1 /*
2  * Windfarm PowerMac thermal control. iMac G5 iSight
3  *
4  * (c) Copyright 2007 Étienne Bersac <bersace@gmail.com>
5  *
6  * Bits & pieces from windfarm_pm81.c by (c) Copyright 2005 Benjamin
7  * Herrenschmidt, IBM Corp. <benh@kernel.crashing.org>
8  *
9  * Released under the term of the GNU GPL v2.
10  *
11  *
12  *
13  * PowerMac12,1
14  * ============
15  *
16  *
17  * The algorithm used is the PID control algorithm, used the same way
18  * the published Darwin code does, using the same values that are
19  * present in the Darwin 8.10 snapshot property lists (note however
20  * that none of the code has been re-used, it's a complete
21  * re-implementation
22  *
23  * There is two models using PowerMac12,1. Model 2 is iMac G5 iSight
24  * 17" while Model 3 is iMac G5 20". They do have both the same
25  * controls with a tiny difference. The control-ids of hard-drive-fan
26  * and cpu-fan is swapped.
27  *
28  *
29  * Target Correction :
30  *
31  * controls have a target correction calculated as :
32  *
33  * new_min = ((((average_power * slope) >> 16) + offset) >> 16) + min_value
34  * new_value = max(new_value, max(new_min, 0))
35  *
36  * OD Fan control correction.
37  *
38  * # model_id: 2
39  *   offset		: -19563152
40  *   slope		:  1956315
41  *
42  * # model_id: 3
43  *   offset		: -15650652
44  *   slope		:  1565065
45  *
46  * HD Fan control correction.
47  *
48  * # model_id: 2
49  *   offset		: -15650652
50  *   slope		:  1565065
51  *
52  * # model_id: 3
53  *   offset		: -19563152
54  *   slope		:  1956315
55  *
56  * CPU Fan control correction.
57  *
58  * # model_id: 2
59  *   offset		: -25431900
60  *   slope		:  2543190
61  *
62  * # model_id: 3
63  *   offset		: -15650652
64  *   slope		:  1565065
65  *
66  *
67  * Target rubber-banding :
68  *
69  * Some controls have a target correction which depends on another
70  * control value. The correction is computed in the following way :
71  *
72  * new_min = ref_value * slope + offset
73  *
74  * ref_value is the value of the reference control. If new_min is
75  * greater than 0, then we correct the target value using :
76  *
77  * new_target = max (new_target, new_min >> 16)
78  *
79  *
80  * # model_id : 2
81  *   control	: cpu-fan
82  *   ref	: optical-drive-fan
83  *   offset	: -15650652
84  *   slope	: 1565065
85  *
86  * # model_id : 3
87  *   control	: optical-drive-fan
88  *   ref	: hard-drive-fan
89  *   offset	: -32768000
90  *   slope	: 65536
91  *
92  *
93  * In order to have the moste efficient correction with those
94  * dependencies, we must trigger HD loop before OD loop before CPU
95  * loop.
96  *
97  *
98  * The various control loops found in Darwin config file are:
99  *
100  * HD Fan control loop.
101  *
102  * # model_id: 2
103  *   control        : hard-drive-fan
104  *   sensor         : hard-drive-temp
105  *   PID params     : G_d = 0x00000000
106  *                    G_p = 0x002D70A3
107  *                    G_r = 0x00019999
108  *                    History = 2 entries
109  *                    Input target = 0x370000
110  *                    Interval = 5s
111  *
112  * # model_id: 3
113  *   control        : hard-drive-fan
114  *   sensor         : hard-drive-temp
115  *   PID params     : G_d = 0x00000000
116  *                    G_p = 0x002170A3
117  *                    G_r = 0x00019999
118  *                    History = 2 entries
119  *                    Input target = 0x370000
120  *                    Interval = 5s
121  *
122  * OD Fan control loop.
123  *
124  * # model_id: 2
125  *   control        : optical-drive-fan
126  *   sensor         : optical-drive-temp
127  *   PID params     : G_d = 0x00000000
128  *                    G_p = 0x001FAE14
129  *                    G_r = 0x00019999
130  *                    History = 2 entries
131  *                    Input target = 0x320000
132  *                    Interval = 5s
133  *
134  * # model_id: 3
135  *   control        : optical-drive-fan
136  *   sensor         : optical-drive-temp
137  *   PID params     : G_d = 0x00000000
138  *                    G_p = 0x001FAE14
139  *                    G_r = 0x00019999
140  *                    History = 2 entries
141  *                    Input target = 0x320000
142  *                    Interval = 5s
143  *
144  * GPU Fan control loop.
