Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland...
[linux-2.6] / drivers / sbus / char / bbc_envctrl.c
1 /* $Id: bbc_envctrl.c,v 1.4 2001/04/06 16:48:08 davem Exp $
2  * bbc_envctrl.c: UltraSPARC-III environment control driver.
3  *
4  * Copyright (C) 2001 David S. Miller (davem@redhat.com)
5  */
6
7 #include <linux/kthread.h>
8 #include <linux/delay.h>
9 #include <linux/kmod.h>
10 #include <linux/reboot.h>
11 #include <asm/oplib.h>
12 #include <asm/ebus.h>
13
14 #include "bbc_i2c.h"
15 #include "max1617.h"
16
17 #undef ENVCTRL_TRACE
18
19 /* WARNING: Making changes to this driver is very dangerous.
20  *          If you misprogram the sensor chips they can
21  *          cut the power on you instantly.
22  */
23
24 /* Two temperature sensors exist in the SunBLADE-1000 enclosure.
25  * Both are implemented using max1617 i2c devices.  Each max1617
26  * monitors 2 temperatures, one for one of the cpu dies and the other
27  * for the ambient temperature.
28  *
29  * The max1617 is capable of being programmed with power-off
30  * temperature values, one low limit and one high limit.  These
31  * can be controlled independently for the cpu or ambient temperature.
32  * If a limit is violated, the power is simply shut off.  The frequency
33  * with which the max1617 does temperature sampling can be controlled
34  * as well.
35  *
36  * Three fans exist inside the machine, all three are controlled with
37  * an i2c digital to analog converter.  There is a fan directed at the
38  * two processor slots, another for the rest of the enclosure, and the
39  * third is for the power supply.  The first two fans may be speed
40  * controlled by changing the voltage fed to them.  The third fan may
41  * only be completely off or on.  The third fan is meant to only be
42  * disabled/enabled when entering/exiting the lowest power-saving
43  * mode of the machine.
44  *
45  * An environmental control kernel thread periodically monitors all
46  * temperature sensors.  Based upon the samples it will adjust the
47  * fan speeds to try and keep the system within a certain temperature
48  * range (the goal being to make the fans as quiet as possible without
49  * allowing the system to get too hot).
50  *
51  * If the temperature begins to rise/fall outside of the acceptable
52  * operating range, a periodic warning will be sent to the kernel log.
53  * The fans will be put on full blast to attempt to deal with this
54  * situation.  After exceeding the acceptable operating range by a
55  * certain threshold, the kernel thread will shut down the system.
56  * Here, the thread is attempting to shut the machine down cleanly
57  * before the hardware based power-off event is triggered.
58  */
59
60 /* These settings are in Celsius.  We use these defaults only
61  * if we cannot interrogate the cpu-fru SEEPROM.
62  */
63 struct temp_limits {
64         s8 high_pwroff, high_shutdown, high_warn;
65         s8 low_warn, low_shutdown, low_pwroff;
66 };
67
68 static struct temp_limits cpu_temp_limits[2] = {
69         { 100, 85, 80, 5, -5, -10 },
70         { 100, 85, 80, 5, -5, -10 },
71 };
72
73 static struct temp_limits amb_temp_limits[2] = {
74         { 65, 55, 40, 5, -5, -10 },
75         { 65, 55, 40, 5, -5, -10 },
76 };
77
78 enum fan_action { FAN_SLOWER, FAN_SAME, FAN_FASTER, FAN_FULLBLAST, FAN_STATE_MAX };
79
80 struct bbc_cpu_temperature {
81         struct bbc_cpu_temperature      *next;
82
83         struct bbc_i2c_client           *client;
84         int                             index;
85
86         /* Current readings, and history. */
87         s8                              curr_cpu_temp;
88         s8                              curr_amb_temp;
89         s8                              prev_cpu_temp;
90         s8                              prev_amb_temp;
91         s8                              avg_cpu_temp;
92         s8                              avg_amb_temp;
93
94         int                             sample_tick;
95
96         enum fan_action                 fan_todo[2];
97 #define FAN_AMBIENT     0
98 #define FAN_CPU         1
99 };
100
101 struct bbc_cpu_temperature *all_bbc_temps;
102
103 struct bbc_fan_control {
104         struct bbc_fan_control  *next;
105
106         struct bbc_i2c_client   *client;
107         int                     index;
108
109         int                     psupply_fan_on;
110         int                     cpu_fan_speed;
111         int                     system_fan_speed;
112 };
113
114 struct bbc_fan_control *all_bbc_fans;
115
116 #define CPU_FAN_REG     0xf0
117 #define SYS_FAN_REG     0xf2
118 #define PSUPPLY_FAN_REG 0xf4
119
120 #define FAN_SPEED_MIN   0x0c
121 #define FAN_SPEED_MAX   0x3f
122
123 #define PSUPPLY_FAN_ON  0x1f
124 #define PSUPPLY_FAN_OFF 0x00
125
126 static void set_fan_speeds(struct bbc_fan_control *fp)
127 {
128         /* Put temperatures into range so we don't mis-program
129          * the hardware.
