xref: /linux/drivers/macintosh/windfarm_pm81.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
1 /*
2  * Windfarm PowerMac thermal control. iMac G5
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5  *                    <benh@kernel.crashing.org>
6  *
7  * Released under the term of the GNU GPL v2.
8  *
9  * The algorithm used is the PID control algorithm, used the same
10  * way the published Darwin code does, using the same values that
11  * are present in the Darwin 8.2 snapshot property lists (note however
12  * that none of the code has been re-used, it's a complete re-implementation
13  *
14  * The various control loops found in Darwin config file are:
15  *
16  * PowerMac8,1 and PowerMac8,2
17  * ===========================
18  *
19  * System Fans control loop. Different based on models. In addition to the
20  * usual PID algorithm, the control loop gets 2 additional pairs of linear
21  * scaling factors (scale/offsets) expressed as 4.12 fixed point values
22  * signed offset, unsigned scale)
23  *
24  * The targets are modified such as:
25  *  - the linked control (second control) gets the target value as-is
26  *    (typically the drive fan)
27  *  - the main control (first control) gets the target value scaled with
28  *    the first pair of factors, and is then modified as below
29  *  - the value of the target of the CPU Fan control loop is retrieved,
30  *    scaled with the second pair of factors, and the max of that and
31  *    the scaled target is applied to the main control.
32  *
33  * # model_id: 2
34  *   controls       : system-fan, drive-bay-fan
35  *   sensors        : hd-temp
36  *   PID params     : G_d = 0x15400000
37  *                    G_p = 0x00200000
38  *                    G_r = 0x000002fd
39  *                    History = 2 entries
40  *                    Input target = 0x3a0000
41  *                    Interval = 5s
42  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
43  *                    offset = 0x0208 scale  = 0x07ae
44  *
45  * # model_id: 3
46  *   controls       : system-fan, drive-bay-fan
47  *   sensors        : hd-temp
48  *   PID params     : G_d = 0x08e00000
49  *                    G_p = 0x00566666
50  *                    G_r = 0x0000072b
51  *                    History = 2 entries
52  *                    Input target = 0x350000
53  *                    Interval = 5s
54  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
55  *                    offset = 0x0000 scale  = 0x0000
56  *
57  * # model_id: 5
58  *   controls       : system-fan
59  *   sensors        : hd-temp
60  *   PID params     : G_d = 0x15400000
61  *                    G_p = 0x00233333
62  *                    G_r = 0x000002fd
63  *                    History = 2 entries
64  *                    Input target = 0x3a0000
65  *                    Interval = 5s
66  *   linear-factors : offset = 0x0000 scale  = 0x1000
67  *                    offset = 0x0091 scale  = 0x0bae
68  *
69  * CPU Fan control loop. The loop is identical for all models. it
70  * has an additional pair of scaling factor. This is used to scale the
71  * systems fan control loop target result (the one before it gets scaled
72  * by the System Fans control loop itself). Then, the max value of the
73  * calculated target value and system fan value is sent to the fans
74  *
75  *   controls       : cpu-fan
76  *   sensors        : cpu-temp cpu-power
77  *   PID params     : From SMU sdb partition
78  *   linear-factors : offset = 0xfb50 scale  = 0x1000
79  *
80  * CPU Slew control loop. Not implemented. The cpufreq driver in linux is
81  * completely separate for now, though we could find a way to link it, either
