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 <linux/of.h>
16 #include <linux/slab.h>
17 
18 #include <asm/smu.h>
19 
20 #include "windfarm.h"
21 #include "windfarm_pid.h"
22 
23 #define VERSION "0.2"
24 
25 #define DEBUG
26 #undef LOTSA_DEBUG
27 
28 #ifdef DEBUG
29 #define DBG(args...)	printk(args)
30 #else
31 #define DBG(args...)	do { } while(0)
32 #endif
33 
34 #ifdef LOTSA_DEBUG
35 #define DBG_LOTS(args...)	printk(args)
36 #else
37 #define DBG_LOTS(args...)	do { } while(0)
38 #endif
39 
40 /* define this to force CPU overtemp to 60 degree, useful for testing
41  * the overtemp code
42  */
43 #undef HACKED_OVERTEMP
44 
45 /* We currently only handle 2 chips, 4 cores... */
46 #define NR_CHIPS	2
47 #define NR_CORES	4
48 #define NR_CPU_FANS	3 * NR_CHIPS
49 
50 /* Controls and sensors */
51 static struct wf_sensor *sens_cpu_temp[NR_CORES];
52 static struct wf_sensor *sens_cpu_power[NR_CORES];
53 static struct wf_sensor *hd_temp;
54 static struct wf_sensor *slots_power;
55 static struct wf_sensor *u4_temp;
56 
57 static struct wf_control *cpu_fans[NR_CPU_FANS];
58 static char *cpu_fan_names[NR_CPU_FANS] = {
59 	"cpu-rear-fan-0",
60 	"cpu-rear-fan-1",
61 	"cpu-front-fan-0",
62 	"cpu-front-fan-1",
63 	"cpu-pump-0",
64 	"cpu-pump-1",
65 };
66 static struct wf_control *cpufreq_clamp;
67 
68 /* Second pump isn't required (and isn't actually present) */
69 #define CPU_FANS_REQD		(NR_CPU_FANS - 2)
70 #define FIRST_PUMP		4
71 #define LAST_PUMP		5
72 
73 /* We keep a temperature history for average calculation of 180s */
74 #define CPU_TEMP_HIST_SIZE	180
75 
76 /* Scale factor for fan speed, *100 */
77 static int cpu_fan_scale[NR_CPU_FANS] = {
78 	100,
79 	100,
80 	97,		/* inlet fans run at 97% of exhaust fan */
81 	97,
82 	100,		/* updated later */
83 	100,		/* updated later */
84 };
85 
86 static struct wf_control *backside_fan;
87 static struct wf_control *slots_fan;
88 static struct wf_control *drive_bay_fan;
89 
90 /* PID loop state */
91 static struct wf_cpu_pid_state cpu_pid[NR_CORES];
92 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
93 static int cpu_thist_pt;
94 static s64 cpu_thist_total;
95 static s32 cpu_all_tmax = 100 << 16;
96 static int cpu_last_target;
97 static struct wf_pid_state backside_pid;
98 static int backside_tick;
99 static struct wf_pid_state slots_pid;
100 static bool slots_started;
101 static struct wf_pid_state drive_bay_pid;
102 static int drive_bay_tick;
103 
104 static int nr_cores;
105 static int have_all_controls;
106 static int have_all_sensors;
107 static bool started;
108 
109 static int failure_state;
110 #define FAILURE_SENSOR		1
111 #define FAILURE_FAN		2
112 #define FAILURE_PERM		4
113 #define FAILURE_LOW_OVERTEMP	8
114 #define FAILURE_HIGH_OVERTEMP	16
115 
116 /* Overtemp values */
117 #define LOW_OVER_AVERAGE	0
118 #define LOW_OVER_IMMEDIATE	(10 << 16)
119 #define LOW_OVER_CLEAR		((-10) << 16)
120 #define HIGH_OVER_IMMEDIATE	(14 << 16)
121 #define HIGH_OVER_AVERAGE	(10 << 16)
122 #define HIGH_OVER_IMMEDIATE	(14 << 16)
123 
124 
125 /* Implementation... */
126 static int create_cpu_loop(int cpu)
127 {
128 	int chip = cpu / 2;
129 	int core = cpu & 1;
130 	struct smu_sdbp_header *hdr;
131 	struct smu_sdbp_cpupiddata *piddata;
132 	struct wf_cpu_pid_param pid;
133 	struct wf_control *main_fan = cpu_fans[0];
134 	s32 tmax;
135 	int fmin;
136 
137 	/* Get FVT params to get Tmax; if not found, assume default */
138 	hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
139 	if (hdr) {
140 		struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
141 		tmax = fvt->maxtemp << 16;
142 	} else
143 		tmax = 95 << 16;	/* default to 95 degrees C */
144 
145 	/* We keep a global tmax for overtemp calculations */
