aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/sbus/char/bbc_envctrl.c
blob: 15dab96d05e31328108b89dabc53ee4b2b5aa573 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
/* bbc_envctrl.c: UltraSPARC-III environment control driver.
 *
 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
 */

#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/kmod.h>
#include <linux/reboot.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/oplib.h>

#include "bbc_i2c.h"
#include "max1617.h"

#undef ENVCTRL_TRACE

/* WARNING: Making changes to this driver is very dangerous.
 *          If you misprogram the sensor chips they can
 *          cut the power on you instantly.
 */

/* Two temperature sensors exist in the SunBLADE-1000 enclosure.
 * Both are implemented using max1617 i2c devices.  Each max1617
 * monitors 2 temperatures, one for one of the cpu dies and the other
 * for the ambient temperature.
 *
 * The max1617 is capable of being programmed with power-off
 * temperature values, one low limit and one high limit.  These
 * can be controlled independently for the cpu or ambient temperature.
 * If a limit is violated, the power is simply shut off.  The frequency
 * with which the max1617 does temperature sampling can be controlled
 * as well.
 *
 * Three fans exist inside the machine, all three are controlled with
 * an i2c digital to analog converter.  There is a fan directed at the
 * two processor slots, another for the rest of the enclosure, and the
 * third is for the power supply.  The first two fans may be speed
 * controlled by changing the voltage fed to them.  The third fan may
 * only be completely off or on.  The third fan is meant to only be
 * disabled/enabled when entering/exiting the lowest power-saving
 * mode of the machine.
 *
 * An environmental control kernel thread periodically monitors all
 * temperature sensors.  Based upon the samples it will adjust the
 * fan speeds to try and keep the system within a certain temperature
 * range (the goal being to make the fans as quiet as possible without
 * allowing the system to get too hot).
 *
 * If the temperature begins to rise/fall outside of the acceptable
 * operating range, a periodic warning will be sent to the kernel log.
 * The fans will be put on full blast to attempt to deal with this
 * situation.  After exceeding the acceptable operating range by a
 * certain threshold, the kernel thread will shut down the system.
 * Here, the thread is attempting to shut the machine down cleanly
 * before the hardware based power-off event is triggered.
 */

/* These settings are in Celsius.  We use these defaults only
 * if we cannot interrogate the cpu-fru SEEPROM.
 */
struct temp_limits {
	s8 high_pwroff, high_shutdown, high_warn;
	s8 low_warn, low_shutdown, low_pwroff;
};

static struct temp_limits cpu_temp_limits[2] = {
	{ 100, 85, 80, 5, -5, -10 },
	{ 100, 85, 80, 5, -5, -10 },
};

static struct temp_limits amb_temp_limits[2] = {
	{ 65, 55, 40, 5, -5, -10 },
	{ 65, 55, 40, 5, -5, -10 },
};

static LIST_HEAD(all_temps);
static LIST_HEAD(all_fans);

#define CPU_FAN_REG	0xf0
#define SYS_FAN_REG	0xf2
#define PSUPPLY_FAN_REG	0xf4

#define FAN_SPEED_MIN	0x0c
#define FAN_SPEED_MAX	0x3f

#define PSUPPLY_FAN_ON	0x1f
#define PSUPPLY_FAN_OFF	0x00

static void set_fan_speeds(struct bbc_fan_control *fp)
{
	/* Put temperatures into range so we don't mis-program
	 * the hardware.
	 */
	if (fp->cpu_fan_speed < FAN_SPEED_MIN)
		fp->cpu_fan_speed = FAN_SPEED_MIN;
	if (fp->cpu_fan_speed > FAN_SPEED_MAX)
		fp->cpu_fan_speed = FAN_SPEED_MAX;
	if (fp->system_fan_speed < FAN_SPEED_MIN)
		fp->system_fan_speed = FAN_SPEED_MIN;
	if (fp->system_fan_speed > FAN_SPEED_MAX)
		fp->system_fan_speed = FAN_SPEED_MAX;
#ifdef ENVCTRL_TRACE
	printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
	       fp->index,
	       fp->cpu_fan_speed, fp->system_fan_speed);
#endif

	bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
	bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
	bbc_i2c_writeb(fp->client,
		       (fp->psupply_fan_on ?
			PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
		       PSUPPLY_FAN_REG);
}

static void get_current_temps(struct bbc_cpu_temperature *tp)
{
	tp->prev_amb_temp = tp->curr_amb_temp;
	bbc_i2c_readb(tp->client,
		      (unsigned char *) &tp->curr_amb_temp,
		      MAX1617_AMB_TEMP);
	tp->prev_cpu_temp = tp->curr_cpu_temp;
	bbc_i2c_readb(tp->client,
		      (unsigned char *) &tp->curr_cpu_temp,
		      MAX1617_CPU_TEMP);
#ifdef ENVCTRL_TRACE
	printk("temp%d: cpu(%d C) amb(%d C)\n",
	       tp->index,
	       (int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
#endif
}


static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
{
	static int shutting_down = 0;
	char *type = "???";
	s8 val = -1;

	if (shutting_down != 0)
		return;

	if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
	    tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
		type = "ambient";
		val = tp->curr_amb_temp;
	} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
		   tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
		type = "CPU";
		val = tp->curr_cpu_temp;
	}

	printk(KERN_CRIT "temp%d: Outside of safe %s "
	       "operating temperature, %d C.\n",
	       tp->index, type, val);

	printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");

	shutting_down = 1;
	if (orderly_poweroff(true) < 0)
		printk(KERN_CRIT "envctrl: shutdown execution failed\n");
}

#define WARN_INTERVAL	(30 * HZ)

static void analyze_ambient_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
{
	int ret = 0;

	if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
		if (tp->curr_amb_temp >=
		    amb_temp_limits[tp->index].high_warn) {
			printk(KERN_WARNING "temp%d: "
			       "Above safe ambient operating temperature, %d C.\n",
			       tp->index, (int) tp->curr_amb_temp);
			ret = 1;
		} else if (tp->curr_amb_temp <
			   amb_temp_limits[tp->index].low_warn) {
			printk(KERN_WARNING "temp%d: "
			       "Below safe ambient operating temperature, %d C.\n",
			       tp->index, (int) tp->curr_amb_temp);
			ret = 1;
		}
		if (ret)
			*last_warn = jiffies;
	} else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn ||
		   tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
		ret = 1;

	/* Now check the shutdown limits. */
	if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
	    tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
		do_envctrl_shutdown(tp);
		ret = 1;
	}

	if (ret) {
		tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
	} else if ((tick & (8 - 1)) == 0) {
		s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
		s8 amb_goal_lo;

		amb_goal_lo = amb_goal_hi - 3;

		/* We do not try to avoid 'too cold' events.  Basically we
		 * only try to deal with over-heating and fan noise reduction.
		 */
		if (tp->avg_amb_temp < amb_goal_hi) {
			if (tp->avg_amb_temp >= amb_goal_lo)
				tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
			else
				tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
		} else {
			tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
		}
	} else {
		tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
	}
}

static void analyze_cpu_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
{
	int ret = 0;

	if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
		if (tp->curr_cpu_temp >=
		    cpu_temp_limits[tp->index].high_warn) {
			printk(KERN_WARNING "temp%d: "
			       "Above safe CPU operating temperature, %d C.\n",
			       tp->index, (int) tp->curr_cpu_temp);
			ret = 1;
		} else if (tp->curr_cpu_temp <
			   cpu_temp_limits[tp->index].low_warn) {
			printk(KERN_WARNING "temp%d: "
			       "Below safe CPU operating temperature, %d C.\n",
			       tp->index, (int) tp->curr_cpu_temp);
			ret = 1;
		}
		if (ret)
			*last_warn = jiffies;
	} else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn ||
		   tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
		ret = 1;

	/* Now check the shutdown limits. */
	if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
	    tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
		do_envctrl_shutdown(tp);
		ret = 1;
	}

	if (ret) {
		tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
	} else if ((tick & (8 - 1)) == 0) {
		s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
		s8 cpu_goal_lo;

		cpu_goal_lo = cpu_goal_hi - 3;

