1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control. iMac G5
4  *
5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *                    <benh@kernel.crashing.org>
7  *
8  * The algorithm used is the PID control algorithm, used the same
9  * way the published Darwin code does, using the same values that
10  * are present in the Darwin 8.2 snapshot property lists (note however
11  * that none of the code has been re-used, it's a complete re-implementation
12  *
13  * The various control loops found in Darwin config file are:
14  *
15  * PowerMac8,1 and PowerMac8,2
16  * ===========================
17  *
18  * System Fans control loop. Different based on models. In addition to the
19  * usual PID algorithm, the control loop gets 2 additional pairs of linear
20  * scaling factors (scale/offsets) expressed as 4.12 fixed point values
21  * signed offset, unsigned scale)
22  *
23  * The targets are modified such as:
24  *  - the linked control (second control) gets the target value as-is
25  *    (typically the drive fan)
26  *  - the main control (first control) gets the target value scaled with
27  *    the first pair of factors, and is then modified as below
28  *  - the value of the target of the CPU Fan control loop is retrieved,
29  *    scaled with the second pair of factors, and the max of that and
30  *    the scaled target is applied to the main control.
31  *
32  * # model_id: 2
33  *   controls       : system-fan, drive-bay-fan
34  *   sensors        : hd-temp
35  *   PID params     : G_d = 0x15400000
36  *                    G_p = 0x00200000
37  *                    G_r = 0x000002fd
38  *                    History = 2 entries
39  *                    Input target = 0x3a0000
40  *                    Interval = 5s
41  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
42  *                    offset = 0x0208 scale  = 0x07ae
43  *
44  * # model_id: 3
45  *   controls       : system-fan, drive-bay-fan
46  *   sensors        : hd-temp
47  *   PID params     : G_d = 0x08e00000
48  *                    G_p = 0x00566666
49  *                    G_r = 0x0000072b
50  *                    History = 2 entries
51  *                    Input target = 0x350000
52  *                    Interval = 5s
53  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
54  *                    offset = 0x0000 scale  = 0x0000
55  *
56  * # model_id: 5
57  *   controls       : system-fan
58  *   sensors        : hd-temp
59  *   PID params     : G_d = 0x15400000
60  *                    G_p = 0x00233333
61  *                    G_r = 0x000002fd
62  *                    History = 2 entries
63  *                    Input target = 0x3a0000
64  *                    Interval = 5s
65  *   linear-factors : offset = 0x0000 scale  = 0x1000
66  *                    offset = 0x0091 scale  = 0x0bae
67  *
68  * CPU Fan control loop. The loop is identical for all models. it
69  * has an additional pair of scaling factor. This is used to scale the
70  * systems fan control loop target result (the one before it gets scaled
71  * by the System Fans control loop itself). Then, the max value of the
72  * calculated target value and system fan value is sent to the fans
73  *
74  *   controls       : cpu-fan
75  *   sensors        : cpu-temp cpu-power
76  *   PID params     : From SMU sdb partition
77  *   linear-factors : offset = 0xfb50 scale  = 0x1000
78  *
79  * CPU Slew control loop. Not implemented. The cpufreq driver in linux is
80  * completely separate for now, though we could find a way to link it, either
81  * as a client reacting to overtemp notifications, or directling monitoring
