1/*
2 * Windfarm PowerMac thermal control.
3 * Control loops for RackMack3,1 (Xserve G5)
4 *
5 * Copyright (C) 2012 Benjamin Herrenschmidt, IBM Corp.
6 *
7 * Use and redistribute under the terms of the GNU GPL v2.
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#include "windfarm_mpu.h"
21
22#define VERSION "1.0"
23
24#undef 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 */
45#define NR_CHIPS	2
46#define NR_CPU_FANS	3 * NR_CHIPS
47
48/* Controls and sensors */
49static struct wf_sensor *sens_cpu_temp[NR_CHIPS];
50static struct wf_sensor *sens_cpu_volts[NR_CHIPS];
51static struct wf_sensor *sens_cpu_amps[NR_CHIPS];
52static struct wf_sensor *backside_temp;
53static struct wf_sensor *slots_temp;
54static struct wf_sensor *dimms_temp;
55
56static struct wf_control *cpu_fans[NR_CHIPS][3];
57static struct wf_control *backside_fan;
58static struct wf_control *slots_fan;
59static struct wf_control *cpufreq_clamp;
60
61/* We keep a temperature history for average calculation of 180s */
62#define CPU_TEMP_HIST_SIZE	180
63
64/* PID loop state */
65static const struct mpu_data *cpu_mpu_data[NR_CHIPS];
66static struct wf_cpu_pid_state cpu_pid[NR_CHIPS];
67static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
68static int cpu_thist_pt;
69static s64 cpu_thist_total;
70static s32 cpu_all_tmax = 100 << 16;
71static struct wf_pid_state backside_pid;
72static int backside_tick;
73static struct wf_pid_state slots_pid;
74static int slots_tick;
75static int slots_speed;
76static struct wf_pid_state dimms_pid;
77static int dimms_output_clamp;
78
79static int nr_chips;
80static bool have_all_controls;
81static bool have_all_sensors;
82static bool started;
83
84static int failure_state;
85#define FAILURE_SENSOR		1
86#define FAILURE_FAN		2
87#define FAILURE_PERM		4
88#define FAILURE_LOW_OVERTEMP	8
89#define FAILURE_HIGH_OVERTEMP	16
90
91/* Overtemp values */
92#define LOW_OVER_AVERAGE	0
93#define LOW_OVER_IMMEDIATE	(10 << 16)
94#define LOW_OVER_CLEAR		((-10) << 16)
95#define HIGH_OVER_IMMEDIATE	(14 << 16)
96#define HIGH_OVER_AVERAGE	(10 << 16)
97#define HIGH_OVER_IMMEDIATE	(14 << 16)
98
99
100static void cpu_max_all_fans(void)
101{
102	int i;
103
104	/* We max all CPU fans in case of a sensor error. We also do the
105	 * cpufreq clamping now, even if it's supposedly done later by the
106	 * generic code anyway, we do it earlier here to react faster
107	 */
108	if (cpufreq_clamp)
109		wf_control_set_max(cpufreq_clamp);
110	for (i = 0; i < nr_chips; i++) {
111		if (cpu_fans[i][0])
112			wf_control_set_max(cpu_fans[i][0]);
113		if (cpu_fans[i][1])
114			wf_control_set_max(cpu_fans[i][1]);
115		if (cpu_fans[i][2])
116			wf_control_set_max(cpu_fans[i][2]);
117	}
118}
119
120static int cpu_check_overtemp(s32 temp)
121{
122	int new_state = 0;
123	s32 t_avg, t_old;
124	static bool first = true;
125
126	/* First check for immediate overtemps */
127	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
128		new_state |= FAILURE_LOW_OVERTEMP;
129		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
130			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
131			       " temperature !\n");
132	}
133	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
134		new_state |= FAILURE_HIGH_OVERTEMP;
