2 * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops
4 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5 * <benh@kernel.crashing.org>
7 * Released under the term of the GNU GPL v2.
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
14 * The various control loops found in Darwin config file are:
19 * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't
20 * try to play with other control loops fans). Drive bay is rather basic PID
21 * with one sensor and one fan. Slots area is a bit different as the Darwin
22 * driver is supposed to be capable of working in a special "AGP" mode which
23 * involves the presence of an AGP sensor and an AGP fan (possibly on the
24 * AGP card itself). I can't deal with that special mode as I don't have
25 * access to those additional sensor/fans for now (though ultimately, it would
26 * be possible to add sensor objects for them) so I'm only implementing the
27 * basic PCI slot control loop
30 #include <linux/types.h>
31 #include <linux/errno.h>
32 #include <linux/kernel.h>
33 #include <linux/delay.h>
34 #include <linux/slab.h>
35 #include <linux/init.h>
36 #include <linux/spinlock.h>
37 #include <linux/wait.h>
38 #include <linux/kmod.h>
39 #include <linux/device.h>
40 #include <linux/platform_device.h>
42 #include <asm/machdep.h>
44 #include <asm/sections.h>
48 #include "windfarm_pid.h"
55 #define DBG(args...) printk(args)
57 #define DBG(args...) do { } while(0)
60 /* define this to force CPU overtemp to 74 degree, useful for testing
63 #undef HACKED_OVERTEMP
65 /* Controls & sensors */
66 static struct wf_sensor *sensor_cpu_power;
67 static struct wf_sensor *sensor_cpu_temp;
68 static struct wf_sensor *sensor_hd_temp;
69 static struct wf_sensor *sensor_slots_power;
70 static struct wf_control *fan_cpu_main;
71 static struct wf_control *fan_cpu_second;
72 static struct wf_control *fan_cpu_third;
73 static struct wf_control *fan_hd;
74 static struct wf_control *fan_slots;
75 static struct wf_control *cpufreq_clamp;
77 /* Set to kick the control loop into life */
78 static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok, wf_smu_started;
80 /* Failure handling.. could be nicer */
81 #define FAILURE_FAN 0x01
82 #define FAILURE_SENSOR 0x02
83 #define FAILURE_OVERTEMP 0x04
85 static unsigned int wf_smu_failure_state;
86 static int wf_smu_readjust, wf_smu_skipping;
89 * ****** CPU Fans Control Loop ******
94 #define WF_SMU_CPU_FANS_INTERVAL 1
95 #define WF_SMU_CPU_FANS_MAX_HISTORY 16
97 /* State data used by the cpu fans control loop
99 struct wf_smu_cpu_fans_state {
102 struct wf_cpu_pid_state pid;
105 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
110 * ****** Drive Fan Control Loop ******
114 struct wf_smu_drive_fans_state {
117 struct wf_pid_state pid;
120 static struct wf_smu_drive_fans_state *wf_smu_drive_fans;
123 * ****** Slots Fan Control Loop ******
127 struct wf_smu_slots_fans_state {
130 struct wf_pid_state pid;
133 static struct wf_smu_slots_fans_state *wf_smu_slots_fans;
136 * ***** Implementation *****
141 static void wf_smu_create_cpu_fans(void)
143 struct wf_cpu_pid_param pid_param;
144 const struct smu_sdbp_header *hdr;
145 struct smu_sdbp_cpupiddata *piddata;
146 struct smu_sdbp_fvt *fvt;
147 s32 tmax, tdelta, maxpow, powadj;
149 /* First, locate the PID params in SMU SBD */
150 hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
152 printk(KERN_WARNING "windfarm: CPU PID fan config not found "
156 piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
158 /* Get the FVT params for operating point 0 (the only supported one
159 * for now) in order to get tmax
161 hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