		/* We do not try to avoid 'too cold' events.  Basically we
		 * only try to deal with over-heating and fan noise reduction.
		 */
		if (tp->avg_cpu_temp < cpu_goal_hi) {
			if (tp->avg_cpu_temp >= cpu_goal_lo)
				tp->fan_todo[FAN_CPU] = FAN_SAME;
			else
				tp->fan_todo[FAN_CPU] = FAN_SLOWER;
		} else {
			tp->fan_todo[FAN_CPU] = FAN_FASTER;
		}
	} else {
		tp->fan_todo[FAN_CPU] = FAN_SAME;
	}
}

static void analyze_temps(struct bbc_cpu_temperature *tp, unsigned long *last_warn)
{
	tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
	tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);

	analyze_ambient_temp(tp, last_warn, tp->sample_tick);
	analyze_cpu_temp(tp, last_warn, tp->sample_tick);

	tp->sample_tick++;
}

static enum fan_action prioritize_fan_action(int which_fan)
{
	struct bbc_cpu_temperature *tp;
	enum fan_action decision = FAN_STATE_MAX;

	/* Basically, prioritize what the temperature sensors
	 * recommend we do, and perform that action on all the
	 * fans.
	 */
	list_for_each_entry(tp, &all_temps, glob_list) {
		if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
			decision = FAN_FULLBLAST;
			break;
		}
		if (tp->fan_todo[which_fan] == FAN_SAME &&
		    decision != FAN_FASTER)
			decision = FAN_SAME;
		else if (tp->fan_todo[which_fan] == FAN_FASTER)
			decision = FAN_FASTER;
		else if (decision != FAN_FASTER &&
			 decision != FAN_SAME &&
			 tp->fan_todo[which_fan] == FAN_SLOWER)
			decision = FAN_SLOWER;
	}
	if (decision == FAN_STATE_MAX)
		decision = FAN_SAME;

	return decision;
}

static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
{
	enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
	int ret;

	if (decision == FAN_SAME)
		return 0;

	ret = 1;
	if (decision == FAN_FULLBLAST) {
		if (fp->system_fan_speed >= FAN_SPEED_MAX)
			ret = 0;
		else
			fp->system_fan_speed = FAN_SPEED_MAX;
	} else {
		if (decision == FAN_FASTER) {
			if (fp->system_fan_speed >= FAN_SPEED_MAX)
				ret = 0;
			else
				fp->system_fan_speed += 2;
		} else {
			int orig_speed = fp->system_fan_speed;

			if (orig_speed <= FAN_SPEED_MIN ||
			    orig_speed <= (fp->cpu_fan_speed - 3))
				ret = 0;
			else
				fp->system_fan_speed -= 1;
		}
	}

	return ret;
}

static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
{
	enum fan_action decision = prioritize_fan_action(FAN_CPU);
	int ret;

	if (decision == FAN_SAME)
		return 0;

	ret = 1;
	if (decision == FAN_FULLBLAST) {
		if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
			ret = 0;
		else
			fp->cpu_fan_speed = FAN_SPEED_MAX;
	} else {
		if (decision == FAN_FASTER) {
			if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
				ret = 0;
			else {
				fp->cpu_fan_speed += 2;
				if (fp->system_fan_speed <
				    (fp->cpu_fan_speed - 3))
					fp->system_fan_speed =
						fp->cpu_fan_speed - 3;
			}
		} else {
			if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
				ret = 0;
			else
				fp->cpu_fan_speed -= 1;
		}
	}

	return ret;
}

static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
{
	int new;

	new  = maybe_new_ambient_fan_speed(fp);
	new |= maybe_new_cpu_fan_speed(fp);

	if (new)
		set_fan_speeds(fp);
}

static void fans_full_blast(void)
{
	struct bbc_fan_control *fp;

	/* Since we will not be monitoring things anymore, put
	 * the fans on full blast.
	 */
	list_for_each_entry(fp, &all_fans, glob_list) {
		fp->cpu_fan_speed = FAN_SPEED_MAX;
		fp->system_fan_speed = FAN_SPEED_MAX;
		fp->psupply_fan_on = 1;
		set_fan_speeds(fp);
	}
}