145  *
146  * # model_id: 2
147  *   control        : hard-drive-fan
148  *   sensor         : gpu-temp
149  *   PID params     : G_d = 0x00000000
150  *                    G_p = 0x002A6666
151  *                    G_r = 0x00019999
152  *                    History = 2 entries
153  *                    Input target = 0x5A0000
154  *                    Interval = 5s
155  *
156  * # model_id: 3
157  *   control        : cpu-fan
158  *   sensor         : gpu-temp
159  *   PID params     : G_d = 0x00000000
160  *                    G_p = 0x0010CCCC
161  *                    G_r = 0x00019999
162  *                    History = 2 entries
163  *                    Input target = 0x500000
164  *                    Interval = 5s
165  *
166  * KODIAK (aka northbridge) Fan control loop.
167  *
168  * # model_id: 2
169  *   control        : optical-drive-fan
170  *   sensor         : north-bridge-temp
171  *   PID params     : G_d = 0x00000000
172  *                    G_p = 0x003BD70A
173  *                    G_r = 0x00019999
174  *                    History = 2 entries
175  *                    Input target = 0x550000
176  *                    Interval = 5s
177  *
178  * # model_id: 3
179  *   control        : hard-drive-fan
180  *   sensor         : north-bridge-temp
181  *   PID params     : G_d = 0x00000000
182  *                    G_p = 0x0030F5C2
183  *                    G_r = 0x00019999
184  *                    History = 2 entries
185  *                    Input target = 0x550000
186  *                    Interval = 5s
187  *
188  * CPU Fan control loop.
189  *
190  *   control        : cpu-fan
191  *   sensors        : cpu-temp, cpu-power
192  *   PID params     : from SDB partition
193  *
194  *
195  * CPU Slew control loop.
196  *
197  *   control        : cpufreq-clamp
198  *   sensor         : cpu-temp
199  *
200  */
201 
202 #undef	DEBUG
203 
204 #include <linux/types.h>
205 #include <linux/errno.h>
206 #include <linux/kernel.h>
207 #include <linux/delay.h>
208 #include <linux/slab.h>
209 #include <linux/init.h>
210 #include <linux/spinlock.h>
211 #include <linux/wait.h>
212 #include <linux/kmod.h>
213 #include <linux/device.h>
214 #include <linux/platform_device.h>
215 #include <asm/prom.h>
216 #include <asm/machdep.h>
217 #include <asm/io.h>
218 #include <asm/sections.h>
219 #include <asm/smu.h>
220 
221 #include "windfarm.h"
222 #include "windfarm_pid.h"
223 
224 #define VERSION "0.3"
225 
226 static int pm121_mach_model;	/* machine model id */
227 
228 /* Controls & sensors */
229 static struct wf_sensor	*sensor_cpu_power;
230 static struct wf_sensor	*sensor_cpu_temp;
231 static struct wf_sensor	*sensor_cpu_voltage;
232 static struct wf_sensor	*sensor_cpu_current;
233 static struct wf_sensor	*sensor_gpu_temp;
234 static struct wf_sensor	*sensor_north_bridge_temp;
235 static struct wf_sensor	*sensor_hard_drive_temp;
236 static struct wf_sensor	*sensor_optical_drive_temp;
237 static struct wf_sensor	*sensor_incoming_air_temp; /* unused ! */
238 
239 enum {
240 	FAN_CPU,
241 	FAN_HD,
242 	FAN_OD,
243 	CPUFREQ,
244 	N_CONTROLS
245 };
246 static struct wf_control *controls[N_CONTROLS] = {};
247 
248 /* Set to kick the control loop into life */
249 static int pm121_all_controls_ok, pm121_all_sensors_ok, pm121_started;
250 
251 enum {
252 	FAILURE_FAN		= 1 << 0,
253 	FAILURE_SENSOR		= 1 << 1,
254 	FAILURE_OVERTEMP	= 1 << 2
255 };
256 
257 /* All sys loops. Note the HD before the OD loop in order to have it
258    run before. */
259 enum {
260 	LOOP_GPU,		/* control = hd or cpu, but luckily,
261 				   it doesn't matter */
