2 * Windfarm PowerMac thermal control.
3 * Control loops for machines with SMU and PPC970MP processors.
5 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
6 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
8 * Use and redistribute under the terms of the GNU GPL v2.
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/device.h>
14 #include <linux/platform_device.h>
15 #include <linux/reboot.h>
20 #include "windfarm_pid.h"
28 #define DBG(args...) printk(args)
30 #define DBG(args...) do { } while(0)
34 #define DBG_LOTS(args...) printk(args)
36 #define DBG_LOTS(args...) do { } while(0)
39 /* define this to force CPU overtemp to 60 degree, useful for testing
42 #undef HACKED_OVERTEMP
44 /* We currently only handle 2 chips, 4 cores... */
47 #define NR_CPU_FANS 3 * NR_CHIPS
49 /* Controls and sensors */
50 static struct wf_sensor *sens_cpu_temp[NR_CORES];
51 static struct wf_sensor *sens_cpu_power[NR_CORES];
52 static struct wf_sensor *hd_temp;
53 static struct wf_sensor *slots_power;
54 static struct wf_sensor *u4_temp;
56 static struct wf_control *cpu_fans[NR_CPU_FANS];
57 static char *cpu_fan_names[NR_CPU_FANS] = {
65 static struct wf_control *cpufreq_clamp;
67 /* Second pump isn't required (and isn't actually present) */
68 #define CPU_FANS_REQD (NR_CPU_FANS - 2)
72 /* We keep a temperature history for average calculation of 180s */
73 #define CPU_TEMP_HIST_SIZE 180
75 /* Scale factor for fan speed, *100 */
76 static int cpu_fan_scale[NR_CPU_FANS] = {
79 97, /* inlet fans run at 97% of exhaust fan */
81 100, /* updated later */
82 100, /* updated later */
85 static struct wf_control *backside_fan;
86 static struct wf_control *slots_fan;
87 static struct wf_control *drive_bay_fan;
90 static struct wf_cpu_pid_state cpu_pid[NR_CORES];
91 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
92 static int cpu_thist_pt;
93 static s64 cpu_thist_total;
94 static s32 cpu_all_tmax = 100 << 16;
95 static int cpu_last_target;
96 static struct wf_pid_state backside_pid;
97 static int backside_tick;
98 static struct wf_pid_state slots_pid;
99 static int slots_started;
100 static struct wf_pid_state drive_bay_pid;
101 static int drive_bay_tick;
104 static int have_all_controls;
105 static int have_all_sensors;
108 static int failure_state;
109 #define FAILURE_SENSOR 1
110 #define FAILURE_FAN 2
111 #define FAILURE_PERM 4
112 #define FAILURE_LOW_OVERTEMP 8
113 #define FAILURE_HIGH_OVERTEMP 16
115 /* Overtemp values */
116 #define LOW_OVER_AVERAGE 0
117 #define LOW_OVER_IMMEDIATE (10 << 16)
118 #define LOW_OVER_CLEAR ((-10) << 16)
119 #define HIGH_OVER_IMMEDIATE (14 << 16)
120 #define HIGH_OVER_AVERAGE (10 << 16)
121 #define HIGH_OVER_IMMEDIATE (14 << 16)
124 /* Implementation... */
125 static int create_cpu_loop(int cpu)
129 struct smu_sdbp_header *hdr;
130 struct smu_sdbp_cpupiddata *piddata;
131 struct wf_cpu_pid_param pid;
132 struct wf_control *main_fan = cpu_fans[0];
136 /* Get PID params from the appropriate SAT */
137 hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
139 printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
142 piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
144 /* Get FVT params to get Tmax; if not found, assume default */
145 hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
147 struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
148 tmax = fvt->maxtemp << 16;
150 tmax = 95 << 16; /* default to 95 degrees C */
152 /* We keep a global tmax for overtemp calculations */
153 if (tmax < cpu_all_tmax)
157 * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
158 * 515 for the 2-way. That appears to be overkill, so for now,
159 * impose a minimum of 750 or 515.