135		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
136			printk(KERN_ERR "windfarm: Critical overtemp due to"
137			       " immediate CPU temperature !\n");
138	}
139
140	/*
141	 * The first time around, initialize the array with the first
142	 * temperature reading
143	 */
144	if (first) {
145		int i;
146
147		cpu_thist_total = 0;
148		for (i = 0; i < CPU_TEMP_HIST_SIZE; i++) {
149			cpu_thist[i] = temp;
150			cpu_thist_total += temp;
151		}
152		first = false;
153	}
154
155	/*
156	 * We calculate a history of max temperatures and use that for the
157	 * overtemp management
158	 */
159	t_old = cpu_thist[cpu_thist_pt];
160	cpu_thist[cpu_thist_pt] = temp;
161	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
162	cpu_thist_total -= t_old;
163	cpu_thist_total += temp;
164	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
165
166	DBG_LOTS("  t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
167		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
168
169	/* Now check for average overtemps */
170	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
171		new_state |= FAILURE_LOW_OVERTEMP;
172		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
173			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
174			       " temperature !\n");
175	}
176	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
177		new_state |= FAILURE_HIGH_OVERTEMP;
178		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
179			printk(KERN_ERR "windfarm: Critical overtemp due to"
180			       " average CPU temperature !\n");
181	}
182
183	/* Now handle overtemp conditions. We don't currently use the windfarm
184	 * overtemp handling core as it's not fully suited to the needs of those
185	 * new machine. This will be fixed later.
186	 */
187	if (new_state) {
188		/* High overtemp -> immediate shutdown */
189		if (new_state & FAILURE_HIGH_OVERTEMP)
190			machine_power_off();
191		if ((failure_state & new_state) != new_state)
192			cpu_max_all_fans();
193		failure_state |= new_state;
194	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
195		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
196		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
197		failure_state &= ~FAILURE_LOW_OVERTEMP;
198	}
199
200	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
201}
202
203static int read_one_cpu_vals(int cpu, s32 *temp, s32 *power)
204{
205	s32 dtemp, volts, amps;
206	int rc;
207
208	/* Get diode temperature */
209	rc = wf_sensor_get(sens_cpu_temp[cpu], &dtemp);
210	if (rc) {
211		DBG("  CPU%d: temp reading error !\n", cpu);
212		return -EIO;
213	}
214	DBG_LOTS("  CPU%d: temp   = %d.%03d\n", cpu, FIX32TOPRINT((dtemp)));
215	*temp = dtemp;
216
217	/* Get voltage */
218	rc = wf_sensor_get(sens_cpu_volts[cpu], &volts);
219	if (rc) {
220		DBG("  CPU%d, volts reading error !\n", cpu);
221		return -EIO;
222	}
223	DBG_LOTS("  CPU%d: volts  = %d.%03d\n", cpu, FIX32TOPRINT((volts)));
224
225	/* Get current */
226	rc = wf_sensor_get(sens_cpu_amps[cpu], &amps);
227	if (rc) {
228		DBG("  CPU%d, current reading error !\n", cpu);
229		return -EIO;
230	}
231	DBG_LOTS("  CPU%d: amps   = %d.%03d\n", cpu, FIX32TOPRINT((amps)));
232
233	/* Calculate power */
234
235	/* Scale voltage and current raw sensor values according to fixed scales