82  * the CPU temperature
83  *
84  * WARNING ! The CPU control loop requires the CPU tmax for the current
85  * operating point. However, we currently are completely separated from
86  * the cpufreq driver and thus do not know what the current operating
87  * point is. Fortunately, we also do not have any hardware supporting anything
88  * but operating point 0 at the moment, thus we just peek that value directly
89  * from the SDB partition. If we ever end up with actually slewing the system
90  * clock and thus changing operating points, we'll have to find a way to
91  * communicate with the CPU freq driver;
92  */
93 
94 #include <linux/types.h>
95 #include <linux/errno.h>
96 #include <linux/kernel.h>
97 #include <linux/delay.h>
98 #include <linux/slab.h>
99 #include <linux/init.h>
100 #include <linux/spinlock.h>
101 #include <linux/wait.h>
102 #include <linux/kmod.h>
103 #include <linux/device.h>
104 #include <linux/platform_device.h>
105 #include <linux/of.h>
106 
107 #include <asm/machdep.h>
108 #include <asm/io.h>
109 #include <asm/sections.h>
110 #include <asm/smu.h>
111 
112 #include "windfarm.h"
113 #include "windfarm_pid.h"
114 
115 #define VERSION "0.4"
116 
117 #undef DEBUG
118 
119 #ifdef DEBUG
120 #define DBG(args...)	printk(args)
121 #else
122 #define DBG(args...)	do { } while(0)
123 #endif
124 
125 /* define this to force CPU overtemp to 74 degree, useful for testing
126  * the overtemp code
127  */
128 #undef HACKED_OVERTEMP
129 
130 static int wf_smu_mach_model;	/* machine model id */
131 
132 /* Controls & sensors */
133 static struct wf_sensor	*sensor_cpu_power;
134 static struct wf_sensor	*sensor_cpu_temp;
135 static struct wf_sensor	*sensor_hd_temp;
136 static struct wf_control *fan_cpu_main;
137 static struct wf_control *fan_hd;
138 static struct wf_control *fan_system;
139 static struct wf_control *cpufreq_clamp;
140 
141 /* Set to kick the control loop into life */
142 static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok;
143 static bool wf_smu_started;
144 
145 /* Failure handling.. could be nicer */
146 #define FAILURE_FAN		0x01
147 #define FAILURE_SENSOR		0x02
148 #define FAILURE_OVERTEMP	0x04
149 
150 static unsigned int wf_smu_failure_state;
151 static int wf_smu_readjust, wf_smu_skipping;
152 static bool wf_smu_overtemp;
153 
154 /*
155  * ****** System Fans Control Loop ******
156  *
157  */
158 
159 /* Parameters for the System Fans control loop. Parameters
160  * not in this table such as interval, history size, ...
161  * are common to all versions and thus hard coded for now.
162  */
163 struct wf_smu_sys_fans_param {
164 	int	model_id;
165 	s32	itarget;
166 	s32	gd, gp, gr;
167 
168 	s16	offset0;
169 	u16	scale0;
170 	s16	offset1;
171 	u16	scale1;
172 };
173 
174 #define WF_SMU_SYS_FANS_INTERVAL	5
175 #define WF_SMU_SYS_FANS_HISTORY_SIZE	2
176 
177 /* State data used by the system fans control loop
178  */
179 struct wf_smu_sys_fans_state {
180 	int			ticks;
181 	s32			sys_setpoint;
182 	s32			hd_setpoint;
183 	s16			offset0;
184 	u16			scale0;
185 	s16			offset1;
186 	u16			scale1;
187 	struct wf_pid_state	pid;
188 };
189 
190 /*
191  * Configs for SMU System Fan control loop
192  */
193 static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = {
194 	/* Model ID 2 */
195 	{
196 		.model_id	= 2,
197 		.itarget	= 0x3a0000,
198 		.gd		= 0x15400000,
199 		.gp		= 0x00200000,
200 		.gr		= 0x000002fd,
201 		.offset0	= 0xff38,
202 		.scale0		= 0x0ccd,
203 		.offset1	= 0x0208,
204 		.scale1		= 0x07ae,
205 	},
206 	/* Model ID 3 */
207 	{
208 		.model_id	= 3,
209 		.itarget	= 0x350000,
