2 * Windfarm PowerMac thermal control. iMac G5
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:
16 * PowerMac8,1 and PowerMac8,2
17 * ===========================
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)
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.
34 * controls : system-fan, drive-bay-fan
36 * PID params : G_d = 0x15400000
40 * Input target = 0x3a0000
42 * linear-factors : offset = 0xff38 scale = 0x0ccd
43 * offset = 0x0208 scale = 0x07ae
46 * controls : system-fan, drive-bay-fan
48 * PID params : G_d = 0x08e00000
52 * Input target = 0x350000
54 * linear-factors : offset = 0xff38 scale = 0x0ccd
55 * offset = 0x0000 scale = 0x0000
58 * controls : system-fan
60 * PID params : G_d = 0x15400000
64 * Input target = 0x3a0000
66 * linear-factors : offset = 0x0000 scale = 0x1000
67 * offset = 0x0091 scale = 0x0bae
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
76 * sensors : cpu-temp cpu-power
77 * PID params : From SMU sdb partition
78 * linear-factors : offset = 0xfb50 scale = 0x1000
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
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;
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>
110 #include <asm/sections.h>
113 #include "windfarm.h"
114 #include "windfarm_pid.h"
116 #define VERSION "0.4"
121 #define DBG(args...) printk(args)
123 #define DBG(args...) do { } while(0)
126 /* define this to force CPU overtemp to 74 degree, useful for testing
129 #undef HACKED_OVERTEMP
131 static int wf_smu_mach_model
; /* machine model id */
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
;
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
;
146 /* Failure handling.. could be nicer */
147 #define FAILURE_FAN 0x01
148 #define FAILURE_SENSOR 0x02
149 #define FAILURE_OVERTEMP 0x04
151 static unsigned int wf_smu_failure_state
;
152 static int wf_smu_readjust
, wf_smu_skipping
;
153 static bool wf_smu_overtemp
;
156 * ****** System Fans Control Loop ******
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.
164 struct wf_smu_sys_fans_param
{
175 #define WF_SMU_SYS_FANS_INTERVAL 5
176 #define WF_SMU_SYS_FANS_HISTORY_SIZE 2
178 /* State data used by the system fans control loop
180 struct wf_smu_sys_fans_state
{
188 struct wf_pid_state pid
;
192 * Configs for SMU System Fan control loop
194 static struct wf_smu_sys_fans_param wf_smu_sys_all_params
[] = {
232 #define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)
234 static struct wf_smu_sys_fans_state
*wf_smu_sys_fans
;
237 * ****** CPU Fans Control Loop ******
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
247 /* State data used by the cpu fans control loop
249 struct wf_smu_cpu_fans_state
{
254 struct wf_cpu_pid_state pid
;
257 static struct wf_smu_cpu_fans_state
*wf_smu_cpu_fans
;
262 * ***** Implementation *****
266 static void wf_smu_create_sys_fans(void)
268 struct wf_smu_sys_fans_param
*param
= NULL
;
269 struct wf_pid_param pid_param
;
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
];
279 /* No params found, put fans to max */
281 printk(KERN_WARNING
"windfarm: System fan config not found "
282 "for this machine model, max fan speed\n");
286 /* Alloc & initialize state */
287 wf_smu_sys_fans
= kmalloc(sizeof(struct wf_smu_sys_fans_state
),
289 if (wf_smu_sys_fans
== NULL
