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1// SPDX-License-Identifier: GPL-2.0
2/* bbc_envctrl.c: UltraSPARC-III environment control driver.
3 *
4 * Copyright (C) 2001, 2008 David S. Miller ([email protected])
5 */
6
7#include <linux/kthread.h>
8#include <linux/delay.h>
9#include <linux/kmod.h>
10#include <linux/reboot.h>
11#include <linux/of.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <asm/oplib.h>
15
16#include "bbc_i2c.h"
17#include "max1617.h"
18
19#undef ENVCTRL_TRACE
20
21/* WARNING: Making changes to this driver is very dangerous.
22 * If you misprogram the sensor chips they can
23 * cut the power on you instantly.
24 */
25
26/* Two temperature sensors exist in the SunBLADE-1000 enclosure.
27 * Both are implemented using max1617 i2c devices. Each max1617
28 * monitors 2 temperatures, one for one of the cpu dies and the other
29 * for the ambient temperature.
30 *
31 * The max1617 is capable of being programmed with power-off
32 * temperature values, one low limit and one high limit. These
33 * can be controlled independently for the cpu or ambient temperature.
34 * If a limit is violated, the power is simply shut off. The frequency
35 * with which the max1617 does temperature sampling can be controlled
36 * as well.
37 *
38 * Three fans exist inside the machine, all three are controlled with
39 * an i2c digital to analog converter. There is a fan directed at the
40 * two processor slots, another for the rest of the enclosure, and the
41 * third is for the power supply. The first two fans may be speed
42 * controlled by changing the voltage fed to them. The third fan may
43 * only be completely off or on. The third fan is meant to only be
44 * disabled/enabled when entering/exiting the lowest power-saving
45 * mode of the machine.
46 *
47 * An environmental control kernel thread periodically monitors all
48 * temperature sensors. Based upon the samples it will adjust the
49 * fan speeds to try and keep the system within a certain temperature
50 * range (the goal being to make the fans as quiet as possible without
51 * allowing the system to get too hot).
52 *
53 * If the temperature begins to rise/fall outside of the acceptable
54 * operating range, a periodic warning will be sent to the kernel log.
55 * The fans will be put on full blast to attempt to deal with this
56 * situation. After exceeding the acceptable operating range by a
57 * certain threshold, the kernel thread will shut down the system.
58 * Here, the thread is attempting to shut the machine down cleanly
59 * before the hardware based power-off event is triggered.
60 */
61
62/* These settings are in Celsius. We use these defaults only
63 * if we cannot interrogate the cpu-fru SEEPROM.
64 */
65struct temp_limits {
66 s8 high_pwroff, high_shutdown, high_warn;
67 s8 low_warn, low_shutdown, low_pwroff;
68};
69
70static struct temp_limits cpu_temp_limits[2] = {
71 { 100, 85, 80, 5, -5, -10 },
72 { 100, 85, 80, 5, -5, -10 },
73};
74
75static struct temp_limits amb_temp_limits[2] = {
76 { 65, 55, 40, 5, -5, -10 },
77 { 65, 55, 40, 5, -5, -10 },
78};
79
80static LIST_HEAD(all_temps);
81static LIST_HEAD(all_fans);
82
83#define CPU_FAN_REG 0xf0
84#define SYS_FAN_REG 0xf2
85#define PSUPPLY_FAN_REG 0xf4
86
87#define FAN_SPEED_MIN 0x0c
88#define FAN_SPEED_MAX 0x3f
89
90#define PSUPPLY_FAN_ON 0x1f
91#define PSUPPLY_FAN_OFF 0x00
92
93static void set_fan_speeds(struct bbc_fan_control *fp)
94{
95 /* Put temperatures into range so we don't mis-program
96 * the hardware.
97 */
98 if (fp->cpu_fan_speed < FAN_SPEED_MIN)
99 fp->cpu_fan_speed = FAN_SPEED_MIN;
100 if (fp->cpu_fan_speed > FAN_SPEED_MAX)
101 fp->cpu_fan_speed = FAN_SPEED_MAX;
102 if (fp->system_fan_speed < FAN_SPEED_MIN)
103 fp->system_fan_speed = FAN_SPEED_MIN;
104 if (fp->system_fan_speed > FAN_SPEED_MAX)
105 fp->system_fan_speed = FAN_SPEED_MAX;
106#ifdef ENVCTRL_TRACE
107 printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
108 fp->index,
109 fp->cpu_fan_speed, fp->system_fan_speed);
110#endif
111
112 bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
113 bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
114 bbc_i2c_writeb(fp->client,
115 (fp->psupply_fan_on ?
