drivers/macintosh/windfarm_pm112.c

   1 /*
   2  * Windfarm PowerMac thermal control.
   3  * Control loops for machines with SMU and PPC970MP processors.
   4  *
   5  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
   6  * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
   7  *
   8  * Use and redistribute under the terms of the GNU GPL v2.
   9  */
  10 #include <linux/types.h>
  11 #include <linux/errno.h>
  12 #include <linux/kernel.h>
  13 #include <linux/device.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/reboot.h>
  16 #include <asm/prom.h>
  17 #include <asm/smu.h>
  18
  19 #include "windfarm.h"
  20 #include "windfarm_pid.h"
  21
  22 #define VERSION "0.2"
  23
  24 #define DEBUG
  25 #undef LOTSA_DEBUG
  26
  27 #ifdef DEBUG
  28 #define DBG(args...)    printk(args)
  29 #else
  30 #define DBG(args...)    do { } while(0)
  31 #endif
  32
  33 #ifdef LOTSA_DEBUG
  34 #define DBG_LOTS(args...)       printk(args)
  35 #else
  36 #define DBG_LOTS(args...)       do { } while(0)
  37 #endif
  38
  39 /* define this to force CPU overtemp to 60 degree, useful for testing
  40  * the overtemp code
  41  */
  42 #undef HACKED_OVERTEMP
  43
  44 /* We currently only handle 2 chips, 4 cores... */
  45 #define NR_CHIPS        2
  46 #define NR_CORES        4
  47 #define NR_CPU_FANS     3 * NR_CHIPS
  48
  49 /* Controls and sensors */
  50 static struct wf_sensor *sens_cpu_temp[NR_CORES];
  51 static struct wf_sensor *sens_cpu_power[NR_CORES];
  52 static struct wf_sensor *hd_temp;
  53 static struct wf_sensor *slots_power;
  54 static struct wf_sensor *u4_temp;
  55
  56 static struct wf_control *cpu_fans[NR_CPU_FANS];
  57 static char *cpu_fan_names[NR_CPU_FANS] = {
  58         "cpu-rear-fan-0",
  59         "cpu-rear-fan-1",
  60         "cpu-front-fan-0",
  61         "cpu-front-fan-1",
  62         "cpu-pump-0",
  63         "cpu-pump-1",
  64 };
  65 static struct wf_control *cpufreq_clamp;
  66
  67 /* Second pump isn't required (and isn't actually present) */
  68 #define CPU_FANS_REQD           (NR_CPU_FANS - 2)
  69 #define FIRST_PUMP              4
  70 #define LAST_PUMP               5
  71
  72 /* We keep a temperature history for average calculation of 180s */
  73 #define CPU_TEMP_HIST_SIZE      180
  74
  75 /* Scale factor for fan speed, *100 */
  76 static int cpu_fan_scale[NR_CPU_FANS] = {
  77         100,
  78         100,
  79         97,             /* inlet fans run at 97% of exhaust fan */
  80         97,
  81         100,            /* updated later */
  82         100,            /* updated later */
  83 };
  84
  85 static struct wf_control *backside_fan;
  86 static struct wf_control *slots_fan;
  87 static struct wf_control *drive_bay_fan;
  88
  89 /* PID loop state */
  90 static struct wf_cpu_pid_state cpu_pid[NR_CORES];
  91 static u32 cpu_thist[CPU_TEMP_HIST_SIZE];
  92 static int cpu_thist_pt;
  93 static s64 cpu_thist_total;
  94 static s32 cpu_all_tmax = 100 << 16;
  95 static int cpu_last_target;
  96 static struct wf_pid_state backside_pid;
  97 static int backside_tick;
  98 static struct wf_pid_state slots_pid;
  99 static int slots_started;
 100 static struct wf_pid_state drive_bay_pid;
 101 static int drive_bay_tick;
 102
 103 static int nr_cores;
 104 static int have_all_controls;
 105 static int have_all_sensors;
 106 static int started;
 107
 108 static int failure_state;
 109 #define FAILURE_SENSOR          1
 110 #define FAILURE_FAN             2
 111 #define FAILURE_PERM            4
 112 #define FAILURE_LOW_OVERTEMP    8
 113 #define FAILURE_HIGH_OVERTEMP   16
 114
 115 /* Overtemp values */
 116 #define LOW_OVER_AVERAGE        0
 117 #define LOW_OVER_IMMEDIATE      (10 << 16)
 118 #define LOW_OVER_CLEAR          ((-10) << 16)
 119 #define HIGH_OVER_IMMEDIATE     (14 << 16)
