)
509 {
510 	int i, last_failure;
511 
512 	if (!started) {
513 		started = true;
514 		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
515 		for (i = 0; i < nr_cores; ++i) {
516 			if (create_cpu_loop(i) < 0) {
517 				failure_state = FAILURE_PERM;
518 				set_fail_state();
519 				break;
520 			}
521 		}
522 		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
523 
524 #ifdef HACKED_OVERTEMP
525 		cpu_all_tmax = 60 << 16;
526 #endif
527 	}
528 
529 	/* Permanent failure, bail out */
530 	if (failure_state & FAILURE_PERM)
531 		return;
532 	/* Clear all failure bits except low overtemp which will be eventually
533 	 * cleared by the control loop itself
534 	 */
535 	last_failure = failure_state;
536 	failure_state &= FAILURE_LOW_OVERTEMP;
537 	cpu_fans_tick();
538 	backside_fan_tick();
539 	slots_fan_tick();
540 	drive_bay_fan_tick();
541 
542 	DBG_LOTS("last_failure: 0x%x, failure_state: %x\n",
543 		 last_failure, failure_state);
544 
545 	/* Check for failures. Any failure causes cpufreq clamping */
546 	if (failure_state && last_failure == 0 && cpufreq_clamp)
547 		wf_control_set_max(cpufreq_clamp);
548 	if (failure_state == 0 && last_failure && cpufreq_clamp)
549 		wf_control_set_min(cpufreq_clamp);
550 
551 	/* That's it for now, we might want to deal with other failures
552 	 * differently in the future though
553 	 */
554 }
555 
556 static void pm112_new_control(struct wf_control *ct)
557 {
558 	int i, max_exhaust;
559 
560 	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
561 		if (wf_get_control(ct) == 0)
562 			cpufreq_clamp = ct;
563 	}
564 
565 	for (i = 0; i < NR_CPU_FANS; ++i) {
566 		if (!strcmp(ct->name, cpu_fan_names[i])) {
567 			if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
568 				cpu_fans[i] = ct;
569 			break;
570 		}
571 	}
572 	if (i >= NR_CPU_FANS) {
573 		/* not a CPU fan, try the others */
574 		if (!strcmp(ct->name, "backside-fan")) {
575 			if (backside_fan == NULL && wf_get_control(ct) == 0)
576 				backside_fan = ct;
577 		} else if (!strcmp(ct->name, "slots-fan")) {
578 			if (slots_fan == NULL && wf_get_control(ct) == 0)
579 				slots_fan = ct;
580 		} else if (!strcmp(ct->name, "drive-bay-fan")) {
581 			if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
582 				drive_bay_fan = ct;
583 		}
584 		return;
585 	}
586 
587 	for (i = 0; i < CPU_FANS_REQD; ++i)
588 		if (cpu_fans[i] == NULL)
589 			return;
590 
591 	/* work out pump scaling factors */
592 	max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
593 	for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
594 		if ((ct = cpu_fans[i]) != NULL)
595 			cpu_fan_scale[i] =
596 				ct->ops->get_max(ct) * 100 / max_exhaust;
597 
598 	have_all_controls = 1;
599 }
600 
601 static void pm112_new_sensor(struct wf_sensor *sr)
602 {
603 	unsigned int i;
604 
605 	if (!strncmp(sr->name, "cpu-temp-", 9)) {
606 		i = sr->name[9] - '0';
607 		if (sr->name[10] == 0 && i < NR_CORES &&
608 		    sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
609 			sens_cpu_temp[i] = sr;
610 
611 	} else if (!strncmp(sr->name, "cpu-power-", 10)) {
612 		i = sr->name[10] - '0';
613 		if (sr->name[11] == 0 && i < NR_CORES &&
614 		    sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
615 			sens_cpu_power[i] = sr;
616 	} else if (!strcmp(sr->name, "hd-temp")) {
617 		if (hd_temp == NULL && wf_get_sensor(sr) == 0)
618 			hd_temp = sr;
619 	} else if (!strcmp(sr->name, "slots-power")) {
620 		if (slots_power == NULL && wf_get_sensor(sr) == 0)
621 			slots_power = sr;
622 	} else if (!strcmp(sr->name, "backside-temp")) {
623 		if (u4_temp == NULL && wf_get_sensor(sr) == 0)
624 			u4_temp = sr;
625 	} else
626 		return;
627 
628 	/* check if we have all the sensors we need */
629 	for (i = 0; i < nr_cores; ++i)
630 		if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
631 			return;
632 
633 	have_all_sensors = 1;
634 }
635 
636 static int pm112_wf_notify(struct notifier_block *self,
637 			   unsigned long event, void *data)
638 {
639 	switch (event) {
640 	case WF_EVENT_NEW_SENSOR:
641 		pm112_new_sensor(data);
642 		break;
643 	case WF_EVENT_NEW_CONTROL:
644 		pm112_new_control(data);
645 		break;
646 	case WF_EVENT_TICK:
647 		if (have_all_controls && have_all_sensors)
648 			pm112_tick();
649 	}
650 	return 0;
651 }
652 
653 static struct notifier_block pm112_events = {
654 	.notifier_call = pm112_wf_notify,
655 };
656 
657 static int wf_pm112_probe(struct platform_device *dev)
658 {
659 	wf_register_client(&pm112_events);
660 	return 0;
661 }
662 
663 static int wf_pm112_remove(struct platform_device *dev)
664 {
665 	wf_unregister_client(&pm112_events);
666 	/* should release all sensors and controls */
667 	return 0;
668 }
669 
670 static struct platform_driver wf_pm112_driver = {
671 	.probe = wf_pm112_probe,
672 	.remove = wf_pm112_remove,
673 	.driver = {
674 		.name = "windfarm",
675 	},
676 };
677 
678 static int __init wf_pm112_init(void)
679 {
680 	struct device_node *cpu;
681 
682 	if (!of_machine_is_compatible("PowerMac11,2"))
683 		return -ENODEV;
684 
685 	/* Count the number of CPU cores */
686 	nr_cores = 0;
687 	for_each_node_by_type(cpu, "cpu")
688 		++nr_cores;
689 
690 	printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
691 
692 #ifdef MODULE
693 	request_module("windfarm_smu_controls");
694 	request_module("windfarm_smu_sensors");
695 	request_module("windfarm_smu_sat");
696 	request_module("windfarm_lm75_sensor");
697 	request_module("windfarm_max6690_sensor");
698 	request_module("windfarm_cpufreq_clamp");
699 
700 #endif /* MODULE */
701 
702 	platform_driver_register(&wf_pm112_driver);
703 	return 0;
704 }
705 
706 static void __exit wf_pm112_exit(void)
707 {
708 	platform_driver_unregister(&wf_pm112_driver);
709 }
710 
711 module_init(wf_pm112_init);
712 module_exit(wf_pm112_exit);
713 
714 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
715 MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
716 MODULE_LICENSE("GPL");
717 MODULE_ALIAS("platform:windfarm");
718