windfarm_rm31.c 17.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740
/*
 * Windfarm PowerMac thermal control.
 * Control loops for RackMack3,1 (Xserve G5)
 *
 * Copyright (C) 2012 Benjamin Herrenschmidt, IBM Corp.
 *
 * Use and redistribute under the terms of the GNU GPL v2.
 */
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <asm/prom.h>
#include <asm/smu.h>

#include "windfarm.h"
#include "windfarm_pid.h"
#include "windfarm_mpu.h"

#define VERSION "1.0"

#undef DEBUG
#undef LOTSA_DEBUG

#ifdef DEBUG
#define DBG(args...)	printk(args)
#else
#define DBG(args...)	do { } while(0)
#endif

#ifdef LOTSA_DEBUG
#define DBG_LOTS(args...)	printk(args)
#else
#define DBG_LOTS(args...)	do { } while(0)
#endif

/* define this to force CPU overtemp to 60 degree, useful for testing
 * the overtemp code
 */
#undef HACKED_OVERTEMP

/* We currently only handle 2 chips */
#define NR_CHIPS	2
#define NR_CPU_FANS	3 * NR_CHIPS

/* Controls and sensors */
static struct wf_sensor *sens_cpu_temp[NR_CHIPS];
static struct wf_sensor *sens_cpu_volts[NR_CHIPS];
static struct wf_sensor *sens_cpu_amps[NR_CHIPS];
static struct wf_sensor *backside_temp;
static struct wf_sensor *slots_temp;
static struct wf_sensor *dimms_temp;

static struct wf_control *cpu_fans[NR_CHIPS][3];
static struct wf_control *backside_fan;
static struct wf_control *slots_fan;
static struct wf_control *cpufreq_clamp;

/* We keep a temperature history for average calculation of 180s */
#define CPU_TEMP_HIST_SIZE	180

/* PID loop state */
static const struct mpu_data *cpu_mpu_data[NR_CHIPS];
static struct wf_cpu_pid_state cpu_pid[NR_CHIPS];
static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
static int cpu_thist_pt;
static s64 cpu_thist_total;
static s32 cpu_all_tmax = 100 << 16;
static struct wf_pid_state backside_pid;
static int backside_tick;
static struct wf_pid_state slots_pid;
static int slots_tick;
static int slots_speed;
static struct wf_pid_state dimms_pid;
static int dimms_output_clamp;

static int nr_chips;
static bool have_all_controls;
static bool have_all_sensors;
static bool started;

static int failure_state;
#define FAILURE_SENSOR		1
#define FAILURE_FAN		2
#define FAILURE_PERM		4
#define FAILURE_LOW_OVERTEMP	8
#define FAILURE_HIGH_OVERTEMP	16

/* Overtemp values */
#define LOW_OVER_AVERAGE	0
#define LOW_OVER_IMMEDIATE	(10 << 16)
#define LOW_OVER_CLEAR		((-10) << 16)
#define HIGH_OVER_IMMEDIATE	(14 << 16)
#define HIGH_OVER_AVERAGE	(10 << 16)
#define HIGH_OVER_IMMEDIATE	(14 << 16)


static void cpu_max_all_fans(void)
{
	int i;

	/* We max all CPU fans in case of a sensor error. We also do the
	 * cpufreq clamping now, even if it's supposedly done later by the
	 * generic code anyway, we do it earlier here to react faster
	 */
	if (cpufreq_clamp)
		wf_control_set_max(cpufreq_clamp);
	for (i = 0; i < nr_chips; i++) {
		if (cpu_fans[i][0])
			wf_control_set_max(cpu_fans[i][0]);
		if (cpu_fans[i][1])
			wf_control_set_max(cpu_fans[i][1]);
		if (cpu_fans[i][2])
			wf_control_set_max(cpu_fans[i][2]);
	}
}

static int cpu_check_overtemp(s32 temp)
{
	int new_state = 0;
	s32 t_avg, t_old;
	static bool first = true;

	/* First check for immediate overtemps */
	if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
		new_state |= FAILURE_LOW_OVERTEMP;
		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
			       " temperature !\n");
	}
	if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
		new_state |= FAILURE_HIGH_OVERTEMP;
		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Critical overtemp due to"
			       " immediate CPU temperature !\n");
	}

	/*
	 * The first time around, initialize the array with the first
	 * temperature reading
	 */
	if (first) {
		int i;

		cpu_thist_total = 0;
		for (i = 0; i < CPU_TEMP_HIST_SIZE; i++) {
			cpu_thist[i] = temp;
			cpu_thist_total += temp;
		}
		first = false;
	}