262 	LOOP_HD,		/* control = hd */
263 	LOOP_KODIAK,		/* control = hd or od */
264 	LOOP_OD,		/* control = od */
265 	N_LOOPS
266 };
267 
268 static const char *loop_names[N_LOOPS] = {
269 	"GPU",
270 	"HD",
271 	"KODIAK",
272 	"OD",
273 };
274 
275 #define	PM121_NUM_CONFIGS	2
276 
277 static unsigned int pm121_failure_state;
278 static int pm121_readjust, pm121_skipping;
279 static s32 average_power;
280 
281 struct pm121_correction {
282 	int	offset;
283 	int	slope;
284 };
285 
286 static struct pm121_correction corrections[N_CONTROLS][PM121_NUM_CONFIGS] = {
287 	/* FAN_OD */
288 	{
289 		/* MODEL 2 */
290 		{ .offset	= -19563152,
291 		  .slope	=  1956315
292 		},
293 		/* MODEL 3 */
294 		{ .offset	= -15650652,
295 		  .slope	=  1565065
296 		},
297 	},
298 	/* FAN_HD */
299 	{
300 		/* MODEL 2 */
301 		{ .offset	= -15650652,
302 		  .slope	=  1565065
303 		},
304 		/* MODEL 3 */
305 		{ .offset	= -19563152,
306 		  .slope	=  1956315
307 		},
308 	},
309 	/* FAN_CPU */
310 	{
311 		/* MODEL 2 */
312 		{ .offset	= -25431900,
313 		  .slope	=  2543190
314 		},
315 		/* MODEL 3 */
316 		{ .offset	= -15650652,
317 		  .slope	=  1565065
318 		},
319 	},
320 	/* CPUFREQ has no correction (and is not implemented at all) */
321 };
322 
323 struct pm121_connection {
324 	unsigned int	control_id;
325 	unsigned int	ref_id;
326 	struct pm121_correction	correction;
327 };
328 
329 static struct pm121_connection pm121_connections[] = {
330 	/* MODEL 2 */
331 	{ .control_id	= FAN_CPU,
332 	  .ref_id	= FAN_OD,
333 	  { .offset	= -32768000,
334 	    .slope	=  65536
335 	  }
336 	},
337 	/* MODEL 3 */
338 	{ .control_id	= FAN_OD,
339 	  .ref_id	= FAN_HD,
340 	  { .offset	= -32768000,
341 	    .slope	=  65536
342 	  }
343 	},
344 };
345 
346 /* pointer to the current model connection */
347 static struct pm121_connection *pm121_connection;
348 
349 /*
350  * ****** System Fans Control Loop ******
351  *
352  */
353 
354 /* Since each loop handles only one control and we want to avoid
355  * writing virtual control, we store the control correction with the
356  * loop params. Some data are not set, there are common to all loop
357  * and thus, hardcoded.
358  */
359 struct pm121_sys_param {
360 	/* purely informative since we use mach_model-2 as index */
361 	int			model_id;
362 	struct wf_sensor	**sensor; /* use sensor_id instead ? */
363 	s32			gp, itarget;
364 	unsigned int		control_id;
365 };
366 
367 static struct pm121_sys_param
368 pm121_sys_all_params[N_LOOPS][PM121_NUM_CONFIGS] = {
369 	/* GPU Fan control loop */
370 	{
371 		{ .model_id	= 2,
372 		  .sensor	= &sensor_gpu_temp,
373 		  .gp		= 0x002A6666,
374 		  .itarget	= 0x5A0000,
375 		  .control_id	= FAN_HD,
376 		},
377 		{ .model_id	= 3,
378 		  .sensor	= &sensor_gpu_temp,
379 		  .gp		= 0x0010CCCC,
380 		  .itarget	= 0x500000,
381 		  .control_id	= FAN_CPU,
382 		},
383 	},
384 	/* HD Fan control loop */
385 	{
386 		{ .model_id	= 2,
387 		  .sensor	= &sensor_hard_drive_temp,
388 		  .gp		= 0x002D70A3,
389 		  .itarget	= 0x370000,
390 		  .control_id	= FAN_HD,
391 		},
392 		{ .model_id	= 3,
393 		  .sensor	= &sensor_hard_drive_temp,
394 		  .gp		= 0x002170A3,
395 		  .itarget	= 0x370000,
396 		  .control_id	= FAN_HD,
397 		},
398 	},
399 	/* KODIAK Fan control loop */
400 	{
401 		{ .model_id	= 2,
402 		  .sensor	= &sensor_north_bridge_temp,
403 		  .gp		= 0x003BD70A,
404 		  .itarget	= 0x550000,
405 		  .control_id	= FAN_OD,
406 		},
407 		{ .model_id	= 3,
408 		  .sensor	= &sensor_north_bridge_temp,
409 		  .gp		= 0x0030F5C2,
410 		  .itarget	= 0x550000,
411 		  .control_id	= FAN_HD,