236	 * obtained in Darwin and calculate power from I and V
237	 */
238	*power = (((u64)volts) * ((u64)amps)) >> 16;
239
240	DBG_LOTS("  CPU%d: power  = %d.%03d\n", cpu, FIX32TOPRINT((*power)));
241
242	return 0;
243
244}
245
246static void cpu_fans_tick(void)
247{
248	int err, cpu, i;
249	s32 speed, temp, power, t_max = 0;
250
251	DBG_LOTS("* cpu fans_tick_split()\n");
252
253	for (cpu = 0; cpu < nr_chips; ++cpu) {
254		struct wf_cpu_pid_state *sp = &cpu_pid[cpu];
255
256		/* Read current speed */
257		wf_control_get(cpu_fans[cpu][0], &sp->target);
258
259		err = read_one_cpu_vals(cpu, &temp, &power);
260		if (err) {
261			failure_state |= FAILURE_SENSOR;
262			cpu_max_all_fans();
263			return;
264		}
265
266		/* Keep track of highest temp */
267		t_max = max(t_max, temp);
268
269		/* Handle possible overtemps */
270		if (cpu_check_overtemp(t_max))
271			return;
272
273		/* Run PID */
274		wf_cpu_pid_run(sp, power, temp);
275
276		DBG_LOTS("  CPU%d: target = %d RPM\n", cpu, sp->target);
277
278		/* Apply DIMMs clamp */
279		speed = max(sp->target, dimms_output_clamp);
280
281		/* Apply result to all cpu fans */
282		for (i = 0; i < 3; i++) {
283			err = wf_control_set(cpu_fans[cpu][i], speed);
284			if (err) {
285				pr_warning("wf_rm31: Fan %s reports error %d\n",
286					   cpu_fans[cpu][i]->name, err);
287				failure_state |= FAILURE_FAN;
288			}
289		}
290	}
291}
292
293/* Implementation... */
294static int cpu_setup_pid(int cpu)
295{
296	struct wf_cpu_pid_param pid;
297	const struct mpu_data *mpu = cpu_mpu_data[cpu];
298	s32 tmax, ttarget, ptarget;
299	int fmin, fmax, hsize;
300
301	/* Get PID params from the appropriate MPU EEPROM */
302	tmax = mpu->tmax << 16;
303	ttarget = mpu->ttarget << 16;
304	ptarget = ((s32)(mpu->pmaxh - mpu->padjmax)) << 16;
305
306	DBG("wf_72: CPU%d ttarget = %d.%03d, tmax = %d.%03d\n",
307	    cpu, FIX32TOPRINT(ttarget), FIX32TOPRINT(tmax));
308
309	/* We keep a global tmax for overtemp calculations */
310	if (tmax < cpu_all_tmax)
311		cpu_all_tmax = tmax;
312
313	/* Set PID min/max by using the rear fan min/max */
314	fmin = wf_control_get_min(cpu_fans[cpu][0]);
315	fmax = wf_control_get_max(cpu_fans[cpu][0]);
316	DBG("wf_72: CPU%d max RPM range = [%d..%d]\n", cpu, fmin, fmax);
317
318	/* History size */
319	hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);
320	DBG("wf_72: CPU%d history size = %d\n", cpu, hsize);
321
322	/* Initialize PID loop */
323	pid.interval	= 1;	/* seconds */
324	pid.history_len = hsize;
325	pid.gd		= mpu->pid_gd;
326	pid.gp		= mpu->pid_gp;
327	pid.gr		= mpu->pid_gr;
328	pid.tmax	= tmax;
329	pid.ttarget	= ttarget;
330	pid.pmaxadj	= ptarget;
331	pid.min		= fmin;
332	pid.max		= fmax;
333
334	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
335	cpu_pid[cpu].target = 4000;
336
337	return 0;
338}
339
340/* Backside/U3 fan */
341static struct wf_pid_param backside_param = {
342	.interval	= 1,
343	.history_len	= 2,
344	.gd		= 0x00500000,
345	.gp		= 0x0004cccc,
346	.gr		= 0,
347	.itarget	= 70 << 16,
348	.additive	= 0,
349	.min		= 20,
350	.max		= 100,
351};
352
353/* DIMMs temperature (clamp the backside fan) */
354static struct wf_pid_param dimms_param = {
355	.interval	= 1,
356	.history_len	= 20,
357	.gd		= 0,
358	.gp		= 0,
359	.gr		= 0x06553600,
