1 // SPDX-License-Identifier: GPL-2.0-only
3 * Windfarm PowerMac thermal control. SMU based 1 CPU desktop control loops
5 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6 * <benh@kernel.crashing.org>
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
13 * The various control loops found in Darwin config file are:
18 * Has 3 control loops: CPU fans is similar to PowerMac8,1 (though it doesn't
19 * try to play with other control loops fans). Drive bay is rather basic PID
20 * with one sensor and one fan. Slots area is a bit different as the Darwin
21 * driver is supposed to be capable of working in a special "AGP" mode which
22 * involves the presence of an AGP sensor and an AGP fan (possibly on the
23 * AGP card itself). I can't deal with that special mode as I don't have
24 * access to those additional sensor/fans for now (though ultimately, it would
25 * be possible to add sensor objects for them) so I'm only implementing the
26 * basic PCI slot control loop
29 #include <linux/types.h>
30 #include <linux/errno.h>
31 #include <linux/kernel.h>
32 #include <linux/delay.h>
33 #include <linux/slab.h>
34 #include <linux/init.h>
35 #include <linux/spinlock.h>
36 #include <linux/wait.h>
37 #include <linux/kmod.h>
38 #include <linux/device.h>
39 #include <linux/platform_device.h>
41 #include <asm/machdep.h>
43 #include <asm/sections.h>
47 #include "windfarm_pid.h"
54 #define DBG(args...) printk(args)
56 #define DBG(args...) do { } while(0)
59 /* define this to force CPU overtemp to 74 degree, useful for testing
62 #undef HACKED_OVERTEMP
64 /* Controls & sensors */
65 static struct wf_sensor
*sensor_cpu_power
;
66 static struct wf_sensor
*sensor_cpu_temp
;
67 static struct wf_sensor
*sensor_hd_temp
;
68 static struct wf_sensor
*sensor_slots_power
;
69 static struct wf_control
*fan_cpu_main
;
70 static struct wf_control
*fan_cpu_second
;
71 static struct wf_control
*fan_cpu_third
;
72 static struct wf_control
*fan_hd
;
73 static struct wf_control
*fan_slots
;
74 static struct wf_control
*cpufreq_clamp
;
76 /* Set to kick the control loop into life */
77 static int wf_smu_all_controls_ok
, wf_smu_all_sensors_ok
;
78 static bool wf_smu_started
;
79 static bool wf_smu_overtemp
;
81 /* Failure handling.. could be nicer */
82 #define FAILURE_FAN 0x01
83 #define FAILURE_SENSOR 0x02
84 #define FAILURE_OVERTEMP 0x04
86 static unsigned int wf_smu_failure_state
;
87 static int wf_smu_readjust
, wf_smu_skipping
;
90 * ****** CPU Fans Control Loop ******
95 #define WF_SMU_CPU_FANS_INTERVAL 1
96 #define WF_SMU_CPU_FANS_MAX_HISTORY 16
98 /* State data used by the cpu fans control loop
100 struct wf_smu_cpu_fans_state
{
103 struct wf_cpu_pid_state pid
;
106 static struct wf_smu_cpu_fans_state
*wf_smu_cpu_fans
;
111 * ****** Drive Fan Control Loop ******
115 struct wf_smu_drive_fans_state
{
118 struct wf_pid_state pid
;
121 static struct wf_smu_drive_fans_state
*wf_smu_drive_fans
;
124 * ****** Slots Fan Control Loop ******
128 struct wf_smu_slots_fans_state
{
131 struct wf_pid_state pid
;
134 static struct wf_smu_slots_fans_state
*wf_smu_slots_fans
;
137 * ***** Implementation *****
142 static void wf_smu_create_cpu_fans(void)
144 struct wf_cpu_pid_param pid_param
;
145 const struct smu_sdbp_header
*hdr
;
146 struct smu_sdbp_cpupiddata
*piddata
;
147 struct smu_sdbp_fvt
*fvt
