1 // SPDX-License-Identifier: GPL-2.0
2 /* bbc_envctrl.c: UltraSPARC-III environment control driver.
4 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
7 #include <linux/kthread.h>
8 #include <linux/delay.h>
9 #include <linux/kmod.h>
10 #include <linux/reboot.h>
12 #include <linux/slab.h>
13 #include <linux/of_device.h>
14 #include <asm/oplib.h>
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.
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.
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
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.
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).
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.
62 /* These settings are in Celsius. We use these defaults only
63 * if we cannot interrogate the cpu-fru SEEPROM.
66 s8 high_pwroff
, high_shutdown
, high_warn
;
67 s8 low_warn
, low_shutdown
, low_pwroff
;
70 static struct temp_limits cpu_temp_limits
[2] = {
71 { 100, 85, 80, 5, -5, -10 },
72 { 100, 85, 80, 5, -5, -10 },
75 static struct temp_limits amb_temp_limits
[2] = {
76 { 65, 55, 40, 5, -5, -10 },
77 { 65, 55, 40, 5, -5, -10 },
80 static LIST_HEAD(all_temps
);
81 static LIST_HEAD(all_fans
);
83 #define CPU_FAN_REG 0xf0
84 #define SYS_FAN_REG 0xf2
85 #define PSUPPLY_FAN_REG 0xf4
87 #define FAN_SPEED_MIN 0x0c
88 #define FAN_SPEED_MAX 0x3f
90 #define PSUPPLY_FAN_ON 0x1f
91 #define PSUPPLY_FAN_OFF 0x00
93 static void set_fan_speeds(struct bbc_fan_control
*fp
)
95 /* Put temperatures into range so we don't mis-program
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
;
107 printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
109 fp
->cpu_fan_speed
, fp
->system_fan_speed
);
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
),
120 static void get_current_temps(struct bbc_cpu_temperature
*tp
)
122 tp
->prev_amb_temp
= tp
->curr_amb_temp
;
123 bbc_i2c_readb(tp
->client
,
124 (unsigned char *) &tp
->curr_amb_temp
,
126 tp
->prev_cpu_temp
= tp
->curr_cpu_temp
;
127 bbc_i2c_readb(tp
->client
,
128 (unsigned char *) &tp
->curr_cpu_temp
,
131 printk("temp%d: cpu(%d C) amb(%d C)\n",
133 (int) tp
->curr_cpu_temp
, (int) tp
->curr_amb_temp
);
138 static void do_envctrl_shutdown(struct bbc_cpu_temperature
*tp
)
140 static int shutting_down
= 0;
144 if (shutting_down
!= 0)
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
) {
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
) {
154 val
= tp
->curr_cpu_temp
;
157 printk(KERN_CRIT
"temp%d: Outside of safe %s "
158 "operating temperature, %d C.\n",
159 tp
->index
, type
, val
);
161 printk(KERN_CRIT
"kenvctrld: Shutting down the system now.\n");
164 orderly_poweroff(true);
167 #define WARN_INTERVAL (30 * HZ)
169 static void analyze_ambient_temp(struct bbc_cpu_temperature
*tp
, unsigned long *last_warn
, int tick
)
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
);
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
);
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
)
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
);
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;
206 amb_goal_lo
= amb_goal_hi
- 3;
208 /* We do not try to avoid 'too cold' events. Basically we
209 * only try to deal with over-heating and fan noise reduction.
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
;
215 tp
->fan_todo
[FAN_AMBIENT
] = FAN_SLOWER
;
217 tp
->fan_todo
[FAN_AMBIENT
] = FAN_FASTER
;
220 tp
->fan_todo
[FAN_AMBIENT
] = FAN_SAME
;
224 static void analyze_cpu_temp(struct bbc_cpu_temperature
*tp
, unsigned long *last_warn
, int tick
)
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
);
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
);
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
)
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
);
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;
261 cpu_goal_lo
= cpu_goal_hi
- 3;
263 /* We do not try to avoid 'too cold' events. Basically we
264 * only try to deal with over-heating and fan noise reduction.