161 fmin = (nr_cores > 2) ? 750 : 515;
163 /* Initialize PID loop */
164 pid.interval = 1; /* seconds */
165 pid.history_len = piddata->history_len;
166 pid.gd = piddata->gd;
167 pid.gp = piddata->gp;
168 pid.gr = piddata->gr / piddata->history_len;
169 pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
170 pid.ttarget = tmax - (piddata->target_temp_delta << 16);
172 pid.min = main_fan->ops->get_min(main_fan);
173 pid.max = main_fan->ops->get_max(main_fan);
177 wf_cpu_pid_init(&cpu_pid[cpu], &pid);
181 static void cpu_max_all_fans(void)
185 /* We max all CPU fans in case of a sensor error. We also do the
186 * cpufreq clamping now, even if it's supposedly done later by the
187 * generic code anyway, we do it earlier here to react faster
190 wf_control_set_max(cpufreq_clamp);
191 for (i = 0; i < NR_CPU_FANS; ++i)
193 wf_control_set_max(cpu_fans[i]);
196 static int cpu_check_overtemp(s32 temp)
201 /* First check for immediate overtemps */
202 if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
203 new_state |= FAILURE_LOW_OVERTEMP;
204 if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
205 printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
208 if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
209 new_state |= FAILURE_HIGH_OVERTEMP;
210 if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
211 printk(KERN_ERR "windfarm: Critical overtemp due to"
212 " immediate CPU temperature !\n");
215 /* We calculate a history of max temperatures and use that for the
216 * overtemp management
218 t_old = cpu_thist[cpu_thist_pt];
219 cpu_thist[cpu_thist_pt] = temp;
220 cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
221 cpu_thist_total -= t_old;
222 cpu_thist_total += temp;
223 t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
225 DBG_LOTS("t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
226 FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
228 /* Now check for average overtemps */
229 if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
230 new_state |= FAILURE_LOW_OVERTEMP;
231 if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
232 printk(KERN_ERR "windfarm: Overtemp due to average CPU"
235 if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
236 new_state |= FAILURE_HIGH_OVERTEMP;
237 if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
238 printk(KERN_ERR "windfarm: Critical overtemp due to"
239 " average CPU temperature !\n");
242 /* Now handle overtemp conditions. We don't currently use the windfarm
243 * overtemp handling core as it's not fully suited to the needs of those
244 * new machine. This will be fixed later.
247 /* High overtemp -> immediate shutdown */
248 if (new_state & FAILURE_HIGH_OVERTEMP)
250 if ((failure_state & new_state) != new_state)
252 failure_state |= new_state;
253 } else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
254 (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
255 printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
256 failure_state &= ~FAILURE_LOW_OVERTEMP;
259 return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
262 static void cpu_fans_tick(void)
265 s32 greatest_delta = 0;
266 s32 temp, power, t_max = 0;
267 int i, t, target = 0;
268 struct wf_sensor *sr;
269 struct wf_control *ct;
270 struct wf_cpu_pid_state *sp;
272 DBG_LOTS(KERN_DEBUG);
273 for (cpu = 0; cpu < nr_cores; ++cpu) {
274 /* Get CPU core temperature */
275 sr = sens_cpu_temp[cpu];
276 err = sr->ops->get_value(sr, &temp);
279 printk(KERN_WARNING "windfarm: CPU %d temperature "
280 "sensor error %d\n", cpu, err);
281 failure_state |= FAILURE_SENSOR;
286 /* Keep track of highest temp */
287 t_max = max(t_max, temp);
290 sr = sens_cpu_power[cpu];
291 err = sr->ops->get_value(sr, &power);
294 printk(KERN_WARNING "windfarm: CPU %d power "
295 "sensor error %d\n", cpu, err);
296 failure_state |= FAILURE_SENSOR;
303 t = wf_cpu_pid_run(sp, power, temp);
305 if (cpu == 0 || sp->last_delta > greatest_delta) {
306 greatest_delta = sp->last_delta;
