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/system.h>
111
#include <asm/sections.h>
114
#include "windfarm.h"
115
#include "windfarm_pid.h"
117
#define VERSION "0.4"
122
#define DBG(args...) printk(args)
124
#define DBG(args...) do { } while(0)
127
/* define this to force CPU overtemp to 74 degree, useful for testing
130
#undef HACKED_OVERTEMP
132
static int wf_smu_mach_model; /* machine model id */
134
/* Controls & sensors */
135
static struct wf_sensor *sensor_cpu_power;
136
static struct wf_sensor *sensor_cpu_temp;
137
static struct wf_sensor *sensor_hd_temp;
138
static struct wf_control *fan_cpu_main;
139
static struct wf_control *fan_hd;
140
static struct wf_control *fan_system;
141
static struct wf_control *cpufreq_clamp;
143
/* Set to kick the control loop into life */
144
static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok, 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;
155
* ****** System Fans Control Loop ******
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.
163
struct wf_smu_sys_fans_param {
174
#define WF_SMU_SYS_FANS_INTERVAL 5
175
#define WF_SMU_SYS_FANS_HISTORY_SIZE 2
177
/* State data used by the system fans control loop
179
struct wf_smu_sys_fans_state {
187
struct wf_pid_state pid;
191
* Configs for SMU System Fan control loop
193
static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = {
231
#define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)
233
static struct wf_smu_sys_fans_state *wf_smu_sys_fans;
236
* ****** CPU Fans Control Loop ******
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
246
/* State data used by the cpu fans control loop
248
struct wf_smu_cpu_fans_state {
253
struct wf_cpu_pid_state pid;
256
static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
261
* ***** Implementation *****
265
static void wf_smu_create_sys_fans(void)
267
struct wf_smu_sys_fans_param *param = NULL;
268
struct wf_pid_param pid_param;
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];
278
/* No params found, put fans to max */
280
printk(KERN_WARNING "windfarm: System fan config not found "
281
"for this machine model, max fan speed\n");
285
/* Alloc & initialize state */
286
wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state),
288
if (wf_smu_sys_fans == NULL) {
289
printk(KERN_WARNING "windfarm: Memory allocation error"
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;
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 = fan_system->ops->get_min(fan_system);
307
pid_param.max = fan_system->ops->get_max(fan_system);
310
max(pid_param.min,fan_hd->ops->get_min(fan_hd));
312
min(pid_param.max,fan_hd->ops->get_max(fan_hd));
314
wf_pid_init(&wf_smu_sys_fans->pid, &pid_param);
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);
324
wf_control_set_max(fan_system);
326
wf_control_set_max(fan_hd);
329
static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st)
331
s32 new_setpoint, temp, scaled, cputarget;
334
if (--st->ticks != 0) {
339
st->ticks = WF_SMU_SYS_FANS_INTERVAL;
341
rc = sensor_hd_temp->ops->get_value(sensor_hd_temp, &temp);
343
printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
345
wf_smu_failure_state |= FAILURE_SENSOR;
349
DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
352
if (temp > (st->pid.param.itarget + 0x50000))
353
wf_smu_failure_state |= FAILURE_OVERTEMP;
355
new_setpoint = wf_pid_run(&st->pid, temp);
357
DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
359
scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;
361
DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled);
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);
369
DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled);
371
if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint)
373
st->sys_setpoint = scaled;
374
st->hd_setpoint = new_setpoint;
376
if (fan_system && wf_smu_failure_state == 0) {
377
rc = fan_system->ops->set_value(fan_system, st->sys_setpoint);
