drivers/sbus/char/bbc_envctrl.c

   1 /* bbc_envctrl.c: UltraSPARC-III environment control driver.
   2  *
   3  * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
   4  */
   5
   6 #include <linux/kthread.h>
   7 #include <linux/delay.h>
   8 #include <linux/kmod.h>
   9 #include <linux/reboot.h>
  10 #include <linux/of.h>
  11 #include <linux/of_device.h>
  12 #include <asm/oplib.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 static LIST_HEAD(all_temps);
  79 static LIST_HEAD(all_fans);
  80
  81 #define CPU_FAN_REG     0xf0
  82 #define SYS_FAN_REG     0xf2
  83 #define PSUPPLY_FAN_REG 0xf4
  84
  85 #define FAN_SPEED_MIN   0x0c
  86 #define FAN_SPEED_MAX   0x3f
  87
  88 #define PSUPPLY_FAN_ON  0x1f
  89 #define PSUPPLY_FAN_OFF 0x00
  90
  91 static void set_fan_speeds(struct bbc_fan_control *fp)
  92 {
  93         /* Put temperatures into range so we don't mis-program
  94          * the hardware.
  95          */
  96         if (fp->cpu_fan_speed < FAN_SPEED_MIN)
  97                 fp->cpu_fan_speed = FAN_SPEED_MIN;
  98         if (fp->cpu_fan_speed > FAN_SPEED_MAX)
  99                 fp->cpu_fan_speed = FAN_SPEED_MAX;
 100         if (fp->system_fan_speed < FAN_SPEED_MIN)
 101                 fp->system_fan_speed = FAN_SPEED_MIN;
 102         if (fp->system_fan_speed > FAN_SPEED_MAX)
 103                 fp->system_fan_speed = FAN_SPEED_MAX;
 104 #ifdef ENVCTRL_TRACE
 105         printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n",
 106                fp->index,
 107                fp->cpu_fan_speed, fp->system_fan_speed);
 108 #endif
 109
 110         bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG);
 111         bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG);
 112         bbc_i2c_writeb(fp->client,
 113                        (fp->psupply_fan_on ?
 114                         PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF),
 115                        PSUPPLY_FAN_REG);
 116 }
 117
 118 static void get_current_temps(struct bbc_cpu_temperature *tp)
 119 {
 120         tp->prev_amb_temp = tp->curr_amb_temp;
 121         bbc_i2c_readb(tp->client,
 122                       (unsigned char *) &tp->curr_amb_temp,
 123                       MAX1617_AMB_TEMP);
 124         tp->prev_cpu_temp = tp->curr_cpu_temp;
 125         bbc_i2c_readb(tp->client,
 126                       (unsigned char *) &tp->curr_cpu_temp,
 127                       MAX1617_CPU_TEMP);
 128 #ifdef ENVCTRL_TRACE
 129         printk("temp%d: cpu(%d C) amb(%d C)\n",
 130                tp->index,
 131                (int) tp->curr_cpu_temp, (int) tp->curr_amb_temp);
 132 #endif
 133 }
 134
 135
 136 static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp)
 137 {
 138         static int shutting_down = 0;
 139         char *type = "???";
 140         s8 val = -1;
 141
 142         if (shutting_down != 0)
 143                 return;
 144
 145         if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
 146             tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
 147                 type = "ambient";
 148                 val = tp->curr_amb_temp;
 149         } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
 150                    tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
 151                 type = "CPU";
 152                 val = tp->curr_cpu_temp;
 153         }
 154
 155         printk(KERN_CRIT "temp%d: Outside of safe %s "
 156                "operating temperature, %d C.\n",
 157                tp->index, type, val);
 158
 159         printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n");
 160
 161         shutting_down = 1;
 162         if (orderly_poweroff(true) < 0)
 163                 printk(KERN_CRIT "envctrl: shutdown execution failed\n");
 164 }
 165
 166 #define WARN_INTERVAL   (30 * HZ)
 167
 168 static void analyze_ambient_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
 169 {
 170         int ret = 0;
 171
 172         if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
 173                 if (tp->curr_amb_temp >=
 174                     amb_temp_limits[tp->index].high_warn) {
 175                         printk(KERN_WARNING "temp%d: "