 120 #define HIGH_OVER_AVERAGE       (10 << 16)
 121 #define HIGH_OVER_IMMEDIATE     (14 << 16)
 122
 123
 124 /* Implementation... */
 125 static int create_cpu_loop(int cpu)
 126 {
 127         int chip = cpu / 2;
 128         int core = cpu & 1;
 129         struct smu_sdbp_header *hdr;
 130         struct smu_sdbp_cpupiddata *piddata;
 131         struct wf_cpu_pid_param pid;
 132         struct wf_control *main_fan = cpu_fans[0];
 133         s32 tmax;
 134         int fmin;
 135
 136         /* Get PID params from the appropriate SAT */
 137         hdr = smu_sat_get_sdb_partition(chip, 0xC8 + core, NULL);
 138         if (hdr == NULL) {
 139                 printk(KERN_WARNING"windfarm: can't get CPU PID fan config\n");
 140                 return -EINVAL;
 141         }
 142         piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
 143
 144         /* Get FVT params to get Tmax; if not found, assume default */
 145         hdr = smu_sat_get_sdb_partition(chip, 0xC4 + core, NULL);
 146         if (hdr) {
 147                 struct smu_sdbp_fvt *fvt = (struct smu_sdbp_fvt *)&hdr[1];
 148                 tmax = fvt->maxtemp << 16;
 149         } else
 150                 tmax = 95 << 16;        /* default to 95 degrees C */
 151
 152         /* We keep a global tmax for overtemp calculations */
 153         if (tmax < cpu_all_tmax)
 154                 cpu_all_tmax = tmax;
 155
 156         /*
 157          * Darwin has a minimum fan speed of 1000 rpm for the 4-way and
 158          * 515 for the 2-way.  That appears to be overkill, so for now,
 159          * impose a minimum of 750 or 515.
 160          */
 161         fmin = (nr_cores > 2) ? 750 : 515;
 162
 163         /* Initialize PID loop */
 164         pid.interval = 1;       /* seconds */
 165         pid.history_len = piddata->history_len;
 166         pid.gd = piddata->gd;
 167         pid.gp = piddata->gp;
 168         pid.gr = piddata->gr / piddata->history_len;
 169         pid.pmaxadj = (piddata->max_power << 16) - (piddata->power_adj << 8);
 170         pid.ttarget = tmax - (piddata->target_temp_delta << 16);
 171         pid.tmax = tmax;
 172         pid.min = main_fan->ops->get_min(main_fan);
 173         pid.max = main_fan->ops->get_max(main_fan);
 174         if (pid.min < fmin)
 175                 pid.min = fmin;
 176
 177         wf_cpu_pid_init(&cpu_pid[cpu], &pid);
 178         return 0;
 179 }
 180
 181 static void cpu_max_all_fans(void)
 182 {
 183         int i;
 184
 185         /* We max all CPU fans in case of a sensor error. We also do the
 186          * cpufreq clamping now, even if it's supposedly done later by the
 187          * generic code anyway, we do it earlier here to react faster
 188          */
 189         if (cpufreq_clamp)
 190                 wf_control_set_max(cpufreq_clamp);
 191         for (i = 0; i < NR_CPU_FANS; ++i)
 192                 if (cpu_fans[i])
 193                         wf_control_set_max(cpu_fans[i]);
 194 }
 195
 196 static int cpu_check_overtemp(s32 temp)
 197 {
 198         int new_state = 0;
 199         s32 t_avg, t_old;
 200
 201         /* First check for immediate overtemps */
 202         if (temp >= (cpu_all_tmax + LOW_OVER_IMMEDIATE)) {
 203                 new_state |= FAILURE_LOW_OVERTEMP;
 204                 if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
 205                         printk(KERN_ERR "windfarm: Overtemp due to immediate CPU"
 206                                " temperature !\n");
 207         }
 208         if (temp >= (cpu_all_tmax + HIGH_OVER_IMMEDIATE)) {
 209                 new_state |= FAILURE_HIGH_OVERTEMP;
 210                 if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
 211                         printk(KERN_ERR "windfarm: Critical overtemp due to"