163 fvt = (struct smu_sdbp_fvt *)&hdr[1];
164 tmax = ((s32)fvt->maxtemp) << 16;
166 tmax = 0x5e0000; /* 94 degree default */
168 /* Alloc & initialize state */
169 wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
171 if (wf_smu_cpu_fans == NULL)
173 wf_smu_cpu_fans->ticks = 1;
175 /* Fill PID params */
176 pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
177 pid_param.history_len = piddata->history_len;
178 if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
179 printk(KERN_WARNING "windfarm: History size overflow on "
180 "CPU control loop (%d)\n", piddata->history_len);
181 pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
183 pid_param.gd = piddata->gd;
184 pid_param.gp = piddata->gp;
185 pid_param.gr = piddata->gr / pid_param.history_len;
187 tdelta = ((s32)piddata->target_temp_delta) << 16;
188 maxpow = ((s32)piddata->max_power) << 16;
189 powadj = ((s32)piddata->power_adj) << 16;
191 pid_param.tmax = tmax;
192 pid_param.ttarget = tmax - tdelta;
193 pid_param.pmaxadj = maxpow - powadj;
195 pid_param.min = wf_control_get_min(fan_cpu_main);
196 pid_param.max = wf_control_get_max(fan_cpu_main);
198 wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
200 DBG("wf: CPU Fan control initialized.\n");
201 DBG(" ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
202 FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
203 pid_param.min, pid_param.max);
208 printk(KERN_WARNING "windfarm: CPU fan config not found\n"
209 "for this machine model, max fan speed\n");
212 wf_control_set_max(cpufreq_clamp);
214 wf_control_set_max(fan_cpu_main);
217 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
219 s32 new_setpoint, temp, power;
222 if (--st->ticks != 0) {
227 st->ticks = WF_SMU_CPU_FANS_INTERVAL;
229 rc = wf_sensor_get(sensor_cpu_temp, &temp);
231 printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
233 wf_smu_failure_state |= FAILURE_SENSOR;
237 rc = wf_sensor_get(sensor_cpu_power, &power);
239 printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
241 wf_smu_failure_state |= FAILURE_SENSOR;
245 DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
246 FIX32TOPRINT(temp), FIX32TOPRINT(power));
248 #ifdef HACKED_OVERTEMP
250 wf_smu_failure_state |= FAILURE_OVERTEMP;
252 if (temp > st->pid.param.tmax)
253 wf_smu_failure_state |= FAILURE_OVERTEMP;
255 new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
257 DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
259 if (st->cpu_setpoint == new_setpoint)
261 st->cpu_setpoint = new_setpoint;
263 if (fan_cpu_main && wf_smu_failure_state == 0) {
264 rc = wf_control_set(fan_cpu_main, st->cpu_setpoint);
266 printk(KERN_WARNING "windfarm: CPU main fan"
268 wf_smu_failure_state |= FAILURE_FAN;
271 if (fan_cpu_second && wf_smu_failure_state == 0) {
272 rc = wf_control_set(fan_cpu_second, st->cpu_setpoint);
274 printk(KERN_WARNING "windfarm: CPU second fan"
276 wf_smu_failure_state |= FAILURE_FAN;
279 if (fan_cpu_third && wf_smu_failure_state == 0) {
280 rc = wf_control_set(fan_cpu_third, st->cpu_setpoint);
282 printk(KERN_WARNING "windfarm: CPU third fan"
284 wf_smu_failure_state |= FAILURE_FAN;
289 static void wf_smu_create_drive_fans(void)
291 struct wf_pid_param param = {
297 .itarget = 0x00200000,
300 /* Alloc & initialize state */
301 wf_smu_drive_fans = kmalloc(sizeof(struct wf_smu_drive_fans_state),
303 if (wf_smu_drive_fans == NULL) {
304 printk(KERN_WARNING "windfarm: Memory allocation error"
308 wf_smu_drive_fans->ticks = 1;
310 /* Fill PID params */
311 param.additive = (fan_hd->type == WF_CONTROL_RPM_FAN);
312 param.min = wf_control_get_min(fan_hd);