 176                                "Above safe ambient operating temperature, %d C.\n",
 177                                tp->index, (int) tp->curr_amb_temp);
 178                         ret = 1;
 179                 } else if (tp->curr_amb_temp <
 180                            amb_temp_limits[tp->index].low_warn) {
 181                         printk(KERN_WARNING "temp%d: "
 182                                "Below safe ambient operating temperature, %d C.\n",
 183                                tp->index, (int) tp->curr_amb_temp);
 184                         ret = 1;
 185                 }
 186                 if (ret)
 187                         *last_warn = jiffies;
 188         } else if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_warn ||
 189                    tp->curr_amb_temp < amb_temp_limits[tp->index].low_warn)
 190                 ret = 1;
 191
 192         /* Now check the shutdown limits. */
 193         if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown ||
 194             tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) {
 195                 do_envctrl_shutdown(tp);
 196                 ret = 1;
 197         }
 198
 199         if (ret) {
 200                 tp->fan_todo[FAN_AMBIENT] = FAN_FULLBLAST;
 201         } else if ((tick & (8 - 1)) == 0) {
 202                 s8 amb_goal_hi = amb_temp_limits[tp->index].high_warn - 10;
 203                 s8 amb_goal_lo;
 204
 205                 amb_goal_lo = amb_goal_hi - 3;
 206
 207                 /* We do not try to avoid 'too cold' events.  Basically we
 208                  * only try to deal with over-heating and fan noise reduction.
 209                  */
 210                 if (tp->avg_amb_temp < amb_goal_hi) {
 211                         if (tp->avg_amb_temp >= amb_goal_lo)
 212                                 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
 213                         else
 214                                 tp->fan_todo[FAN_AMBIENT] = FAN_SLOWER;
 215                 } else {
 216                         tp->fan_todo[FAN_AMBIENT] = FAN_FASTER;
 217                 }
 218         } else {
 219                 tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
 220         }
 221 }
 222
 223 static void analyze_cpu_temp(struct bbc_cpu_temperature *tp, unsigned long *last_warn, int tick)
 224 {
 225         int ret = 0;
 226
 227         if (time_after(jiffies, (*last_warn + WARN_INTERVAL))) {
 228                 if (tp->curr_cpu_temp >=
 229                     cpu_temp_limits[tp->index].high_warn) {
 230                         printk(KERN_WARNING "temp%d: "
 231                                "Above safe CPU operating temperature, %d C.\n",
 232                                tp->index, (int) tp->curr_cpu_temp);
 233                         ret = 1;
 234                 } else if (tp->curr_cpu_temp <
 235                            cpu_temp_limits[tp->index].low_warn) {
 236                         printk(KERN_WARNING "temp%d: "
 237                                "Below safe CPU operating temperature, %d C.\n",
 238                                tp->index, (int) tp->curr_cpu_temp);
 239                         ret = 1;
 240                 }
 241                 if (ret)
 242                         *last_warn = jiffies;
 243         } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_warn ||
 244                    tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_warn)
 245                 ret = 1;
 246
 247         /* Now check the shutdown limits. */
 248         if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown ||
 249             tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) {
 250                 do_envctrl_shutdown(tp);
 251                 ret = 1;
 252         }
 253
 254         if (ret) {
 255                 tp->fan_todo[FAN_CPU] = FAN_FULLBLAST;
 256         } else if ((tick & (8 - 1)) == 0) {
 257                 s8 cpu_goal_hi = cpu_temp_limits[tp->index].high_warn - 10;
 258                 s8 cpu_goal_lo;
 259
 260                 cpu_goal_lo = cpu_goal_hi - 3;
 261
 262                 /* We do not try to avoid 'too cold' events.  Basically we
 263                  * only try to deal with over-heating and fan noise reduction.