82  * as a client reacting to overtemp notifications, or directling monitoring
83  * the CPU temperature
84  *
85  * WARNING ! The CPU control loop requires the CPU tmax for the current
86  * operating point. However, we currently are completely separated from
87  * the cpufreq driver and thus do not know what the current operating
88  * point is. Fortunately, we also do not have any hardware supporting anything
89  * but operating point 0 at the moment, thus we just peek that value directly
90  * from the SDB partition. If we ever end up with actually slewing the system
91  * clock and thus changing operating points, we'll have to find a way to
92  * communicate with the CPU freq driver;
93  *
94  */
95 
96 #include <linux/types.h>
97 #include <linux/errno.h>
98 #include <linux/kernel.h>
99 #include <linux/delay.h>
100 #include <linux/slab.h>
101 #include <linux/init.h>
102 #include <linux/spinlock.h>
103 #include <linux/wait.h>
104 #include <linux/kmod.h>
105 #include <linux/device.h>
106 #include <linux/platform_device.h>
107 #include <asm/prom.h>
108 #include <asm/machdep.h>
109 #include <asm/io.h>
110 #include <asm/system.h>
111 #include <asm/sections.h>
112 #include <asm/smu.h>
113 
114 #include "windfarm.h"
115 #include "windfarm_pid.h"
116 
117 #define VERSION "0.4"
118 
119 #undef DEBUG
120 
121 #ifdef DEBUG
122 #define DBG(args...)	printk(args)
123 #else
124 #define DBG(args...)	do { } while(0)
125 #endif
126 
127 /* define this to force CPU overtemp to 74 degree, useful for testing
128  * the overtemp code
129  */
130 #undef HACKED_OVERTEMP
131 
132 static int wf_smu_mach_model;	/* machine model id */
133 
134 static struct device *wf_smu_dev;
135 
136 /* Controls & sensors */
137 static struct wf_sensor	*sensor_cpu_power;
138 static struct wf_sensor	*sensor_cpu_temp;
139 static struct wf_sensor	*sensor_hd_temp;
140 static struct wf_control *fan_cpu_main;
141 static struct wf_control *fan_hd;
142 static struct wf_control *fan_system;
143 static struct wf_control *cpufreq_clamp;
144 
145 /* Set to kick the control loop into life */
146 static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok, wf_smu_started;
147 
148 /* Failure handling.. could be nicer */
149 #define FAILURE_FAN		0x01
150 #define FAILURE_SENSOR		0x02
151 #define FAILURE_OVERTEMP	0x04
152 
153 static unsigned int wf_smu_failure_state;
154 static int wf_smu_readjust, wf_smu_skipping;
155 
156 /*
157  * ****** System Fans Control Loop ******
158  *
159  */
160 
161 /* Parameters for the System Fans control loop. Parameters
162  * not in this table such as interval, history size, ...
163  * are common to all versions and thus hard coded for now.
164  */
165 struct wf_smu_sys_fans_param {
166 	int	model_id;
167 	s32	itarget;
168 	s32	gd, gp, gr;
169 
170 	s16	offset0;
171 	u16	scale0;
172 	s16	offset1;
173 	u16	scale1;
174 };
175 
176 #define WF_SMU_SYS_FANS_INTERVAL	5
177 #define WF_SMU_SYS_FANS_HISTORY_SIZE	2
178 
179 /* State data used by the system fans control loop
180  */
181 struct wf_smu_sys_fans_state {
182 	int			ticks;
183 	s32			sys_setpoint;
184 	s32			hd_setpoint;
185 	s16			offset0;
186 	u16			scale0;
187 	s16			offset1;
188 	u16			scale1;
189 	struct wf_pid_state	pid;
190 };
191 
192 /*
193  * Configs for SMU Sytem Fan control loop
194  */
195 static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = {
196 	/* Model ID 2 */
197 	{
198 		.model_id	= 2,
199 		.itarget	= 0x3a0000,
200 		.gd		= 0x15400000,
201 		.gp		= 0x00200000,
202 		.gr		= 0x000002fd,
203 		.offset0	= 0xff38,
204 		.scale0		= 0x0ccd,
205 		.offset1	= 0x0208,
206 		.scale1		= 0x07ae,
207 	},
208 	/* Model ID 3 */