412 		},
413 	},
414 	/* OD Fan control loop */
415 	{
416 		{ .model_id	= 2,
417 		  .sensor	= &sensor_optical_drive_temp,
418 		  .gp		= 0x001FAE14,
419 		  .itarget	= 0x320000,
420 		  .control_id	= FAN_OD,
421 		},
422 		{ .model_id	= 3,
423 		  .sensor	= &sensor_optical_drive_temp,
424 		  .gp		= 0x001FAE14,
425 		  .itarget	= 0x320000,
426 		  .control_id	= FAN_OD,
427 		},
428 	},
429 };
430 
431 /* the hardcoded values */
432 #define	PM121_SYS_GD		0x00000000
433 #define	PM121_SYS_GR		0x00019999
434 #define	PM121_SYS_HISTORY_SIZE	2
435 #define	PM121_SYS_INTERVAL	5
436 
437 /* State data used by the system fans control loop
438  */
439 struct pm121_sys_state {
440 	int			ticks;
441 	s32			setpoint;
442 	struct wf_pid_state	pid;
443 };
444 
445 struct pm121_sys_state *pm121_sys_state[N_LOOPS] = {};
446 
447 /*
448  * ****** CPU Fans Control Loop ******
449  *
450  */
451 
452 #define PM121_CPU_INTERVAL	1
453 
454 /* State data used by the cpu fans control loop
455  */
456 struct pm121_cpu_state {
457 	int			ticks;
458 	s32			setpoint;
459 	struct wf_cpu_pid_state	pid;
460 };
461 
462 static struct pm121_cpu_state *pm121_cpu_state;
463 
464 
465 
466 /*
467  * ***** Implementation *****
468  *
469  */
470 
471 /* correction the value using the output-low-bound correction algo */
472 static s32 pm121_correct(s32 new_setpoint,
473 			 unsigned int control_id,
474 			 s32 min)
475 {
476 	s32 new_min;
477 	struct pm121_correction *correction;
478 	correction = &corrections[control_id][pm121_mach_model - 2];
479 
480 	new_min = (average_power * correction->slope) >> 16;
481 	new_min += correction->offset;
482 	new_min = (new_min >> 16) + min;
483 
484 	return max3(new_setpoint, new_min, 0);
485 }
486 
487 static s32 pm121_connect(unsigned int control_id, s32 setpoint)
488 {
489 	s32 new_min, value, new_setpoint;
490 
491 	if (pm121_connection->control_id == control_id) {
492 		controls[control_id]->ops->get_value(controls[control_id],
493 						     &value);
494 		new_min = value * pm121_connection->correction.slope;
495 		new_min += pm121_connection->correction.offset;
496 		if (new_min > 0) {
497 			new_setpoint = max(setpoint, (new_min >> 16));
498 			if (new_setpoint != setpoint) {
499 				pr_debug("pm121: %s depending on %s, "
500 					 "corrected from %d to %d RPM\n",
501 					 controls[control_id]->name,
502 					 controls[pm121_connection->ref_id]->name,
503 					 (int) setpoint, (int) new_setpoint);
504 			}
505 		} else
506 			new_setpoint = setpoint;
507 	}
508 	/* no connection */
509 	else
510 		new_setpoint = setpoint;
511 
512 	return new_setpoint;
513 }
514 
515 /* FAN LOOPS */
516 static void pm121_create_sys_fans(int loop_id)
517 {
518 	struct pm121_sys_param *param = NULL;
519 	struct wf_pid_param pid_param;
520 	struct wf_control *control = NULL;
521 	int i;
522 
523 	/* First, locate the params for this model */
524 	for (i = 0; i < PM121_NUM_CONFIGS; i++) {
525 		if (pm121_sys_all_params[loop_id][i].model_id == pm121_mach_model) {
526 			param = &(pm121_sys_all_params[loop_id][i]);
527 			break;
528 		}
529 	}
530 
531 	/* No params found, put fans to max */
532 	if (param == NULL) {
533 		printk(KERN_WARNING "pm121: %s fan config not found "
534 		       " for this machine model\n",
535 		       loop_names[loop_id]);
536 		goto fail;
537 	}
538 
539 	control = controls[param->control_id];
540 
541 	/* Alloc & initialize state */
542 	pm121_sys_state[loop_id] = kmalloc(sizeof(struct pm121_sys_state),
543 					   GFP_KERNEL);
544 	if (pm121_sys_state[loop_id] == NULL) {
