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