116 PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
117 PSUPPLY_FAN_REG);
118}
119
120static void get_current_temps(struct bbc_cpu_temperature *tp)
121{
122 tp->prev_amb_temp = tp->curr_amb_temp;
123 bbc_i2c_readb(tp->client,
124 (unsigned char *) &tp->curr_amb_temp,
125 MAX1617_AMB_TEMP);
126 tp->prev_cpu_temp = tp->curr_cpu_temp;
127 bbc_i2c_readb(tp->client,
128 (unsigned char *) &tp->curr_cpu_temp,
129 MAX1617_CPU_TEMP);
130#ifdef ENVCTRL_TRACE
131 printk("temp%d: cpu(%d C) amb(%d C)\n",
132 tp->index,
133 (int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
134#endif
135}
136
137
138static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
139{
140 static int shutting_down = 0;
141 char *type = "???";
142 s8 val = -1;
143
144 if (shutting_down != 0)
145 return;
146
147 if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
148 tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
149 type = "ambient";
150 val = tp->curr_amb_temp;
151 } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
152 tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
153 type = "CPU";
154 val = tp->curr_cpu_temp;
155 }
156
157 printk(KERN_CRIT "temp%d: Outside of safe %s "
158 "operating temperature, %d C.\n",
159 tp->index, type, val);
160
161 printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
162
163 shutting_down = 1;
164 orderly_poweroff(true);
165}
166
167#define WARN_INTERVAL (30 * HZ)
168
169static void analyze_ambient_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
170{
171 int ret = 0;
172
173 if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
174 if (tp->curr_amb_temp >=
175 amb_temp_limits[tp->index].high_warn) {
176 printk(KERN_WARNING "temp%d: "
177 "Above safe ambient operating temperature, %d C.\n",
178 tp->index, (int) tp->curr_amb_temp);
179 ret = 1;
180 } else if (tp->curr_amb_temp <
181 amb_temp_limits[tp->index].low_warn) {
182 printk(KERN_WARNING "temp%d: "
183 "Below safe ambient operating temperature, %d C.\n",
184 tp->index, (int) tp->curr_amb_temp);
185 ret = 1;
186 }
187 if (ret)
188 *last_warn = jiffies;
189 } else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn ||
190 tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
191 ret = 1;
192
193 /* Now check the shutdown limits. */
194 if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
195 tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
196 do_envctrl_shutdown(tp);
197 ret = 1;
198 }
199
200 if (ret) {
201 tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
202 } else if ((tick & (8 - 1)) == 0) {
203 s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
204 s8 amb_goal_lo;
205
206 amb_goal_lo = amb_goal_hi - 3;
207
208 /* We do not try to avoid 'too cold' events. Basically we
209 * only try to deal with over-heating and fan noise reduction.
210 */
211 if (tp->avg_amb_temp < amb_goal_hi) {
212 if (tp->avg_amb_temp >= amb_goal_lo)
213 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
214 else
215 tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
216 } else {
217 tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
218 }
219 } else {
220 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
221 }
222}
223
224static void analyze_cpu_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
225{
226 int ret = 0;
227
228 if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
229 if (tp->curr_cpu_temp >=
230 cpu_temp_limits[tp->index].high_warn) {
231 printk(KERN_WARNING "temp%d: "
232 "Above safe CPU operating temperature, %d C.\n",
233 tp->index, (int) tp->curr_cpu_temp);
234 ret = 1;
235 } else if (tp->curr_cpu_temp <
236 cpu_temp_limits[tp->index].low_warn) {
237 printk(KERN_WARNING "temp%d: "
238 "Below safe CPU operating temperature, %d C.\n",
239 tp->index, (int) tp->curr_cpu_temp);
240 ret = 1;
241 }
242 if (ret)
243 *last_warn = jiffies;
244 } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn ||
245 tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
246 ret = 1;
247
248 /* Now check the shutdown limits. */
249 if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
250 tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
251 do_envctrl_shutdown(tp);
252 ret = 1;
253 }
254
255 if (ret) {
256 tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
257 } else if ((tick & (8 - 1)) == 0) {
258 s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
259 s8 cpu_goal_lo;
260
261 cpu_goal_lo = cpu_goal_hi - 3;
262
263 /* We do not try to avoid 'too cold' events. Basically we
264 * only try to deal with over-heating and fan noise reduction.