	/*
	 * We calculate a history of max temperatures and use that for the
	 * overtemp management
	 */
	t_old = cpu_thist[cpu_thist_pt];
	cpu_thist[cpu_thist_pt] = temp;
	cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
	cpu_thist_total -= t_old;
	cpu_thist_total += temp;
	t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;

	DBG_LOTS("  t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
		 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));

	/* Now check for average overtemps */
	if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
		new_state |= FAILURE_LOW_OVERTEMP;
		if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Overtemp due to average CPU"
			       " temperature !\n");
	}
	if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
		new_state |= FAILURE_HIGH_OVERTEMP;
		if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
			printk(KERN_ERR "windfarm: Critical overtemp due to"
			       " average CPU temperature !\n");
	}

	/* Now handle overtemp conditions. We don't currently use the windfarm
	 * overtemp handling core as it's not fully suited to the needs of those
	 * new machine. This will be fixed later.
	 */
	if (new_state) {
		/* High overtemp -> immediate shutdown */
		if (new_state & FAILURE_HIGH_OVERTEMP)
			machine_power_off();
		if ((failure_state & new_state) != new_state)
			cpu_max_all_fans();
		failure_state |= new_state;
	} else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
		   (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
		printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
		failure_state &= ~FAILURE_LOW_OVERTEMP;
	}

	return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
}

static int read_one_cpu_vals(int cpu, s32 *temp, s32 *power)
{
	s32 dtemp, volts, amps;
	int rc;

	/* Get diode temperature */
	rc = wf_sensor_get(sens_cpu_temp[cpu], &dtemp);
	if (rc) {
		DBG("  CPU%d: temp reading error !\n", cpu);
		return -EIO;
	}
	DBG_LOTS("  CPU%d: temp   = %d.%03d\n", cpu, FIX32TOPRINT((dtemp)));
	*temp = dtemp;

	/* Get voltage */
	rc = wf_sensor_get(sens_cpu_volts[cpu], &volts);
	if (rc) {
		DBG("  CPU%d, volts reading error !\n", cpu);
		return -EIO;
	}
	DBG_LOTS("  CPU%d: volts  = %d.%03d\n", cpu, FIX32TOPRINT((volts)));

	/* Get current */
	rc = wf_sensor_get(sens_cpu_amps[cpu], &amps);
	if (rc) {
		DBG("  CPU%d, current reading error !\n", cpu);
		return -EIO;
	}
	DBG_LOTS("  CPU%d: amps   = %d.%03d\n", cpu, FIX32TOPRINT((amps)));

	/* Calculate power */

	/* Scale voltage and current raw sensor values according to fixed scales
	 * obtained in Darwin and calculate power from I and V
	 */
	*power = (((u64)volts) * ((u64)amps)) >> 16;

	DBG_LOTS("  CPU%d: power  = %d.%03d\n", cpu, FIX32TOPRINT((*power)));

	return 0;

}

static void cpu_fans_tick(void)
{
	int err, cpu, i;
	s32 speed, temp, power, t_max = 0;

	DBG_LOTS("* cpu fans_tick_split()\n");

	for (cpu = 0; cpu < nr_chips; ++cpu) {
		struct wf_cpu_pid_state *sp = &cpu_pid[cpu];

		/* Read current speed */
		wf_control_get(cpu_fans[cpu][0], &sp->target);

		err = read_one_cpu_vals(cpu, &temp, &power);
		if (err) {
			failure_state |= FAILURE_SENSOR;
			cpu_max_all_fans();
			return;
		}

		/* Keep track of highest temp */
		t_max = max(t_max, temp);

		/* Handle possible overtemps */
		if (cpu_check_overtemp(t_max))
			return;

		/* Run PID */
		wf_cpu_pid_run(sp, power, temp);

		DBG_LOTS("  CPU%d: target = %d RPM\n", cpu, sp->target);

		/* Apply DIMMs clamp */
		speed = max(sp->target, dimms_output_clamp);

		/* Apply result to all cpu fans */
		for (i = 0; i < 3; i++) {
			err = wf_control_set(cpu_fans[cpu][i], speed);
			if (err) {
				pr_warning("wf_rm31: Fan %s reports error %d\n",
					   cpu_fans[cpu][i]->name, err);
				failure_state |= FAILURE_FAN;
			}
		}
	}
}

/* Implementation... */
static int cpu_setup_pid(int cpu)
{
	struct wf_cpu_pid_param pid;
	const struct mpu_data *mpu = cpu_mpu_data[cpu];
	s32 tmax, ttarget, ptarget;
	int fmin, fmax, hsize;

