1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control.
4  * Control loops for RackMack3,1 (Xserve G5)
5  *
6  * Copyright (C) 2012 Benjamin Herrenschmidt, IBM Corp.
7  */
8 #include <linux/types.h>
9 #include <linux/errno.h>
10 #include <linux/kernel.h>
11 #include <linux/device.h>
12 #include <linux/platform_device.h>
13 #include <linux/reboot.h>
14 #include <asm/prom.h>
15 #include <asm/smu.h>
16 
17 #include "windfarm.h"
18 #include "windfarm_pid.h"
19 #include "windfarm_mpu.h"
20 
21 #define VERSION "1.0"
22 
23 #undef 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 */
44 #define NR_CHIPS	2
45 #define NR_CPU_FANS	3 * NR_CHIPS
46 
47 /* Controls and sensors */
48 static struct wf_sensor *sens_cpu_temp[NR_CHIPS];
49 static struct wf_sensor *sens_cpu_volts[NR_CHIPS];
50 static struct wf_sensor *sens_cpu_amps[NR_CHIPS];
51 static struct wf_sensor *backside_temp;
52 static struct wf_sensor *slots_temp;
53 static struct wf_sensor *dimms_temp;
54 
55 static struct wf_control *cpu_fans[NR_CHIPS][3];
56 static struct wf_control *backside_fan;
57 static struct wf_control *slots_fan;
58 static struct wf_control *cpufreq_clamp;
59 
60 /* We keep a temperature history for average calculation of 180s */
61 #define CPU_TEMP_HIST_SIZE	180
62 
63 /* PID loop state */
64 static const struct mpu_data *cpu_mpu_data[NR_CHIPS];
65 static struct wf_cpu_pid_state cpu_pid[NR_CHIPS];
66 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
67 static int cpu_thist_pt;
68 static s64 cpu_thist_total;
69 static s32 cpu_all_tmax = 100 << 16;
70 static struct wf_pid_state backside_pid;
71 static int backside_tick;
72 static struct wf_pid_state slots_pid;
73 static int slots_tick;
74 static int slots_speed;
75 static struct wf_pid_state dimms_pid;
76 static int dimms_output_clamp;
77 
78 static int nr_chips;
79 static bool have_all_controls;
80 static bool have_all_sensors;
81 static bool started;
82 
83 static int failure_state;
84 #define FAILURE_SENSOR		1
85 #define FAILURE_FAN		2
86 #define FAILURE_PERM		4
87 #define FAILURE_LOW_OVERTEMP	8
88 #define FAILURE_HIGH_OVERTEMP	16
89 
90 /* Overtemp values */
91 #define LOW_OVER_AVERAGE	0
92 #define LOW_OVER_IMMEDIATE	(10 << 16)
93 #define LOW_OVER_CLEAR		((-10) << 16)
94 #define HIGH_OVER_IMMEDIATE	(14 << 16)
95 #define HIGH_OVER_AVERAGE	(10 << 16)
96 #define HIGH_OVER_IMMEDIATE	(14 << 16)
97 
98 
99 static void cpu_max_all_fans(void)
100 {
101 	int i;
102 
103 	/* We max all CPU fans in case of a sensor error. We also do the
104 	 * cpufreq clamping now, even if it's supposedly done later by the
105 	 * generic code anyway, we do it earlier here to react faster
106 	 */
107 	if (cpufreq_clamp)
108 		wf_control_set_max(cpufreq_clamp);
109 	for (i = 0; i < nr_chips; i++) {
110 		if (cpu_fans[i][0])
111 			wf_control_set_max(cpu_fans[i][0]);
112 		if (cpu_fans[i][1])
113 			wf_control_set_max(cpu_fans[i][1]);
114 		if (cpu_fans[i][2])
115 			wf_control_set_max(cpu_fans[i][2]);
116 	}
117 }
118 
119 static int cpu_check_overtemp(s32 temp)
120 {
121 	int new_state = 0;
122 	s32 t_avg, t_old;
123 	static bool first = true;
124 
125 	/* First check for immediate overtemps */
126 	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
127 		new_state |= FAILURE_LOW_OVERTEMP;
128 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
129 			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
130 			       " temperature !\n");