;
148 s32 tmax
, tdelta
, maxpow
, powadj
;
150 /* First, locate the PID params in SMU SBD */
151 hdr
= smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID
, NULL
);
153 printk(KERN_WARNING
"windfarm: CPU PID fan config not found "
157 piddata
= (struct smu_sdbp_cpupiddata
*)&hdr
[1];
159 /* Get the FVT params for operating point 0 (the only supported one
160 * for now) in order to get tmax
162 hdr
= smu_get_sdb_partition(SMU_SDB_FVT_ID
, NULL
);
164 fvt
= (struct smu_sdbp_fvt
*)&hdr
[1];
165 tmax
= ((s32
)fvt
->maxtemp
) << 16;
167 tmax
= 0x5e0000; /* 94 degree default */
169 /* Alloc & initialize state */
170 wf_smu_cpu_fans
= kmalloc(sizeof(struct wf_smu_cpu_fans_state
),
172 if (wf_smu_cpu_fans
== NULL
)
174 wf_smu_cpu_fans
->ticks
= 1;
176 /* Fill PID params */
177 pid_param
.interval
= WF_SMU_CPU_FANS_INTERVAL
;
178 pid_param
.history_len
= piddata
->history_len
;
179 if (pid_param
.history_len
> WF_CPU_PID_MAX_HISTORY
) {
180 printk(KERN_WARNING
"windfarm: History size overflow on "
181 "CPU control loop (%d)\n", piddata
->history_len
);
182 pid_param
.history_len
= WF_CPU_PID_MAX_HISTORY
;
184 pid_param
.gd
= piddata
->gd
;
185 pid_param
.gp
= piddata
->gp
;
186 pid_param
.gr
= piddata
->gr
/ pid_param
.history_len
;
188 tdelta
= ((s32
)piddata
->target_temp_delta
) << 16;
189 maxpow
= ((s32
)piddata
->max_power
) << 16;
190 powadj
= ((s32
)piddata
->power_adj
) << 16;
192 pid_param
.tmax
= tmax
;
193 pid_param
.ttarget
= tmax
- tdelta
;
194 pid_param
.pmaxadj
= maxpow
- powadj
;
196 pid_param
.min
= wf_control_get_min(fan_cpu_main
);
197 pid_param
.max
= wf_control_get_max(fan_cpu_main
);
199 wf_cpu_pid_init(&wf_smu_cpu_fans
->pid
, &pid_param
);
201 DBG("wf: CPU Fan control initialized.\n");
202 DBG(" ttarget=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
203 FIX32TOPRINT(pid_param
.ttarget
), FIX32TOPRINT(pid_param
.tmax
),
204 pid_param
.min
, pid_param
.max
);
209 printk(KERN_WARNING
"windfarm: CPU fan config not found\n"
210 "for this machine model, max fan speed\n");
213 wf_control_set_max(cpufreq_clamp
);
215 wf_control_set_max(fan_cpu_main
);
218 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state
*st
)
220 s32 new_setpoint
, temp
, power
;
223 if (--st
->ticks
!= 0) {
228 st
->ticks
= WF_SMU_CPU_FANS_INTERVAL
;
230 rc
= wf_sensor_get(sensor_cpu_temp
, &temp
);
232 printk(KERN_WARNING
"windfarm: CPU temp sensor error %d\n",
234 wf_smu_failure_state
|= FAILURE_SENSOR
;
238 rc
= wf_sensor_get(sensor_cpu_power
, &power
);
240 printk(KERN_WARNING
"windfarm: CPU power sensor error %d\n",
242 wf_smu_failure_state
|= FAILURE_SENSOR
;
246 DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
247 FIX32TOPRINT(temp
), FIX32TOPRINT(power
));
249 #ifdef HACKED_OVERTEMP
251 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
253 if (temp
> st
->pid
.param
.tmax
)
254 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
256 new_setpoint
= wf_cpu_pid_run(&st
->pid
, power
, temp
);
258 DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint
);
260 if (st
->cpu_setpoint
== new_setpoint
)
262 st
->cpu_setpoint
= new_setpoint
;
264 if (fan_cpu_main
&& wf_smu_failure_state
== 0) {
265 rc
= wf_control_set(fan_cpu_main
, st
->cpu_setpoint
);
267 printk(KERN_WARNING
"windfarm: CPU main fan"
269 wf_smu_failure_state
|= FAILURE_FAN
;