210 		.gd		= 0x08e00000,
211 		.gp		= 0x00566666,
212 		.gr		= 0x0000072b,
213 		.offset0	= 0xff38,
214 		.scale0		= 0x0ccd,
215 		.offset1	= 0x0000,
216 		.scale1		= 0x0000,
217 	},
218 	/* Model ID 5 */
219 	{
220 		.model_id	= 5,
221 		.itarget	= 0x3a0000,
222 		.gd		= 0x15400000,
223 		.gp		= 0x00233333,
224 		.gr		= 0x000002fd,
225 		.offset0	= 0x0000,
226 		.scale0		= 0x1000,
227 		.offset1	= 0x0091,
228 		.scale1		= 0x0bae,
229 	},
230 };
231 #define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)
232 
233 static struct wf_smu_sys_fans_state *wf_smu_sys_fans;
234 
235 /*
236  * ****** CPU Fans Control Loop ******
237  *
238  */
239 
240 
241 #define WF_SMU_CPU_FANS_INTERVAL	1
242 #define WF_SMU_CPU_FANS_MAX_HISTORY	16
243 #define WF_SMU_CPU_FANS_SIBLING_SCALE	0x00001000
244 #define WF_SMU_CPU_FANS_SIBLING_OFFSET	0xfffffb50
245 
246 /* State data used by the cpu fans control loop
247  */
248 struct wf_smu_cpu_fans_state {
249 	int			ticks;
250 	s32			cpu_setpoint;
251 	s32			scale;
252 	s32			offset;
253 	struct wf_cpu_pid_state	pid;
254 };
255 
256 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
257 
258 
259 
260 /*
261  * ***** Implementation *****
262  *
263  */
264 
265 static void wf_smu_create_sys_fans(void)
266 {
267 	struct wf_smu_sys_fans_param *param = NULL;
268 	struct wf_pid_param pid_param;
269 	int i;
270 
271 	/* First, locate the params for this model */
272 	for (i = 0; i < WF_SMU_SYS_FANS_NUM_CONFIGS; i++)
273 		if (wf_smu_sys_all_params[i].model_id == wf_smu_mach_model) {
274 			param = &wf_smu_sys_all_params[i];
275 			break;
276 		}
277 
278 	/* No params found, put fans to max */
279 	if (param == NULL) {
280 		printk(KERN_WARNING "windfarm: System fan config not found "
281 		       "for this machine model, max fan speed\n");
282 		goto fail;
283 	}
284 
285 	/* Alloc & initialize state */
286 	wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state),
287 				  GFP_KERNEL);
288 	if (wf_smu_sys_fans == NULL) {
289 		printk(KERN_WARNING "windfarm: Memory allocation error"
290 		       " max fan speed\n");
291 		goto fail;
292 	}
293 	wf_smu_sys_fans->ticks = 1;
294 	wf_smu_sys_fans->scale0 = param->scale0;
295 	wf_smu_sys_fans->offset0 = param->offset0;
296 	wf_smu_sys_fans->scale1 = param->scale1;
297 	wf_smu_sys_fans->offset1 = param->offset1;
298 
299 	/* Fill PID params */
300 	pid_param.gd = param->gd;
301 	pid_param.gp = param->gp;
302 	pid_param.gr = param->gr;
303 	pid_param.interval = WF_SMU_SYS_FANS_INTERVAL;
304 	pid_param.history_len = WF_SMU_SYS_FANS_HISTORY_SIZE;
305 	pid_param.itarget = param->itarget;
306 	pid_param.min = wf_control_get_min(fan_system);
307 	pid_param.max = wf_control_get_max(fan_system);
308 	if (fan_hd) {
309 		pid_param.min =
310 			max(pid_param.min, wf_control_get_min(fan_hd));
311 		pid_param.max =
312 			min(pid_param.max, wf_control_get_max(fan_hd));
313 	}
314 	wf_pid_init(&wf_smu_sys_fans->pid, &pid_param);
315 
316 	DBG("wf: System Fan control initialized.\n");
317 	DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
318 	    FIX32TOPRINT(pid_param.itarget), pid_param.min, pid_param.max);
319 	return;
320 
321  fail:
322 
323 	if (fan_system)
324 		wf_control_set_max(fan_system);
325 	if (fan_hd)
326 		wf_control_set_max(fan_hd);
327 }
328 
329 static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st)
330 {
331 	s32 new_setpoint, temp, scaled, cputarget;
332 	int rc;
333 
334 	if (--st->ticks != 0) {
335 		if (wf_smu_readjust)
336 			goto readjust;
337 		return;
338 	}
339 	st->ticks = WF_SMU_SYS_FANS_INTERVAL;
340 
341 	rc = wf_sensor_get(sensor_hd_temp, &temp);