131 	}
132 	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
133 		new_state |= FAILURE_HIGH_OVERTEMP;
134 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
135 			printk(KERN_ERR "windfarm: Critical overtemp due to"
136 			       " immediate CPU temperature !\n");
137 	}
138 
139 	/*
140 	 * The first time around, initialize the array with the first
141 	 * temperature reading
142 	 */
143 	if (first) {
144 		int i;
145 
146 		cpu_thist_total = 0;
147 		for (i = 0; i < CPU_TEMP_HIST_SIZE; i++) {
148 			cpu_thist[i] = temp;
149 			cpu_thist_total += temp;
150 		}
151 		first = false;
152 	}
153 
154 	/*
155 	 * We calculate a history of max temperatures and use that for the
156 	 * overtemp management
157 	 */
158 	t_old = cpu_thist[cpu_thist_pt];
159 	cpu_thist[cpu_thist_pt] = temp;
160 	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
161 	cpu_thist_total -= t_old;
162 	cpu_thist_total += temp;
163 	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
164 
165 	DBG_LOTS("  t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
166 		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
167 
168 	/* Now check for average overtemps */
169 	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
170 		new_state |= FAILURE_LOW_OVERTEMP;
171 		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
172 			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
173 			       " temperature !\n");
174 	}
175 	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
176 		new_state |= FAILURE_HIGH_OVERTEMP;
177 		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
178 			printk(KERN_ERR "windfarm: Critical overtemp due to"
179 			       " average CPU temperature !\n");
180 	}
181 
182 	/* Now handle overtemp conditions. We don't currently use the windfarm
183 	 * overtemp handling core as it's not fully suited to the needs of those
184 	 * new machine. This will be fixed later.
185 	 */
186 	if (new_state) {
187 		/* High overtemp -> immediate shutdown */
188 		if (new_state & FAILURE_HIGH_OVERTEMP)
189 			machine_power_off();
190 		if ((failure_state & new_state) != new_state)
191 			cpu_max_all_fans();
192 		failure_state |= new_state;
193 	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
194 		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
195 		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
196 		failure_state &= ~FAILURE_LOW_OVERTEMP;
197 	}
198 
199 	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
200 }
201 
202 static int read_one_cpu_vals(int cpu, s32 *temp, s32 *power)
203 {
204 	s32 dtemp, volts, amps;
205 	int rc;
206 
207 	/* Get diode temperature */
208 	rc = wf_sensor_get(sens_cpu_temp[cpu], &dtemp);
209 	if (rc) {
210 		DBG("  CPU%d: temp reading error !\n", cpu);
211 		return -EIO;
212 	}
213 	DBG_LOTS("  CPU%d: temp   = %d.%03d\n", cpu, FIX32TOPRINT((dtemp)));
214 	*temp = dtemp;
215 
216 	/* Get voltage */
217 	rc = wf_sensor_get(sens_cpu_volts[cpu], &volts);
218 	if (rc) {
219 		DBG("  CPU%d, volts reading error !\n", cpu);
220 		return -EIO;
221 	}
222 	DBG_LOTS("  CPU%d: volts  = %d.%03d\n", cpu, FIX32TOPRINT((volts)));
223 
224 	/* Get current */
225 	rc = wf_sensor_get(sens_cpu_amps[cpu], &amps);
226 	if (rc) {
227 		DBG("  CPU%d, current reading error !\n", cpu);
228 		return -EIO;
229 	}
230 	DBG_LOTS("  CPU%d: amps   = %d.%03d\n", cpu, FIX32TOPRINT((amps)));
231 
232 	/* Calculate power */
