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