) {
290 printk(KERN_WARNING
"windfarm: Memory allocation error"
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
;
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
);
311 max(pid_param
.min
, wf_control_get_min(fan_hd
));
313 min(pid_param
.max
, wf_control_get_max(fan_hd
));
315 wf_pid_init(&wf_smu_sys_fans
->pid
, &pid_param
);
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
);
325 wf_control_set_max(fan_system
);
327 wf_control_set_max(fan_hd
);
330 static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state
*st
)
332 s32 new_setpoint
, temp
, scaled
, cputarget
;
335 if (--st
->ticks
!= 0) {
340 st
->ticks
= WF_SMU_SYS_FANS_INTERVAL
;
342 rc
= wf_sensor_get(sensor_hd_temp
, &temp
);
344 printk(KERN_WARNING
"windfarm: HD temp sensor error %d\n",
346 wf_smu_failure_state
|= FAILURE_SENSOR
;
350 DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
353 if (temp
> (st
->pid
.param
.itarget
+ 0x50000))
354 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
356 new_setpoint
= wf_pid_run(&st
->pid
, temp
);
358 DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint
);
360 scaled
= ((((s64
)new_setpoint
) * (s64
)st
->scale0
) >> 12) + st
->offset0
;
362 DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled
);
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
);
370 DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled
);
372 if (st
->sys_setpoint
== scaled
&& new_setpoint
== st
->hd_setpoint
)
374 st
->sys_setpoint
= scaled
;
375 st
->hd_setpoint
= new_setpoint
;
377 if (fan_system
&& wf_smu_failure_state
== 0) {
378 rc
= wf_control_set(fan_system
, st
->sys_setpoint
);
380 printk(KERN_WARNING
"windfarm: Sys fan error %d\n",
382 wf_smu_failure_state
|= FAILURE_FAN
;
385 if (fan_hd
&& wf_smu_failure_state
== 0) {
386 rc
= wf_control_set(fan_hd
, st
->hd_setpoint
);
388 printk(KERN_WARNING
"windfarm: HD fan error %d\n",
390 wf_smu_failure_state
|= FAILURE_FAN
;
395 static void wf_smu_create_cpu_fans(void)
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
;
403 /* First, locate the PID params in SMU SBD */
404 hdr
= smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID
, NULL
);
406 printk(KERN_WARNING
"windfarm: CPU PID fan config not found "
410 piddata
= (struct smu_sdbp_cpupiddata
*)&hdr
[1];
412 /* Get the FVT params for operating point 0 (the only supported one
413 * for now) in order to get tmax
415 hdr
= smu_get_sdb_partition(SMU_SDB_FVT_ID
, NULL
);
417 fvt
= (struct smu_sdbp_fvt
*)&hdr
[1];
418 tmax
= ((s32
)fvt
->maxtemp
) << 16;
420 tmax
= 0x5e0000; /* 94 degree default */
422 /* Alloc & initialize state */
423 wf_smu_cpu_fans
= kmalloc(sizeof(struct wf_smu_cpu_fans_state
),
425 if (wf_smu_cpu_fans
== NULL
)
427 wf_smu_cpu_fans
->ticks
= 1;
429 wf_smu_cpu_fans
->scale
= WF_SMU_CPU_FANS_SIBLING_SCALE
;
430 wf_smu_cpu_fans
->offset
= WF_SMU_CPU_FANS_SIBLING_OFFSET
;
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
;
440 pid_param
.gd
= piddata
->gd
;
441 pid_param
.gp
= piddata
->gp
;
442 pid_param
.gr
= piddata
->gr
/ pid_param
.history_len
;
444 tdelta
= ((s32
)piddata
->target_temp_delta
) << 16;
445 maxpow
= ((s32
)piddata
->max_power
) << 16;
446 powadj
= ((s32
)piddata
->power_adj
) << 16;
448 pid_param
.tmax
= tmax
;
449 pid_param
.ttarget
= tmax
- tdelta
;