233 
234 	/* Scale voltage and current raw sensor values according to fixed scales
235 	 * obtained in Darwin and calculate power from I and V
236 	 */
237 	*power = (((u64)volts) * ((u64)amps)) >> 16;
238 
239 	DBG_LOTS("  CPU%d: power  = %d.%03d\n", cpu, FIX32TOPRINT((*power)));
240 
241 	return 0;
242 
243 }
244 
245 static void cpu_fans_tick(void)
246 {
247 	int err, cpu, i;
248 	s32 speed, temp, power, t_max = 0;
249 
250 	DBG_LOTS("* cpu fans_tick_split()\n");
251 
252 	for (cpu = 0; cpu < nr_chips; ++cpu) {
253 		struct wf_cpu_pid_state *sp = &cpu_pid[cpu];
254 
255 		/* Read current speed */
256 		wf_control_get(cpu_fans[cpu][0], &sp->target);
257 
258 		err = read_one_cpu_vals(cpu, &temp, &power);
259 		if (err) {
260 			failure_state |= FAILURE_SENSOR;
261 			cpu_max_all_fans();
262 			return;
263 		}
264 
265 		/* Keep track of highest temp */
266 		t_max = max(t_max, temp);
267 
268 		/* Handle possible overtemps */
269 		if (cpu_check_overtemp(t_max))
270 			return;
271 
272 		/* Run PID */
273 		wf_cpu_pid_run(sp, power, temp);
274 
275 		DBG_LOTS("  CPU%d: target = %d RPM\n", cpu, sp->target);
276 
277 		/* Apply DIMMs clamp */
278 		speed = max(sp->target, dimms_output_clamp);
279 
280 		/* Apply result to all cpu fans */
281 		for (i = 0; i < 3; i++) {
282 			err = wf_control_set(cpu_fans[cpu][i], speed);
283 			if (err) {
284 				pr_warning("wf_rm31: Fan %s reports error %d\n",
285 					   cpu_fans[cpu][i]->name, err);
286 				failure_state |= FAILURE_FAN;
287 			}
288 		}
289 	}
290 }
291 
292 /* Implementation... */
293 static int cpu_setup_pid(int cpu)
294 {
295 	struct wf_cpu_pid_param pid;
296 	const struct mpu_data *mpu = cpu_mpu_data[cpu];
297 	s32 tmax, ttarget, ptarget;
298 	int fmin, fmax, hsize;
299 
300 	/* Get PID params from the appropriate MPU EEPROM */
301 	tmax = mpu->tmax << 16;
302 	ttarget = mpu->ttarget << 16;
303 	ptarget = ((s32)(mpu->pmaxh - mpu->padjmax)) << 16;
304 
305 	DBG("wf_72: CPU%d ttarget = %d.%03d, tmax = %d.%03d\n",
306 	    cpu, FIX32TOPRINT(ttarget), FIX32TOPRINT(tmax));
307 
308 	/* We keep a global tmax for overtemp calculations */
309 	if (tmax < cpu_all_tmax)
310 		cpu_all_tmax = tmax;
311 
312 	/* Set PID min/max by using the rear fan min/max */
313 	fmin = wf_control_get_min(cpu_fans[cpu][0]);
314 	fmax = wf_control_get_max(cpu_fans[cpu][0]);
315 	DBG("wf_72: CPU%d max RPM range = [%d..%d]\n", cpu, fmin, fmax);
316 
317 	/* History size */
318 	hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);
319 	DBG("wf_72: CPU%d history size = %d\n", cpu, hsize);
320 
321 	/* Initialize PID loop */
322 	pid.interval	= 1;	/* seconds */
323 	pid.history_len = hsize;
324 	pid.gd		= mpu->pid_gd;
325 	pid.gp		= mpu->pid_gp;
326 	pid.gr		= mpu->pid_gr;
327 	pid.tmax	= tmax;
328 	pid.ttarget	= ttarget;
329 	pid.pmaxadj	= ptarget;
330 	pid.min		= fmin;
331 	pid.max		= fmax;
332 
333 	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
334 	cpu_pid[cpu].target = 4000;
335 
336 	return 0;
337 }
338 
339 /* Backside/U3 fan */
340 static const struct wf_pid_param backside_param = {
341 	.interval	= 1,
342 	.history_len	= 2,
343 	.gd		= 0x00500000,
344 	.gp		= 0x0004cccc,
345 	.gr		= 0,
346 	.itarget	= 70 << 16,
347 	.additive	= 0,
348 	.min		= 20,
349 	.max		= 100,
350 };
351 
352 /* DIMMs temperature (clamp the backside fan) */
353 static const struct wf_pid_param dimms_param = {
