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 if (orderly_poweroff(true) < 0) 164 printk(KERN_CRIT "envctrl: shutdown execution failed\n"); 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(sizeof(*tp), GFP_KERNEL); 452 if (!tp) 453 return; 454 455 tp->client = bbc_i2c_attach(bp, op); 456 if (!tp->client) { 457 kfree(tp); 458 return; 459 } 460 461 462 tp->index = temp_idx; 463 464 list_add(&tp->glob_list, &all_temps); 465 list_add(&tp->bp_list, &bp->temps); 466 467 /* Tell it to convert once every 5 seconds, clear all cfg 468 * bits. 469 */ 470 bbc_i2c_writeb(tp->client, 0x00, MAX1617_WR_CFG_BYTE); 471 bbc_i2c_writeb(tp->client, 0x02, MAX1617_WR_CVRATE_BYTE); 472 473 /* Program the hard temperature limits into the chip. */ 474 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].high_pwroff, 475 MAX1617_WR_AMB_HIGHLIM); 476 bbc_i2c_writeb(tp->client, amb_temp_limits[tp->index].low_pwroff, 477 MAX1617_WR_AMB_LOWLIM); 478 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].high_pwroff, 479 MAX1617_WR_CPU_HIGHLIM); 480 bbc_i2c_writeb(tp->client, cpu_temp_limits[tp->index].low_pwroff, 481 MAX1617_WR_CPU_LOWLIM); 482 483 get_current_temps(tp); 484 tp->prev_cpu_temp = tp->avg_cpu_temp = tp->curr_cpu_temp; 485 tp->prev_amb_temp = tp->avg_amb_temp = tp->curr_amb_temp; 486 487 tp->fan_todo[FAN_AMBIENT] = FAN_SAME; 488 tp->fan_todo[FAN_CPU] = FAN_SAME; 489} 490 491static void attach_one_fan(struct bbc_i2c_bus *bp, struct platform_device *op, 492 int fan_idx) 493{ 494 struct bbc_fan_control *fp; 495 496 fp = kzalloc(sizeof(*fp), GFP_KERNEL); 497 if (!fp) 498 return; 499 500 fp->client = bbc_i2c_attach(bp, op); 501 if (!fp->client) { 502 kfree(fp); 503 return; 504 } 505 506 fp->index = fan_idx; 507 508 list_add(&fp->glob_list, &all_fans); 509 list_add(&fp->bp_list, &bp->fans); 510 511 /* The i2c device controlling the fans is write-only. 512 * So the only way to keep track of the current power 513 * level fed to the fans is via software. Choose half 514 * power for cpu/system and 'on' fo the powersupply fan 515 * and set it now. 516 */ 517 fp->psupply_fan_on = 1; 518 fp->cpu_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2; 519 fp->cpu_fan_speed += FAN_SPEED_MIN; 520 fp->system_fan_speed = (FAN_SPEED_MAX - FAN_SPEED_MIN) / 2; 521 fp->system_fan_speed += FAN_SPEED_MIN; 522 523 set_fan_speeds(fp); 524} 525 526static void destroy_one_temp(struct bbc_cpu_temperature *tp) 527{ 528 bbc_i2c_detach(tp->client); 529 kfree(tp); 530} 531 532static void destroy_all_temps(struct bbc_i2c_bus *bp) 533{ 534 struct bbc_cpu_temperature *tp, *tpos; 535 536 list_for_each_entry_safe(tp, tpos, &bp->temps, bp_list) { 537 list_del(&tp->bp_list); 538 list_del(&tp->glob_list); 539 destroy_one_temp(tp); 540 } 541} 542 543static void destroy_one_fan(struct bbc_fan_control *fp) 544{ 545 bbc_i2c_detach(fp->client); 546 kfree(fp); 547} 548 549static void destroy_all_fans(struct bbc_i2c_bus *bp) 550{ 551 struct bbc_fan_control *fp, *fpos; 552 553 list_for_each_entry_safe(fp, fpos, &bp->fans, bp_list) { 554 list_del(&fp->bp_list); 555 list_del(&fp->glob_list); 556 destroy_one_fan(fp); 557 } 558} 559 560int bbc_envctrl_init(struct bbc_i2c_bus *bp) 561{ 562 struct platform_device *op; 563 int temp_index = 0; 564 int fan_index = 0; 565 int devidx = 0; 566 567 while ((op = bbc_i2c_getdev(bp, devidx++)) != NULL) { 568 if (!strcmp(op->dev.of_node->name, "temperature")) 569 attach_one_temp(bp, op, temp_index++); 570 if (!strcmp(op->dev.of_node->name, "fan-control")) 571 attach_one_fan(bp, op, fan_index++); 572 } 573 if (temp_index != 0 && fan_index != 0) { 574 kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld"); 575 if (IS_ERR(kenvctrld_task)) { 576 int err = PTR_ERR(kenvctrld_task); 577 578 kenvctrld_task = NULL; 579 destroy_all_temps(bp); 580 destroy_all_fans(bp); 581 return err; 582 } 583 } 584 585 return 0; 586} 587 588void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp) 589{ 590 if (kenvctrld_task) 591 kthread_stop(kenvctrld_task); 592 593 destroy_all_temps(bp); 594 destroy_all_fans(bp); 595} 596