545 		printk(KERN_WARNING "pm121: Memory allocation error\n");
546 		goto fail;
547 	}
548 	pm121_sys_state[loop_id]->ticks = 1;
549 
550 	/* Fill PID params */
551 	pid_param.gd		= PM121_SYS_GD;
552 	pid_param.gp		= param->gp;
553 	pid_param.gr		= PM121_SYS_GR;
554 	pid_param.interval	= PM121_SYS_INTERVAL;
555 	pid_param.history_len	= PM121_SYS_HISTORY_SIZE;
556 	pid_param.itarget	= param->itarget;
557 	pid_param.min		= control->ops->get_min(control);
558 	pid_param.max		= control->ops->get_max(control);
559 
560 	wf_pid_init(&pm121_sys_state[loop_id]->pid, &pid_param);
561 
562 	pr_debug("pm121: %s Fan control loop initialized.\n"
563 		 "       itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
564 		 loop_names[loop_id], FIX32TOPRINT(pid_param.itarget),
565 		 pid_param.min, pid_param.max);
566 	return;
567 
568  fail:
569 	/* note that this is not optimal since another loop may still
570 	   control the same control */
571 	printk(KERN_WARNING "pm121: failed to set up %s loop "
572 	       "setting \"%s\" to max speed.\n",
573 	       loop_names[loop_id], control->name);
574 
575 	if (control)
576 		wf_control_set_max(control);
577 }
578 
579 static void pm121_sys_fans_tick(int loop_id)
580 {
581 	struct pm121_sys_param *param;
582 	struct pm121_sys_state *st;
583 	struct wf_sensor *sensor;
584 	struct wf_control *control;
585 	s32 temp, new_setpoint;
586 	int rc;
587 
588 	param = &(pm121_sys_all_params[loop_id][pm121_mach_model-2]);
589 	st = pm121_sys_state[loop_id];
590 	sensor = *(param->sensor);
591 	control = controls[param->control_id];
592 
593 	if (--st->ticks != 0) {
594 		if (pm121_readjust)
595 			goto readjust;
596 		return;
597 	}
598 	st->ticks = PM121_SYS_INTERVAL;
599 
600 	rc = sensor->ops->get_value(sensor, &temp);
601 	if (rc) {
602 		printk(KERN_WARNING "windfarm: %s sensor error %d\n",
603 		       sensor->name, rc);
604 		pm121_failure_state |= FAILURE_SENSOR;
605 		return;
606 	}
607 
608 	pr_debug("pm121: %s Fan tick ! %s: %d.%03d\n",
609 		 loop_names[loop_id], sensor->name,
610 		 FIX32TOPRINT(temp));
611 
612 	new_setpoint = wf_pid_run(&st->pid, temp);
613 
614 	/* correction */
615 	new_setpoint = pm121_correct(new_setpoint,
616 				     param->control_id,
617 				     st->pid.param.min);
618 	/* linked corretion */
619 	new_setpoint = pm121_connect(param->control_id, new_setpoint);
620 
621 	if (new_setpoint == st->setpoint)
622 		return;
623 	st->setpoint = new_setpoint;
624 	pr_debug("pm121: %s corrected setpoint: %d RPM\n",
625 		 control->name, (int)new_setpoint);
626  readjust:
627 	if (control && pm121_failure_state == 0) {
628 		rc = control->ops->set_value(control, st->setpoint);
629 		if (rc) {
630 			printk(KERN_WARNING "windfarm: %s fan error %d\n",
631 			       control->name, rc);
632 			pm121_failure_state |= FAILURE_FAN;
633 		}
634 	}
635 }
636 
637 
638 /* CPU LOOP */
639 static void pm121_create_cpu_fans(void)
640 {
641 	struct wf_cpu_pid_param pid_param;
642 	const struct smu_sdbp_header *hdr;
643 	struct smu_sdbp_cpupiddata *piddata;
644 	struct smu_sdbp_fvt *fvt;
645 	struct wf_control *fan_cpu;
646 	s32 tmax, tdelta, maxpow, powadj;
647 
648 	fan_cpu = controls[FAN_CPU];
649 
650 	/* First, locate the PID params in SMU SBD */
651 	hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
652 	if (hdr == 0) {
653 		printk(KERN_WARNING "pm121: CPU PID fan config not found.\n");
654 		goto fail;
655 	}
656 	piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
657 
658 	/* Get the FVT params for operating point 0 (the only supported one
659 	 * for now) in order to get tmax
660 	 */