354 	.interval	= 1,
355 	.history_len	= 20,
356 	.gd		= 0,
357 	.gp		= 0,
358 	.gr		= 0x06553600,
359 	.itarget	= 50 << 16,
360 	.additive	= 0,
361 	.min		= 4000,
362 	.max		= 14000,
363 };
364 
365 static void backside_fan_tick(void)
366 {
367 	s32 temp, dtemp;
368 	int speed, dspeed, fan_min;
369 	int err;
370 
371 	if (!backside_fan || !backside_temp || !dimms_temp || !backside_tick)
372 		return;
373 	if (--backside_tick > 0)
374 		return;
375 	backside_tick = backside_pid.param.interval;
376 
377 	DBG_LOTS("* backside fans tick\n");
378 
379 	/* Update fan speed from actual fans */
380 	err = wf_control_get(backside_fan, &speed);
381 	if (!err)
382 		backside_pid.target = speed;
383 
384 	err = wf_sensor_get(backside_temp, &temp);
385 	if (err) {
386 		printk(KERN_WARNING "windfarm: U3 temp sensor error %d\n",
387 		       err);
388 		failure_state |= FAILURE_SENSOR;
389 		wf_control_set_max(backside_fan);
390 		return;
391 	}
392 	speed = wf_pid_run(&backside_pid, temp);
393 
394 	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
395 		 FIX32TOPRINT(temp), speed);
396 
397 	err = wf_sensor_get(dimms_temp, &dtemp);
398 	if (err) {
399 		printk(KERN_WARNING "windfarm: DIMMs temp sensor error %d\n",
400 		       err);
401 		failure_state |= FAILURE_SENSOR;
402 		wf_control_set_max(backside_fan);
403 		return;
404 	}
405 	dspeed = wf_pid_run(&dimms_pid, dtemp);
406 	dimms_output_clamp = dspeed;
407 
408 	fan_min = (dspeed * 100) / 14000;
409 	fan_min = max(fan_min, backside_param.min);
410 	speed = max(speed, fan_min);
411 
412 	err = wf_control_set(backside_fan, speed);
413 	if (err) {
414 		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
415 		failure_state |= FAILURE_FAN;
416 	}
417 }
418 
419 static void backside_setup_pid(void)
420 {
421 	/* first time initialize things */
422 	s32 fmin = wf_control_get_min(backside_fan);
423 	s32 fmax = wf_control_get_max(backside_fan);
424 	struct wf_pid_param param;
425 
426 	param = backside_param;
427 	param.min = max(param.min, fmin);
428 	param.max = min(param.max, fmax);
429 	wf_pid_init(&backside_pid, &param);
430 
431 	param = dimms_param;
432 	wf_pid_init(&dimms_pid, &param);
433 
434 	backside_tick = 1;
435 
436 	pr_info("wf_rm31: Backside control loop started.\n");
437 }
438 
439 /* Slots fan */
440 static const struct wf_pid_param slots_param = {
441 	.interval	= 1,
442 	.history_len	= 20,
443 	.gd		= 0,
444 	.gp		= 0,
445 	.gr		= 0x00100000,
446 	.itarget	= 3200000,
447 	.additive	= 0,
448 	.min		= 20,
449 	.max		= 100,
450 };
451 
452 static void slots_fan_tick(void)
453 {
454 	s32 temp;
455 	int speed;
456 	int err;
457 
458 	if (!slots_fan || !slots_temp || !slots_tick)
459 		return;
460 	if (--slots_tick > 0)
461 		return;
462 	slots_tick = slots_pid.param.interval;
463 
464 	DBG_LOTS("* slots fans tick\n");
465 
466 	err = wf_sensor_get(slots_temp, &temp);
467 	if (err) {
468 		pr_warning("wf_rm31: slots temp sensor error %d\n", err);
469 		failure_state |= FAILURE_SENSOR;
470 		wf_control_set_max(slots_fan);
471 		return;
472 	}
473 	speed = wf_pid_run(&slots_pid, temp);
474 
475 	DBG_LOTS("slots PID temp=%d.%.3d speed=%d\n",
476 		 FIX32TOPRINT(temp), speed);
477 
478 	slots_speed = speed;
479 	err = wf_control_set(slots_fan, speed);
480 	if (err) {
481 		printk(KERN_WARNING "windfarm: slots bay fan error %d\n", err);
482 		failure_state |= FAILURE_FAN;
483 	}
484 }
485 