146 	if (tmax < cpu_all_tmax)
147 		cpu_all_tmax = tmax;
148 
149 	kfree(hdr);
150 
151 	/* Get PID params from the appropriate SAT */
152 	hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
153 	if (hdr == NULL) {
154 		printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
155 		return -EINVAL;
156 	}
157 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
158 
159 	/*
160 	 * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
161 	 * 515 for the 2-way.  That appears to be overkill, so for now,
162 	 * impose a minimum of 750 or 515.
163 	 */
164 	fmin = (nr_cores > 2) ? 750 : 515;
165 
166 	/* Initialize PID loop */
167 	pid.interval = 1;	/* seconds */
168 	pid.history_len = piddata->history_len;
169 	pid.gd = piddata->gd;
170 	pid.gp = piddata->gp;
171 	pid.gr = piddata->gr / piddata->history_len;
172 	pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
173 	pid.ttarget = tmax - (piddata->target_temp_delta << 16);
174 	pid.tmax = tmax;
175 	pid.min = main_fan->ops->get_min(main_fan);
176 	pid.max = main_fan->ops->get_max(main_fan);
177 	if (pid.min < fmin)
178 		pid.min = fmin;
179 
180 	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
181 
182 	kfree(hdr);
183 
184 	return 0;
185 }
186 
187 static void cpu_max_all_fans(void)
188 {
189 	int i;
190 
191 	/* We max all CPU fans in case of a sensor error. We also do the
192 	 * cpufreq clamping now, even if it's supposedly done later by the
193 	 * generic code anyway, we do it earlier here to react faster
194 	 */
195 	if (cpufreq_clamp)
196 		wf_control_set_max(cpufreq_clamp);
197 	for (i = 0; i < NR_CPU_FANS; ++i)
198 		if (cpu_fans[i])
199 			wf_control_set_max(cpu_fans[i]);
200 }
201 
202 static int cpu_check_overtemp(s32 temp)
203 {
204 	int new_state = 0;
205 	s32 t_avg, t_old;
206 
207 	/* First check for immediate overtemps */
208 	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
209 		new_state |= FAILURE_LOW_OVERTEMP;
210 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
211 			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
212 			       " temperature !\n");
213 	}
214 	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
215 		new_state |= FAILURE_HIGH_OVERTEMP;
216 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
217 			printk(KERN_ERR "windfarm: Critical overtemp due to"
218 			       " immediate CPU temperature !\n");
219 	}
220 
221 	/* We calculate a history of max temperatures and use that for the
222 	 * overtemp management
223 	 */
224 	t_old = cpu_thist[cpu_thist_pt];
225 	cpu_thist[cpu_thist_pt] = temp;
226 	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
227 	cpu_thist_total -= t_old;
228 	cpu_thist_total += temp;
229 	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
230 
231 	DBG_LOTS("t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
232 		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
233 
234 	/* Now check for average overtemps */
235 	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
236 		new_state |= FAILURE_LOW_OVERTEMP;
237 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
238 			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
239 			       " temperature !\n");
240 	}
241 	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
242 		new_state |= FAILURE_HIGH_OVERTEMP;
243 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
244 			printk(KERN_ERR "windfarm: Critical overtemp due to"
245 			       " average CPU temperature !\n");
246 	}
247 
248 	/* Now handle overtemp conditions. We don't currently use the windfarm
249 	 * overtemp handling core as it's not fully suited to the needs of those
250 	 * new machine. This will be fixed later.