265 */
266 if (tp->avg_cpu_temp < cpu_goal_hi) {
267 if (tp->avg_cpu_temp >= cpu_goal_lo)
268 tp->fan_todo[FAN_CPU] = FAN_SAME;
269 else
270 tp->fan_todo[FAN_CPU] = FAN_SLOWER;
271 } else {
272 tp->fan_todo[FAN_CPU] = FAN_FASTER;
273 }
274 } else {
275 tp->fan_todo[FAN_CPU] = FAN_SAME;
276 }
277}
278
279static void analyze_temps(struct bbc_cpu_temperature *tp, unsigned long *last_warn)
280{
281 tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
282 tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);
283
284 analyze_ambient_temp(tp, last_warn, tp->sample_tick);
285 analyze_cpu_temp(tp, last_warn, tp->sample_tick);
286
287 tp->sample_tick++;
288}
289
290static enum fan_action prioritize_fan_action(int which_fan)
291{
292 struct bbc_cpu_temperature *tp;
293 enum fan_action decision = FAN_STATE_MAX;
294
295 /* Basically, prioritize what the temperature sensors
296 * recommend we do, and perform that action on all the
297 * fans.
298 */
299 list_for_each_entry(tp, &all_temps, glob_list) {
300 if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
301 decision = FAN_FULLBLAST;
302 break;
303 }
304 if (tp->fan_todo[which_fan] == FAN_SAME &&
305 decision != FAN_FASTER)
306 decision = FAN_SAME;
307 else if (tp->fan_todo[which_fan] == FAN_FASTER)
308 decision = FAN_FASTER;
309 else if (decision != FAN_FASTER &&
310 decision != FAN_SAME &&
311 tp->fan_todo[which_fan] == FAN_SLOWER)
312 decision = FAN_SLOWER;
313 }
314 if (decision == FAN_STATE_MAX)
315 decision = FAN_SAME;
316
317 return decision;
318}
319
320static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
321{
322 enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
323 int ret;
324
325 if (decision == FAN_SAME)
326 return 0;
327
328 ret = 1;
329 if (decision == FAN_FULLBLAST) {
330 if (fp->system_fan_speed >= FAN_SPEED_MAX)
331 ret = 0;
332 else
333 fp->system_fan_speed = FAN_SPEED_MAX;
334 } else {
335 if (decision == FAN_FASTER) {
336 if (fp->system_fan_speed >= FAN_SPEED_MAX)
337 ret = 0;
338 else
339 fp->system_fan_speed += 2;
340 } else {
341 int orig_speed = fp->system_fan_speed;
342
343 if (orig_speed <= FAN_SPEED_MIN ||
344 orig_speed <= (fp->cpu_fan_speed - 3))
345 ret = 0;
346 else
347 fp->system_fan_speed -= 1;
348 }
349 }
350
351 return ret;
352}
353
354static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
355{
356 enum fan_action decision = prioritize_fan_action(FAN_CPU);
357 int ret;
358
359 if (decision == FAN_SAME)
360 return 0;
361
362 ret = 1;
363 if (decision == FAN_FULLBLAST) {
364 if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
365 ret = 0;
366 else
367 fp->cpu_fan_speed = FAN_SPEED_MAX;
368 } else {
369 if (decision == FAN_FASTER) {
370 if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
371 ret = 0;
372 else {
373 fp->cpu_fan_speed += 2;
374 if (fp->system_fan_speed <
375 (fp->cpu_fan_speed - 3))
376 fp->system_fan_speed =
377 fp->cpu_fan_speed - 3;
378 }
379 } else {
380 if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
381 ret = 0;
382 else
383 fp->cpu_fan_speed -= 1;
384 }
385 }
386
387 return ret;
388}
389
390static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
391{
392 int new;
393
394 new = maybe_new_ambient_fan_speed(fp);
395 new |= maybe_new_cpu_fan_speed(fp);
396
397 if (new)
398 set_fan_speeds(fp);
399}
400
401static void fans_full_blast(void)
402{
403 struct bbc_fan_control *fp;
404
405 /* Since we will not be monitoring things anymore, put
406 * the fans on full blast.