 212                                " immediate CPU temperature !\n");
 213         }
 214
 215         /* We calculate a history of max temperatures and use that for the
 216          * overtemp management
 217          */
 218         t_old = cpu_thist[cpu_thist_pt];
 219         cpu_thist[cpu_thist_pt] = temp;
 220         cpu_thist_pt = (cpu_thist_pt + 1) % CPU_TEMP_HIST_SIZE;
 221         cpu_thist_total -= t_old;
 222         cpu_thist_total += temp;
 223         t_avg = cpu_thist_total / CPU_TEMP_HIST_SIZE;
 224
 225         DBG_LOTS("t_avg = %d.%03d (out: %d.%03d, in: %d.%03d)\n",
 226                  FIX32TOPRINT(t_avg), FIX32TOPRINT(t_old), FIX32TOPRINT(temp));
 227
 228         /* Now check for average overtemps */
 229         if (t_avg >= (cpu_all_tmax + LOW_OVER_AVERAGE)) {
 230                 new_state |= FAILURE_LOW_OVERTEMP;
 231                 if ((failure_state & FAILURE_LOW_OVERTEMP) == 0)
 232                         printk(KERN_ERR "windfarm: Overtemp due to average CPU"
 233                                " temperature !\n");
 234         }
 235         if (t_avg >= (cpu_all_tmax + HIGH_OVER_AVERAGE)) {
 236                 new_state |= FAILURE_HIGH_OVERTEMP;
 237                 if ((failure_state & FAILURE_HIGH_OVERTEMP) == 0)
 238                         printk(KERN_ERR "windfarm: Critical overtemp due to"
 239                                " average CPU temperature !\n");
 240         }
 241
 242         /* Now handle overtemp conditions. We don't currently use the windfarm
 243          * overtemp handling core as it's not fully suited to the needs of those
 244          * new machine. This will be fixed later.
 245          */
 246         if (new_state) {
 247                 /* High overtemp -> immediate shutdown */
 248                 if (new_state & FAILURE_HIGH_OVERTEMP)
 249                         machine_power_off();
 250                 if ((failure_state & new_state) != new_state)
 251                         cpu_max_all_fans();
 252                 failure_state |= new_state;
 253         } else if ((failure_state & FAILURE_LOW_OVERTEMP) &&
 254                    (temp < (cpu_all_tmax + LOW_OVER_CLEAR))) {
 255                 printk(KERN_ERR "windfarm: Overtemp condition cleared !\n");
 256                 failure_state &= ~FAILURE_LOW_OVERTEMP;
 257         }
 258
 259         return failure_state & (FAILURE_LOW_OVERTEMP | FAILURE_HIGH_OVERTEMP);
 260 }
 261
 262 static void cpu_fans_tick(void)
 263 {
 264         int err, cpu;
 265         s32 greatest_delta = 0;
 266         s32 temp, power, t_max = 0;
 267         int i, t, target = 0;
 268         struct wf_sensor *sr;
 269         struct wf_control *ct;
 270         struct wf_cpu_pid_state *sp;
 271
 272         DBG_LOTS(KERN_DEBUG);
 273         for (cpu = 0; cpu < nr_cores; ++cpu) {
 274                 /* Get CPU core temperature */
 275                 sr = sens_cpu_temp[cpu];
 276                 err = sr->ops->get_value(sr, &temp);
 277                 if (err) {
 278                         DBG("\n");
 279                         printk(KERN_WARNING "windfarm: CPU %d temperature "
 280                                "sensor error %d\n", cpu, err);
 281                         failure_state |= FAILURE_SENSOR;
 282                         cpu_max_all_fans();
 283                         return;
 284                 }
 285
 286                 /* Keep track of highest temp */
 287                 t_max = max(t_max, temp);
 288
 289                 /* Get CPU power */
 290                 sr = sens_cpu_power[cpu];
 291                 err = sr->ops->get_value(sr, &power);
 292                 if (err) {
 293                         DBG("\n");
 294                         printk(KERN_WARNING "windfarm: CPU %d power "