342 	if (rc) {
343 		printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
344 		       rc);
345 		wf_smu_failure_state |= FAILURE_SENSOR;
346 		return;
347 	}
348 
349 	DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
350 	    FIX32TOPRINT(temp));
351 
352 	if (temp > (st->pid.param.itarget + 0x50000))
353 		wf_smu_failure_state |= FAILURE_OVERTEMP;
354 
355 	new_setpoint = wf_pid_run(&st->pid, temp);
356 
357 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
358 
359 	scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;
360 
361 	DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled);
362 
363 	cputarget = wf_smu_cpu_fans ? wf_smu_cpu_fans->pid.target : 0;
364 	cputarget = ((((s64)cputarget) * (s64)st->scale1) >> 12) + st->offset1;
365 	scaled = max(scaled, cputarget);
366 	scaled = max(scaled, st->pid.param.min);
367 	scaled = min(scaled, st->pid.param.max);
368 
369 	DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled);
370 
371 	if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint)
372 		return;
373 	st->sys_setpoint = scaled;
374 	st->hd_setpoint = new_setpoint;
375  readjust:
376 	if (fan_system && wf_smu_failure_state == 0) {
377 		rc = wf_control_set(fan_system, st->sys_setpoint);
378 		if (rc) {
379 			printk(KERN_WARNING "windfarm: Sys fan error %d\n",
380 			       rc);
381 			wf_smu_failure_state |= FAILURE_FAN;
382 		}
383 	}
384 	if (fan_hd && wf_smu_failure_state == 0) {
385 		rc = wf_control_set(fan_hd, st->hd_setpoint);
386 		if (rc) {
387 			printk(KERN_WARNING "windfarm: HD fan error %d\n",
388 			       rc);
389 			wf_smu_failure_state |= FAILURE_FAN;
390 		}
391 	}
392 }
393 
394 static void wf_smu_create_cpu_fans(void)
395 {
396 	struct wf_cpu_pid_param pid_param;
397 	const struct smu_sdbp_header *hdr;
398 	struct smu_sdbp_cpupiddata *piddata;
399 	struct smu_sdbp_fvt *fvt;
400 	s32 tmax, tdelta, maxpow, powadj;
401 
402 	/* First, locate the PID params in SMU SBD */
403 	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
404 	if (hdr == 0) {
405 		printk(KERN_WARNING "windfarm: CPU PID fan config not found "
406 		       "max fan speed\n");
407 		goto fail;
408 	}
409 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
410 
411 	/* Get the FVT params for operating point 0 (the only supported one
412 	 * for now) in order to get tmax
413 	 */
414 	hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
415 	if (hdr) {
416 		fvt = (struct smu_sdbp_fvt *)&hdr[1];
417 		tmax = ((s32)fvt->maxtemp) << 16;
418 	} else
419 		tmax = 0x5e0000; /* 94 degree default */
420 
421 	/* Alloc & initialize state */
422 	wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
423 				  GFP_KERNEL);
424 	if (wf_smu_cpu_fans == NULL)
425 		goto fail;
426        	wf_smu_cpu_fans->ticks = 1;
427 
428 	wf_smu_cpu_fans->scale = WF_SMU_CPU_FANS_SIBLING_SCALE;
429 	wf_smu_cpu_fans->offset = WF_SMU_CPU_FANS_SIBLING_OFFSET;
430 
431 	/* Fill PID params */
432 	pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
433 	pid_param.history_len = piddata->history_len;
434 	if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
435 		printk(KERN_WARNING "windfarm: History size overflow on "
436 		       "CPU control loop (%d)\n", piddata->history_len);
437 		pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
438 	}
439 	pid_param.gd = piddata->gd;
440 	pid_param.gp = piddata->gp;
441 	pid_param.gr = piddata->gr / pid_param.history_len;
442 
443 	tdelta = ((s32)piddata->target_temp_delta) << 16;
444 	maxpow = ((s32)piddata->max_power) << 16;
445 	powadj = ((s32)piddata->power_adj) << 16;
446 