379
printk(KERN_WARNING "windfarm: Sys fan error %d\n",
381
wf_smu_failure_state |= FAILURE_FAN;
384
if (fan_hd && wf_smu_failure_state == 0) {
385
rc = fan_hd->ops->set_value(fan_hd, st->hd_setpoint);
387
printk(KERN_WARNING "windfarm: HD fan error %d\n",
389
wf_smu_failure_state |= FAILURE_FAN;
394
static void wf_smu_create_cpu_fans(void)
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;
402
/* First, locate the PID params in SMU SBD */
403
hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
405
printk(KERN_WARNING "windfarm: CPU PID fan config not found "
409
piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
411
/* Get the FVT params for operating point 0 (the only supported one
412
* for now) in order to get tmax
414
hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
416
fvt = (struct smu_sdbp_fvt *)&hdr[1];
417
tmax = ((s32)fvt->maxtemp) << 16;
419
tmax = 0x5e0000; /* 94 degree default */
421
/* Alloc & initialize state */
422
wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
424
if (wf_smu_cpu_fans == NULL)
426
wf_smu_cpu_fans->ticks = 1;
428
wf_smu_cpu_fans->scale = WF_SMU_CPU_FANS_SIBLING_SCALE;
429
wf_smu_cpu_fans->offset = WF_SMU_CPU_FANS_SIBLING_OFFSET;
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;
439
pid_param.gd = piddata->gd;
440
pid_param.gp = piddata->gp;
441
pid_param.gr = piddata->gr / pid_param.history_len;
443
tdelta = ((s32)piddata->target_temp_delta) << 16;
444
maxpow = ((s32)piddata->max_power) << 16;
445
powadj = ((s32)piddata->power_adj) << 16;
447
pid_param.tmax = tmax;
448
pid_param.ttarget = tmax - tdelta;
449
pid_param.pmaxadj = maxpow - powadj;
451
pid_param.min = fan_cpu_main->ops->get_min(fan_cpu_main);
452
pid_param.max = fan_cpu_main->ops->get_max(fan_cpu_main);
454
wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
456
DBG("wf: CPU Fan control initialized.\n");
457
DBG(" ttarged=%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);
464
printk(KERN_WARNING "windfarm: CPU fan config not found\n"
465
"for this machine model, max fan speed\n");
468
wf_control_set_max(cpufreq_clamp);
470
wf_control_set_max(fan_cpu_main);
473
static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
475
s32 new_setpoint, temp, power, systarget;
478
if (--st->ticks != 0) {
483
st->ticks = WF_SMU_CPU_FANS_INTERVAL;
485
rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
487
printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
489
wf_smu_failure_state |= FAILURE_SENSOR;
493
rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
495
printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
497
wf_smu_failure_state |= FAILURE_SENSOR;
501
DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
502
FIX32TOPRINT(temp), FIX32TOPRINT(power));
504
#ifdef HACKED_OVERTEMP
506
wf_smu_failure_state |= FAILURE_OVERTEMP;
508
if (temp > st->pid.param.tmax)
509
wf_smu_failure_state |= FAILURE_OVERTEMP;
511
new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
513
DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
515
systarget = wf_smu_sys_fans ? wf_smu_sys_fans->pid.target : 0;
516
systarget = ((((s64)systarget) * (s64)st->scale) >> 12)
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);
522
DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint);
524
if (st->cpu_setpoint == new_setpoint)
526
st->cpu_setpoint = new_setpoint;
528
if (fan_cpu_main && wf_smu_failure_state == 0) {
529
rc = fan_cpu_main->ops->set_value(fan_cpu_main,
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();
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) {
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
606
if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
610
static void wf_smu_new_control(struct wf_control *ct)
612
if (wf_smu_all_controls_ok)
615
if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-fan")) {
616
if (wf_get_control(ct) == 0)
620