	/* Get PID params from the appropriate MPU EEPROM */
	tmax = mpu->tmax << 16;
	ttarget = mpu->ttarget << 16;
	ptarget = ((s32)(mpu->pmaxh - mpu->padjmax)) << 16;

	DBG("wf_72: CPU%d ttarget = %d.%03d, tmax = %d.%03d\n",
	    cpu, FIX32TOPRINT(ttarget), FIX32TOPRINT(tmax));

	/* We keep a global tmax for overtemp calculations */
	if (tmax < cpu_all_tmax)
		cpu_all_tmax = tmax;

	/* Set PID min/max by using the rear fan min/max */
	fmin = wf_control_get_min(cpu_fans[cpu][0]);
	fmax = wf_control_get_max(cpu_fans[cpu][0]);
	DBG("wf_72: CPU%d max RPM range = [%d..%d]\n", cpu, fmin, fmax);

	/* History size */
	hsize = min_t(int, mpu->tguardband, WF_PID_MAX_HISTORY);
	DBG("wf_72: CPU%d history size = %d\n", cpu, hsize);

	/* Initialize PID loop */
	pid.interval	= 1;	/* seconds */
	pid.history_len = hsize;
	pid.gd		= mpu->pid_gd;
	pid.gp		= mpu->pid_gp;
	pid.gr		= mpu->pid_gr;
	pid.tmax	= tmax;
	pid.ttarget	= ttarget;
	pid.pmaxadj	= ptarget;
	pid.min		= fmin;
	pid.max		= fmax;

	wf_cpu_pid_init(&cpu_pid[cpu], &pid);
	cpu_pid[cpu].target = 4000;
	
	return 0;
}

/* Backside/U3 fan */
static struct wf_pid_param backside_param = {
	.interval	= 1,
	.history_len	= 2,
	.gd		= 0x00500000,
	.gp		= 0x0004cccc,
	.gr		= 0,
	.itarget	= 70 << 16,
	.additive	= 0,
	.min		= 20,
	.max		= 100,
};

/* DIMMs temperature (clamp the backside fan) */
static struct wf_pid_param dimms_param = {
	.interval	= 1,
	.history_len	= 20,
	.gd		= 0,
	.gp		= 0,
	.gr		= 0x06553600,
	.itarget	= 50 << 16,
	.additive	= 0,
	.min		= 4000,
	.max		= 14000,
};

static void backside_fan_tick(void)
{
	s32 temp, dtemp;
	int speed, dspeed, fan_min;
	int err;

	if (!backside_fan || !backside_temp || !dimms_temp || !backside_tick)
		return;
	if (--backside_tick > 0)
		return;
	backside_tick = backside_pid.param.interval;

	DBG_LOTS("* backside fans tick\n");

	/* Update fan speed from actual fans */
	err = wf_control_get(backside_fan, &speed);
	if (!err)
		backside_pid.target = speed;

	err = wf_sensor_get(backside_temp, &temp);
	if (err) {
		printk(KERN_WARNING "windfarm: U3 temp sensor error %d\n",
		       err);
		failure_state |= FAILURE_SENSOR;
		wf_control_set_max(backside_fan);
		return;
	}
	speed = wf_pid_run(&backside_pid, temp);

	DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
		 FIX32TOPRINT(temp), speed);

	err = wf_sensor_get(dimms_temp, &dtemp);
	if (err) {
		printk(KERN_WARNING "windfarm: DIMMs temp sensor error %d\n",
		       err);
		failure_state |= FAILURE_SENSOR;
		wf_control_set_max(backside_fan);
		return;
	}
	dspeed = wf_pid_run(&dimms_pid, dtemp);
	dimms_output_clamp = dspeed;

	fan_min = (dspeed * 100) / 14000;
	fan_min = max(fan_min, backside_param.min);
	speed = max(speed, fan_min);

	err = wf_control_set(backside_fan, speed);
	if (err) {
		printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
		failure_state |= FAILURE_FAN;
	}
}

static void backside_setup_pid(void)
{
	/* first time initialize things */
	s32 fmin = wf_control_get_min(backside_fan);
	s32 fmax = wf_control_get_max(backside_fan);
	struct wf_pid_param param;

	param = backside_param;
	param.min = max(param.min, fmin);
	param.max = min(param.max, fmax);
	wf_pid_init(&backside_pid, &param);

	param = dimms_param;
	wf_pid_init(&dimms_pid, &param);

	backside_tick = 1;

	pr_info("wf_rm31: Backside control loop started.\n");
}

/* Slots fan */
static const struct wf_pid_param slots_param = {
	.interval	= 1,
	.history_len	= 20,
	.gd		= 0,
	.gp		= 0,
	.gr		= 0x00100000,
	.itarget	= 3200000,
	.additive	= 0,
	.min		= 20,
	.max		= 100,
};

static void slots_fan_tick(void)
{
	s32 temp;
	int speed;
	int err;

	if (!slots_fan || !slots_temp || !slots_tick)
		return;
	if (--slots_tick > 0)
		return;
	slots_tick = slots_pid.param.interval;