450 pid_param
.pmaxadj
= maxpow
- powadj
;
452 pid_param
.min
= wf_control_get_min(fan_cpu_main
);
453 pid_param
.max
= wf_control_get_max(fan_cpu_main
);
455 wf_cpu_pid_init(&wf_smu_cpu_fans
->pid
, &pid_param
);
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
);
465 printk(KERN_WARNING
"windfarm: CPU fan config not found\n"
466 "for this machine model, max fan speed\n");
469 wf_control_set_max(cpufreq_clamp
);
471 wf_control_set_max(fan_cpu_main
);
474 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state
*st
)
476 s32 new_setpoint
, temp
, power
, systarget
;
479 if (--st
->ticks
!= 0) {
484 st
->ticks
= WF_SMU_CPU_FANS_INTERVAL
;
486 rc
= wf_sensor_get(sensor_cpu_temp
, &temp
);
488 printk(KERN_WARNING
"windfarm: CPU temp sensor error %d\n",
490 wf_smu_failure_state
|= FAILURE_SENSOR
;
494 rc
= wf_sensor_get(sensor_cpu_power
, &power
);
496 printk(KERN_WARNING
"windfarm: CPU power sensor error %d\n",
498 wf_smu_failure_state
|= FAILURE_SENSOR
;
502 DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
503 FIX32TOPRINT(temp
), FIX32TOPRINT(power
));
505 #ifdef HACKED_OVERTEMP
507 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
509 if (temp
> st
->pid
.param
.tmax
)
510 wf_smu_failure_state
|= FAILURE_OVERTEMP
;
512 new_setpoint
= wf_cpu_pid_run(&st
->pid
, power
, temp
);
514 DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint
);
516 systarget
= wf_smu_sys_fans
? wf_smu_sys_fans
->pid
.target
: 0;
517 systarget
= ((((s64
)systarget
) * (s64
)st
->scale
) >> 12)
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
);
523 DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint
);
525 if (st
->cpu_setpoint
== new_setpoint
)
527 st
->cpu_setpoint
= new_setpoint
;
529 if (fan_cpu_main
&& wf_smu_failure_state
== 0) {
530 rc
= wf_control_set(fan_cpu_main
, st
->cpu_setpoint
);
532 printk(KERN_WARNING
"windfarm: CPU main fan"
534 wf_smu_failure_state
|= FAILURE_FAN
;
540 * ****** Setup / Init / Misc ... ******
544 static void wf_smu_tick(void)
546 unsigned int last_failure
= wf_smu_failure_state
;
547 unsigned int new_failure
;
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;
557 if (wf_smu_skipping
&& --wf_smu_skipping
)
560 wf_smu_failure_state
= 0;
562 wf_smu_sys_fans_tick(wf_smu_sys_fans
);
564 wf_smu_cpu_fans_tick(wf_smu_cpu_fans
);
567 new_failure
= wf_smu_failure_state
& ~last_failure
;
569 /* If entering failure mode, clamp cpufreq and ramp all
570 * fans to full speed.
572 if (wf_smu_failure_state
&& !last_failure
) {
574 wf_control_set_max(cpufreq_clamp
);
576 wf_control_set_max(fan_system
);
578 wf_control_set_max(fan_cpu_main
);
580 wf_control_set_max(fan_hd
);
583 /* If leaving failure mode, unclamp cpufreq and readjust
584 * all fans on next iteration
586 if (!wf_smu_failure_state
&& last_failure
) {
588 wf_control_set_min(cpufreq_clamp
);
592 /* Overtemp condition detected, notify and start skipping a couple
593 * ticks to let the temperature go down
595 if (new_failure
& FAILURE_OVERTEMP
) {
598 wf_smu_overtemp
= true;
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
607 if (!wf_smu_failure_state
&& wf_smu_overtemp
) {
609 wf_smu_overtemp
= false;
613 static void wf_smu_new_control(struct wf_control
*ct
)
615 if (wf_smu_all_controls_ok
)
618 if (fan_cpu_main
== NULL
&& !strcmp(ct
->name