447 	pid_param.tmax = tmax;
448 	pid_param.ttarget = tmax - tdelta;
449 	pid_param.pmaxadj = maxpow - powadj;
450 
451 	pid_param.min = wf_control_get_min(fan_cpu_main);
452 	pid_param.max = wf_control_get_max(fan_cpu_main);
453 
454 	wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
455 
456 	DBG("wf: CPU Fan control initialized.\n");
457 	DBG("    ttarget=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
458 	    FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
459 	    pid_param.min, pid_param.max);
460 
461 	return;
462 
463  fail:
464 	printk(KERN_WARNING "windfarm: CPU fan config not found\n"
465 	       "for this machine model, max fan speed\n");
466 
467 	if (cpufreq_clamp)
468 		wf_control_set_max(cpufreq_clamp);
469 	if (fan_cpu_main)
470 		wf_control_set_max(fan_cpu_main);
471 }
472 
473 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
474 {
475 	s32 new_setpoint, temp, power, systarget;
476 	int rc;
477 
478 	if (--st->ticks != 0) {
479 		if (wf_smu_readjust)
480 			goto readjust;
481 		return;
482 	}
483 	st->ticks = WF_SMU_CPU_FANS_INTERVAL;
484 
485 	rc = wf_sensor_get(sensor_cpu_temp, &temp);
486 	if (rc) {
487 		printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
488 		       rc);
489 		wf_smu_failure_state |= FAILURE_SENSOR;
490 		return;
491 	}
492 
493 	rc = wf_sensor_get(sensor_cpu_power, &power);
494 	if (rc) {
495 		printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
496 		       rc);
497 		wf_smu_failure_state |= FAILURE_SENSOR;
498 		return;
499 	}
500 
501 	DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
502 	    FIX32TOPRINT(temp), FIX32TOPRINT(power));
503 
504 #ifdef HACKED_OVERTEMP
505 	if (temp > 0x4a0000)
506 		wf_smu_failure_state |= FAILURE_OVERTEMP;
507 #else
508 	if (temp > st->pid.param.tmax)
509 		wf_smu_failure_state |= FAILURE_OVERTEMP;
510 #endif
511 	new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
512 
513 	DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
514 
515 	systarget = wf_smu_sys_fans ? wf_smu_sys_fans->pid.target : 0;
516 	systarget = ((((s64)systarget) * (s64)st->scale) >> 12)
517 		+ st->offset;
518 	new_setpoint = max(new_setpoint, systarget);
519 	new_setpoint = max(new_setpoint, st->pid.param.min);
520 	new_setpoint = min(new_setpoint, st->pid.param.max);
521 
522 	DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint);
523 
524 	if (st->cpu_setpoint == new_setpoint)
525 		return;
526 	st->cpu_setpoint = new_setpoint;
527  readjust:
528 	if (fan_cpu_main && wf_smu_failure_state == 0) {
529 		rc = wf_control_set(fan_cpu_main, st->cpu_setpoint);
530 		if (rc) {
531 			printk(KERN_WARNING "windfarm: CPU main fan"
532 			       " error %d\n", rc);
533 			wf_smu_failure_state |= FAILURE_FAN;
534 		}
535 	}
536 }
537 
538 /*
539  * ****** Setup / Init / Misc ... ******
540  *
541  */
542 
543 static void wf_smu_tick(void)
544 {
545 	unsigned int last_failure = wf_smu_failure_state;
546 	unsigned int new_failure;
547 
548 	if (!wf_smu_started) {
549 		DBG("wf: creating control loops !\n");
550 		wf_smu_create_sys_fans();
551 		wf_smu_create_cpu_fans();
552 		wf_smu_started = true;
553 	}
554 
555 	/* Skipping ticks */
556 	if (wf_smu_skipping && --wf_smu_skipping)
557 		return;
558 
559 	wf_smu_failure_state = 0;
560 	if (wf_smu_sys_fans)
561 		wf_smu_sys_fans_tick(wf_smu_sys_fans);
562 	if (wf_smu_cpu_fans)
563 		wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
564 
565 	wf_smu_readjust = 0;
566 	new_failure = wf_smu_failure_state & ~last_failure;
567 
568 	/* If entering failure mode, clamp cpufreq and ramp all
569 	 * fans to full speed.