272 if (fan_cpu_second
&& wf_smu_failure_state
== 0) {
273 rc
= wf_control_set(fan_cpu_second
, st
->cpu_setpoint
);
275 printk(KERN_WARNING
"windfarm: CPU second fan"
277 wf_smu_failure_state
|= FAILURE_FAN
;
280 if (fan_cpu_third
&& wf_smu_failure_state
== 0) {
281 rc
= wf_control_set(fan_cpu_third
, st
->cpu_setpoint
);
283 printk(KERN_WARNING
"windfarm: CPU third fan"
285 wf_smu_failure_state
|= FAILURE_FAN
;
290 static void wf_smu_create_drive_fans(void)
292 struct wf_pid_param param
= {
298 .itarget
= 0x00200000,
301 /* Alloc & initialize state */
302 wf_smu_drive_fans
= kmalloc(sizeof(struct wf_smu_drive_fans_state
),
304 if (wf_smu_drive_fans
== NULL
) {
305 printk(KERN_WARNING
"windfarm: Memory allocation error"
309 wf_smu_drive_fans
->ticks
= 1;
311 /* Fill PID params */
312 param
.additive
= (fan_hd
->type
== WF_CONTROL_RPM_FAN
);
313 param
.min
= wf_control_get_min(fan_hd
);
314 param
.max
= wf_control_get_max(fan_hd
);
315 wf_pid_init(&wf_smu_drive_fans
->pid
, ¶m
);
317 DBG("wf: Drive Fan control initialized.\n");
318 DBG(" itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
319 FIX32TOPRINT(param
.itarget
), param
.min
, param
.max
);
324 wf_control_set_max(fan_hd
);
327 static void wf_smu_drive_fans_tick(struct wf_smu_drive_fans_state
*st
)
329 s32 new_setpoint
, temp
;
332 if (--st
->ticks
!= 0) {
337 st
->ticks
= st
->pid
.param
.interval
;
339 rc
= wf_sensor_get(sensor_hd_temp
, &temp
);
341 printk(KERN_WARNING
"windfarm: HD temp sensor error %d\n",
343 wf_smu_failure_state
|= FAILURE_SENSOR
;
347 DBG("wf_smu: Drive Fans tick ! HD temp: %d.%03d\n",
350 if (temp
> (st
->pid
.param
.itarget
+ 0x50000))
351 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
353 new_setpoint
= wf_pid_run(&st
->pid
, temp
);
355 DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint
);
357 if (st
->setpoint
== new_setpoint
)
359 st
->setpoint
= new_setpoint
;
361 if (fan_hd
&& wf_smu_failure_state
== 0) {
362 rc
= wf_control_set(fan_hd
, st
->setpoint
);
364 printk(KERN_WARNING
"windfarm: HD fan error %d\n",
366 wf_smu_failure_state
|= FAILURE_FAN
;
371 static void wf_smu_create_slots_fans(void)
373 struct wf_pid_param param
= {
379 .itarget
= 0x00000000
382 /* Alloc & initialize state */
383 wf_smu_slots_fans
= kmalloc(sizeof(struct wf_smu_slots_fans_state
),
385 if (wf_smu_slots_fans
== NULL
) {
386 printk(KERN_WARNING
"windfarm: Memory allocation error"
390 wf_smu_slots_fans
->ticks
= 1;
392 /* Fill PID params */
393 param
.additive
= (fan_slots
->type
== WF_CONTROL_RPM_FAN
);
394 param
.min
= wf_control_get_min(fan_slots
);
395 param
.max
= wf_control_get_max(fan_slots
);
396 wf_pid_init(&wf_smu_slots_fans
->pid
, ¶m
);
398 DBG("wf: Slots Fan control initialized.\n");
399 DBG(" itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
400 FIX32TOPRINT(param
.itarget
), param
.min
, param
.max
);
405 wf_control_set_max(fan_slots
);
408 static void wf_smu_slots_fans_tick(struct wf_smu_slots_fans_state
*st
)
410 s32 new_setpoint
, power
;
413 if (--st
->ticks
!= 0) {
418 st
->ticks
= st
->pid
.param
.interval
;
420 rc
= wf_sensor_get(sensor_slots_power
, &power
);
422 printk(KERN_WARNING
"windfarm: Slots power sensor error %d\n",
424 wf_smu_failure_state
|= FAILURE_SENSOR
;
428 DBG("wf_smu: Slots Fans tick ! Slots power: %d.%03d\n",
429 FIX32TOPRINT(power
));