 295                                "sensor error %d\n", cpu, err);
 296                         failure_state |= FAILURE_SENSOR;
 297                         cpu_max_all_fans();
 298                         return;
 299                 }
 300
 301                 /* Run PID */
 302                 sp = &cpu_pid[cpu];
 303                 t = wf_cpu_pid_run(sp, power, temp);
 304
 305                 if (cpu == 0 || sp->last_delta > greatest_delta) {
 306                         greatest_delta = sp->last_delta;
 307                         target = t;
 308                 }
 309                 DBG_LOTS("[%d] P=%d.%.3d T=%d.%.3d ",
 310                     cpu, FIX32TOPRINT(power), FIX32TOPRINT(temp));
 311         }
 312         DBG_LOTS("fans = %d, t_max = %d.%03d\n", target, FIX32TOPRINT(t_max));
 313
 314         /* Darwin limits decrease to 20 per iteration */
 315         if (target < (cpu_last_target - 20))
 316                 target = cpu_last_target - 20;
 317         cpu_last_target = target;
 318         for (cpu = 0; cpu < nr_cores; ++cpu)
 319                 cpu_pid[cpu].target = target;
 320
 321         /* Handle possible overtemps */
 322         if (cpu_check_overtemp(t_max))
 323                 return;
 324
 325         /* Set fans */
 326         for (i = 0; i < NR_CPU_FANS; ++i) {
 327                 ct = cpu_fans[i];
 328                 if (ct == NULL)
 329                         continue;
 330                 err = ct->ops->set_value(ct, target * cpu_fan_scale[i] / 100);
 331                 if (err) {
 332                         printk(KERN_WARNING "windfarm: fan %s reports "
 333                                "error %d\n", ct->name, err);
 334                         failure_state |= FAILURE_FAN;
 335                         break;
 336                 }
 337         }
 338 }
 339
 340 /* Backside/U4 fan */
 341 static struct wf_pid_param backside_param = {
 342         .interval       = 5,
 343         .history_len    = 2,
 344         .gd             = 48 << 20,
 345         .gp             = 5 << 20,
 346         .gr             = 0,
 347         .itarget        = 64 << 16,
 348         .additive       = 1,
 349 };
 350
 351 static void backside_fan_tick(void)
 352 {
 353         s32 temp;
 354         int speed;
 355         int err;
 356
 357         if (!backside_fan || !u4_temp)
 358                 return;
 359         if (!backside_tick) {
 360                 /* first time; initialize things */
 361                 backside_param.min = backside_fan->ops->get_min(backside_fan);
 362                 backside_param.max = backside_fan->ops->get_max(backside_fan);
 363                 wf_pid_init(&backside_pid, &backside_param);
 364                 backside_tick = 1;
 365         }
 366         if (--backside_tick > 0)
 367                 return;
 368         backside_tick = backside_pid.param.interval;
 369
 370         err = u4_temp->ops->get_value(u4_temp, &temp);
 371         if (err) {
 372                 printk(KERN_WARNING "windfarm: U4 temp sensor error %d\n",
 373                        err);
 374                 failure_state |= FAILURE_SENSOR;
 375                 wf_control_set_max(backside_fan);
 376                 return;
 377         }
 378         speed = wf_pid_run(&backside_pid, temp);
 379         DBG_LOTS("backside PID temp=%d.%.3d speed=%d\n",
 380                  FIX32TOPRINT(temp), speed);
 381
 382         err = backside_fan->ops->set_value(backside_fan, speed);
 383         if (err) {
 384                 printk(KERN_WARNING "windfarm: backside fan error %d\n", err);
 385                 failure_state |= FAILURE_FAN;
 386         }
 387 }
 388
 389 /* Drive bay fan */
 390 static struct wf_pid_param drive_bay_prm = {
 391         .interval       = 5,