	DBG_LOTS("* slots fans tick\n");

	err = wf_sensor_get(slots_temp, &temp);
	if (err) {
		pr_warning("wf_rm31: slots temp sensor error %d\n", err);
		failure_state |= FAILURE_SENSOR;
		wf_control_set_max(slots_fan);
		return;
	}
	speed = wf_pid_run(&slots_pid, temp);

	DBG_LOTS("slots PID temp=%d.%.3d speed=%d\n",
		 FIX32TOPRINT(temp), speed);

	slots_speed = speed;
	err = wf_control_set(slots_fan, speed);
	if (err) {
		printk(KERN_WARNING "windfarm: slots bay fan error %d\n", err);
		failure_state |= FAILURE_FAN;
	}
}

static void slots_setup_pid(void)
{
	/* first time initialize things */
	s32 fmin = wf_control_get_min(slots_fan);
	s32 fmax = wf_control_get_max(slots_fan);
	struct wf_pid_param param = slots_param;

	param.min = max(param.min, fmin);
	param.max = min(param.max, fmax);
	wf_pid_init(&slots_pid, &param);
	slots_tick = 1;

	pr_info("wf_rm31: Slots control loop started.\n");
}

static void set_fail_state(void)
{
	cpu_max_all_fans();

	if (backside_fan)
		wf_control_set_max(backside_fan);
	if (slots_fan)
		wf_control_set_max(slots_fan);
}

static void rm31_tick(void)
{
	int i, last_failure;

	if (!started) {
		started = 1;
		printk(KERN_INFO "windfarm: CPUs control loops started.\n");
		for (i = 0; i < nr_chips; ++i) {
			if (cpu_setup_pid(i) < 0) {
				failure_state = FAILURE_PERM;
				set_fail_state();
				break;
			}
		}
		DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));

		backside_setup_pid();
		slots_setup_pid();

#ifdef HACKED_OVERTEMP
		cpu_all_tmax = 60 << 16;
#endif
	}

	/* Permanent failure, bail out */
	if (failure_state & FAILURE_PERM)
		return;

	/*
	 * Clear all failure bits except low overtemp which will be eventually
	 * cleared by the control loop itself
	 */
	last_failure = failure_state;
	failure_state &= FAILURE_LOW_OVERTEMP;
	backside_fan_tick();
	slots_fan_tick();

	/* We do CPUs last because they can be clamped high by
	 * DIMM temperature
	 */
	cpu_fans_tick();

	DBG_LOTS("  last_failure: 0x%x, failure_state: %x\n",
		 last_failure, failure_state);

	/* Check for failures. Any failure causes cpufreq clamping */
	if (failure_state && last_failure == 0 && cpufreq_clamp)
		wf_control_set_max(cpufreq_clamp);
	if (failure_state == 0 && last_failure && cpufreq_clamp)
		wf_control_set_min(cpufreq_clamp);

	/* That's it for now, we might want to deal with other failures
	 * differently in the future though
	 */
}

static void rm31_new_control(struct wf_control *ct)
{
	bool all_controls;

	if (!strcmp(ct->name, "cpu-fan-a-0"))
		cpu_fans[0][0] = ct;
	else if (!strcmp(ct->name, "cpu-fan-b-0"))
		cpu_fans[0][1] = ct;
	else if (!strcmp(ct->name, "cpu-fan-c-0"))
		cpu_fans[0][2] = ct;
	else if (!strcmp(ct->name, "cpu-fan-a-1"))
		cpu_fans[1][0] = ct;
	else if (!strcmp(ct->name, "cpu-fan-b-1"))
		cpu_fans[1][1] = ct;
	else if (!strcmp(ct->name, "cpu-fan-c-1"))
		cpu_fans[1][2] = ct;
	else if (!strcmp(ct->name, "backside-fan"))
		backside_fan = ct;
	else if (!strcmp(ct->name, "slots-fan"))
		slots_fan = ct;
	else if (!strcmp(ct->name, "cpufreq-clamp"))
		cpufreq_clamp = ct;