130          */
131         if (fp->cpu_fan_speed < FAN_SPEED_MIN)
132                 fp->cpu_fan_speed = FAN_SPEED_MIN;
133         if (fp->cpu_fan_speed > FAN_SPEED_MAX)
134                 fp->cpu_fan_speed = FAN_SPEED_MAX;
135         if (fp->system_fan_speed < FAN_SPEED_MIN)
136                 fp->system_fan_speed = FAN_SPEED_MIN;
137         if (fp->system_fan_speed > FAN_SPEED_MAX)
138                 fp->system_fan_speed = FAN_SPEED_MAX;
139 #ifdef ENVCTRL_TRACE
140         printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
141                fp->index,
142                fp->cpu_fan_speed, fp->system_fan_speed);
143 #endif
144
145         bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
146         bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
147         bbc_i2c_writeb(fp->client,
148                        (fp->psupply_fan_on ?
149                         PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
150                        PSUPPLY_FAN_REG);
151 }
152
153 static void get_current_temps(struct bbc_cpu_temperature *tp)
154 {
155         tp->prev_amb_temp = tp->curr_amb_temp;
156         bbc_i2c_readb(tp->client,
157                       (unsigned char *) &tp->curr_amb_temp,
158                       MAX1617_AMB_TEMP);
159         tp->prev_cpu_temp = tp->curr_cpu_temp;
160         bbc_i2c_readb(tp->client,
161                       (unsigned char *) &tp->curr_cpu_temp,
162                       MAX1617_CPU_TEMP);
163 #ifdef ENVCTRL_TRACE
164         printk("temp%d: cpu(%d C) amb(%d C)\n",
165                tp->index,
166                (int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
167 #endif
168 }
169
170
171 static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
172 {
173         static int shutting_down = 0;
174         char *type = "???";
175         s8 val = -1;
176
177         if (shutting_down != 0)
178                 return;
179
180         if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
181             tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
182                 type = "ambient";
183                 val = tp->curr_amb_temp;
184         } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
185                    tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
186                 type = "CPU";
187                 val = tp->curr_cpu_temp;
188         }
189
190         printk(KERN_CRIT "temp%d: Outside of safe %s "
191                "operating temperature, %d C.\n",
192                tp->index, type, val);
193
194         printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
195
196         shutting_down = 1;
197         if (orderly_poweroff(true) < 0)
198                 printk(KERN_CRIT "envctrl: shutdown execution failed\n");
199 }
200
201 #define WARN_INTERVAL   (30 * HZ)
202
203 static void analyze_ambient_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
204 {
205         int ret = 0;
206
207         if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
208                 if (tp->curr_amb_temp >=
209                     amb_temp_limits[tp->index].high_warn) {
210                         printk(KERN_WARNING "temp%d: "
211                                "Above safe ambient operating temperature, %d C.\n",
212                                tp->index, (int) tp->curr_amb_temp);
213                         ret = 1;
214                 } else if (tp->curr_amb_temp <
215                            amb_temp_limits[tp->index].low_warn) {
216                         printk(KERN_WARNING "temp%d: "
217                                "Below safe ambient operating temperature, %d C.\n",
218                                tp->index, (int) tp->curr_amb_temp);
219                         ret = 1;
220                 }
221                 if (ret)
222                         *last_warn = jiffies;
223         } else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn ||
224                    tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
225                 ret = 1;
226
227         /* Now check the shutdown limits. */
228         if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
229             tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
230                 do_envctrl_shutdown(tp);
231                 ret = 1;
232         }
233
234         if (ret) {
235                 tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
236         } else if ((tick & (8 - 1)) == 0) {
237                 s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
238                 s8 amb_goal_lo;
239
240                 amb_goal_lo = amb_goal_hi - 3;
241
242                 /* We do not try to avoid 'too cold' events.  Basically we
243                  * only try to deal with over-heating and fan noise reduction.