309 DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
310 cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
312 DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
314 /* Darwin limits decrease to 20 per iteration */
315 if (target < (cpu_last_target - 20))
316 target = cpu_last_target - 20;
317 cpu_last_target = target;
318 for (cpu = 0; cpu < nr_cores; ++cpu)
319 cpu_pid[cpu].target = target;
321 /* Handle possible overtemps */
322 if (cpu_check_overtemp(t_max))
326 for (i = 0; i < NR_CPU_FANS; ++i) {
330 err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
332 printk(KERN_WARNING "windfarm: fan %s reports "
333 "error %d\n", ct->name, err);
334 failure_state |= FAILURE_FAN;
340 /* Backside/U4 fan */
341 static struct wf_pid_param backside_param = {
351 static void backside_fan_tick(void)
357 if (!backside_fan || !u4_temp)
359 if (!backside_tick) {
360 /* first time; initialize things */
361 backside_param.min = backside_fan->ops->get_min(backside_fan);
362 backside_param.max = backside_fan->ops->get_max(backside_fan);
363 wf_pid_init(&backside_pid, &backside_param);
366 if (--backside_tick > 0)
368 backside_tick = backside_pid.param.interval;
370 err = u4_temp->ops->get_value(u4_temp, &temp);
372 printk(KERN_WARNING "windfarm: U4 temp sensor error %d\n",
374 failure_state |= FAILURE_SENSOR;
375 wf_control_set_max(backside_fan);
378 speed = wf_pid_run(&backside_pid, temp);
379 DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
380 FIX32TOPRINT(temp), speed);
382 err = backside_fan->ops->set_value(backside_fan, speed);
384 printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
385 failure_state |= FAILURE_FAN;
390 static struct wf_pid_param drive_bay_prm = {
400 static void drive_bay_fan_tick(void)
406 if (!drive_bay_fan || !hd_temp)
408 if (!drive_bay_tick) {
409 /* first time; initialize things */
410 drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
411 drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
412 wf_pid_init(&drive_bay_pid, &drive_bay_prm);
415 if (--drive_bay_tick > 0)
417 drive_bay_tick = drive_bay_pid.param.interval;
419 err = hd_temp->ops->get_value(hd_temp, &temp);
421 printk(KERN_WARNING "windfarm: drive bay temp sensor "
423 failure_state |= FAILURE_SENSOR;
424 wf_control_set_max(drive_bay_fan);
427 speed = wf_pid_run(&drive_bay_pid, temp);
428 DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
429 FIX32TOPRINT(temp), speed);
431 err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
433 printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
434 failure_state |= FAILURE_FAN;
438 /* PCI slots area fan */
439 /* This makes the fan speed proportional to the power consumed */
440 static struct wf_pid_param slots_param = {
451 static void slots_fan_tick(void)
457 if (!slots_fan || !slots_power)
459 if (!slots_started) {
460 /* first time; initialize things */
461 wf_pid_init(&slots_pid, &slots_param);
465 err = slots_power->ops->get_value(slots_power, &power);
467 printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
469 failure_state |= FAILURE_SENSOR;
470 wf_control_set_max(slots_fan);
473 speed = wf_pid_run(&slots_pid, power);
474 DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
475 FIX32TOPRINT(power), speed);
477 err = slots_fan->ops->set_value(slots_fan, speed);
479 printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
480 failure_state |= FAILURE_FAN;
484 static void set_fail_state(void)
489 wf_control_set_max(cpufreq_clamp);
490 for (i = 0; i < NR_CPU_FANS; ++i)
492 wf_control_set_max(cpu_fans[i]);
494 wf_control_set_max(backside_fan);
496 wf_control_set_max(slots_fan);
498 wf_control_set_max(drive_bay_fan);
501 static void pm112_tick(void)
507 for (i = 0; i < nr_cores; ++i) {
508 if (create_cpu_loop(i) < 0) {
509 failure_state = FAILURE_PERM;
514 DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
516 #ifdef HACKED_OVERTEMP
517 cpu_all_tmax = 60 << 16;
521 /* Permanent failure, bail out */
522 if (failure_state & FAILURE_PERM)