	all_controls =
		cpu_fans[0][0] &&
		cpu_fans[0][1] &&
		cpu_fans[0][2] &&
		backside_fan &&
		slots_fan;
	if (nr_chips > 1)
		all_controls &=
			cpu_fans[1][0] &&
			cpu_fans[1][1] &&
			cpu_fans[1][2];
	have_all_controls = all_controls;
}


static void rm31_new_sensor(struct wf_sensor *sr)
{
	bool all_sensors;

	if (!strcmp(sr->name, "cpu-diode-temp-0"))
		sens_cpu_temp[0] = sr;
	else if (!strcmp(sr->name, "cpu-diode-temp-1"))
		sens_cpu_temp[1] = sr;
	else if (!strcmp(sr->name, "cpu-voltage-0"))
		sens_cpu_volts[0] = sr;
	else if (!strcmp(sr->name, "cpu-voltage-1"))
		sens_cpu_volts[1] = sr;
	else if (!strcmp(sr->name, "cpu-current-0"))
		sens_cpu_amps[0] = sr;
	else if (!strcmp(sr->name, "cpu-current-1"))
		sens_cpu_amps[1] = sr;
	else if (!strcmp(sr->name, "backside-temp"))
		backside_temp = sr;
	else if (!strcmp(sr->name, "slots-temp"))
		slots_temp = sr;
	else if (!strcmp(sr->name, "dimms-temp"))
		dimms_temp = sr;

	all_sensors =
		sens_cpu_temp[0] &&
		sens_cpu_volts[0] &&
		sens_cpu_amps[0] &&
		backside_temp &&
		slots_temp &&
		dimms_temp;
	if (nr_chips > 1)
		all_sensors &=
			sens_cpu_temp[1] &&
			sens_cpu_volts[1] &&
			sens_cpu_amps[1];

	have_all_sensors = all_sensors;
}

static int rm31_wf_notify(struct notifier_block *self,
			  unsigned long event, void *data)
{
	switch (event) {
	case WF_EVENT_NEW_SENSOR:
		rm31_new_sensor(data);
		break;
	case WF_EVENT_NEW_CONTROL:
		rm31_new_control(data);
		break;
	case WF_EVENT_TICK:
		if (have_all_controls && have_all_sensors)
			rm31_tick();
	}
	return 0;
}

static struct notifier_block rm31_events = {
	.notifier_call = rm31_wf_notify,
};

static int wf_rm31_probe(struct platform_device *dev)
{
	wf_register_client(&rm31_events);
	return 0;
}

static int wf_rm31_remove(struct platform_device *dev)
{
	wf_unregister_client(&rm31_events);

	/* should release all sensors and controls */
	return 0;
}

static struct platform_driver wf_rm31_driver = {
	.probe	= wf_rm31_probe,
	.remove	= wf_rm31_remove,
	.driver	= {
		.name = "windfarm",
		.owner	= THIS_MODULE,
	},
};

static int __init wf_rm31_init(void)
{
	struct device_node *cpu;
	int i;

	if (!of_machine_is_compatible("RackMac3,1"))
		return -ENODEV;

	/* Count the number of CPU cores */
	nr_chips = 0;
	for_each_node_by_type(cpu, "cpu")
		++nr_chips;
	if (nr_chips > NR_CHIPS)
		nr_chips = NR_CHIPS;

	pr_info("windfarm: Initializing for desktop G5 with %d chips\n",
		nr_chips);

	/* Get MPU data for each CPU */
	for (i = 0; i < nr_chips; i++) {
		cpu_mpu_data[i] = wf_get_mpu(i);
		if (!cpu_mpu_data[i]) {
			pr_err("wf_rm31: Failed to find MPU data for CPU %d\n", i);
			return -ENXIO;
		}
	}

#ifdef MODULE
	request_module("windfarm_fcu_controls");
	request_module("windfarm_lm75_sensor");
	request_module("windfarm_lm87_sensor");
	request_module("windfarm_ad7417_sensor");
	request_module("windfarm_max6690_sensor");
	request_module("windfarm_cpufreq_clamp");
#endif /* MODULE */

	platform_driver_register(&wf_rm31_driver);
	return 0;
}

static void __exit wf_rm31_exit(void)
{
	platform_driver_unregister(&wf_rm31_driver);
}

module_init(wf_rm31_init);
module_exit(wf_rm31_exit);

MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
MODULE_DESCRIPTION("Thermal control for Xserve G5");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:windfarm");