244                  */
245                 if (tp->avg_amb_temp < amb_goal_hi) {
246                         if (tp->avg_amb_temp >= amb_goal_lo)
247                                 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
248                         else
249                                 tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
250                 } else {
251                         tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
252                 }
253         } else {
254                 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
255         }
256 }
257
258 static void analyze_cpu_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
259 {
260         int ret = 0;
261
262         if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
263                 if (tp->curr_cpu_temp >=
264                     cpu_temp_limits[tp->index].high_warn) {
265                         printk(KERN_WARNING "temp%d: "
266                                "Above safe CPU operating temperature, %d C.\n",
267                                tp->index, (int) tp->curr_cpu_temp);
268                         ret = 1;
269                 } else if (tp->curr_cpu_temp <
270                            cpu_temp_limits[tp->index].low_warn) {
271                         printk(KERN_WARNING "temp%d: "
272                                "Below safe CPU operating temperature, %d C.\n",
273                                tp->index, (int) tp->curr_cpu_temp);
274                         ret = 1;
275                 }
276                 if (ret)
277                         *last_warn = jiffies;
278         } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn ||
279                    tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
280                 ret = 1;
281
282         /* Now check the shutdown limits. */
283         if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
284             tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
285                 do_envctrl_shutdown(tp);
286                 ret = 1;
287         }
288
289         if (ret) {
290                 tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
291         } else if ((tick & (8 - 1)) == 0) {
292                 s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
293                 s8 cpu_goal_lo;
294
295                 cpu_goal_lo = cpu_goal_hi - 3;
296
297                 /* We do not try to avoid 'too cold' events.  Basically we
298                  * only try to deal with over-heating and fan noise reduction.
299                  */
300                 if (tp->avg_cpu_temp < cpu_goal_hi) {
301                         if (tp->avg_cpu_temp >= cpu_goal_lo)
302                                 tp->fan_todo[FAN_CPU] = FAN_SAME;
303                         else
304                                 tp->fan_todo[FAN_CPU] = FAN_SLOWER;
305                 } else {
306                         tp->fan_todo[FAN_CPU] = FAN_FASTER;
307                 }
308         } else {
309                 tp->fan_todo[FAN_CPU] = FAN_SAME;
310         }
311 }
312
313 static void analyze_temps(struct bbc_cpu_temperature *tp, unsigned long *last_warn)
314 {
315         tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
316         tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);
317
318         analyze_ambient_temp(tp, last_warn, tp->sample_tick);
319         analyze_cpu_temp(tp, last_warn, tp->sample_tick);
320
321         tp->sample_tick++;
322 }
323
324 static enum fan_action prioritize_fan_action(int which_fan)
325 {
326         struct bbc_cpu_temperature *tp;
327         enum fan_action decision = FAN_STATE_MAX;
328
329         /* Basically, prioritize what the temperature sensors
330          * recommend we do, and perform that action on all the
331          * fans.