#define POLL_INTERVAL	(5 * 1000)
static unsigned long last_warning_jiffies;
static struct task_struct *kenvctrld_task;

static int kenvctrld(void *__unused)
{
	printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
	last_warning_jiffies = jiffies - WARN_INTERVAL;
	for (;;) {
		struct bbc_cpu_temperature *tp;
		struct bbc_fan_control *fp;

		msleep_interruptible(POLL_INTERVAL);
		if (kthread_should_stop())
			break;

		list_for_each_entry(tp, &all_temps, glob_list) {
			get_current_temps(tp);
			analyze_temps(tp, &last_warning_jiffies);
		}
		list_for_each_entry(fp, &all_fans, glob_list)
			maybe_new_fan_speeds(fp);
	}
	printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");

	fans_full_blast();

	return 0;
}

static void attach_one_temp(struct bbc_i2c_bus *bp, struct of_device *op,
			    int temp_idx)
{
	struct bbc_cpu_temperature *tp;

	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
	if (!tp)
		return;

	tp->client = bbc_i2c_attach(bp, op);
	if (!tp->client) {
		kfree(tp);
		return;
	}


	tp->index = temp_idx;

	list_add(&tp->glob_list, &all_temps);
	list_add(&tp->bp_list, &bp->temps);

	/* Tell it to convert once every 5 seconds, clear all cfg
	 * bits.
	 */
	bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
	bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);

	/* Program the hard temperature limits into the chip. */
	bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
		       MAX1617_WR_AMB_HIGHLIM);
	bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
		       MAX1617_WR_AMB_LOWLIM);
	bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
		       MAX1617_WR_CPU_HIGHLIM);
	bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
		       MAX1617_WR_CPU_LOWLIM);

	get_current_temps(tp);
	tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
	tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;

	tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
	tp->fan_todo[FAN_CPU] = FAN_SAME;
}

static void attach_one_fan(struct bbc_i2c_bus *bp, struct of_device *op,
			   int fan_idx)
{
	struct bbc_fan_control *fp;

	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
	if (!fp)
		return;

	fp->client = bbc_i2c_attach(bp, op);
	if (!fp->client) {
		kfree(fp);
		return;
	}

	fp->index = fan_idx;

	list_add(&fp->glob_list, &all_fans);
	list_add(&fp->bp_list, &bp->fans);

	/* The i2c device controlling the fans is write-only.
	 * So the only way to keep track of the current power
	 * level fed to the fans is via software.  Choose half
	 * power for cpu/system and 'on' fo the powersupply fan
	 * and set it now.
	 */
	fp->psupply_fan_on = 1;
	fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
	fp->cpu_fan_speed += FAN_SPEED_MIN;
	fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
	fp->system_fan_speed += FAN_SPEED_MIN;

	set_fan_speeds(fp);
}

int bbc_envctrl_init(struct bbc_i2c_bus *bp)
{
	struct of_device *op;
	int temp_index = 0;
	int fan_index = 0;
	int devidx = 0;

	while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) {
		if (!strcmp(op->node->name, "temperature"))
			attach_one_temp(bp, op, temp_index++);
		if (!strcmp(op->node->name, "fan-control"))
			attach_one_fan(bp, op, fan_index++);
	}
	if (temp_index != 0 && fan_index != 0) {
		kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
		if (IS_ERR(kenvctrld_task))
			return PTR_ERR(kenvctrld_task);
	}

	return 0;
}

static void destroy_one_temp(struct bbc_cpu_temperature *tp)
{
	bbc_i2c_detach(tp->client);
	kfree(tp);
}

static void destroy_one_fan(struct bbc_fan_control *fp)
{
	bbc_i2c_detach(fp->client);
	kfree(fp);
}

void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp)
{
	struct bbc_cpu_temperature *tp, *tpos;
	struct bbc_fan_control *fp, *fpos;

	kthread_stop(kenvctrld_task);

	list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) {
		list_del(&tp->bp_list);
		list_del(&tp->glob_list);
		destroy_one_temp(tp);
	}

	list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) {
		list_del(&fp->bp_list);
		list_del(&fp->glob_list);
		destroy_one_fan(fp);
	}
}