209 	{
210 		.model_id	= 3,
211 		.itarget	= 0x350000,
212 		.gd		= 0x08e00000,
213 		.gp		= 0x00566666,
214 		.gr		= 0x0000072b,
215 		.offset0	= 0xff38,
216 		.scale0		= 0x0ccd,
217 		.offset1	= 0x0000,
218 		.scale1		= 0x0000,
219 	},
220 	/* Model ID 5 */
221 	{
222 		.model_id	= 5,
223 		.itarget	= 0x3a0000,
224 		.gd		= 0x15400000,
225 		.gp		= 0x00233333,
226 		.gr		= 0x000002fd,
227 		.offset0	= 0x0000,
228 		.scale0		= 0x1000,
229 		.offset1	= 0x0091,
230 		.scale1		= 0x0bae,
231 	},
232 };
233 #define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)
234 
235 static struct wf_smu_sys_fans_state *wf_smu_sys_fans;
236 
237 /*
238  * ****** CPU Fans Control Loop ******
239  *
240  */
241 
242 
243 #define WF_SMU_CPU_FANS_INTERVAL	1
244 #define WF_SMU_CPU_FANS_MAX_HISTORY	16
245 #define WF_SMU_CPU_FANS_SIBLING_SCALE	0x00001000
246 #define WF_SMU_CPU_FANS_SIBLING_OFFSET	0xfffffb50
247 
248 /* State data used by the cpu fans control loop
249  */
250 struct wf_smu_cpu_fans_state {
251 	int			ticks;
252 	s32			cpu_setpoint;
253 	s32			scale;
254 	s32			offset;
255 	struct wf_cpu_pid_state	pid;
256 };
257 
258 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
259 
260 
261 
262 /*
263  * ***** Implementation *****
264  *
265  */
266 
267 static void wf_smu_create_sys_fans(void)
268 {
269 	struct wf_smu_sys_fans_param *param = NULL;
270 	struct wf_pid_param pid_param;
271 	int i;
272 
273 	/* First, locate the params for this model */
274 	for (i = 0; i < WF_SMU_SYS_FANS_NUM_CONFIGS; i++)
275 		if (wf_smu_sys_all_params[i].model_id == wf_smu_mach_model) {
276 			param = &wf_smu_sys_all_params[i];
277 			break;
278 		}
279 
280 	/* No params found, put fans to max */
281 	if (param == NULL) {
282 		printk(KERN_WARNING "windfarm: System fan config not found "
283 		       "for this machine model, max fan speed\n");
284 		goto fail;
285 	}
286 
287 	/* Alloc & initialize state */
288 	wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state),
289 				  GFP_KERNEL);
290 	if (wf_smu_sys_fans == NULL) {
291 		printk(KERN_WARNING "windfarm: Memory allocation error"
292 		       " max fan speed\n");
293 		goto fail;
294 	}
295 	wf_smu_sys_fans->ticks = 1;
296 	wf_smu_sys_fans->scale0 = param->scale0;
297 	wf_smu_sys_fans->offset0 = param->offset0;
298 	wf_smu_sys_fans->scale1 = param->scale1;
299 	wf_smu_sys_fans->offset1 = param->offset1;
300 
301 	/* Fill PID params */
302 	pid_param.gd = param->gd;
303 	pid_param.gp = param->gp;
304 	pid_param.gr = param->gr;
305 	pid_param.interval = WF_SMU_SYS_FANS_INTERVAL;
306 	pid_param.history_len = WF_SMU_SYS_FANS_HISTORY_SIZE;
307 	pid_param.itarget = param->itarget;
308 	pid_param.min = fan_system->ops->get_min(fan_system);
309 	pid_param.max = fan_system->ops->get_max(fan_system);
310 	if (fan_hd) {
311 		pid_param.min =
312 			max(pid_param.min,fan_hd->ops->get_min(fan_hd));
313 		pid_param.max =
314 			min(pid_param.max,fan_hd->ops->get_max(fan_hd));
315 	}
316 	wf_pid_init(&wf_smu_sys_fans->pid, &pid_param);
317 
318 	DBG("wf: System Fan control initialized.\n");
319 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
320 	    FIX32TOPRINT(pid_param.itarget), pid_param.min, pid_param.max);
321 	return;
322 
323  fail:
324 
325 	if (fan_system)
326 		wf_control_set_max(fan_system);
327 	if (fan_hd)
328 		wf_control_set_max(fan_hd);
329 }
330 
331 static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st)
332 {
333 	s32 new_setpoint, temp, scaled, cputarget;
334 	int rc;
335 
336 	if (--st->ticks != 0) {
337 		if (wf_smu_readjust)
338 			goto readjust;
339 		return;
340 	}
341 	st->ticks = WF_SMU_SYS_FANS_INTERVAL;
342 