524 /* Clear all failure bits except low overtemp which will be eventually
525 * cleared by the control loop itself
527 last_failure = failure_state;
528 failure_state &= FAILURE_LOW_OVERTEMP;
532 drive_bay_fan_tick();
534 DBG_LOTS("last_failure: 0x%x, failure_state: %x\n",
535 last_failure, failure_state);
537 /* Check for failures. Any failure causes cpufreq clamping */
538 if (failure_state && last_failure == 0 && cpufreq_clamp)
539 wf_control_set_max(cpufreq_clamp);
540 if (failure_state == 0 && last_failure && cpufreq_clamp)
541 wf_control_set_min(cpufreq_clamp);
543 /* That's it for now, we might want to deal with other failures
544 * differently in the future though
548 static void pm112_new_control(struct wf_control *ct)
552 if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
553 if (wf_get_control(ct) == 0)
557 for (i = 0; i < NR_CPU_FANS; ++i) {
558 if (!strcmp(ct->name, cpu_fan_names[i])) {
559 if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
564 if (i >= NR_CPU_FANS) {
565 /* not a CPU fan, try the others */
566 if (!strcmp(ct->name, "backside-fan")) {
567 if (backside_fan == NULL && wf_get_control(ct) == 0)
569 } else if (!strcmp(ct->name, "slots-fan")) {
570 if (slots_fan == NULL && wf_get_control(ct) == 0)
572 } else if (!strcmp(ct->name, "drive-bay-fan")) {
573 if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
579 for (i = 0; i < CPU_FANS_REQD; ++i)
580 if (cpu_fans[i] == NULL)
583 /* work out pump scaling factors */
584 max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
585 for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
586 if ((ct = cpu_fans[i]) != NULL)
588 ct->ops->get_max(ct) * 100 / max_exhaust;
590 have_all_controls = 1;
593 static void pm112_new_sensor(struct wf_sensor *sr)
597 if (have_all_sensors)
599 if (!strncmp(sr->name, "cpu-temp-", 9)) {
600 i = sr->name[9] - '0';
601 if (sr->name[10] == 0 && i < NR_CORES &&
602 sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
603 sens_cpu_temp[i] = sr;
605 } else if (!strncmp(sr->name, "cpu-power-", 10)) {
606 i = sr->name[10] - '0';
607 if (sr->name[11] == 0 && i < NR_CORES &&
608 sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
609 sens_cpu_power[i] = sr;
610 } else if (!strcmp(sr->name, "hd-temp")) {
611 if (hd_temp == NULL && wf_get_sensor(sr) == 0)
613 } else if (!strcmp(sr->name, "slots-power")) {
614 if (slots_power == NULL && wf_get_sensor(sr) == 0)
616 } else if (!strcmp(sr->name, "u4-temp")) {
617 if (u4_temp == NULL && wf_get_sensor(sr) == 0)
622 /* check if we have all the sensors we need */
623 for (i = 0; i < nr_cores; ++i)
624 if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
627 have_all_sensors = 1;
630 static int pm112_wf_notify(struct notifier_block *self,
631 unsigned long event, void *data)
634 case WF_EVENT_NEW_SENSOR:
635 pm112_new_sensor(data);
637 case WF_EVENT_NEW_CONTROL:
638 pm112_new_control(data);
641 if (have_all_controls && have_all_sensors)
647 static struct notifier_block pm112_events = {
648 .notifier_call = pm112_wf_notify,
651 static int wf_pm112_probe(struct device *dev)
653 wf_register_client(&pm112_events);
657 static int wf_pm112_remove(struct device *dev)
659 wf_unregister_client(&pm112_events);
660 /* should release all sensors and controls */
664 static struct device_driver wf_pm112_driver = {
666 .bus = &platform_bus_type,
667 .probe = wf_pm112_probe,
668 .remove = wf_pm112_remove,
671 static int __init wf_pm112_init(void)
673 struct device_node *cpu;
675 if (!machine_is_compatible("PowerMac11,2"))
678 /* Count the number of CPU cores */
680 for (cpu = NULL; (cpu = of_find_node_by_type(cpu, "cpu")) != NULL; )
683 printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
684 driver_register(&wf_pm112_driver);
688 static void __exit wf_pm112_exit(void)
690 driver_unregister(&wf_pm112_driver);
693 module_init(wf_pm112_init);
694 module_exit(wf_pm112_exit);
696 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
697 MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
698 MODULE_LICENSE("GPL");