360	.itarget	= 50 << 16,
361	.additive	= 0,
362	.min		= 4000,
363	.max		= 14000,
364};
365
366static void backside_fan_tick(void)
367{
368	s32 temp, dtemp;
369	int speed, dspeed, fan_min;
370	int err;
371
372	if (!backside_fan || !backside_temp || !dimms_temp || !backside_tick)
373		return;
374	if (--backside_tick > 0)
375		return;
376	backside_tick = backside_pid.param.interval;
377
378	DBG_LOTS("* backside fans tick\n");
379
380	/* Update fan speed from actual fans */
381	err = wf_control_get(backside_fan, &speed);
382	if (!err)
383		backside_pid.target = speed;
384
385	err = wf_sensor_get(backside_temp, &temp);
386	if (err) {
387		printk(KERN_WARNING "windfarm: U3 temp sensor error %d\n",
388		       err);
389		failure_state |= FAILURE_SENSOR;
390		wf_control_set_max(backside_fan);
391		return;
392	}
393	speed = wf_pid_run(&backside_pid, temp);
394
395	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
396		 FIX32TOPRINT(temp), speed);
397
398	err = wf_sensor_get(dimms_temp, &dtemp);
399	if (err) {
400		printk(KERN_WARNING "windfarm: DIMMs temp sensor error %d\n",
401		       err);
402		failure_state |= FAILURE_SENSOR;
403		wf_control_set_max(backside_fan);
404		return;
405	}
406	dspeed = wf_pid_run(&dimms_pid, dtemp);
407	dimms_output_clamp = dspeed;
408
409	fan_min = (dspeed * 100) / 14000;
410	fan_min = max(fan_min, backside_param.min);
411	speed = max(speed, fan_min);
412
413	err = wf_control_set(backside_fan, speed);
414	if (err) {
415		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
416		failure_state |= FAILURE_FAN;
417	}
418}
419
420static void backside_setup_pid(void)
421{
422	/* first time initialize things */
423	s32 fmin = wf_control_get_min(backside_fan);
424	s32 fmax = wf_control_get_max(backside_fan);
425	struct wf_pid_param param;
426
427	param = backside_param;
428	param.min = max(param.min, fmin);
429	param.max = min(param.max, fmax);
430	wf_pid_init(&backside_pid, &param);
431
432	param = dimms_param;
433	wf_pid_init(&dimms_pid, &param);
434
435	backside_tick = 1;
436
437	pr_info("wf_rm31: Backside control loop started.\n");
438}
439
440/* Slots fan */
441static const struct wf_pid_param slots_param = {
442	.interval	= 1,
443	.history_len	= 20,
444	.gd		= 0,
445	.gp		= 0,
446	.gr		= 0x00100000,
447	.itarget	= 3200000,
448	.additive	= 0,
449	.min		= 20,
450	.max		= 100,
451};
452
453static void slots_fan_tick(void)
454{
455	s32 temp;
456	int speed;
457	int err;
458
459	if (!slots_fan || !slots_temp || !slots_tick)
460		return;
461	if (--slots_tick > 0)
462		return;
463	slots_tick = slots_pid.param.interval;
464
465	DBG_LOTS("* slots fans tick\n");
466
467	err = wf_sensor_get(slots_temp, &temp);
468	if (err) {
469		pr_warning("wf_rm31: slots temp sensor error %d\n", err);
470		failure_state |= FAILURE_SENSOR;
471		wf_control_set_max(slots_fan);
472		return;
473	}
474	speed = wf_pid_run(&slots_pid, temp);
475
476	DBG_LOTS("slots PID temp=%d.%.3d speed=%d\n",
477		 FIX32TOPRINT(temp), speed);
478
479	slots_speed = speed;
480	err = wf_control_set(slots_fan, speed);
481	if (err) {
482		printk(KERN_WARNING "windfarm: slots bay fan error %d\n", err);
483		failure_state |= FAILURE_FAN;
484	}
485}
486
487static void slots_setup_pid(void)
488{
489	/* first time initialize things */