if (fan_system == NULL && !strcmp(ct->name, "system-fan")) {
621
if (wf_get_control(ct) == 0)
625
if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
626
if (wf_get_control(ct) == 0)
630
/* Darwin property list says the HD fan is only for model ID
634
if (wf_smu_mach_model > 3) {
635
if (fan_system && fan_cpu_main && cpufreq_clamp)
636
wf_smu_all_controls_ok = 1;
640
if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
641
if (wf_get_control(ct) == 0)
645
if (fan_system && fan_hd && fan_cpu_main && cpufreq_clamp)
646
wf_smu_all_controls_ok = 1;
649
static void wf_smu_new_sensor(struct wf_sensor *sr)
651
if (wf_smu_all_sensors_ok)
654
if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
655
if (wf_get_sensor(sr) == 0)
656
sensor_cpu_power = sr;
659
if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
660
if (wf_get_sensor(sr) == 0)
661
sensor_cpu_temp = sr;
664
if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
665
if (wf_get_sensor(sr) == 0)
669
if (sensor_cpu_power && sensor_cpu_temp && sensor_hd_temp)
670
wf_smu_all_sensors_ok = 1;
674
static int wf_smu_notify(struct notifier_block *self,
675
unsigned long event, void *data)
678
case WF_EVENT_NEW_CONTROL:
679
DBG("wf: new control %s detected\n",
680
((struct wf_control *)data)->name);
681
wf_smu_new_control(data);
684
case WF_EVENT_NEW_SENSOR:
685
DBG("wf: new sensor %s detected\n",
686
((struct wf_sensor *)data)->name);
687
wf_smu_new_sensor(data);
690
if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
697
static struct notifier_block wf_smu_events = {
698
.notifier_call = wf_smu_notify,
701
static int wf_init_pm(void)
703
const struct smu_sdbp_header *hdr;
705
hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL);
707
struct smu_sdbp_sensortree *st =
708
(struct smu_sdbp_sensortree *)&hdr[1];
709
wf_smu_mach_model = st->model_id;
712
printk(KERN_INFO "windfarm: Initializing for iMacG5 model ID %d\n",
718
static int wf_smu_probe(struct platform_device *ddev)
720
wf_register_client(&wf_smu_events);
725
static int __devexit wf_smu_remove(struct platform_device *ddev)
727
wf_unregister_client(&wf_smu_events);
729
/* XXX We don't have yet a guarantee that our callback isn't
730
* in progress when returning from wf_unregister_client, so
731
* we add an arbitrary delay. I'll have to fix that in the core
735
/* Release all sensors */
736
/* One more crappy race: I don't think we have any guarantee here
737
* that the attribute callback won't race with the sensor beeing
738
* disposed of, and I'm not 100% certain what best way to deal
739
* with that except by adding locks all over... I'll do that
740
* eventually but heh, who ever rmmod this module anyway ?
742
if (sensor_cpu_power)
743
wf_put_sensor(sensor_cpu_power);
745
wf_put_sensor(sensor_cpu_temp);
747
wf_put_sensor(sensor_hd_temp);
749
/* Release all controls */
751
wf_put_control(fan_cpu_main);
753
wf_put_control(fan_hd);
755
wf_put_control(fan_system);
757
wf_put_control(cpufreq_clamp);
759
/* Destroy control loops state structures */
760
kfree(wf_smu_sys_fans);
761
kfree(wf_smu_cpu_fans);
766
static struct platform_driver wf_smu_driver = {
767
.probe = wf_smu_probe,
768
.remove = __devexit_p(wf_smu_remove),
771
.owner = THIS_MODULE,
776
static int __init wf_smu_init(void)
780
if (of_machine_is_compatible("PowerMac8,1") ||
781
of_machine_is_compatible("PowerMac8,2"))
786
request_module("windfarm_smu_controls");
787
request_module("windfarm_smu_sensors");
788
request_module("windfarm_lm75_sensor");
789
request_module("windfarm_cpufreq_clamp");
792
platform_driver_register(&wf_smu_driver);
798
static void __exit wf_smu_exit(void)
801
platform_driver_unregister(&wf_smu_driver);
805
module_init(wf_smu_init);
806
module_exit(wf_smu_exit);
808
MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
809
MODULE_DESCRIPTION("Thermal control logic for iMac G5");
810
MODULE_LICENSE("GPL");
811
MODULE_ALIAS("platform:windfarm");