313 param.max = wf_control_get_max(fan_hd);
314 wf_pid_init(&wf_smu_drive_fans->pid, ¶m);
316 DBG("wf: Drive Fan control initialized.\n");
317 DBG(" itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
318 FIX32TOPRINT(param.itarget), param.min, param.max);
323 wf_control_set_max(fan_hd);
326 static void wf_smu_drive_fans_tick(struct wf_smu_drive_fans_state *st)
328 s32 new_setpoint, temp;
331 if (--st->ticks != 0) {
336 st->ticks = st->pid.param.interval;
338 rc = wf_sensor_get(sensor_hd_temp, &temp);
340 printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
342 wf_smu_failure_state |= FAILURE_SENSOR;
346 DBG("wf_smu: Drive Fans tick ! HD temp: %d.%03d\n",
349 if (temp > (st->pid.param.itarget + 0x50000))
350 wf_smu_failure_state |= FAILURE_OVERTEMP;
352 new_setpoint = wf_pid_run(&st->pid, temp);
354 DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
356 if (st->setpoint == new_setpoint)
358 st->setpoint = new_setpoint;
360 if (fan_hd && wf_smu_failure_state == 0) {
361 rc = wf_control_set(fan_hd, st->setpoint);
363 printk(KERN_WARNING "windfarm: HD fan error %d\n",
365 wf_smu_failure_state |= FAILURE_FAN;
370 static void wf_smu_create_slots_fans(void)
372 struct wf_pid_param param = {
378 .itarget = 0x00000000
381 /* Alloc & initialize state */
382 wf_smu_slots_fans = kmalloc(sizeof(struct wf_smu_slots_fans_state),
384 if (wf_smu_slots_fans == NULL) {
385 printk(KERN_WARNING "windfarm: Memory allocation error"
389 wf_smu_slots_fans->ticks = 1;
391 /* Fill PID params */
392 param.additive = (fan_slots->type == WF_CONTROL_RPM_FAN);
393 param.min = wf_control_get_min(fan_slots);
394 param.max = wf_control_get_max(fan_slots);
395 wf_pid_init(&wf_smu_slots_fans->pid, ¶m);
397 DBG("wf: Slots Fan control initialized.\n");
398 DBG(" itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
399 FIX32TOPRINT(param.itarget), param.min, param.max);
404 wf_control_set_max(fan_slots);
407 static void wf_smu_slots_fans_tick(struct wf_smu_slots_fans_state *st)
409 s32 new_setpoint, power;
412 if (--st->ticks != 0) {
417 st->ticks = st->pid.param.interval;
419 rc = wf_sensor_get(sensor_slots_power, &power);
421 printk(KERN_WARNING "windfarm: Slots power sensor error %d\n",
423 wf_smu_failure_state |= FAILURE_SENSOR;
427 DBG("wf_smu: Slots Fans tick ! Slots power: %d.%03d\n",
428 FIX32TOPRINT(power));
430 #if 0 /* Check what makes a good overtemp condition */
431 if (power > (st->pid.param.itarget + 0x50000))
432 wf_smu_failure_state |= FAILURE_OVERTEMP;
435 new_setpoint = wf_pid_run(&st->pid, power);
437 DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint);
439 if (st->setpoint == new_setpoint)
441 st->setpoint = new_setpoint;
443 if (fan_slots && wf_smu_failure_state == 0) {
444 rc = wf_control_set(fan_slots, st->setpoint);
446 printk(KERN_WARNING "windfarm: Slots fan error %d\n",
448 wf_smu_failure_state |= FAILURE_FAN;
455 * ****** Setup / Init / Misc ... ******
459 static void wf_smu_tick(void)
461 unsigned int last_failure = wf_smu_failure_state;
462 unsigned int new_failure;
464 if (!wf_smu_started) {
465 DBG("wf: creating control loops !\n");
466 wf_smu_create_drive_fans();
467 wf_smu_create_slots_fans();
468 wf_smu_create_cpu_fans();
473 if (wf_smu_skipping && --wf_smu_skipping)
476 wf_smu_failure_state = 0;
477 if (wf_smu_drive_fans)
478 wf_smu_drive_fans_tick(wf_smu_drive_fans);
479 if (wf_smu_slots_fans)
480 wf_smu_slots_fans_tick(wf_smu_slots_fans);
482 wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
485 new_failure = wf_smu_failure_state & ~last_failure;
487 /* If entering failure mode, clamp cpufreq and ramp all
488 * fans to full speed.