251 	 */
252 	if (new_state) {
253 		/* High overtemp -> immediate shutdown */
254 		if (new_state & FAILURE_HIGH_OVERTEMP)
255 			machine_power_off();
256 		if ((failure_state & new_state) != new_state)
257 			cpu_max_all_fans();
258 		failure_state |= new_state;
259 	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
260 		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
261 		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
262 		failure_state &= ~FAILURE_LOW_OVERTEMP;
263 	}
264 
265 	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
266 }
267 
268 static void cpu_fans_tick(void)
269 {
270 	int err, cpu;
271 	s32 greatest_delta = 0;
272 	s32 temp, power, t_max = 0;
273 	int i, t, target = 0;
274 	struct wf_sensor *sr;
275 	struct wf_control *ct;
276 	struct wf_cpu_pid_state *sp;
277 
278 	DBG_LOTS(KERN_DEBUG);
279 	for (cpu = 0; cpu < nr_cores; ++cpu) {
280 		/* Get CPU core temperature */
281 		sr = sens_cpu_temp[cpu];
282 		err = sr->ops->get_value(sr, &temp);
283 		if (err) {
284 			DBG("\n");
285 			printk(KERN_WARNING "windfarm: CPU %d temperature "
286 			       "sensor error %d\n", cpu, err);
287 			failure_state |= FAILURE_SENSOR;
288 			cpu_max_all_fans();
289 			return;
290 		}
291 
292 		/* Keep track of highest temp */
293 		t_max = max(t_max, temp);
294 
295 		/* Get CPU power */
296 		sr = sens_cpu_power[cpu];
297 		err = sr->ops->get_value(sr, &power);
298 		if (err) {
299 			DBG("\n");
300 			printk(KERN_WARNING "windfarm: CPU %d power "
301 			       "sensor error %d\n", cpu, err);
302 			failure_state |= FAILURE_SENSOR;
303 			cpu_max_all_fans();
304 			return;
305 		}
306 
307 		/* Run PID */
308 		sp = &cpu_pid[cpu];
309 		t = wf_cpu_pid_run(sp, power, temp);
310 
311 		if (cpu == 0 || sp->last_delta > greatest_delta) {
312 			greatest_delta = sp->last_delta;
313 			target = t;
314 		}
315 		DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
316 		    cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
317 	}
318 	DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
319 
320 	/* Darwin limits decrease to 20 per iteration */
321 	if (target < (cpu_last_target - 20))
322 		target = cpu_last_target - 20;
323 	cpu_last_target = target;
324 	for (cpu = 0; cpu < nr_cores; ++cpu)
325 		cpu_pid[cpu].target = target;
326 
327 	/* Handle possible overtemps */
328 	if (cpu_check_overtemp(t_max))
329 		return;
330 
331 	/* Set fans */
332 	for (i = 0; i < NR_CPU_FANS; ++i) {
333 		ct = cpu_fans[i];
334 		if (ct == NULL)
335 			continue;
336 		err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
337 		if (err) {
338 			printk(KERN_WARNING "windfarm: fan %s reports "
339 			       "error %d\n", ct->name, err);
340 			failure_state |= FAILURE_FAN;
341 			break;
342 		}
343 	}
344 }
345 
346 /* Backside/U4 fan */
347 static struct wf_pid_param backside_param = {
348 	.interval	= 5,
349 	.history_len	= 2,
350 	.gd		= 48 << 20,
351 	.gp		= 5 << 20,
352 	.gr		= 0,
353 	.itarget	= 64 << 16,
354 	.additive	= 1,
355 };
356 
357 static void backside_fan_tick(void)
358 {
359 	s32 temp;
360 	int speed;
361 	int err;
362 
363 	if (!backside_fan || !u4_temp)
364 		return;
365 	if (!backside_tick) {
366 		/* first time; initialize things */
367 		printk(KERN_INFO "windfarm: Backside control loop started.\n");
368 		backside_param.min = backside_fan->ops->get_min(backside_fan);