490	s32 fmin = wf_control_get_min(slots_fan);
491	s32 fmax = wf_control_get_max(slots_fan);
492	struct wf_pid_param param = slots_param;
493
494	param.min = max(param.min, fmin);
495	param.max = min(param.max, fmax);
496	wf_pid_init(&slots_pid, &param);
497	slots_tick = 1;
498
499	pr_info("wf_rm31: Slots control loop started.\n");
500}
501
502static void set_fail_state(void)
503{
504	cpu_max_all_fans();
505
506	if (backside_fan)
507		wf_control_set_max(backside_fan);
508	if (slots_fan)
509		wf_control_set_max(slots_fan);
510}
511
512static void rm31_tick(void)
513{
514	int i, last_failure;
515
516	if (!started) {
517		started = 1;
518		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
519		for (i = 0; i < nr_chips; ++i) {
520			if (cpu_setup_pid(i) < 0) {
521				failure_state = FAILURE_PERM;
522				set_fail_state();
523				break;
524			}
525		}
526		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
527
528		backside_setup_pid();
529		slots_setup_pid();
530
531#ifdef HACKED_OVERTEMP
532		cpu_all_tmax = 60 << 16;
533#endif
534	}
535
536	/* Permanent failure, bail out */
537	if (failure_state & FAILURE_PERM)
538		return;
539
540	/*
541	 * Clear all failure bits except low overtemp which will be eventually
542	 * cleared by the control loop itself
543	 */
544	last_failure = failure_state;
545	failure_state &= FAILURE_LOW_OVERTEMP;
546	backside_fan_tick();
547	slots_fan_tick();
548
549	/* We do CPUs last because they can be clamped high by
550	 * DIMM temperature
551	 */
552	cpu_fans_tick();
553
554	DBG_LOTS("  last_failure: 0x%x, failure_state: %x\n",
555		 last_failure, failure_state);
556
557	/* Check for failures. Any failure causes cpufreq clamping */
558	if (failure_state && last_failure == 0 && cpufreq_clamp)
559		wf_control_set_max(cpufreq_clamp);
560	if (failure_state == 0 && last_failure && cpufreq_clamp)
561		wf_control_set_min(cpufreq_clamp);
562
563	/* That's it for now, we might want to deal with other failures
564	 * differently in the future though
565	 */
566}
567
568static void rm31_new_control(struct wf_control *ct)
569{
570	bool all_controls;
571
572	if (!strcmp(ct->name, "cpu-fan-a-0"))
573		cpu_fans[0][0] = ct;
574	else if (!strcmp(ct->name, "cpu-fan-b-0"))
575		cpu_fans[0][1] = ct;
576	else if (!strcmp(ct->name, "cpu-fan-c-0"))
577		cpu_fans[0][2] = ct;
578	else if (!strcmp(ct->name, "cpu-fan-a-1"))
579		cpu_fans[1][0] = ct;
580	else if (!strcmp(ct->name, "cpu-fan-b-1"))
581		cpu_fans[1][1] = ct;
582	else if (!strcmp(ct->name, "cpu-fan-c-1"))
583		cpu_fans[1][2] = ct;
584	else if (!strcmp(ct->name, "backside-fan"))
585		backside_fan = ct;
586	else if (!strcmp(ct->name, "slots-fan"))
587		slots_fan = ct;
588	else if (!strcmp(ct->name, "cpufreq-clamp"))
589		cpufreq_clamp = ct;
590
591	all_controls =
592		cpu_fans[0][0] &&
593		cpu_fans[0][1] &&
594		cpu_fans[0][2] &&
595		backside_fan &&
596		slots_fan;
597	if (nr_chips > 1)
598		all_controls &=
599			cpu_fans[1][0] &&
600			cpu_fans[1][1] &&
601			cpu_fans[1][2];
602	have_all_controls = all_controls;
603}
604
605
606static void rm31_new_sensor(struct wf_sensor *sr)
607{
608	bool all_sensors;
609
610	if (!strcmp(sr->name, "cpu-diode-temp-0"))
611		sens_cpu_temp[0] = sr;
612	else if (!strcmp(sr->name, "cpu-diode-temp-1"))