343 	rc = sensor_hd_temp->ops->get_value(sensor_hd_temp, &temp);
344 	if (rc) {
345 		printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
346 		       rc);
347 		wf_smu_failure_state |= FAILURE_SENSOR;
348 		return;
349 	}
350 
351 	DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
352 	    FIX32TOPRINT(temp));
353 
354 	if (temp > (st->pid.param.itarget + 0x50000))
355 		wf_smu_failure_state |= FAILURE_OVERTEMP;
356 
357 	new_setpoint = wf_pid_run(&st->pid, temp);
358 
359 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
360 
361 	scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;
362 
363 	DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled);
364 
365 	cputarget = wf_smu_cpu_fans ? wf_smu_cpu_fans->pid.target : 0;
366 	cputarget = ((((s64)cputarget) * (s64)st->scale1) >> 12) + st->offset1;
367 	scaled = max(scaled, cputarget);
368 	scaled = max(scaled, st->pid.param.min);
369 	scaled = min(scaled, st->pid.param.max);
370 
371 	DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled);
372 
373 	if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint)
374 		return;
375 	st->sys_setpoint = scaled;
376 	st->hd_setpoint = new_setpoint;
377  readjust:
378 	if (fan_system && wf_smu_failure_state == 0) {
379 		rc = fan_system->ops->set_value(fan_system, st->sys_setpoint);
380 		if (rc) {
381 			printk(KERN_WARNING "windfarm: Sys fan error %d\n",
382 			       rc);
383 			wf_smu_failure_state |= FAILURE_FAN;
384 		}
385 	}
386 	if (fan_hd && wf_smu_failure_state == 0) {
387 		rc = fan_hd->ops->set_value(fan_hd, st->hd_setpoint);
388 		if (rc) {
389 			printk(KERN_WARNING "windfarm: HD fan error %d\n",
390 			       rc);
391 			wf_smu_failure_state |= FAILURE_FAN;
392 		}
393 	}
394 }
395 
396 static void wf_smu_create_cpu_fans(void)
397 {
398 	struct wf_cpu_pid_param pid_param;
399 	struct smu_sdbp_header *hdr;
400 	struct smu_sdbp_cpupiddata *piddata;
401 	struct smu_sdbp_fvt *fvt;
402 	s32 tmax, tdelta, maxpow, powadj;
403 
404 	/* First, locate the PID params in SMU SBD */
405 	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
406 	if (hdr == 0) {
407 		printk(KERN_WARNING "windfarm: CPU PID fan config not found "
408 		       "max fan speed\n");
409 		goto fail;
410 	}
411 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
412 
413 	/* Get the FVT params for operating point 0 (the only supported one
414 	 * for now) in order to get tmax
415 	 */
416 	hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
417 	if (hdr) {
418 		fvt = (struct smu_sdbp_fvt *)&hdr[1];
419 		tmax = ((s32)fvt->maxtemp) << 16;
420 	} else
421 		tmax = 0x5e0000; /* 94 degree default */
422 
423 	/* Alloc & initialize state */
424 	wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
425 				  GFP_KERNEL);
426 	if (wf_smu_cpu_fans == NULL)
427 		goto fail;
428        	wf_smu_cpu_fans->ticks = 1;
429 
430 	wf_smu_cpu_fans->scale = WF_SMU_CPU_FANS_SIBLING_SCALE;
431 	wf_smu_cpu_fans->offset = WF_SMU_CPU_FANS_SIBLING_OFFSET;
432 
433 	/* Fill PID params */
434 	pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
435 	pid_param.history_len = piddata->history_len;
436 	if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
437 		printk(KERN_WARNING "windfarm: History size overflow on "
438 		       "CPU control loop (%d)\n", piddata->history_len);
439 		pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
440 	}
441 	pid_param.gd = piddata->gd;
442 	pid_param.gp = piddata->gp;
443 	pid_param.gr = piddata->gr / pid_param.history_len;
444 
445 	tdelta = ((s32)piddata->target_temp_delta) << 16;
446 	maxpow = ((s32)piddata->max_power) << 16;
447 	powadj = ((s32)piddata->power_adj) << 16;
448 