661 	hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
662 	if (hdr) {
663 		fvt = (struct smu_sdbp_fvt *)&hdr[1];
664 		tmax = ((s32)fvt->maxtemp) << 16;
665 	} else
666 		tmax = 0x5e0000; /* 94 degree default */
667 
668 	/* Alloc & initialize state */
669 	pm121_cpu_state = kmalloc(sizeof(struct pm121_cpu_state),
670 				  GFP_KERNEL);
671 	if (pm121_cpu_state == NULL)
672 		goto fail;
673 	pm121_cpu_state->ticks = 1;
674 
675 	/* Fill PID params */
676 	pid_param.interval = PM121_CPU_INTERVAL;
677 	pid_param.history_len = piddata->history_len;
678 	if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
679 		printk(KERN_WARNING "pm121: History size overflow on "
680 		       "CPU control loop (%d)\n", piddata->history_len);
681 		pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
682 	}
683 	pid_param.gd = piddata->gd;
684 	pid_param.gp = piddata->gp;
685 	pid_param.gr = piddata->gr / pid_param.history_len;
686 
687 	tdelta = ((s32)piddata->target_temp_delta) << 16;
688 	maxpow = ((s32)piddata->max_power) << 16;
689 	powadj = ((s32)piddata->power_adj) << 16;
690 
691 	pid_param.tmax = tmax;
692 	pid_param.ttarget = tmax - tdelta;
693 	pid_param.pmaxadj = maxpow - powadj;
694 
695 	pid_param.min = fan_cpu->ops->get_min(fan_cpu);
696 	pid_param.max = fan_cpu->ops->get_max(fan_cpu);
697 
698 	wf_cpu_pid_init(&pm121_cpu_state->pid, &pid_param);
699 
700 	pr_debug("pm121: CPU Fan control initialized.\n");
701 	pr_debug("       ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM,\n",
702 		 FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
703 		 pid_param.min, pid_param.max);
704 
705 	return;
706 
707  fail:
708 	printk(KERN_WARNING "pm121: CPU fan config not found, max fan speed\n");
709 
710 	if (controls[CPUFREQ])
711 		wf_control_set_max(controls[CPUFREQ]);
712 	if (fan_cpu)
713 		wf_control_set_max(fan_cpu);
714 }
715 
716 
717 static void pm121_cpu_fans_tick(struct pm121_cpu_state *st)
718 {
719 	s32 new_setpoint, temp, power;
720 	struct wf_control *fan_cpu = NULL;
721 	int rc;
722 
723 	if (--st->ticks != 0) {
724 		if (pm121_readjust)
725 			goto readjust;
726 		return;
727 	}
728 	st->ticks = PM121_CPU_INTERVAL;
729 
730 	fan_cpu = controls[FAN_CPU];
731 
732 	rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
733 	if (rc) {
734 		printk(KERN_WARNING "pm121: CPU temp sensor error %d\n",
735 		       rc);
736 		pm121_failure_state |= FAILURE_SENSOR;
737 		return;
738 	}
739 
740 	rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
741 	if (rc) {
742 		printk(KERN_WARNING "pm121: CPU power sensor error %d\n",
743 		       rc);
744 		pm121_failure_state |= FAILURE_SENSOR;
745 		return;
746 	}
747 
748 	pr_debug("pm121: CPU Fans tick ! CPU temp: %d.%03d°C, power: %d.%03d\n",
749 		 FIX32TOPRINT(temp), FIX32TOPRINT(power));
750 
751 	if (temp > st->pid.param.tmax)
752 		pm121_failure_state |= FAILURE_OVERTEMP;
753 
754 	new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
755 
756 	/* correction */
757 	new_setpoint = pm121_correct(new_setpoint,
758 				     FAN_CPU,
759 				     st->pid.param.min);
760 
761 	/* connected correction */
762 	new_setpoint = pm121_connect(FAN_CPU, new_setpoint);
763 
764 	if (st->setpoint == new_setpoint)
765 		return;
766 	st->setpoint = new_setpoint;
767 	pr_debug("pm121: CPU corrected setpoint: %d RPM\n", (int)new_setpoint);
768 
769  readjust:
770 	if (fan_cpu && pm121_failure_state == 0) {
771 		rc = fan_cpu->ops->set_value(fan_cpu, st->setpoint);
772 		if (rc) {
773 			printk(KERN_WARNING "pm121: %s fan error %d\n",
774 			       fan_cpu->name, rc);