431 #if 0 /* Check what makes a good overtemp condition */
432 if (power
> (st
->pid
.param
.itarget
+ 0x50000))
433 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
436 new_setpoint
= wf_pid_run(&st
->pid
, power
);
438 DBG("wf_smu: new_setpoint: %d\n", (int)new_setpoint
);
440 if (st
->setpoint
== new_setpoint
)
442 st
->setpoint
= new_setpoint
;
444 if (fan_slots
&& wf_smu_failure_state
== 0) {
445 rc
= wf_control_set(fan_slots
, st
->setpoint
);
447 printk(KERN_WARNING
"windfarm: Slots fan error %d\n",
449 wf_smu_failure_state
|= FAILURE_FAN
;
456 * ****** Setup / Init / Misc ... ******
460 static void wf_smu_tick(void)
462 unsigned int last_failure
= wf_smu_failure_state
;
463 unsigned int new_failure
;
465 if (!wf_smu_started
) {
466 DBG("wf: creating control loops !\n");
467 wf_smu_create_drive_fans();
468 wf_smu_create_slots_fans();
469 wf_smu_create_cpu_fans();
470 wf_smu_started
= true;
474 if (wf_smu_skipping
&& --wf_smu_skipping
)
477 wf_smu_failure_state
= 0;
478 if (wf_smu_drive_fans
)
479 wf_smu_drive_fans_tick(wf_smu_drive_fans
);
480 if (wf_smu_slots_fans
)
481 wf_smu_slots_fans_tick(wf_smu_slots_fans
);
483 wf_smu_cpu_fans_tick(wf_smu_cpu_fans
);
486 new_failure
= wf_smu_failure_state
& ~last_failure
;
488 /* If entering failure mode, clamp cpufreq and ramp all
489 * fans to full speed.
491 if (wf_smu_failure_state
&& !last_failure
) {
493 wf_control_set_max(cpufreq_clamp
);
495 wf_control_set_max(fan_cpu_main
);
497 wf_control_set_max(fan_cpu_second
);
499 wf_control_set_max(fan_cpu_third
);
501 wf_control_set_max(fan_hd
);
503 wf_control_set_max(fan_slots
);
506 /* If leaving failure mode, unclamp cpufreq and readjust
507 * all fans on next iteration
509 if (!wf_smu_failure_state
&& last_failure
) {
511 wf_control_set_min(cpufreq_clamp
);
515 /* Overtemp condition detected, notify and start skipping a couple
516 * ticks to let the temperature go down
518 if (new_failure
& FAILURE_OVERTEMP
) {
521 wf_smu_overtemp
= true;
524 /* We only clear the overtemp condition if overtemp is cleared
525 * _and_ no other failure is present. Since a sensor error will
526 * clear the overtemp condition (can't measure temperature) at
527 * the control loop levels, but we don't want to keep it clear
530 if (!wf_smu_failure_state
&& wf_smu_overtemp
) {
532 wf_smu_overtemp
= false;
537 static void wf_smu_new_control(struct wf_control
*ct
)
539 if (wf_smu_all_controls_ok
)
542 if (fan_cpu_main
== NULL
&& !strcmp(ct
->name
, "cpu-rear-fan-0")) {
543 if (wf_get_control(ct
) == 0)
547 if (fan_cpu_second
== NULL
&& !strcmp(ct
->name
, "cpu-rear-fan-1")) {
548 if (wf_get_control(ct
) == 0)
552 if (fan_cpu_third
== NULL
&& !strcmp(ct
->name
, "cpu-front-fan-0")) {
553 if (wf_get_control(ct
) == 0)
557 if (cpufreq_clamp
== NULL
&& !strcmp(ct
->name
, "cpufreq-clamp")) {
558 if (wf_get_control(ct
) == 0)
562 if (fan_hd
== NULL
&& !strcmp(ct
->name
, "drive-bay-fan")) {
563 if (wf_get_control(ct
) == 0)
567 if (fan_slots
== NULL
&& !strcmp(ct
->name
, "slots-fan")) {
568 if (wf_get_control(ct
) == 0)
572 if (fan_cpu_main
&& (fan_cpu_second
|| fan_cpu_third
) && fan_hd
&&
573 fan_slots
&& cpufreq_clamp
)
574 wf_smu_all_controls_ok
= 1;
577 static void wf_smu_new_sensor(struct wf_sensor
*sr
)
579 if (wf_smu_all_sensors_ok
)
582 if (sensor_cpu_power
== NULL
&& !strcmp(sr