332          */
333         for (tp = all_bbc_temps; tp; tp = tp->next) {
334                 if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
335                         decision = FAN_FULLBLAST;
336                         break;
337                 }
338                 if (tp->fan_todo[which_fan] == FAN_SAME &&
339                     decision != FAN_FASTER)
340                         decision = FAN_SAME;
341                 else if (tp->fan_todo[which_fan] == FAN_FASTER)
342                         decision = FAN_FASTER;
343                 else if (decision != FAN_FASTER &&
344                          decision != FAN_SAME &&
345                          tp->fan_todo[which_fan] == FAN_SLOWER)
346                         decision = FAN_SLOWER;
347         }
348         if (decision == FAN_STATE_MAX)
349                 decision = FAN_SAME;
350
351         return decision;
352 }
353
354 static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
355 {
356         enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
357         int ret;
358
359         if (decision == FAN_SAME)
360                 return 0;
361
362         ret = 1;
363         if (decision == FAN_FULLBLAST) {
364                 if (fp->system_fan_speed >= FAN_SPEED_MAX)
365                         ret = 0;
366                 else
367                         fp->system_fan_speed = FAN_SPEED_MAX;
368         } else {
369                 if (decision == FAN_FASTER) {
370                         if (fp->system_fan_speed >= FAN_SPEED_MAX)
371                                 ret = 0;
372                         else
373                                 fp->system_fan_speed += 2;
374                 } else {
375                         int orig_speed = fp->system_fan_speed;
376
377                         if (orig_speed <= FAN_SPEED_MIN ||
378                             orig_speed <= (fp->cpu_fan_speed - 3))
379                                 ret = 0;
380                         else
381                                 fp->system_fan_speed -= 1;
382                 }
383         }
384
385         return ret;
386 }
387
388 static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
389 {
390         enum fan_action decision = prioritize_fan_action(FAN_CPU);
391         int ret;
392
393         if (decision == FAN_SAME)
394                 return 0;
395
396         ret = 1;
397         if (decision == FAN_FULLBLAST) {
398                 if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
399                         ret = 0;
400                 else
401                         fp->cpu_fan_speed = FAN_SPEED_MAX;
402         } else {
403                 if (decision == FAN_FASTER) {
404                         if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
405                                 ret = 0;
406                         else {
407                                 fp->cpu_fan_speed += 2;
408                                 if (fp->system_fan_speed <
409                                     (fp->cpu_fan_speed - 3))
410                                         fp->system_fan_speed =
411                                                 fp->cpu_fan_speed - 3;
412                         }
413                 } else {
414                         if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
415                                 ret = 0;
416                         else
417                                 fp->cpu_fan_speed -= 1;
418                 }
419         }
420
421         return ret;
422 }
423
424 static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
425 {
426         int new;
427
428         new  = maybe_new_ambient_fan_speed(fp);
429         new |= maybe_new_cpu_fan_speed(fp);
430
431         if (new)
432                 set_fan_speeds(fp);
433 }
434
435 static void fans_full_blast(void)
436 {
437         struct bbc_fan_control *fp;
438
439         /* Since we will not be monitoring things anymore, put
440          * the fans on full blast.
441          */
442         for (fp = all_bbc_fans; fp; fp = fp->next) {
443                 fp->cpu_fan_speed = FAN_SPEED_MAX;
444                 fp->system_fan_speed = FAN_SPEED_MAX;
445                 fp->psupply_fan_on = 1;
446                 set_fan_speeds(fp);
447         }
448 }
449
450 #define POLL_INTERVAL   (5 * 1000)
451 static unsigned long last_warning_jiffies;
452 static struct task_struct *kenvctrld_task;
453
454 static int kenvctrld(void *__unused)
455 {
456         printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
457         last_warning_jiffies = jiffies - WARN_INTERVAL;
458         for (;;) {
459                 struct bbc_cpu_temperature *tp;
460                 struct bbc_fan_control *fp;
461
462                 msleep_interruptible(POLL_INTERVAL);
463                 if (kthread_should_stop())
464                         break;
465
466                 for (tp = all_bbc_temps; tp; tp = tp->next) {
467                         get_current_temps(tp);
468                         analyze_temps(tp, &last_warning_jiffies);
469                 }
470                 for (fp = all_bbc_fans; fp; fp = fp->next)
471                         maybe_new_fan_speeds(fp);
472         }
473         printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");
474
475         fans_full_blast();
476
477         return 0;
478 }
479
480 static void attach_one_temp(struct linux_ebus_child *echild, int temp_idx)
481 {
482         struct bbc_cpu_temperature *tp;
483
484         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
485         if (!tp)
486                 return;
487
488         tp->client = bbc_i2c_attach(echild);
489         if (!tp->client) {
490                 kfree(tp);
491                 return;
492         }
493
494         tp->index = temp_idx;
495         {
496                 struct bbc_cpu_temperature **tpp = &all_bbc_temps;
497                 while (*tpp)
498                         tpp = &((*tpp)->next);
499                 tp->next = NULL;
500                 *tpp = tp;
501         }
502
503         /* Tell it to convert once every 5 seconds, clear all cfg
504          * bits.