775 			pm121_failure_state |= FAILURE_FAN;
776 		}
777 	}
778 }
779 
780 /*
781  * ****** Common ******
782  *
783  */
784 
785 static void pm121_tick(void)
786 {
787 	unsigned int last_failure = pm121_failure_state;
788 	unsigned int new_failure;
789 	s32 total_power;
790 	int i;
791 
792 	if (!pm121_started) {
793 		pr_debug("pm121: creating control loops !\n");
794 		for (i = 0; i < N_LOOPS; i++)
795 			pm121_create_sys_fans(i);
796 
797 		pm121_create_cpu_fans();
798 		pm121_started = 1;
799 	}
800 
801 	/* skipping ticks */
802 	if (pm121_skipping && --pm121_skipping)
803 		return;
804 
805 	/* compute average power */
806 	total_power = 0;
807 	for (i = 0; i < pm121_cpu_state->pid.param.history_len; i++)
808 		total_power += pm121_cpu_state->pid.powers[i];
809 
810 	average_power = total_power / pm121_cpu_state->pid.param.history_len;
811 
812 
813 	pm121_failure_state = 0;
814 	for (i = 0 ; i < N_LOOPS; i++) {
815 		if (pm121_sys_state[i])
816 			pm121_sys_fans_tick(i);
817 	}
818 
819 	if (pm121_cpu_state)
820 		pm121_cpu_fans_tick(pm121_cpu_state);
821 
822 	pm121_readjust = 0;
823 	new_failure = pm121_failure_state & ~last_failure;
824 
825 	/* If entering failure mode, clamp cpufreq and ramp all
826 	 * fans to full speed.
827 	 */
828 	if (pm121_failure_state && !last_failure) {
829 		for (i = 0; i < N_CONTROLS; i++) {
830 			if (controls[i])
831 				wf_control_set_max(controls[i]);
832 		}
833 	}
834 
835 	/* If leaving failure mode, unclamp cpufreq and readjust
836 	 * all fans on next iteration
837 	 */
838 	if (!pm121_failure_state && last_failure) {
839 		if (controls[CPUFREQ])
840 			wf_control_set_min(controls[CPUFREQ]);
841 		pm121_readjust = 1;
842 	}
843 
844 	/* Overtemp condition detected, notify and start skipping a couple
845 	 * ticks to let the temperature go down
846 	 */
847 	if (new_failure & FAILURE_OVERTEMP) {
848 		wf_set_overtemp();
849 		pm121_skipping = 2;
850 	}
851 
852 	/* We only clear the overtemp condition if overtemp is cleared
853 	 * _and_ no other failure is present. Since a sensor error will
854 	 * clear the overtemp condition (can't measure temperature) at
855 	 * the control loop levels, but we don't want to keep it clear
856 	 * here in this case
857 	 */
858 	if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
859 		wf_clear_overtemp();
860 }
861 
862 
863 static struct wf_control* pm121_register_control(struct wf_control *ct,
864 						 const char *match,
865 						 unsigned int id)
866 {
867 	if (controls[id] == NULL && !strcmp(ct->name, match)) {
868 		if (wf_get_control(ct) == 0)
869 			controls[id] = ct;
870 	}
871 	return controls[id];
872 }
873 
874 static void pm121_new_control(struct wf_control *ct)
875 {
876 	int all = 1;
877 
878 	if (pm121_all_controls_ok)
879 		return;
880 
881 	all = pm121_register_control(ct, "optical-drive-fan", FAN_OD) && all;
882 	all = pm121_register_control(ct, "hard-drive-fan", FAN_HD) && all;
883 	all = pm121_register_control(ct, "cpu-fan", FAN_CPU) && all;
884 	all = pm121_register_control(ct, "cpufreq-clamp", CPUFREQ) && all;
885 
886 	if (all)
887 		pm121_all_controls_ok = 1;
888 }
889 
890 
891 
892 
893 static struct wf_sensor* pm121_register_sensor(struct wf_sensor *sensor,
894 					       const char *match,
895 					       struct wf_sensor **var)
896 {
897 	if (*var == NULL && !strcmp(sensor->name, match)) {
898 		if (wf_get_sensor(sensor) == 0)
899 			*var = sensor;
900 	}
901 	return *var;
902 }
903 
904 static void pm121_new_sensor(struct wf_sensor *sr)
905 {
906 	int all = 1;
907 
908 	if (pm121_all_sensors_ok)
909 		return;
910 