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
;
270 tp
->fan_todo
[FAN_CPU
] = FAN_SLOWER
;
272 tp
->fan_todo
[FAN_CPU
] = FAN_FASTER
;
275 tp
->fan_todo
[FAN_CPU
] = FAN_SAME
;
279 static void analyze_temps(struct bbc_cpu_temperature
*tp
, unsigned long *last_warn
)
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);
284 analyze_ambient_temp(tp
, last_warn
, tp
->sample_tick
);
285 analyze_cpu_temp(tp
, last_warn
, tp
->sample_tick
);
290 static enum fan_action
prioritize_fan_action(int which_fan
)
292 struct bbc_cpu_temperature
*tp
;
293 enum fan_action decision
= FAN_STATE_MAX
;
295 /* Basically, prioritize what the temperature sensors
296 * recommend we do, and perform that action on all the
299 list_for_each_entry(tp
, &all_temps
, glob_list
) {
300 if (tp
->fan_todo
[which_fan
] == FAN_FULLBLAST
) {
301 decision
= FAN_FULLBLAST
;
304 if (tp
->fan_todo
[which_fan
] == FAN_SAME
&&
305 decision
!= FAN_FASTER
)
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
;
314 if (decision
== FAN_STATE_MAX
)
320 static int maybe_new_ambient_fan_speed(struct bbc_fan_control
*fp
)
322 enum fan_action decision
= prioritize_fan_action(FAN_AMBIENT
);
325 if (decision
== FAN_SAME
)
329 if (decision
== FAN_FULLBLAST
) {
330 if (fp
->system_fan_speed
>= FAN_SPEED_MAX
)
333 fp
->system_fan_speed
= FAN_SPEED_MAX
;
335 if (decision
== FAN_FASTER
) {
336 if (fp
->system_fan_speed
>= FAN_SPEED_MAX
)
339 fp
->system_fan_speed
+= 2;
341 int orig_speed
= fp
->system_fan_speed
;
343 if (orig_speed
<= FAN_SPEED_MIN
||
344 orig_speed
<= (fp
->cpu_fan_speed
- 3))
347 fp
->system_fan_speed
-= 1;
354 static int maybe_new_cpu_fan_speed(struct bbc_fan_control
*fp
)
356 enum fan_action decision
= prioritize_fan_action(FAN_CPU
);
359 if (decision
== FAN_SAME
)
363 if (decision
== FAN_FULLBLAST
) {
364 if (fp
->cpu_fan_speed
>= FAN_SPEED_MAX
)
367 fp
->cpu_fan_speed
= FAN_SPEED_MAX
;
369 if (decision
== FAN_FASTER
) {
370 if (fp
->cpu_fan_speed
>= FAN_SPEED_MAX
)
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;
380 if (fp
->cpu_fan_speed
<= FAN_SPEED_MIN
)
383 fp
->cpu_fan_speed
-= 1;
390 static void maybe_new_fan_speeds(struct bbc_fan_control
*fp
)
394 new = maybe_new_ambient_fan_speed(fp
);
395 new |= maybe_new_cpu_fan_speed(fp
);
401 static void fans_full_blast(void)
403 struct bbc_fan_control
*fp
;
405 /* Since we will not be monitoring things anymore, put
406 * the fans on full blast.