570 	 */
571 	if (wf_smu_failure_state && !last_failure) {
572 		if (cpufreq_clamp)
573 			wf_control_set_max(cpufreq_clamp);
574 		if (fan_system)
575 			wf_control_set_max(fan_system);
576 		if (fan_cpu_main)
577 			wf_control_set_max(fan_cpu_main);
578 		if (fan_hd)
579 			wf_control_set_max(fan_hd);
580 	}
581 
582 	/* If leaving failure mode, unclamp cpufreq and readjust
583 	 * all fans on next iteration
584 	 */
585 	if (!wf_smu_failure_state && last_failure) {
586 		if (cpufreq_clamp)
587 			wf_control_set_min(cpufreq_clamp);
588 		wf_smu_readjust = 1;
589 	}
590 
591 	/* Overtemp condition detected, notify and start skipping a couple
592 	 * ticks to let the temperature go down
593 	 */
594 	if (new_failure & FAILURE_OVERTEMP) {
595 		wf_set_overtemp();
596 		wf_smu_skipping = 2;
597 		wf_smu_overtemp = true;
598 	}
599 
600 	/* We only clear the overtemp condition if overtemp is cleared
601 	 * _and_ no other failure is present. Since a sensor error will
602 	 * clear the overtemp condition (can't measure temperature) at
603 	 * the control loop levels, but we don't want to keep it clear
604 	 * here in this case
605 	 */
606 	if (!wf_smu_failure_state && wf_smu_overtemp) {
607 		wf_clear_overtemp();
608 		wf_smu_overtemp = false;
609 	}
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 	const 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 platform_device *ddev)
721 {
722 	wf_register_client(&wf_smu_events);
723 
724 	return 0;
725 }
726 
727 static int wf_smu_remove(struct platform_device *ddev)
728 {
729 	wf_unregister_client(&wf_smu_events);
730 
731 	/* XXX We don't have yet a guarantee that our callback isn't
732 	 * in progress when returning from wf_unregister_client, so
733 	 * we add an arbitrary delay. I'll have to fix that in the core
734 	 */
735 	msleep(1000);
736 
737 	/* Release all sensors */
738 	/* One more crappy race: I don't think we have any guarantee here
739 	 * that the attribute callback won't race with the sensor beeing
740 	 * disposed of, and I'm not 100% certain what best way to deal
741 	 * with that except by adding locks all over... I'll do that
742 	 * eventually but heh, who ever rmmod this module anyway ?
743 	 */
744 	if (sensor_cpu_power)
745 		wf_put_sensor(sensor_cpu_power);
746 	if (sensor_cpu_temp)
747 		wf_put_sensor(sensor_cpu_temp);
748 	if (sensor_hd_temp)
749 		wf_put_sensor(sensor_hd_temp);
750 
751 	/* Release all controls */
752 	if (fan_cpu_main)
753 		wf_put_control(fan_cpu_main);
754 	if (fan_hd)
755 		wf_put_control(fan_hd);
756 	if (fan_system)
757 		wf_put_control(fan_system);
758 	if (cpufreq_clamp)
759 		wf_put_control(cpufreq_clamp);
760 
761 	/* Destroy control loops state structures */
762 	kfree(wf_smu_sys_fans);
763 	kfree(wf_smu_cpu_fans);
764 
765 	return 0;
766 }
767 
768 static struct platform_driver wf_smu_driver = {
769         .probe = wf_smu_probe,
770         .remove = wf_smu_remove,
771 	.driver = {
772 		.name = "windfarm",
773 	},
774 };
775 
776 
777 static int __init wf_smu_init(void)
778 {
779 	int rc = -ENODEV;
780 
781 	if (of_machine_is_compatible("PowerMac8,1") ||
782 	    of_machine_is_compatible("PowerMac8,2"))
783 		rc = wf_init_pm();
784 
785 	if (rc == 0) {
786 #ifdef MODULE
787 		request_module("windfarm_smu_controls");
788 		request_module("windfarm_smu_sensors");
789 		request_module("windfarm_lm75_sensor");
790 		request_module("windfarm_cpufreq_clamp");
791 
792 #endif /* MODULE */
793 		platform_driver_register(&wf_smu_driver);
794 	}
795 
796 	return rc;
797 }
798 
799 static void __exit wf_smu_exit(void)
800 {
801 
802 	platform_driver_unregister(&wf_smu_driver);
803 }
804 
805 
806 module_init(wf_smu_init);
807 module_exit(wf_smu_exit);
808 
809 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
810 MODULE_DESCRIPTION("Thermal control logic for iMac G5");
811 MODULE_LICENSE("GPL");
812 MODULE_ALIAS("platform:windfarm");
813