369 		backside_param.max = backside_fan->ops->get_max(backside_fan);
370 		wf_pid_init(&backside_pid, &backside_param);
371 		backside_tick = 1;
372 	}
373 	if (--backside_tick > 0)
374 		return;
375 	backside_tick = backside_pid.param.interval;
376 
377 	err = u4_temp->ops->get_value(u4_temp, &temp);
378 	if (err) {
379 		printk(KERN_WARNING "windfarm: U4 temp sensor error %d\n",
380 		       err);
381 		failure_state |= FAILURE_SENSOR;
382 		wf_control_set_max(backside_fan);
383 		return;
384 	}
385 	speed = wf_pid_run(&backside_pid, temp);
386 	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
387 		 FIX32TOPRINT(temp), speed);
388 
389 	err = backside_fan->ops->set_value(backside_fan, speed);
390 	if (err) {
391 		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
392 		failure_state |= FAILURE_FAN;
393 	}
394 }
395 
396 /* Drive bay fan */
397 static struct wf_pid_param drive_bay_prm = {
398 	.interval	= 5,
399 	.history_len	= 2,
400 	.gd		= 30 << 20,
401 	.gp		= 5 << 20,
402 	.gr		= 0,
403 	.itarget	= 40 << 16,
404 	.additive	= 1,
405 };
406 
407 static void drive_bay_fan_tick(void)
408 {
409 	s32 temp;
410 	int speed;
411 	int err;
412 
413 	if (!drive_bay_fan || !hd_temp)
414 		return;
415 	if (!drive_bay_tick) {
416 		/* first time; initialize things */
417 		printk(KERN_INFO "windfarm: Drive bay control loop started.\n");
418 		drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
419 		drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
420 		wf_pid_init(&drive_bay_pid, &drive_bay_prm);
421 		drive_bay_tick = 1;
422 	}
423 	if (--drive_bay_tick > 0)
424 		return;
425 	drive_bay_tick = drive_bay_pid.param.interval;
426 
427 	err = hd_temp->ops->get_value(hd_temp, &temp);
428 	if (err) {
429 		printk(KERN_WARNING "windfarm: drive bay temp sensor "
430 		       "error %d\n", err);
431 		failure_state |= FAILURE_SENSOR;
432 		wf_control_set_max(drive_bay_fan);
433 		return;
434 	}
435 	speed = wf_pid_run(&drive_bay_pid, temp);
436 	DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
437 		 FIX32TOPRINT(temp), speed);
438 
439 	err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
440 	if (err) {
441 		printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
442 		failure_state |= FAILURE_FAN;
443 	}
444 }
445 
446 /* PCI slots area fan */
447 /* This makes the fan speed proportional to the power consumed */
448 static struct wf_pid_param slots_param = {
449 	.interval	= 1,
450 	.history_len	= 2,
451 	.gd		= 0,
452 	.gp		= 0,
453 	.gr		= 0x1277952,
454 	.itarget	= 0,
455 	.min		= 1560,
456 	.max		= 3510,
457 };
458 
459 static void slots_fan_tick(void)
460 {
461 	s32 power;
462 	int speed;
463 	int err;
464 
465 	if (!slots_fan || !slots_power)
466 		return;
467 	if (!slots_started) {
468 		/* first time; initialize things */
469 		printk(KERN_INFO "windfarm: Slots control loop started.\n");
470 		wf_pid_init(&slots_pid, &slots_param);
471 		slots_started = true;
472 	}
473 
474 	err = slots_power->ops->get_value(slots_power, &power);
475 	if (err) {
476 		printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
477 		       err);
478 		failure_state |= FAILURE_SENSOR;
479 		wf_control_set_max(slots_fan);
480 		return;
481 	}
482 	speed = wf_pid_run(&slots_pid, power);
483 	DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