449 	pid_param.tmax = tmax;
450 	pid_param.ttarget = tmax - tdelta;
451 	pid_param.pmaxadj = maxpow - powadj;
452 
453 	pid_param.min = fan_cpu_main->ops->get_min(fan_cpu_main);
454 	pid_param.max = fan_cpu_main->ops->get_max(fan_cpu_main);
455 
456 	wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
457 
458 	DBG("wf: CPU Fan control initialized.\n");
459 	DBG("    ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
460 	    FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
461 	    pid_param.min, pid_param.max);
462 
463 	return;
464 
465  fail:
466 	printk(KERN_WARNING "windfarm: CPU fan config not found\n"
467 	       "for this machine model, max fan speed\n");
468 
469 	if (cpufreq_clamp)
470 		wf_control_set_max(cpufreq_clamp);
471 	if (fan_cpu_main)
472 		wf_control_set_max(fan_cpu_main);
473 }
474 
475 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
476 {
477 	s32 new_setpoint, temp, power, systarget;
478 	int rc;
479 
480 	if (--st->ticks != 0) {
481 		if (wf_smu_readjust)
482 			goto readjust;
483 		return;
484 	}
485 	st->ticks = WF_SMU_CPU_FANS_INTERVAL;
486 
487 	rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
488 	if (rc) {
489 		printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
490 		       rc);
491 		wf_smu_failure_state |= FAILURE_SENSOR;
492 		return;
493 	}
494 
495 	rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
496 	if (rc) {
497 		printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
498 		       rc);
499 		wf_smu_failure_state |= FAILURE_SENSOR;
500 		return;
501 	}
502 
503 	DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
504 	    FIX32TOPRINT(temp), FIX32TOPRINT(power));
505 
506 #ifdef HACKED_OVERTEMP
507 	if (temp > 0x4a0000)
508 		wf_smu_failure_state |= FAILURE_OVERTEMP;
509 #else
510 	if (temp > st->pid.param.tmax)
511 		wf_smu_failure_state |= FAILURE_OVERTEMP;
512 #endif
513 	new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
514 
515 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
516 
517 	systarget = wf_smu_sys_fans ? wf_smu_sys_fans->pid.target : 0;
518 	systarget = ((((s64)systarget) * (s64)st->scale) >> 12)
519 		+ st->offset;
520 	new_setpoint = max(new_setpoint, systarget);
521 	new_setpoint = max(new_setpoint, st->pid.param.min);
522 	new_setpoint = min(new_setpoint, st->pid.param.max);
523 
524 	DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint);
525 
526 	if (st->cpu_setpoint == new_setpoint)
527 		return;
528 	st->cpu_setpoint = new_setpoint;
529  readjust:
530 	if (fan_cpu_main && wf_smu_failure_state == 0) {
531 		rc = fan_cpu_main->ops->set_value(fan_cpu_main,
532 						  st->cpu_setpoint);
533 		if (rc) {
534 			printk(KERN_WARNING "windfarm: CPU main fan"
535 			       " error %d\n", rc);
536 			wf_smu_failure_state |= FAILURE_FAN;
537 		}
538 	}
539 }
540 
541 /*
542  * ****** Setup / Init / Misc ... ******
543  *
544  */
545 
546 static void wf_smu_tick(void)
547 {
548 	unsigned int last_failure = wf_smu_failure_state;
549 	unsigned int new_failure;
550 
551 	if (!wf_smu_started) {
552 		DBG("wf: creating control loops !\n");
553 		wf_smu_create_sys_fans();
554 		wf_smu_create_cpu_fans();
555 		wf_smu_started = 1;
556 	}
557 
558 	/* Skipping ticks */
559 	if (wf_smu_skipping && --wf_smu_skipping)
560 		return;
561 
562 	wf_smu_failure_state = 0;
563 	if (wf_smu_sys_fans)
564 		wf_smu_sys_fans_tick(wf_smu_sys_fans);
565 	if (wf_smu_cpu_fans)
566 		wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
567 
568 	wf_smu_readjust = 0;
569 	new_failure = wf_smu_failure_state & ~last_failure;
570 
571 	/* If entering failure mode, clamp cpufreq and ramp all
572 	 * fans to full speed.
