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 Sytem 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 */
761 kfree(wf_smu_sys_fans);
763 kfree(wf_smu_cpu_fans);
768 static struct platform_driver wf_smu_driver = {
769 .probe = wf_smu_probe,
770 .remove = __devexit_p(wf_smu_remove),
773 .owner = THIS_MODULE,
778 static int __init wf_smu_init(void)
782 if (machine_is_compatible("PowerMac8,1") ||
783 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");