486 static void slots_setup_pid(void)
487 {
488 	/* first time initialize things */
489 	s32 fmin = wf_control_get_min(slots_fan);
490 	s32 fmax = wf_control_get_max(slots_fan);
491 	struct wf_pid_param param = slots_param;
492 
493 	param.min = max(param.min, fmin);
494 	param.max = min(param.max, fmax);
495 	wf_pid_init(&slots_pid, &param);
496 	slots_tick = 1;
497 
498 	pr_info("wf_rm31: Slots control loop started.\n");
499 }
500 
501 static void set_fail_state(void)
502 {
503 	cpu_max_all_fans();
504 
505 	if (backside_fan)
506 		wf_control_set_max(backside_fan);
507 	if (slots_fan)
508 		wf_control_set_max(slots_fan);
509 }
510 
511 static void rm31_tick(void)
512 {
513 	int i, last_failure;
514 
515 	if (!started) {
516 		started = true;
517 		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
518 		for (i = 0; i < nr_chips; ++i) {
519 			if (cpu_setup_pid(i) < 0) {
520 				failure_state = FAILURE_PERM;
521 				set_fail_state();
522 				break;
523 			}
524 		}
525 		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
526 
527 		backside_setup_pid();
528 		slots_setup_pid();
529 
530 #ifdef HACKED_OVERTEMP
531 		cpu_all_tmax = 60 << 16;
532 #endif
533 	}
534 
535 	/* Permanent failure, bail out */
536 	if (failure_state & FAILURE_PERM)
537 		return;
538 
539 	/*
540 	 * Clear all failure bits except low overtemp which will be eventually
541 	 * cleared by the control loop itself
542 	 */
543 	last_failure = failure_state;
544 	failure_state &= FAILURE_LOW_OVERTEMP;
545 	backside_fan_tick();
546 	slots_fan_tick();
547 
548 	/* We do CPUs last because they can be clamped high by
549 	 * DIMM temperature
550 	 */
551 	cpu_fans_tick();
552 
553 	DBG_LOTS("  last_failure: 0x%x, failure_state: %x\n",
554 		 last_failure, failure_state);
555 
556 	/* Check for failures. Any failure causes cpufreq clamping */
557 	if (failure_state && last_failure == 0 && cpufreq_clamp)
558 		wf_control_set_max(cpufreq_clamp);
559 	if (failure_state == 0 && last_failure && cpufreq_clamp)
560 		wf_control_set_min(cpufreq_clamp);
561 
562 	/* That's it for now, we might want to deal with other failures
563 	 * differently in the future though
564 	 */
565 }
566 
567 static void rm31_new_control(struct wf_control *ct)
568 {
569 	bool all_controls;
570 
571 	if (!strcmp(ct->name, "cpu-fan-a-0"))
572 		cpu_fans[0][0] = ct;
573 	else if (!strcmp(ct->name, "cpu-fan-b-0"))
574 		cpu_fans[0][1] = ct;
575 	else if (!strcmp(ct->name, "cpu-fan-c-0"))
576 		cpu_fans[0][2] = ct;
577 	else if (!strcmp(ct->name, "cpu-fan-a-1"))
578 		cpu_fans[1][0] = ct;
579 	else if (!strcmp(ct->name, "cpu-fan-b-1"))
580 		cpu_fans[1][1] = ct;
581 	else if (!strcmp(ct->name, "cpu-fan-c-1"))
582 		cpu_fans[1][2] = ct;
583 	else if (!strcmp(ct->name, "backside-fan"))
584 		backside_fan = ct;
585 	else if (!strcmp(ct->name, "slots-fan"))
586 		slots_fan = ct;
587 	else if (!strcmp(ct->name, "cpufreq-clamp"))
588 		cpufreq_clamp = ct;
589 
590 	all_controls =
591 		cpu_fans[0][0] &&
592 		cpu_fans[0][1] &&
593 		cpu_fans[0][2] &&
594 		backside_fan &&
595 		slots_fan;
596 	if (nr_chips > 1)
597 		all_controls &=
598 			cpu_fans[1][0] &&
599 			cpu_fans[1][1] &&
600 			cpu_fans[1][2];
601 	have_all_controls = all_controls;
602 }
603 
604 
605 static void rm31_new_sensor(struct wf_sensor *sr)
606 {
607 	bool all_sensors;
608 
609 	if (!strcmp(sr->name, "cpu-diode-temp-0"))
610 		sens_cpu_temp[0] = sr;