573 	 */
574 	if (wf_smu_failure_state && !last_failure) {
575 		if (cpufreq_clamp)
576 			wf_control_set_max(cpufreq_clamp);
577 		if (fan_system)
578 			wf_control_set_max(fan_system);
579 		if (fan_cpu_main)
580 			wf_control_set_max(fan_cpu_main);
581 		if (fan_hd)
582 			wf_control_set_max(fan_hd);
583 	}
584 
585 	/* If leaving failure mode, unclamp cpufreq and readjust
586 	 * all fans on next iteration
587 	 */
588 	if (!wf_smu_failure_state && last_failure) {
589 		if (cpufreq_clamp)
590 			wf_control_set_min(cpufreq_clamp);
591 		wf_smu_readjust = 1;
592 	}
593 
594 	/* Overtemp condition detected, notify and start skipping a couple
595 	 * ticks to let the temperature go down
596 	 */
597 	if (new_failure & FAILURE_OVERTEMP) {
598 		wf_set_overtemp();
599 		wf_smu_skipping = 2;
600 	}
601 
602 	/* We only clear the overtemp condition if overtemp is cleared
603 	 * _and_ no other failure is present. Since a sensor error will
604 	 * clear the overtemp condition (can't measure temperature) at
605 	 * the control loop levels, but we don't want to keep it clear
606 	 * here in this case
607 	 */
608 	if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
609 		wf_clear_overtemp();
610 }
611 
612 static void wf_smu_new_control(struct wf_control *ct)
613 {
614 	if (wf_smu_all_controls_ok)
615 		return;
616 
617 	if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-fan")) {
618 		if (wf_get_control(ct) == 0)
619 			fan_cpu_main = ct;
620 	}
621 
622 	if (fan_system == NULL && !strcmp(ct->name, "system-fan")) {
623 		if (wf_get_control(ct) == 0)
624 			fan_system = ct;
625 	}
626 
627 	if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
628 		if (wf_get_control(ct) == 0)
629 			cpufreq_clamp = ct;
630 	}
631 
632 	/* Darwin property list says the HD fan is only for model ID
633 	 * 0, 1, 2 and 3
634 	 */
635 
636 	if (wf_smu_mach_model > 3) {
637 		if (fan_system && fan_cpu_main && cpufreq_clamp)
638 			wf_smu_all_controls_ok = 1;
639 		return;
640 	}
641 
642 	if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
643 		if (wf_get_control(ct) == 0)
644 			fan_hd = ct;
645 	}
646 
647 	if (fan_system && fan_hd && fan_cpu_main && cpufreq_clamp)
648 		wf_smu_all_controls_ok = 1;
649 }
650 
651 static void wf_smu_new_sensor(struct wf_sensor *sr)
652 {
653 	if (wf_smu_all_sensors_ok)
654 		return;
655 
656 	if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
657 		if (wf_get_sensor(sr) == 0)
658 			sensor_cpu_power = sr;
659 	}
660 
661 	if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
662 		if (wf_get_sensor(sr) == 0)
663 			sensor_cpu_temp = sr;
664 	}
665 
666 	if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
667 		if (wf_get_sensor(sr) == 0)
668 			sensor_hd_temp = sr;
669 	}
670 
671 	if (sensor_cpu_power && sensor_cpu_temp && sensor_hd_temp)
672 		wf_smu_all_sensors_ok = 1;
673 }
674 
675 
676 static int wf_smu_notify(struct notifier_block *self,
677 			       unsigned long event, void *data)
678 {
679 	switch(event) {
680 	case WF_EVENT_NEW_CONTROL:
681 		DBG("wf: new control %s detected\n",
682 		    ((struct wf_control *)data)->name);
683 		wf_smu_new_control(data);
684 		wf_smu_readjust = 1;
685 		break;
686 	case WF_EVENT_NEW_SENSOR:
687 		DBG("wf: new sensor %s detected\n",
688 		    ((struct wf_sensor *)data)->name);