484 		 FIX32TOPRINT(power), speed);
485 
486 	err = slots_fan->ops->set_value(slots_fan, speed);
487 	if (err) {
488 		printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
489 		failure_state |= FAILURE_FAN;
490 	}
491 }
492 
493 static void set_fail_state(void)
494 {
495 	int i;
496 
497 	if (cpufreq_clamp)
498 		wf_control_set_max(cpufreq_clamp);
499 	for (i = 0; i < NR_CPU_FANS; ++i)
500 		if (cpu_fans[i])
501 			wf_control_set_max(cpu_fans[i]);
502 	if (backside_fan)
503 		wf_control_set_max(backside_fan);
504 	if (slots_fan)
505 		wf_control_set_max(slots_fan);
506 	if (drive_bay_fan)
507 		wf_control_set_max(drive_bay_fan);
508 }
509 
510 static void pm112_tick(void)
511 {
512 	int i, last_failure;
513 
514 	if (!started) {
515 		started = true;
516 		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
517 		for (i = 0; i < nr_cores; ++i) {
518 			if (create_cpu_loop(i) < 0) {
519 				failure_state = FAILURE_PERM;
520 				set_fail_state();
521 				break;
522 			}
523 		}
524 		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
525 
526 #ifdef HACKED_OVERTEMP
527 		cpu_all_tmax = 60 << 16;
528 #endif
529 	}
530 
531 	/* Permanent failure, bail out */
532 	if (failure_state & FAILURE_PERM)
533 		return;
534 	/* Clear all failure bits except low overtemp which will be eventually
535 	 * cleared by the control loop itself
536 	 */
537 	last_failure = failure_state;
538 	failure_state &= FAILURE_LOW_OVERTEMP;
539 	cpu_fans_tick();
540 	backside_fan_tick();
541 	slots_fan_tick();
542 	drive_bay_fan_tick();
543 
544 	DBG_LOTS("last_failure: 0x%x, failure_state: %x\n",
545 		 last_failure, failure_state);
546 
547 	/* Check for failures. Any failure causes cpufreq clamping */
548 	if (failure_state && last_failure == 0 && cpufreq_clamp)
549 		wf_control_set_max(cpufreq_clamp);
550 	if (failure_state == 0 && last_failure && cpufreq_clamp)
551 		wf_control_set_min(cpufreq_clamp);
552 
553 	/* That's it for now, we might want to deal with other failures
554 	 * differently in the future though
555 	 */
556 }
557 
558 static void pm112_new_control(struct wf_control *ct)
559 {
560 	int i, max_exhaust;
561 
562 	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
563 		if (wf_get_control(ct) == 0)
564 			cpufreq_clamp = ct;
565 	}
566 
567 	for (i = 0; i < NR_CPU_FANS; ++i) {
568 		if (!strcmp(ct->name, cpu_fan_names[i])) {
569 			if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
570 				cpu_fans[i] = ct;
571 			break;
572 		}
573 	}
574 	if (i >= NR_CPU_FANS) {
575 		/* not a CPU fan, try the others */
576 		if (!strcmp(ct->name, "backside-fan")) {
577 			if (backside_fan == NULL && wf_get_control(ct) == 0)
578 				backside_fan = ct;
579 		} else if (!strcmp(ct->name, "slots-fan")) {
580 			if (slots_fan == NULL && wf_get_control(ct) == 0)
581 				slots_fan = ct;
582 		} else if (!strcmp(ct->name, "drive-bay-fan")) {
583 			if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
584 				drive_bay_fan = ct;
585 		}
586 		return;
587 	}
588 
589 	for (i = 0; i < CPU_FANS_REQD; ++i)
590 		if (cpu_fans[i] == NULL)
591 			return;
592 
593 	/* work out pump scaling factors */
594 	max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
595 	for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
596 		if ((ct = cpu_fans[i]) != NULL)
597 			cpu_fan_scale[i] =
598 				ct->ops->get_max(ct) * 100 / max_exhaust;