 392         .history_len    = 2,
 393         .gd             = 30 << 20,
 394         .gp             = 5 << 20,
 395         .gr             = 0,
 396         .itarget        = 40 << 16,
 397         .additive       = 1,
 398 };
 399
 400 static void drive_bay_fan_tick(void)
 401 {
 402         s32 temp;
 403         int speed;
 404         int err;
 405
 406         if (!drive_bay_fan || !hd_temp)
 407                 return;
 408         if (!drive_bay_tick) {
 409                 /* first time; initialize things */
 410                 drive_bay_prm.min = drive_bay_fan->ops->get_min(drive_bay_fan);
 411                 drive_bay_prm.max = drive_bay_fan->ops->get_max(drive_bay_fan);
 412                 wf_pid_init(&drive_bay_pid, &drive_bay_prm);
 413                 drive_bay_tick = 1;
 414         }
 415         if (--drive_bay_tick > 0)
 416                 return;
 417         drive_bay_tick = drive_bay_pid.param.interval;
 418
 419         err = hd_temp->ops->get_value(hd_temp, &temp);
 420         if (err) {
 421                 printk(KERN_WARNING "windfarm: drive bay temp sensor "
 422                        "error %d\n", err);
 423                 failure_state |= FAILURE_SENSOR;
 424                 wf_control_set_max(drive_bay_fan);
 425                 return;
 426         }
 427         speed = wf_pid_run(&drive_bay_pid, temp);
 428         DBG_LOTS("drive_bay PID temp=%d.%.3d speed=%d\n",
 429                  FIX32TOPRINT(temp), speed);
 430
 431         err = drive_bay_fan->ops->set_value(drive_bay_fan, speed);
 432         if (err) {
 433                 printk(KERN_WARNING "windfarm: drive bay fan error %d\n", err);
 434                 failure_state |= FAILURE_FAN;
 435         }
 436 }
 437
 438 /* PCI slots area fan */
 439 /* This makes the fan speed proportional to the power consumed */
 440 static struct wf_pid_param slots_param = {
 441         .interval       = 1,
 442         .history_len    = 2,
 443         .gd             = 0,
 444         .gp             = 0,
 445         .gr             = 0x1277952,
 446         .itarget        = 0,
 447         .min            = 1560,
 448         .max            = 3510,
 449 };
 450
 451 static void slots_fan_tick(void)
 452 {
 453         s32 power;
 454         int speed;
 455         int err;
 456
 457         if (!slots_fan || !slots_power)
 458                 return;
 459         if (!slots_started) {
 460                 /* first time; initialize things */
 461                 wf_pid_init(&slots_pid, &slots_param);
 462                 slots_started = 1;
 463         }
 464
 465         err = slots_power->ops->get_value(slots_power, &power);
 466         if (err) {
 467                 printk(KERN_WARNING "windfarm: slots power sensor error %d\n",
 468                        err);
 469                 failure_state |= FAILURE_SENSOR;
 470                 wf_control_set_max(slots_fan);
 471                 return;
 472         }
 473         speed = wf_pid_run(&slots_pid, power);
 474         DBG_LOTS("slots PID power=%d.%.3d speed=%d\n",
 475                  FIX32TOPRINT(power), speed);
 476
 477         err = slots_fan->ops->set_value(slots_fan, speed);
 478         if (err) {
 479                 printk(KERN_WARNING "windfarm: slots fan error %d\n", err);
 480                 failure_state |= FAILURE_FAN;
 481         }
 482 }
 483
 484 static void set_fail_state(void)
 485 {
 486         int i;
 487
 488         if (cpufreq_clamp)
 489                 wf_control_set_max(cpufreq_clamp);
 490         for (i = 0; i < NR_CPU_FANS; ++i)
 491                 if (cpu_fans[i])
 492                         wf_control_set_max(cpu_fans[i]);
 493         if (backside_fan)
 494                 wf_control_set_max(backside_fan);
 495         if (slots_fan)