->name
, "cpu-power")) {
583 if (wf_get_sensor(sr
) == 0)
584 sensor_cpu_power
= sr
;
587 if (sensor_cpu_temp
== NULL
&& !strcmp(sr
->name
, "cpu-temp")) {
588 if (wf_get_sensor(sr
) == 0)
589 sensor_cpu_temp
= sr
;
592 if (sensor_hd_temp
== NULL
&& !strcmp(sr
->name
, "hd-temp")) {
593 if (wf_get_sensor(sr
) == 0)
597 if (sensor_slots_power
== NULL
&& !strcmp(sr
->name
, "slots-power")) {
598 if (wf_get_sensor(sr
) == 0)
599 sensor_slots_power
= sr
;
602 if (sensor_cpu_power
&& sensor_cpu_temp
&&
603 sensor_hd_temp
&& sensor_slots_power
)
604 wf_smu_all_sensors_ok
= 1;
608 static int wf_smu_notify(struct notifier_block
*self
,
609 unsigned long event
, void *data
)
612 case WF_EVENT_NEW_CONTROL
:
613 DBG("wf: new control %s detected\n",
614 ((struct wf_control
*)data
)->name
);
615 wf_smu_new_control(data
);
618 case WF_EVENT_NEW_SENSOR
:
619 DBG("wf: new sensor %s detected\n",
620 ((struct wf_sensor
*)data
)->name
);
621 wf_smu_new_sensor(data
);
624 if (wf_smu_all_controls_ok
&& wf_smu_all_sensors_ok
)
631 static struct notifier_block wf_smu_events
= {
632 .notifier_call
= wf_smu_notify
,
635 static int wf_init_pm(void)
637 printk(KERN_INFO
"windfarm: Initializing for Desktop G5 model\n");
642 static int wf_smu_probe(struct platform_device
*ddev
)
644 wf_register_client(&wf_smu_events
);
649 static int wf_smu_remove(struct platform_device
*ddev
)
651 wf_unregister_client(&wf_smu_events
);
653 /* XXX We don't have yet a guarantee that our callback isn't
654 * in progress when returning from wf_unregister_client, so
655 * we add an arbitrary delay. I'll have to fix that in the core
659 /* Release all sensors */
660 /* One more crappy race: I don't think we have any guarantee here
661 * that the attribute callback won't race with the sensor beeing
662 * disposed of, and I'm not 100% certain what best way to deal
663 * with that except by adding locks all over... I'll do that
664 * eventually but heh, who ever rmmod this module anyway ?
666 if (sensor_cpu_power
)
667 wf_put_sensor(sensor_cpu_power
);
669 wf_put_sensor(sensor_cpu_temp
);
671 wf_put_sensor(sensor_hd_temp
);
672 if (sensor_slots_power
)
673 wf_put_sensor(sensor_slots_power
);
675 /* Release all controls */
677 wf_put_control(fan_cpu_main
);
679 wf_put_control(fan_cpu_second
);
681 wf_put_control(fan_cpu_third
);
683 wf_put_control(fan_hd
);
685 wf_put_control(fan_slots
);
687 wf_put_control(cpufreq_clamp
);
689 /* Destroy control loops state structures */
690 kfree(wf_smu_slots_fans
);
691 kfree(wf_smu_drive_fans
);
692 kfree(wf_smu_cpu_fans
);
697 static struct platform_driver wf_smu_driver
= {
698 .probe
= wf_smu_probe
,
699 .remove
= wf_smu_remove
,
706 static int __init
wf_smu_init(void)
710 if (of_machine_is_compatible("PowerMac9,1"))
715 request_module("windfarm_smu_controls");
716 request_module("windfarm_smu_sensors");
717 request_module("windfarm_lm75_sensor");
718 request_module("windfarm_cpufreq_clamp");
721 platform_driver_register(&wf_smu_driver
);
727 static void __exit
wf_smu_exit(void)
730 platform_driver_unregister(&wf_smu_driver
);
734 module_init(wf_smu_init
);
735 module_exit(wf_smu_exit
);
737 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
738 MODULE_DESCRIPTION("Thermal control logic for PowerMac9,1");
739 MODULE_LICENSE("GPL");
741 MODULE_ALIAS("platform:windfarm");