611 	else if (!strcmp(sr->name, "cpu-diode-temp-1"))
612 		sens_cpu_temp[1] = sr;
613 	else if (!strcmp(sr->name, "cpu-voltage-0"))
614 		sens_cpu_volts[0] = sr;
615 	else if (!strcmp(sr->name, "cpu-voltage-1"))
616 		sens_cpu_volts[1] = sr;
617 	else if (!strcmp(sr->name, "cpu-current-0"))
618 		sens_cpu_amps[0] = sr;
619 	else if (!strcmp(sr->name, "cpu-current-1"))
620 		sens_cpu_amps[1] = sr;
621 	else if (!strcmp(sr->name, "backside-temp"))
622 		backside_temp = sr;
623 	else if (!strcmp(sr->name, "slots-temp"))
624 		slots_temp = sr;
625 	else if (!strcmp(sr->name, "dimms-temp"))
626 		dimms_temp = sr;
627 
628 	all_sensors =
629 		sens_cpu_temp[0] &&
630 		sens_cpu_volts[0] &&
631 		sens_cpu_amps[0] &&
632 		backside_temp &&
633 		slots_temp &&
634 		dimms_temp;
635 	if (nr_chips > 1)
636 		all_sensors &=
637 			sens_cpu_temp[1] &&
638 			sens_cpu_volts[1] &&
639 			sens_cpu_amps[1];
640 
641 	have_all_sensors = all_sensors;
642 }
643 
644 static int rm31_wf_notify(struct notifier_block *self,
645 			  unsigned long event, void *data)
646 {
647 	switch (event) {
648 	case WF_EVENT_NEW_SENSOR:
649 		rm31_new_sensor(data);
650 		break;
651 	case WF_EVENT_NEW_CONTROL:
652 		rm31_new_control(data);
653 		break;
654 	case WF_EVENT_TICK:
655 		if (have_all_controls && have_all_sensors)
656 			rm31_tick();
657 	}
658 	return 0;
659 }
660 
661 static struct notifier_block rm31_events = {
662 	.notifier_call = rm31_wf_notify,
663 };
664 
665 static int wf_rm31_probe(struct platform_device *dev)
666 {
667 	wf_register_client(&rm31_events);
668 	return 0;
669 }
670 
671 static int wf_rm31_remove(struct platform_device *dev)
672 {
673 	wf_unregister_client(&rm31_events);
674 
675 	/* should release all sensors and controls */
676 	return 0;
677 }
678 
679 static struct platform_driver wf_rm31_driver = {
680 	.probe	= wf_rm31_probe,
681 	.remove	= wf_rm31_remove,
682 	.driver	= {
683 		.name = "windfarm",
684 	},
685 };
686 
687 static int __init wf_rm31_init(void)
688 {
689 	struct device_node *cpu;
690 	int i;
691 
692 	if (!of_machine_is_compatible("RackMac3,1"))
693 		return -ENODEV;
694 
695 	/* Count the number of CPU cores */
696 	nr_chips = 0;
697 	for_each_node_by_type(cpu, "cpu")
698 		++nr_chips;
699 	if (nr_chips > NR_CHIPS)
700 		nr_chips = NR_CHIPS;
701 
702 	pr_info("windfarm: Initializing for desktop G5 with %d chips\n",
703 		nr_chips);
704 
705 	/* Get MPU data for each CPU */
706 	for (i = 0; i < nr_chips; i++) {
707 		cpu_mpu_data[i] = wf_get_mpu(i);
708 		if (!cpu_mpu_data[i]) {
709 			pr_err("wf_rm31: Failed to find MPU data for CPU %d\n", i);
710 			return -ENXIO;
711 		}
712 	}
713 
714 #ifdef MODULE
715 	request_module("windfarm_fcu_controls");
716 	request_module("windfarm_lm75_sensor");
717 	request_module("windfarm_lm87_sensor");
718 	request_module("windfarm_ad7417_sensor");
719 	request_module("windfarm_max6690_sensor");
720 	request_module("windfarm_cpufreq_clamp");
721 #endif /* MODULE */
722 
723 	platform_driver_register(&wf_rm31_driver);
724 	return 0;
725 }
726 
727 static void __exit wf_rm31_exit(void)
728 {
729 	platform_driver_unregister(&wf_rm31_driver);
730 }
731 
732 module_init(wf_rm31_init);
733 module_exit(wf_rm31_exit);
734 
735 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
736 MODULE_DESCRIPTION("Thermal control for Xserve G5");
737 MODULE_LICENSE("GPL");
738 MODULE_ALIAS("platform:windfarm");
739