 496                 wf_control_set_max(slots_fan);
 497         if (drive_bay_fan)
 498                 wf_control_set_max(drive_bay_fan);
 499 }
 500
 501 static void pm112_tick(void)
 502 {
 503         int i, last_failure;
 504
 505         if (!started) {
 506                 started = 1;
 507                 for (i = 0; i < nr_cores; ++i) {
 508                         if (create_cpu_loop(i) < 0) {
 509                                 failure_state = FAILURE_PERM;
 510                                 set_fail_state();
 511                                 break;
 512                         }
 513                 }
 514                 DBG_LOTS("cpu_all_tmax=%d.%03d\n", FIX32TOPRINT(cpu_all_tmax));
 515
 516 #ifdef HACKED_OVERTEMP
 517                 cpu_all_tmax = 60 << 16;
 518 #endif
 519         }
 520
 521         /* Permanent failure, bail out */
 522         if (failure_state & FAILURE_PERM)
 523                 return;
 524         /* Clear all failure bits except low overtemp which will be eventually
 525          * cleared by the control loop itself
 526          */
 527         last_failure = failure_state;
 528         failure_state &= FAILURE_LOW_OVERTEMP;
 529         cpu_fans_tick();
 530         backside_fan_tick();
 531         slots_fan_tick();
 532         drive_bay_fan_tick();
 533
 534         DBG_LOTS("last_failure: 0x%x, failure_state: %x\n",
 535                  last_failure, failure_state);
 536
 537         /* Check for failures. Any failure causes cpufreq clamping */
 538         if (failure_state && last_failure == 0 && cpufreq_clamp)
 539                 wf_control_set_max(cpufreq_clamp);
 540         if (failure_state == 0 && last_failure && cpufreq_clamp)
 541                 wf_control_set_min(cpufreq_clamp);
 542
 543         /* That's it for now, we might want to deal with other failures
 544          * differently in the future though
 545          */
 546 }
 547
 548 static void pm112_new_control(struct wf_control *ct)
 549 {
 550         int i, max_exhaust;
 551
 552         if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
 553                 if (wf_get_control(ct) == 0)
 554                         cpufreq_clamp = ct;
 555         }
 556
 557         for (i = 0; i < NR_CPU_FANS; ++i) {
 558                 if (!strcmp(ct->name, cpu_fan_names[i])) {
 559                         if (cpu_fans[i] == NULL && wf_get_control(ct) == 0)
 560                                 cpu_fans[i] = ct;
 561                         break;
 562                 }
 563         }
 564         if (i >= NR_CPU_FANS) {
 565                 /* not a CPU fan, try the others */
 566                 if (!strcmp(ct->name, "backside-fan")) {
 567                         if (backside_fan == NULL && wf_get_control(ct) == 0)
 568                                 backside_fan = ct;
 569                 } else if (!strcmp(ct->name, "slots-fan")) {
 570                         if (slots_fan == NULL && wf_get_control(ct) == 0)
 571                                 slots_fan = ct;
 572                 } else if (!strcmp(ct->name, "drive-bay-fan")) {
 573                         if (drive_bay_fan == NULL && wf_get_control(ct) == 0)
 574                                 drive_bay_fan = ct;
 575                 }
 576                 return;
 577         }
 578
 579         for (i = 0; i < CPU_FANS_REQD; ++i)
 580                 if (cpu_fans[i] == NULL)
 581                         return;
 582
 583         /* work out pump scaling factors */
 584         max_exhaust = cpu_fans[0]->ops->get_max(cpu_fans[0]);
 585         for (i = FIRST_PUMP; i <= LAST_PUMP; ++i)
 586                 if ((ct = cpu_fans[i]) != NULL)
 587                         cpu_fan_scale[i] =
 588                                 ct->ops->get_max(ct) * 100 / max_exhaust;