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;
416 #define POLL_INTERVAL (5 * 1000)
417 static unsigned long last_warning_jiffies
;
418 static struct task_struct
*kenvctrld_task
;
420 static int kenvctrld(void *__unused
)
422 printk(KERN_INFO
"bbc_envctrl: kenvctrld starting...\n");
423 last_warning_jiffies
= jiffies
- WARN_INTERVAL
;
425 struct bbc_cpu_temperature
*tp
;
426 struct bbc_fan_control
*fp
;
428 msleep_interruptible(POLL_INTERVAL
);
429 if (kthread_should_stop())
432 list_for_each_entry(tp
, &all_temps
, glob_list
) {
433 get_current_temps(tp
);
434 analyze_temps(tp
, &last_warning_jiffies
);
436 list_for_each_entry(fp
, &all_fans
, glob_list
)
437 maybe_new_fan_speeds(fp
);
439 printk(KERN_INFO
"bbc_envctrl: kenvctrld exiting...\n");
446 static void attach_one_temp(struct bbc_i2c_bus
*bp
, struct platform_device
*op
,
449 struct bbc_cpu_temperature
*tp
;
451 tp
= kzalloc(sizeof(*tp
), GFP_KERNEL
);
455 INIT_LIST_HEAD(&tp
->bp_list
);
456 INIT_LIST_HEAD(&tp
->glob_list
);
458 tp
->client
= bbc_i2c_attach(bp
, op
);
465 tp
->index
= temp_idx
;
467 list_add(&tp
->glob_list
, &all_temps
);
468 list_add(&tp
->bp_list
, &bp
->temps
);
470 /* Tell it to convert once every 5 seconds, clear all cfg
473 bbc_i2c_writeb(tp
->client
, 0x00, MAX1617_WR_CFG_BYTE
);
474 bbc_i2c_writeb(tp
->client
, 0x02, MAX1617_WR_CVRATE_BYTE
);
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
);
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
;
490 tp
->fan_todo
[FAN_AMBIENT
] = FAN_SAME
;
491 tp
->fan_todo
[FAN_CPU
] = FAN_SAME
;
494 static void attach_one_fan(struct bbc_i2c_bus
*bp
, struct platform_device
*op
,
497 struct bbc_fan_control
*fp
;
499 fp
= kzalloc(sizeof(*fp
), GFP_KERNEL
);
503 INIT_LIST_HEAD(&fp
->bp_list
);
504 INIT_LIST_HEAD(&fp
->glob_list
);
506 fp
->client
= bbc_i2c_attach(bp
, op
);
514 list_add(&fp
->glob_list
, &all_fans
);
515 list_add(&fp
->bp_list
, &bp
->fans
);
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
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
;
532 static void destroy_one_temp(struct bbc_cpu_temperature
*tp
)
534 bbc_i2c_detach(tp
->client
);
538 static void destroy_all_temps(struct bbc_i2c_bus
*bp
)
540 struct bbc_cpu_temperature
*tp
, *tpos
;
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
);
549 static void destroy_one_fan(struct bbc_fan_control
*fp
)
551 bbc_i2c_detach(fp
->client
);
555 static void destroy_all_fans(struct bbc_i2c_bus
*bp
)
557 struct bbc_fan_control
*fp
, *fpos
;
559 list_for_each_entry_safe(fp
, fpos
, &bp
->fans
, bp_list
) {
560 list_del(&fp
->bp_list
);
561 list_del(&fp
->glob_list
);
566 int bbc_envctrl_init(struct bbc_i2c_bus
*bp
)
568 struct platform_device
*op
;
573 while ((op
= bbc_i2c_getdev(bp
, devidx
++)) != NULL
) {
574 if (!strcmp(op
->dev
.of_node
->name
, "temperature"))
575 attach_one_temp(bp
, op
, temp_index
++);
576 if (!strcmp(op
->dev
.of_node
->name
, "fan-control"))
577 attach_one_fan(bp
, op
, fan_index
++);
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
);
584 kenvctrld_task
= NULL
;
585 destroy_all_temps(bp
);
586 destroy_all_fans(bp
);
594 void bbc_envctrl_cleanup(struct bbc_i2c_bus
*bp
)
597 kthread_stop(kenvctrld_task
);
599 destroy_all_temps(bp
);
600 destroy_all_fans(bp
);