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/slab.h> 12#include <linux/of_device.h> 13#include <asm/oplib.h> 14 15#include "bbc_i2c.h" 16#include "max1617.h" 17 18#undef ENVCTRL_TRACE 19 20/* WARNING: Making changes to this driver is very dangerous. 21 * If you misprogram the sensor chips they can 22 * cut the power on you instantly. 23 */ 24 25/* Two temperature sensors exist in the SunBLADE-1000 enclosure. 26 * Both are implemented using max1617 i2c devices. Each max1617 27 * monitors 2 temperatures, one for one of the cpu dies and the other 28 * for the ambient temperature. 29 * 30 * The max1617 is capable of being programmed with power-off 31 * temperature values, one low limit and one high limit. These 32 * can be controlled independently for the cpu or ambient temperature. 33 * If a limit is violated, the power is simply shut off. The frequency 34 * with which the max1617 does temperature sampling can be controlled 35 * as well. 36 * 37 * Three fans exist inside the machine, all three are controlled with 38 * an i2c digital to analog converter. There is a fan directed at the 39 * two processor slots, another for the rest of the enclosure, and the 40 * third is for the power supply. The first two fans may be speed 41 * controlled by changing the voltage fed to them. The third fan may 42 * only be completely off or on. The third fan is meant to only be 43 * disabled/enabled when entering/exiting the lowest power-saving 44 * mode of the machine. 45 * 46 * An environmental control kernel thread periodically monitors all 47 * temperature sensors. Based upon the samples it will adjust the 48 * fan speeds to try and keep the system within a certain temperature 49 * range (the goal being to make the fans as quiet as possible without 50 * allowing the system to get too hot). 51 * 52 * If the temperature begins to rise/fall outside of the acceptable 53 * operating range, a periodic warning will be sent to the kernel log. 54 * The fans will be put on full blast to attempt to deal with this 55 * situation. After exceeding the acceptable operating range by a 56 * certain threshold, the kernel thread will shut down the system. 57 * Here, the thread is attempting to shut the machine down cleanly 58 * before the hardware based power-off event is triggered. 59 */ 60 61/* These settings are in Celsius. We use these defaults only 62 * if we cannot interrogate the cpu-fru SEEPROM. 63 */ 64struct temp_limits { 65 s8 high_pwroff, high_shutdown, high_warn; 66 s8 low_warn, low_shutdown, low_pwroff; 67}; 68 69static struct temp_limits cpu_temp_limits[2] = { 70 { 100, 85, 80, 5, -5, -10 }, 71 { 100, 85, 80, 5, -5, -10 }, 72}; 73 74static struct temp_limits amb_temp_limits[2] = { 75 { 65, 55, 40, 5, -5, -10 }, 76 { 65, 55, 40, 5, -5, -10 }, 77}; 78 79static LIST_HEAD(all_temps); 80static LIST_HEAD(all_fans); 81 82#define CPU_FAN_REG 0xf0 83#define SYS_FAN_REG 0xf2 84#define PSUPPLY_FAN_REG 0xf4 85 86#define FAN_SPEED_MIN 0x0c 87#define FAN_SPEED_MAX 0x3f 88 89#define PSUPPLY_FAN_ON 0x1f 90#define PSUPPLY_FAN_OFF 0x00 91 92static void set_fan_speeds(struct bbc_fan_control *fp) 93{ 94 /* Put temperatures into range so we don't mis-program 95 * the hardware. 96 */ 97 if (fp->cpu_fan_speed < FAN_SPEED_MIN) 98 fp->cpu_fan_speed = FAN_SPEED_MIN; 99 if (fp->cpu_fan_speed > FAN_SPEED_MAX) 100 fp->cpu_fan_speed = FAN_SPEED_MAX; 101 if (fp->system_fan_speed < FAN_SPEED_MIN) 102 fp->system_fan_speed = FAN_SPEED_MIN; 103 if (fp->system_fan_speed > FAN_SPEED_MAX) 104 fp->system_fan_speed = FAN_SPEED_MAX; 105#ifdef ENVCTRL_TRACE 106 printk("fan%d: Changed fan speed to cpu(%02x) sys(%02x)\n", 107 fp->index, 108 fp->cpu_fan_speed, fp->system_fan_speed); 109#endif 110 111 bbc_i2c_writeb(fp->client, fp->cpu_fan_speed, CPU_FAN_REG); 112 bbc_i2c_writeb(fp->client, fp->system_fan_speed, SYS_FAN_REG); 113 bbc_i2c_writeb(fp->client, 114 (fp->psupply_fan_on ? 115 PSUPPLY_FAN_ON : PSUPPLY_FAN_OFF), 116 PSUPPLY_FAN_REG); 117} 118 119static void get_current_temps(struct bbc_cpu_temperature *tp) 120{ 121 tp->prev_amb_temp = tp->curr_amb_temp; 122 bbc_i2c_readb(tp->client, 123 (unsigned char *) &tp->curr_amb_temp, 124 MAX1617_AMB_TEMP); 125 tp->prev_cpu_temp = tp->curr_cpu_temp; 126 bbc_i2c_readb(tp->client, 127 (unsigned char *) &tp->curr_cpu_temp, 128 MAX1617_CPU_TEMP); 129#ifdef ENVCTRL_TRACE 130 printk("temp%d: cpu(%d C) amb(%d C)\n", 131 tp->index, 132 (int) tp->curr_cpu_temp, (int) tp->curr_amb_temp); 133#endif 134} 135 136 137static void do_envctrl_shutdown(struct bbc_cpu_temperature *tp) 138{ 139 static int shutting_down = 0; 140 char *type = "???"; 141 s8 val = -1; 142 143 if (shutting_down != 0) 144 return; 145 146 if (tp->curr_amb_temp >= amb_temp_limits[tp->index].high_shutdown || 147 tp->curr_amb_temp < amb_temp_limits[tp->index].low_shutdown) { 148 type = "ambient"; 149 val = tp->curr_amb_temp; 150 } else if (tp->curr_cpu_temp >= cpu_temp_limits[tp->index].high_shutdown || 151 tp->curr_cpu_temp < cpu_temp_limits[tp->index].low_shutdown) { 152 type = "CPU"; 153 val = tp->curr_cpu_temp; 154 } 155 156 printk(KERN_CRIT "temp%d: Outside of safe %s " 157 "operating temperature, %d C.