613		sens_cpu_temp[1] = sr;
614	else if (!strcmp(sr->name, "cpu-voltage-0"))
615		sens_cpu_volts[0] = sr;
616	else if (!strcmp(sr->name, "cpu-voltage-1"))
617		sens_cpu_volts[1] = sr;
618	else if (!strcmp(sr->name, "cpu-current-0"))
619		sens_cpu_amps[0] = sr;
620	else if (!strcmp(sr->name, "cpu-current-1"))
621		sens_cpu_amps[1] = sr;
622	else if (!strcmp(sr->name, "backside-temp"))
623		backside_temp = sr;
624	else if (!strcmp(sr->name, "slots-temp"))
625		slots_temp = sr;
626	else if (!strcmp(sr->name, "dimms-temp"))
627		dimms_temp = sr;
628
629	all_sensors =
630		sens_cpu_temp[0] &&
631		sens_cpu_volts[0] &&
632		sens_cpu_amps[0] &&
633		backside_temp &&
634		slots_temp &&
635		dimms_temp;
636	if (nr_chips > 1)
637		all_sensors &=
638			sens_cpu_temp[1] &&
639			sens_cpu_volts[1] &&
640			sens_cpu_amps[1];
641
642	have_all_sensors = all_sensors;
643}
644
645static int rm31_wf_notify(struct notifier_block *self,
646			  unsigned long event, void *data)
647{
648	switch (event) {
649	case WF_EVENT_NEW_SENSOR:
650		rm31_new_sensor(data);
651		break;
652	case WF_EVENT_NEW_CONTROL:
653		rm31_new_control(data);
654		break;
655	case WF_EVENT_TICK:
656		if (have_all_controls && have_all_sensors)
657			rm31_tick();
658	}
659	return 0;
660}
661
662static struct notifier_block rm31_events = {
663	.notifier_call = rm31_wf_notify,
664};
665
666static int wf_rm31_probe(struct platform_device *dev)
667{
668	wf_register_client(&rm31_events);
669	return 0;
670}
671
672static int wf_rm31_remove(struct platform_device *dev)
673{
674	wf_unregister_client(&rm31_events);
675
676	/* should release all sensors and controls */
677	return 0;
678}
679
680static struct platform_driver wf_rm31_driver = {
681	.probe	= wf_rm31_probe,
682	.remove	= wf_rm31_remove,
683	.driver	= {
684		.name = "windfarm",
685		.owner	= THIS_MODULE,
686	},
687};
688
689static int __init wf_rm31_init(void)
690{
691	struct device_node *cpu;
692	int i;
693
694	if (!of_machine_is_compatible("RackMac3,1"))
695		return -ENODEV;
696
697	/* Count the number of CPU cores */
698	nr_chips = 0;
699	for_each_node_by_type(cpu, "cpu")
700		++nr_chips;
701	if (nr_chips > NR_CHIPS)
702		nr_chips = NR_CHIPS;
703
704	pr_info("windfarm: Initializing for desktop G5 with %d chips\n",
705		nr_chips);
706
707	/* Get MPU data for each CPU */
708	for (i = 0; i < nr_chips; i++) {
709		cpu_mpu_data[i] = wf_get_mpu(i);
710		if (!cpu_mpu_data[i]) {
711			pr_err("wf_rm31: Failed to find MPU data for CPU %d\n", i);
712			return -ENXIO;
713		}
714	}
715
716#ifdef MODULE
717	request_module("windfarm_fcu_controls");
718	request_module("windfarm_lm75_sensor");
719	request_module("windfarm_lm87_sensor");
720	request_module("windfarm_ad7417_sensor");
721	request_module("windfarm_max6690_sensor");
722	request_module("windfarm_cpufreq_clamp");
723#endif /* MODULE */
724
725	platform_driver_register(&wf_rm31_driver);
726	return 0;
727}
728
729static void __exit wf_rm31_exit(void)
730{
731	platform_driver_unregister(&wf_rm31_driver);
732}
733
734module_init(wf_rm31_init);
735module_exit(wf_rm31_exit);
736
737MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
738MODULE_DESCRIPTION("Thermal control for Xserve G5");
739MODULE_LICENSE("GPL");
740MODULE_ALIAS("platform:windfarm");
741