, "cpu-fan")) {
619 if (wf_get_control(ct
) == 0)
623 if (fan_system
== NULL
&& !strcmp(ct
->name
, "system-fan")) {
624 if (wf_get_control(ct
) == 0)
628 if (cpufreq_clamp
== NULL
&& !strcmp(ct
->name
, "cpufreq-clamp")) {
629 if (wf_get_control(ct
) == 0)
633 /* Darwin property list says the HD fan is only for model ID
637 if (wf_smu_mach_model
> 3) {
638 if (fan_system
&& fan_cpu_main
&& cpufreq_clamp
)
639 wf_smu_all_controls_ok
= 1;
643 if (fan_hd
== NULL
&& !strcmp(ct
->name
, "drive-bay-fan")) {
644 if (wf_get_control(ct
) == 0)
648 if (fan_system
&& fan_hd
&& fan_cpu_main
&& cpufreq_clamp
)
649 wf_smu_all_controls_ok
= 1;
652 static void wf_smu_new_sensor(struct wf_sensor
*sr
)
654 if (wf_smu_all_sensors_ok
)
657 if (sensor_cpu_power
== NULL
&& !strcmp(sr
->name
, "cpu-power")) {
658 if (wf_get_sensor(sr
) == 0)
659 sensor_cpu_power
= sr
;
662 if (sensor_cpu_temp
== NULL
&& !strcmp(sr
->name
, "cpu-temp")) {
663 if (wf_get_sensor(sr
) == 0)
664 sensor_cpu_temp
= sr
;
667 if (sensor_hd_temp
== NULL
&& !strcmp(sr
->name
, "hd-temp")) {
668 if (wf_get_sensor(sr
) == 0)
672 if (sensor_cpu_power
&& sensor_cpu_temp
&& sensor_hd_temp
)
673 wf_smu_all_sensors_ok
= 1;
677 static int wf_smu_notify(struct notifier_block
*self
,
678 unsigned long event
, void *data
)
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
);
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
);
693 if (wf_smu_all_controls_ok
&& wf_smu_all_sensors_ok
)
700 static struct notifier_block wf_smu_events
= {
701 .notifier_call
= wf_smu_notify
,
704 static int wf_init_pm(void)
706 const struct smu_sdbp_header
*hdr
;
708 hdr
= smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID
, NULL
);
710 struct smu_sdbp_sensortree
*st
=
711 (struct smu_sdbp_sensortree
*)&hdr
[1];
712 wf_smu_mach_model
= st
->model_id
;
715 printk(KERN_INFO
"windfarm: Initializing for iMacG5 model ID %d\n",
721 static int wf_smu_probe(struct platform_device
*ddev
)
723 wf_register_client(&wf_smu_events
);
728 static int wf_smu_remove(struct platform_device
*ddev
)
730 wf_unregister_client(&wf_smu_events
);
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
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 ?
745 if (sensor_cpu_power
)
746 wf_put_sensor(sensor_cpu_power
);
748 wf_put_sensor(sensor_cpu_temp
);
750 wf_put_sensor(sensor_hd_temp
);
752 /* Release all controls */
754 wf_put_control(fan_cpu_main
);
756 wf_put_control(fan_hd
);
758 wf_put_control(fan_system
);
760 wf_put_control(cpufreq_clamp
);
762 /* Destroy control loops state structures */
763 kfree(wf_smu_sys_fans
);
764 kfree(wf_smu_cpu_fans
);
769 static struct platform_driver wf_smu_driver
= {
770 .probe
= wf_smu_probe
,
771 .remove
= wf_smu_remove
,
778 static int __init
wf_smu_init(void)
782 if (of_machine_is_compatible("PowerMac8,1") ||
783 of_machine_is_compatible("PowerMac8,2"))
788 request_module("windfarm_smu_controls");
789 request_module("windfarm_smu_sensors");
790 request_module("windfarm_lm75_sensor");
791 request_module("windfarm_cpufreq_clamp");
794 platform_driver_register(&wf_smu_driver
);
800 static void __exit
wf_smu_exit(void)
803 platform_driver_unregister(&wf_smu_driver
);
807 module_init(wf_smu_init
);
808 module_exit(wf_smu_exit
);
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");