505          */
506         bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
507         bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);
508
509         /* Program the hard temperature limits into the chip. */
510         bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
511                        MAX1617_WR_AMB_HIGHLIM);
512         bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
513                        MAX1617_WR_AMB_LOWLIM);
514         bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
515                        MAX1617_WR_CPU_HIGHLIM);
516         bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
517                        MAX1617_WR_CPU_LOWLIM);
518
519         get_current_temps(tp);
520         tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
521         tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;
522
523         tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
524         tp->fan_todo[FAN_CPU] = FAN_SAME;
525 }
526
527 static void attach_one_fan(struct linux_ebus_child *echild, int fan_idx)
528 {
529         struct bbc_fan_control *fp;
530
531         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
532         if (!fp)
533                 return;
534
535         fp->client = bbc_i2c_attach(echild);
536         if (!fp->client) {
537                 kfree(fp);
538                 return;
539         }
540
541         fp->index = fan_idx;
542
543         {
544                 struct bbc_fan_control **fpp = &all_bbc_fans;
545                 while (*fpp)
546                         fpp = &((*fpp)->next);
547                 fp->next = NULL;
548                 *fpp = fp;
549         }
550
551         /* The i2c device controlling the fans is write-only.
552          * So the only way to keep track of the current power
553          * level fed to the fans is via software.  Choose half
554          * power for cpu/system and 'on' fo the powersupply fan
555          * and set it now.
556          */
557         fp->psupply_fan_on = 1;
558         fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
559         fp->cpu_fan_speed += FAN_SPEED_MIN;
560         fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
561         fp->system_fan_speed += FAN_SPEED_MIN;
562
563         set_fan_speeds(fp);
564 }
565
566 int bbc_envctrl_init(void)
567 {
568         struct linux_ebus_child *echild;
569         int temp_index = 0;
570         int fan_index = 0;
571         int devidx = 0;
572
573         while ((echild = bbc_i2c_getdev(devidx++)) != NULL) {
574                 if (!strcmp(echild->prom_node->name, "temperature"))
575                         attach_one_temp(echild, temp_index++);
576                 if (!strcmp(echild->prom_node->name, "fan-control"))
577                         attach_one_fan(echild, fan_index++);
578         }
579         if (temp_index != 0 && fan_index != 0) {
580                 kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
581                 if (IS_ERR(kenvctrld_task))
582                         return PTR_ERR(kenvctrld_task);
583         }
584
585         return 0;
586 }
587
588 static void destroy_one_temp(struct bbc_cpu_temperature *tp)
589 {
590         bbc_i2c_detach(tp->client);
591         kfree(tp);
592 }
593
594 static void destroy_one_fan(struct bbc_fan_control *fp)
595 {
596         bbc_i2c_detach(fp->client);
597         kfree(fp);
598 }
599
600 void bbc_envctrl_cleanup(void)
601 {
602         struct bbc_cpu_temperature *tp;
603         struct bbc_fan_control *fp;
604
605         kthread_stop(kenvctrld_task);
606
607         tp = all_bbc_temps;
608         while (tp != NULL) {
609                 struct bbc_cpu_temperature *next = tp->next;
610                 destroy_one_temp(tp);
611                 tp = next;
612         }
613         all_bbc_temps = NULL;
614
615         fp = all_bbc_fans;
616         while (fp != NULL) {
617                 struct bbc_fan_control *next = fp->next;
618                 destroy_one_fan(fp);
619                 fp = next;
620         }
621         all_bbc_fans = NULL;
622 }