407 */
408 list_for_each_entry(fp, &all_fans, glob_list) {
409 fp->cpu_fan_speed = FAN_SPEED_MAX;
410 fp->system_fan_speed = FAN_SPEED_MAX;
411 fp->psupply_fan_on = 1;
412 set_fan_speeds(fp);
413 }
414}
415
416#define POLL_INTERVAL (5 * 1000)
417static unsigned long last_warning_jiffies;
418static struct task_struct *kenvctrld_task;
419
420static int kenvctrld(void *__unused)
421{
422 printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
423 last_warning_jiffies = jiffies - WARN_INTERVAL;
424 for (;;) {
425 struct bbc_cpu_temperature *tp;
426 struct bbc_fan_control *fp;
427
428 msleep_interruptible(POLL_INTERVAL);
429 if (kthread_should_stop())
430 break;
431
432 list_for_each_entry(tp, &all_temps, glob_list) {
433 get_current_temps(tp);
434 analyze_temps(tp, &last_warning_jiffies);
435 }
436 list_for_each_entry(fp, &all_fans, glob_list)
437 maybe_new_fan_speeds(fp);
438 }
439 printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");
440
441 fans_full_blast();
442
443 return 0;
444}
445
446static void attach_one_temp(struct bbc_i2c_bus *bp, struct platform_device *op,
447 int temp_idx)
448{
449 struct bbc_cpu_temperature *tp;
450
451 tp = kzalloc_obj(*tp);
452 if (!tp)
453 return;
454
455 INIT_LIST_HEAD(&tp->bp_list);
456 INIT_LIST_HEAD(&tp->glob_list);
457
458 tp->client = bbc_i2c_attach(bp, op);
459 if (!tp->client) {
460 kfree(tp);
461 return;
462 }
463
464
465 tp->index = temp_idx;
466
467 list_add(&tp->glob_list, &all_temps);
468 list_add(&tp->bp_list, &bp->temps);
469
470 /* Tell it to convert once every 5 seconds, clear all cfg
471 * bits.
472 */
473 bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
474 bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);
475
476 /* Program the hard temperature limits into the chip. */
477 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
478 MAX1617_WR_AMB_HIGHLIM);
479 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
480 MAX1617_WR_AMB_LOWLIM);
481 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
482 MAX1617_WR_CPU_HIGHLIM);
483 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
484 MAX1617_WR_CPU_LOWLIM);
485
486 get_current_temps(tp);
487 tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
488 tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;
489
490 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
491 tp->fan_todo[FAN_CPU] = FAN_SAME;
492}
493
494static void attach_one_fan(struct bbc_i2c_bus *bp, struct platform_device *op,
495 int fan_idx)
496{
497 struct bbc_fan_control *fp;
498
499 fp = kzalloc_obj(*fp);
500 if (!fp)
501 return;
502
503 INIT_LIST_HEAD(&fp->bp_list);
504 INIT_LIST_HEAD(&fp->glob_list);
505
506 fp->client = bbc_i2c_attach(bp, op);
507 if (!fp->client) {
508 kfree(fp);
509 return;
510 }
511
512 fp->index = fan_idx;
513
514 list_add(&fp->glob_list, &all_fans);
515 list_add(&fp->bp_list, &bp->fans);
516
517 /* The i2c device controlling the fans is write-only.
518 * So the only way to keep track of the current power
519 * level fed to the fans is via software. Choose half
520 * power for cpu/system and 'on' fo the powersupply fan
521 * and set it now.
522 */
523 fp->psupply_fan_on = 1;
524 fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
525 fp->cpu_fan_speed += FAN_SPEED_MIN;
526 fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
527 fp->system_fan_speed += FAN_SPEED_MIN;
528
529 set_fan_speeds(fp);
530}
531
532static void destroy_one_temp(struct bbc_cpu_temperature *tp)
533{
534 bbc_i2c_detach(tp->client);
535 kfree(tp);
536}
537
538static void destroy_all_temps(struct bbc_i2c_bus *bp)
539{
540 struct bbc_cpu_temperature *tp, *tpos;
541
542 list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) {
543 list_del(&tp->bp_list);
544 list_del(&tp->glob_list);
545 destroy_one_temp(tp);
546 }
547}
548
549static void destroy_one_fan(struct bbc_fan_control *fp)
550{
551 bbc_i2c_detach(fp->client);
552 kfree(fp);
553}
554
555static void destroy_all_fans(struct bbc_i2c_bus *bp)
556{
557 struct bbc_fan_control *fp, *fpos;
558
559 list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) {
560 list_del(&fp->bp_list);
561 list_del(&fp->glob_list);
562 destroy_one_fan(fp);
563 }
564}
565
566int bbc_envctrl_init(struct bbc_i2c_bus *bp)
567{
568 struct platform_device *op;
569 int temp_index = 0;
570 int fan_index = 0;
571 int devidx = 0;
572
573 while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) {
574 if (of_node_name_eq(op->dev.of_node, "temperature"))
575 attach_one_temp(bp, op, temp_index++);
576 if (of_node_name_eq(op->dev.of_node, "fan-control"))
577 attach_one_fan(bp, op, 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 int err = PTR_ERR(kenvctrld_task);
583
584 kenvctrld_task = NULL;
585 destroy_all_temps(bp);
586 destroy_all_fans(bp);
587 return err;
588 }
589 }
590
591 return 0;
592}
593
594void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp)
595{
596 if (kenvctrld_task)
597 kthread_stop(kenvctrld_task);
598
599 destroy_all_temps(bp);
600 destroy_all_fans(bp);
601}