911 	all = pm121_register_sensor(sr, "cpu-temp",
912 				    &sensor_cpu_temp) && all;
913 	all = pm121_register_sensor(sr, "cpu-current",
914 				    &sensor_cpu_current) && all;
915 	all = pm121_register_sensor(sr, "cpu-voltage",
916 				    &sensor_cpu_voltage) && all;
917 	all = pm121_register_sensor(sr, "cpu-power",
918 				    &sensor_cpu_power) && all;
919 	all = pm121_register_sensor(sr, "hard-drive-temp",
920 				    &sensor_hard_drive_temp) && all;
921 	all = pm121_register_sensor(sr, "optical-drive-temp",
922 				    &sensor_optical_drive_temp) && all;
923 	all = pm121_register_sensor(sr, "incoming-air-temp",
924 				    &sensor_incoming_air_temp) && all;
925 	all = pm121_register_sensor(sr, "north-bridge-temp",
926 				    &sensor_north_bridge_temp) && all;
927 	all = pm121_register_sensor(sr, "gpu-temp",
928 				    &sensor_gpu_temp) && all;
929 
930 	if (all)
931 		pm121_all_sensors_ok = 1;
932 }
933 
934 
935 
936 static int pm121_notify(struct notifier_block *self,
937 			unsigned long event, void *data)
938 {
939 	switch (event) {
940 	case WF_EVENT_NEW_CONTROL:
941 		pr_debug("pm121: new control %s detected\n",
942 			 ((struct wf_control *)data)->name);
943 		pm121_new_control(data);
944 		break;
945 	case WF_EVENT_NEW_SENSOR:
946 		pr_debug("pm121: new sensor %s detected\n",
947 			 ((struct wf_sensor *)data)->name);
948 		pm121_new_sensor(data);
949 		break;
950 	case WF_EVENT_TICK:
951 		if (pm121_all_controls_ok && pm121_all_sensors_ok)
952 			pm121_tick();
953 		break;
954 	}
955 
956 	return 0;
957 }
958 
959 static struct notifier_block pm121_events = {
960 	.notifier_call	= pm121_notify,
961 };
962 
963 static int pm121_init_pm(void)
964 {
965 	const struct smu_sdbp_header *hdr;
966 
967 	hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL);
968 	if (hdr != 0) {
969 		struct smu_sdbp_sensortree *st =
970 			(struct smu_sdbp_sensortree *)&hdr[1];
971 		pm121_mach_model = st->model_id;
972 	}
973 
974 	pm121_connection = &pm121_connections[pm121_mach_model - 2];
975 
976 	printk(KERN_INFO "pm121: Initializing for iMac G5 iSight model ID %d\n",
977 	       pm121_mach_model);
978 
979 	return 0;
980 }
981 
982 
983 static int pm121_probe(struct platform_device *ddev)
984 {
985 	wf_register_client(&pm121_events);
986 
987 	return 0;
988 }
989 
990 static int __devexit pm121_remove(struct platform_device *ddev)
991 {
992 	wf_unregister_client(&pm121_events);
993 	return 0;
994 }
995 
996 static struct platform_driver pm121_driver = {
997 	.probe = pm121_probe,
998 	.remove = __devexit_p(pm121_remove),
999 	.driver = {
1000 		.name = "windfarm",
1001 		.bus = &platform_bus_type,
1002 	},
1003 };
1004 
1005 
1006 static int __init pm121_init(void)
1007 {
1008 	int rc = -ENODEV;
1009 
1010 	if (of_machine_is_compatible("PowerMac12,1"))
1011 		rc = pm121_init_pm();
1012 
1013 	if (rc == 0) {
1014 		request_module("windfarm_smu_controls");
1015 		request_module("windfarm_smu_sensors");
1016 		request_module("windfarm_smu_sat");
1017 		request_module("windfarm_lm75_sensor");
1018 		request_module("windfarm_max6690_sensor");
1019 		request_module("windfarm_cpufreq_clamp");
1020 		platform_driver_register(&pm121_driver);
1021 	}
1022 
1023 	return rc;
1024 }
1025 
1026 static void __exit pm121_exit(void)
1027 {
1028 
1029 	platform_driver_unregister(&pm121_driver);
1030 }
1031 
1032 
1033 module_init(pm121_init);
1034 module_exit(pm121_exit);
1035 
1036 MODULE_AUTHOR("Étienne Bersac <bersace@gmail.com>");
1037 MODULE_DESCRIPTION("Thermal control logic for iMac G5 (iSight)");
1038 MODULE_LICENSE("GPL");
1039 
1040