 589
 590         have_all_controls = 1;
 591 }
 592
 593 static void pm112_new_sensor(struct wf_sensor *sr)
 594 {
 595         unsigned int i;
 596
 597         if (have_all_sensors)
 598                 return;
 599         if (!strncmp(sr->name, "cpu-temp-", 9)) {
 600                 i = sr->name[9] - '0';
 601                 if (sr->name[10] == 0 && i < NR_CORES &&
 602                     sens_cpu_temp[i] == NULL && wf_get_sensor(sr) == 0)
 603                         sens_cpu_temp[i] = sr;
 604
 605         } else if (!strncmp(sr->name, "cpu-power-", 10)) {
 606                 i = sr->name[10] - '0';
 607                 if (sr->name[11] == 0 && i < NR_CORES &&
 608                     sens_cpu_power[i] == NULL && wf_get_sensor(sr) == 0)
 609                         sens_cpu_power[i] = sr;
 610         } else if (!strcmp(sr->name, "hd-temp")) {
 611                 if (hd_temp == NULL && wf_get_sensor(sr) == 0)
 612                         hd_temp = sr;
 613         } else if (!strcmp(sr->name, "slots-power")) {
 614                 if (slots_power == NULL && wf_get_sensor(sr) == 0)
 615                         slots_power = sr;
 616         } else if (!strcmp(sr->name, "u4-temp")) {
 617                 if (u4_temp == NULL && wf_get_sensor(sr) == 0)
 618                         u4_temp = sr;
 619         } else
 620                 return;
 621
 622         /* check if we have all the sensors we need */
 623         for (i = 0; i < nr_cores; ++i)
 624                 if (sens_cpu_temp[i] == NULL || sens_cpu_power[i] == NULL)
 625                         return;
 626
 627         have_all_sensors = 1;
 628 }
 629
 630 static int pm112_wf_notify(struct notifier_block *self,
 631                            unsigned long event, void *data)
 632 {
 633         switch (event) {
 634         case WF_EVENT_NEW_SENSOR:
 635                 pm112_new_sensor(data);
 636                 break;
 637         case WF_EVENT_NEW_CONTROL:
 638                 pm112_new_control(data);
 639                 break;
 640         case WF_EVENT_TICK:
 641                 if (have_all_controls && have_all_sensors)
 642                         pm112_tick();
 643         }
 644         return 0;
 645 }
 646
 647 static struct notifier_block pm112_events = {
 648         .notifier_call = pm112_wf_notify,
 649 };
 650
 651 static int wf_pm112_probe(struct device *dev)
 652 {
 653         wf_register_client(&pm112_events);
 654         return 0;
 655 }
 656
 657 static int wf_pm112_remove(struct device *dev)
 658 {
 659         wf_unregister_client(&pm112_events);
 660         /* should release all sensors and controls */
 661         return 0;
 662 }
 663
 664 static struct device_driver wf_pm112_driver = {
 665         .name = "windfarm",
 666         .bus = &platform_bus_type,
 667         .probe = wf_pm112_probe,
 668         .remove = wf_pm112_remove,
 669 };
 670
 671 static int __init wf_pm112_init(void)
 672 {
 673         struct device_node *cpu;
 674
 675         if (!machine_is_compatible("PowerMac11,2"))
 676                 return -ENODEV;
 677
 678         /* Count the number of CPU cores */
 679         nr_cores = 0;
 680         for (cpu = NULL; (cpu = of_find_node_by_type(cpu, "cpu")) != NULL; )
 681                 ++nr_cores;
 682
 683         printk(KERN_INFO "windfarm: initializing for dual-core desktop G5\n");
 684         driver_register(&wf_pm112_driver);
 685         return 0;
 686 }
 687
 688 static void __exit wf_pm112_exit(void)
 689 {
 690         driver_unregister(&wf_pm112_driver);
 691 }
 692
 693 module_init(wf_pm112_init);
 694 module_exit(wf_pm112_exit);
 695
 696 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 697 MODULE_DESCRIPTION("Thermal control for PowerMac11,2");
 698 MODULE_LICENSE("GPL");