 264                  */
 265                 if (tp->avg_cpu_temp < cpu_goal_hi) {
 266                         if (tp->avg_cpu_temp >= cpu_goal_lo)
 267                                 tp->fan_todo[FAN_CPU] = FAN_SAME;
 268                         else
 269                                 tp->fan_todo[FAN_CPU] = FAN_SLOWER;
 270                 } else {
 271                         tp->fan_todo[FAN_CPU] = FAN_FASTER;
 272                 }
 273         } else {
 274                 tp->fan_todo[FAN_CPU] = FAN_SAME;
 275         }
 276 }
 277
 278 static void analyze_temps(struct bbc_cpu_temperature *tp, unsigned long *last_warn)
 279 {
 280         tp->avg_amb_temp = (s8)((int)((int)tp->avg_amb_temp + (int)tp->curr_amb_temp) / 2);
 281         tp->avg_cpu_temp = (s8)((int)((int)tp->avg_cpu_temp + (int)tp->curr_cpu_temp) / 2);
 282
 283         analyze_ambient_temp(tp, last_warn, tp->sample_tick);
 284         analyze_cpu_temp(tp, last_warn, tp->sample_tick);
 285
 286         tp->sample_tick++;
 287 }
 288
 289 static enum fan_action prioritize_fan_action(int which_fan)
 290 {
 291         struct bbc_cpu_temperature *tp;
 292         enum fan_action decision = FAN_STATE_MAX;
 293
 294         /* Basically, prioritize what the temperature sensors
 295          * recommend we do, and perform that action on all the
 296          * fans.
 297          */
 298         list_for_each_entry(tp, &all_temps, glob_list) {
 299                 if (tp->fan_todo[which_fan] == FAN_FULLBLAST) {
 300                         decision = FAN_FULLBLAST;
 301                         break;
 302                 }
 303                 if (tp->fan_todo[which_fan] == FAN_SAME &&
 304                     decision != FAN_FASTER)
 305                         decision = FAN_SAME;
 306                 else if (tp->fan_todo[which_fan] == FAN_FASTER)
 307                         decision = FAN_FASTER;
 308                 else if (decision != FAN_FASTER &&
 309                          decision != FAN_SAME &&
 310                          tp->fan_todo[which_fan] == FAN_SLOWER)
 311                         decision = FAN_SLOWER;
 312         }
 313         if (decision == FAN_STATE_MAX)
 314                 decision = FAN_SAME;
 315
 316         return decision;
 317 }
 318
 319 static int maybe_new_ambient_fan_speed(struct bbc_fan_control *fp)
 320 {
 321         enum fan_action decision = prioritize_fan_action(FAN_AMBIENT);
 322         int ret;
 323
 324         if (decision == FAN_SAME)
 325                 return 0;
 326
 327         ret = 1;
 328         if (decision == FAN_FULLBLAST) {
 329                 if (fp->system_fan_speed >= FAN_SPEED_MAX)
 330                         ret = 0;
 331                 else
 332                         fp->system_fan_speed = FAN_SPEED_MAX;
 333         } else {
 334                 if (decision == FAN_FASTER) {
 335                         if (fp->system_fan_speed >= FAN_SPEED_MAX)
 336                                 ret = 0;
 337                         else
 338                                 fp->system_fan_speed += 2;
 339                 } else {
 340                         int orig_speed = fp->system_fan_speed;
 341
 342                         if (orig_speed <= FAN_SPEED_MIN ||
 343                             orig_speed <= (fp->cpu_fan_speed - 3))
 344                                 ret = 0;
 345                         else
 346                                 fp->system_fan_speed -= 1;
 347                 }
 348         }
 349
 350         return ret;
 351 }
 352
 353 static int maybe_new_cpu_fan_speed(struct bbc_fan_control *fp)
 354 {
 355         enum fan_action decision = prioritize_fan_action(FAN_CPU);
 356         int ret;
 357
 358         if (decision == FAN_SAME)
 359                 return 0;