\n", 158 tp->index, type, val); 159 160 printk(KERN_CRIT "kenvctrld: Shutting down the system now.\n"); 161 162 shutting_down = 1; 163 orderly_poweroff(true); 164} 165 166#define WARN_INTERVAL (30 * HZ) 167 168static 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 223static 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 278static 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 289static 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 319static 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 353static 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 389static 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 400static 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) 416static unsigned long last_warning_jiffies; 417static struct task_struct *kenvctrld_task; 418 419static 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 445static void attach_one_temp(struct bbc_i2c_bus *bp, struct platform_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 INIT_LIST_HEAD(&tp->bp_list); 455 INIT_LIST_HEAD(&tp->glob_list); 456 457 tp->client = bbc_i2c_attach(bp, op); 458 if (!tp->client) { 459 kfree(tp); 460 return; 461 } 462 463 464 tp->index = temp_idx; 465 466 list_add(&tp->glob_list, &all_temps); 467 list_add(&tp->bp_list, &bp->temps); 468 469 /* Tell it to convert once every 5 seconds, clear all cfg 470 * bits. 471 */ 472 bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE); 473 bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE); 474 475 /* Program the hard temperature limits into the chip. */ 476 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff, 477 MAX1617_WR_AMB_HIGHLIM); 478 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff, 479 MAX1617_WR_AMB_LOWLIM); 480 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff, 481 MAX1617_WR_CPU_HIGHLIM); 482 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff, 483 MAX1617_WR_CPU_LOWLIM); 484 485 get_current_temps(tp); 486 tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp; 487 tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp; 488 489 tp->fan_todo[FAN_AMBIENT] = FAN_SAME; 490 tp->fan_todo[FAN_CPU] = FAN_SAME; 491} 492 493static void attach_one_fan(struct bbc_i2c_bus *bp, struct platform_device *op, 494 int fan_idx) 495{ 496 struct bbc_fan_control *fp; 497 498 fp = kzalloc(sizeof(*fp), GFP_KERNEL); 499 if (!fp) 500 return; 501 502 INIT_LIST_HEAD(&fp->bp_list); 503 INIT_LIST_HEAD(&fp->glob_list); 504 505 fp->client = bbc_i2c_attach(bp, op); 506 if (!fp->client) { 507 kfree(fp); 508 return; 509 } 510 511 fp->index = fan_idx; 512 513 list_add(&fp->glob_list, &all_fans); 514 list_add(&fp->bp_list, &bp->fans); 515 516 /* The i2c device controlling the fans is write-only. 517 * So the only way to keep track of the current power 518 * level fed to the fans is via software. Choose half 519 * power for cpu/system and 'on' fo the powersupply fan 520 * and set it now. 521 */ 522 fp->psupply_fan_on = 1; 523 fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2; 524 fp->cpu_fan_speed += FAN_SPEED_MIN; 525 fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2; 526 fp->system_fan_speed += FAN_SPEED_MIN; 527 528 set_fan_speeds(fp); 529} 530 531static void destroy_one_temp(struct bbc_cpu_temperature *tp) 532{ 533 bbc_i2c_detach(tp->client); 534 kfree(tp); 535} 536 537static void destroy_all_temps(struct bbc_i2c_bus *bp) 538{ 539 struct bbc_cpu_temperature *tp, *tpos; 540 541 list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) { 542 list_del(&tp->bp_list); 543 list_del(&tp->glob_list); 544 destroy_one_temp(tp); 545 } 546} 547 548static void destroy_one_fan(struct bbc_fan_control *fp) 549{ 550 bbc_i2c_detach(fp->client); 551 kfree(fp); 552} 553 554static void destroy_all_fans(struct bbc_i2c_bus *bp) 555{ 556 struct bbc_fan_control *fp, *fpos; 557 558 list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) { 559 list_del(&fp->bp_list); 560 list_del(&fp->glob_list); 561 destroy_one_fan(fp); 562 } 563} 564 565int bbc_envctrl_init(struct bbc_i2c_bus *bp) 566{ 567 struct platform_device *op; 568 int temp_index = 0; 569 int fan_index = 0; 570 int devidx = 0; 571 572 while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) { 573 if (!strcmp(op->dev.of_node->name, "temperature")) 574 attach_one_temp(bp, op, temp_index++); 575 if (!strcmp(op->dev.of_node->name, "fan-control")) 576 attach_one_fan(bp, op, fan_index++); 577 } 578 if (temp_index != 0 && fan_index != 0) { 579 kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld"); 580 if (IS_ERR(kenvctrld_task)) { 581 int err = PTR_ERR(kenvctrld_task); 582 583 kenvctrld_task = NULL; 584 destroy_all_temps(bp); 585 destroy_all_fans(bp); 586 return err; 587 } 588 } 589 590 return 0; 591} 592 593void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp) 594{ 595 if (kenvctrld_task) 596 kthread_stop(kenvctrld_task); 597 598 destroy_all_temps(bp); 599 destroy_all_fans(bp); 600} 601