490 if (wf_smu_failure_state && !last_failure) {
492 wf_control_set_max(cpufreq_clamp);
494 wf_control_set_max(fan_cpu_main);
496 wf_control_set_max(fan_cpu_second);
498 wf_control_set_max(fan_cpu_third);
500 wf_control_set_max(fan_hd);
502 wf_control_set_max(fan_slots);
505 /* If leaving failure mode, unclamp cpufreq and readjust
506 * all fans on next iteration
508 if (!wf_smu_failure_state && last_failure) {
510 wf_control_set_min(cpufreq_clamp);
514 /* Overtemp condition detected, notify and start skipping a couple
515 * ticks to let the temperature go down
517 if (new_failure & FAILURE_OVERTEMP) {
522 /* We only clear the overtemp condition if overtemp is cleared
523 * _and_ no other failure is present. Since a sensor error will
524 * clear the overtemp condition (can't measure temperature) at
525 * the control loop levels, but we don't want to keep it clear
528 if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
533 static void wf_smu_new_control(struct wf_control *ct)
535 if (wf_smu_all_controls_ok)
538 if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-rear-fan-0")) {
539 if (wf_get_control(ct) == 0)
543 if (fan_cpu_second == NULL && !strcmp(ct->name, "cpu-rear-fan-1")) {
544 if (wf_get_control(ct) == 0)
548 if (fan_cpu_third == NULL && !strcmp(ct->name, "cpu-front-fan-0")) {
549 if (wf_get_control(ct) == 0)
553 if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
554 if (wf_get_control(ct) == 0)
558 if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
559 if (wf_get_control(ct) == 0)
563 if (fan_slots == NULL && !strcmp(ct->name, "slots-fan")) {
564 if (wf_get_control(ct) == 0)
568 if (fan_cpu_main && (fan_cpu_second || fan_cpu_third) && fan_hd &&
569 fan_slots && cpufreq_clamp)
570 wf_smu_all_controls_ok = 1;
573 static void wf_smu_new_sensor(struct wf_sensor *sr)
575 if (wf_smu_all_sensors_ok)
578 if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
579 if (wf_get_sensor(sr) == 0)
580 sensor_cpu_power = sr;
583 if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
584 if (wf_get_sensor(sr) == 0)
585 sensor_cpu_temp = sr;
588 if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
589 if (wf_get_sensor(sr) == 0)
593 if (sensor_slots_power == NULL && !strcmp(sr->name, "slots-power")) {
594 if (wf_get_sensor(sr) == 0)
595 sensor_slots_power = sr;
598 if (sensor_cpu_power && sensor_cpu_temp &&
599 sensor_hd_temp && sensor_slots_power)
600 wf_smu_all_sensors_ok = 1;
604 static int wf_smu_notify(struct notifier_block *self,
605 unsigned long event, void *data)
608 case WF_EVENT_NEW_CONTROL:
609 DBG("wf: new control %s detected\n",
610 ((struct wf_control *)data)->name);
611 wf_smu_new_control(data);
614 case WF_EVENT_NEW_SENSOR:
615 DBG("wf: new sensor %s detected\n",
616 ((struct wf_sensor *)data)->name);
617 wf_smu_new_sensor(data);
620 if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
627 static struct notifier_block wf_smu_events = {
628 .notifier_call = wf_smu_notify,
631 static int wf_init_pm(void)
633 printk(KERN_INFO "windfarm: Initializing for Desktop G5 model\n");
638 static int wf_smu_probe(struct platform_device *ddev)
640 wf_register_client(&wf_smu_events);
645 static int __devexit wf_smu_remove(struct platform_device *ddev)
647 wf_unregister_client(&wf_smu_events);
649 /* XXX We don't have yet a guarantee that our callback isn't
650 * in progress when returning from wf_unregister_client, so
651 * we add an arbitrary delay. I'll have to fix that in the core
655 /* Release all sensors */
656 /* One more crappy race: I don't think we have any guarantee here
657 * that the attribute callback won't race with the sensor beeing
658 * disposed of, and I'm not 100% certain what best way to deal
659 * with that except by adding locks all over... I'll do that
660 * eventually but heh, who ever rmmod this module anyway ?
662 if (sensor_cpu_power)
663 wf_put_sensor(sensor_cpu_power);
665 wf_put_sensor(sensor_cpu_temp);
667 wf_put_sensor(sensor_hd_temp);
668 if (sensor_slots_power)
669 wf_put_sensor(sensor_slots_power);
671 /* Release all controls */
673 wf_put_control(fan_cpu_main);
675 wf_put_control(fan_cpu_second);
677 wf_put_control(fan_cpu_third);
679 wf_put_control(fan_hd);
681 wf_put_control(fan_slots);
683 wf_put_control(cpufreq_clamp);
685 /* Destroy control loops state structures */
686 kfree(wf_smu_slots_fans);
687 kfree(wf_smu_drive_fans);
688 kfree(wf_smu_cpu_fans);
693 static struct platform_driver wf_smu_driver = {
694 .probe = wf_smu_probe,
695 .remove = __devexit_p(wf_smu_remove),
698 .owner = THIS_MODULE,
703 static int __init wf_smu_init(void)
707 if (of_machine_is_compatible("PowerMac9,1"))
712 request_module("windfarm_smu_controls");
713 request_module("windfarm_smu_sensors");
714 request_module("windfarm_lm75_sensor");
715 request_module("windfarm_cpufreq_clamp");
718 platform_driver_register(&wf_smu_driver);
724 static void __exit wf_smu_exit(void)
727 platform_driver_unregister(&wf_smu_driver);
731 module_init(wf_smu_init);
732 module_exit(wf_smu_exit);
734 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
735 MODULE_DESCRIPTION("Thermal control logic for PowerMac9,1");
736 MODULE_LICENSE("GPL");
738 MODULE_ALIAS("platform:windfarm");