 360
 361         ret = 1;
 362         if (decision == FAN_FULLBLAST) {
 363                 if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
 364                         ret = 0;
 365                 else
 366                         fp->cpu_fan_speed = FAN_SPEED_MAX;
 367         } else {
 368                 if (decision == FAN_FASTER) {
 369                         if (fp->cpu_fan_speed >= FAN_SPEED_MAX)
 370                                 ret = 0;
 371                         else {
 372                                 fp->cpu_fan_speed += 2;
 373                                 if (fp->system_fan_speed <
 374                                     (fp->cpu_fan_speed - 3))
 375                                         fp->system_fan_speed =
 376                                                 fp->cpu_fan_speed - 3;
 377                         }
 378                 } else {
 379                         if (fp->cpu_fan_speed <= FAN_SPEED_MIN)
 380                                 ret = 0;
 381                         else
 382                                 fp->cpu_fan_speed -= 1;
 383                 }
 384         }
 385
 386         return ret;
 387 }
 388
 389 static void maybe_new_fan_speeds(struct bbc_fan_control *fp)
 390 {
 391         int new;
 392
 393         new  = maybe_new_ambient_fan_speed(fp);
 394         new |= maybe_new_cpu_fan_speed(fp);
 395
 396         if (new)
 397                 set_fan_speeds(fp);
 398 }
 399
 400 static void fans_full_blast(void)
 401 {
 402         struct bbc_fan_control *fp;
 403
 404         /* Since we will not be monitoring things anymore, put
 405          * the fans on full blast.
 406          */
 407         list_for_each_entry(fp, &all_fans, glob_list) {
 408                 fp->cpu_fan_speed = FAN_SPEED_MAX;
 409                 fp->system_fan_speed = FAN_SPEED_MAX;
 410                 fp->psupply_fan_on = 1;
 411                 set_fan_speeds(fp);
 412         }
 413 }
 414
 415 #define POLL_INTERVAL   (5 * 1000)
 416 static unsigned long last_warning_jiffies;
 417 static struct task_struct *kenvctrld_task;
 418
 419 static int kenvctrld(void *__unused)
 420 {
 421         printk(KERN_INFO "bbc_envctrl: kenvctrld starting...\n");
 422         last_warning_jiffies = jiffies - WARN_INTERVAL;
 423         for (;;) {
 424                 struct bbc_cpu_temperature *tp;
 425                 struct bbc_fan_control *fp;
 426
 427                 msleep_interruptible(POLL_INTERVAL);
 428                 if (kthread_should_stop())
 429                         break;
 430
 431                 list_for_each_entry(tp, &all_temps, glob_list) {
 432                         get_current_temps(tp);
 433                         analyze_temps(tp, &last_warning_jiffies);
 434                 }
 435                 list_for_each_entry(fp, &all_fans, glob_list)
 436                         maybe_new_fan_speeds(fp);
 437         }
 438         printk(KERN_INFO "bbc_envctrl: kenvctrld exiting...\n");
 439
 440         fans_full_blast();
 441
 442         return 0;
 443 }
 444
 445 static void attach_one_temp(struct bbc_i2c_bus *bp, struct of_device *op,
 446                             int temp_idx)
 447 {
 448         struct bbc_cpu_temperature *tp;
 449
 450         tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 451         if (!tp)
 452                 return;
 453
 454         tp->client = bbc_i2c_attach(bp, op);
 455         if (!tp->client) {
 456                 kfree(tp);
 457                 return;
 458         }
 459
 460
 461         tp->index = temp_idx;
 462
 463         list_add(&tp->glob_list, &all_temps);
 464         list_add(&tp->bp_list, &bp->temps);
 465
 466         /* Tell it to convert once every 5 seconds, clear all cfg
 467          * bits.