689 		wf_smu_new_sensor(data);
690 		break;
691 	case WF_EVENT_TICK:
692 		if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
693 			wf_smu_tick();
694 	}
695 
696 	return 0;
697 }
698 
699 static struct notifier_block wf_smu_events = {
700 	.notifier_call	= wf_smu_notify,
701 };
702 
703 static int wf_init_pm(void)
704 {
705 	struct smu_sdbp_header *hdr;
706 
707 	hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL);
708 	if (hdr != 0) {
709 		struct smu_sdbp_sensortree *st =
710 			(struct smu_sdbp_sensortree *)&hdr[1];
711 		wf_smu_mach_model = st->model_id;
712 	}
713 
714 	printk(KERN_INFO "windfarm: Initializing for iMacG5 model ID %d\n",
715 	       wf_smu_mach_model);
716 
717 	return 0;
718 }
719 
720 static int wf_smu_probe(struct device *ddev)
721 {
722 	wf_smu_dev = ddev;
723 
724 	wf_register_client(&wf_smu_events);
725 
726 	return 0;
727 }
728 
729 static int wf_smu_remove(struct device *ddev)
730 {
731 	wf_unregister_client(&wf_smu_events);
732 
733 	/* XXX We don't have yet a guarantee that our callback isn't
734 	 * in progress when returning from wf_unregister_client, so
735 	 * we add an arbitrary delay. I'll have to fix that in the core
736 	 */
737 	msleep(1000);
738 
739 	/* Release all sensors */
740 	/* One more crappy race: I don't think we have any guarantee here
741 	 * that the attribute callback won't race with the sensor beeing
742 	 * disposed of, and I'm not 100% certain what best way to deal
743 	 * with that except by adding locks all over... I'll do that
744 	 * eventually but heh, who ever rmmod this module anyway ?
745 	 */
746 	if (sensor_cpu_power)
747 		wf_put_sensor(sensor_cpu_power);
748 	if (sensor_cpu_temp)
749 		wf_put_sensor(sensor_cpu_temp);
750 	if (sensor_hd_temp)
751 		wf_put_sensor(sensor_hd_temp);
752 
753 	/* Release all controls */
754 	if (fan_cpu_main)
755 		wf_put_control(fan_cpu_main);
756 	if (fan_hd)
757 		wf_put_control(fan_hd);
758 	if (fan_system)
759 		wf_put_control(fan_system);
760 	if (cpufreq_clamp)
761 		wf_put_control(cpufreq_clamp);
762 
763 	/* Destroy control loops state structures */
764 	if (wf_smu_sys_fans)
765 		kfree(wf_smu_sys_fans);
766 	if (wf_smu_cpu_fans)
767 		kfree(wf_smu_cpu_fans);
768 
769 	wf_smu_dev = NULL;
770 
771 	return 0;
772 }
773 
774 static struct device_driver wf_smu_driver = {
775         .name = "windfarm",
776         .bus = &platform_bus_type,
777         .probe = wf_smu_probe,
778         .remove = wf_smu_remove,
779 };
780 
781 
782 static int __init wf_smu_init(void)
783 {
784 	int rc = -ENODEV;
785 
786 	if (machine_is_compatible("PowerMac8,1") ||
787 	    machine_is_compatible("PowerMac8,2"))
788 		rc = wf_init_pm();
789 
790 	if (rc == 0) {
791 #ifdef MODULE
792 		request_module("windfarm_smu_controls");
793 		request_module("windfarm_smu_sensors");
794 		request_module("windfarm_lm75_sensor");
795 
796 #endif /* MODULE */
797 		driver_register(&wf_smu_driver);
798 	}
799 
800 	return rc;
801 }
802 
803 static void __exit wf_smu_exit(void)
804 {
805 
806 	driver_unregister(&wf_smu_driver);
807 }
808 
809 
810 module_init(wf_smu_init);
811 module_exit(wf_smu_exit);
812 
813 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
814 MODULE_DESCRIPTION("Thermal control logic for iMac G5");
815 MODULE_LICENSE("GPL");
816 
817