599 
600 	have_all_controls = 1;
601 }
602 
603 static void pm112_new_sensor(struct wf_sensor *sr)
604 {
605 	unsigned int i;
606 
607 	if (!strncmp(sr->name, "cpu-temp-", 9)) {
608 		i = sr->name[9] - '0';
609 		if (sr->name[10] == 0 && i < NR_CORES &&
610 		    sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
611 			sens_cpu_temp[i] = sr;
612 
613 	} else if (!strncmp(sr->name, "cpu-power-", 10)) {
614 		i = sr->name[10] - '0';
615 		if (sr->name[11] == 0 && i < NR_CORES &&
616 		    sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
617 			sens_cpu_power[i] = sr;
618 	} else if (!strcmp(sr->name, "hd-temp")) {
619 		if (hd_temp == NULL && wf_get_sensor(sr) == 0)
620 			hd_temp = sr;
621 	} else if (!strcmp(sr->name, "slots-power")) {
622 		if (slots_power == NULL && wf_get_sensor(sr) == 0)
623 			slots_power = sr;
624 	} else if (!strcmp(sr->name, "backside-temp")) {
625 		if (u4_temp == NULL && wf_get_sensor(sr) == 0)
626 			u4_temp = sr;
627 	} else
628 		return;
629 
630 	/* check if we have all the sensors we need */
631 	for (i = 0; i < nr_cores; ++i)
632 		if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
633 			return;
634 
635 	have_all_sensors = 1;
636 }
637 
638 static int pm112_wf_notify(struct notifier_block *self,
639 			   unsigned long event, void *data)
640 {
641 	switch (event) {
642 	case WF_EVENT_NEW_SENSOR:
643 		pm112_new_sensor(data);
644 		break;
645 	case WF_EVENT_NEW_CONTROL:
646 		pm112_new_control(data);
647 		break;
648 	case WF_EVENT_TICK:
649 		if (have_all_controls && have_all_sensors)
650 			pm112_tick();
651 	}
652 	return 0;
653 }
654 
655 static struct notifier_block pm112_events = {
656 	.notifier_call = pm112_wf_notify,
657 };
658 
659 static int wf_pm112_probe(struct platform_device *dev)
660 {
661 	wf_register_client(&pm112_events);
662 	return 0;
663 }
664 
665 static int wf_pm112_remove(struct platform_device *dev)
666 {
667 	wf_unregister_client(&pm112_events);
668 	/* should release all sensors and controls */
669 	return 0;
670 }
671 
672 static struct platform_driver wf_pm112_driver = {
673 	.probe = wf_pm112_probe,
674 	.remove = wf_pm112_remove,
675 	.driver = {
676 		.name = "windfarm",
677 	},
678 };
679 
680 static int __init wf_pm112_init(void)
681 {
682 	struct device_node *cpu;
683 
684 	if (!of_machine_is_compatible("PowerMac11,2"))
685 		return -ENODEV;
686 
687 	/* Count the number of CPU cores */
688 	nr_cores = 0;
689 	for_each_node_by_type(cpu, "cpu")
690 		++nr_cores;
691 
692 	printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
693 
694 #ifdef MODULE
695 	request_module("windfarm_smu_controls");
696 	request_module("windfarm_smu_sensors");
697 	request_module("windfarm_smu_sat");
698 	request_module("windfarm_lm75_sensor");
699 	request_module("windfarm_max6690_sensor");
700 	request_module("windfarm_cpufreq_clamp");
701 
702 #endif /* MODULE */
703 
704 	platform_driver_register(&wf_pm112_driver);
705 	return 0;
706 }
707 
708 static void __exit wf_pm112_exit(void)
709 {
710 	platform_driver_unregister(&wf_pm112_driver);
711 }
712 
713 module_init(wf_pm112_init);
714 module_exit(wf_pm112_exit);
715 
716 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
717 MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
718 MODULE_LICENSE("GPL");
719 MODULE_ALIAS("platform:windfarm");
720