 468          */
 469         bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE);
 470         bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE);
 471
 472         /* Program the hard temperature limits into the chip. */
 473         bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff,
 474                        MAX1617_WR_AMB_HIGHLIM);
 475         bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff,
 476                        MAX1617_WR_AMB_LOWLIM);
 477         bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff,
 478                        MAX1617_WR_CPU_HIGHLIM);
 479         bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff,
 480                        MAX1617_WR_CPU_LOWLIM);
 481
 482         get_current_temps(tp);
 483         tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp;
 484         tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp;
 485
 486         tp->fan_todo[FAN_AMBIENT] = FAN_SAME;
 487         tp->fan_todo[FAN_CPU] = FAN_SAME;
 488 }
 489
 490 static void attach_one_fan(struct bbc_i2c_bus *bp, struct of_device *op,
 491                            int fan_idx)
 492 {
 493         struct bbc_fan_control *fp;
 494
 495         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 496         if (!fp)
 497                 return;
 498
 499         fp->client = bbc_i2c_attach(bp, op);
 500         if (!fp->client) {
 501                 kfree(fp);
 502                 return;
 503         }
 504
 505         fp->index = fan_idx;
 506
 507         list_add(&fp->glob_list, &all_fans);
 508         list_add(&fp->bp_list, &bp->fans);
 509
 510         /* The i2c device controlling the fans is write-only.
 511          * So the only way to keep track of the current power
 512          * level fed to the fans is via software.  Choose half
 513          * power for cpu/system and 'on' fo the powersupply fan
 514          * and set it now.
 515          */
 516         fp->psupply_fan_on = 1;
 517         fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
 518         fp->cpu_fan_speed += FAN_SPEED_MIN;
 519         fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2;
 520         fp->system_fan_speed += FAN_SPEED_MIN;
 521
 522         set_fan_speeds(fp);
 523 }
 524
 525 int bbc_envctrl_init(struct bbc_i2c_bus *bp)
 526 {
 527         struct of_device *op;
 528         int temp_index = 0;
 529         int fan_index = 0;
 530         int devidx = 0;
 531
 532         while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) {
 533                 if (!strcmp(op->node->name, "temperature"))
 534                         attach_one_temp(bp, op, temp_index++);
 535                 if (!strcmp(op->node->name, "fan-control"))
 536                         attach_one_fan(bp, op, fan_index++);
 537         }
 538         if (temp_index != 0 && fan_index != 0) {
 539                 kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
 540                 if (IS_ERR(kenvctrld_task)) {
 541                         int err = PTR_ERR(kenvctrld_task);
 542
 543                         kenvctrld_task = NULL;
 544                         return err;
 545                 }
 546         }
 547
 548         return 0;
 549 }
 550
 551 static void destroy_one_temp(struct bbc_cpu_temperature *tp)
 552 {
 553         bbc_i2c_detach(tp->client);
 554         kfree(tp);
 555 }
 556
 557 static void destroy_one_fan(struct bbc_fan_control *fp)
 558 {
 559         bbc_i2c_detach(fp->client);
 560         kfree(fp);
 561 }
 562
 563 void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp)
 564 {
 565         struct bbc_cpu_temperature *tp, *tpos;
 566         struct bbc_fan_control *fp, *fpos;
 567
 568         if (kenvctrld_task)
 569                 kthread_stop(kenvctrld_task);
 570
 571         list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) {
 572                 list_del(&tp->bp_list);
 573                 list_del(&tp->glob_list);
 574                 destroy_one_temp(tp);
 575         }
 576
 577         list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) {
 578                 list_del(&fp->bp_list);
 579                 list_del(&fp->glob_list);
 580                 destroy_one_fan(fp);
 581         }
 582 }