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   1 /*
   2  * Windfarm PowerMac thermal control. iMac G5
   3  *
   4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
   5  *                    <benh@kernel.crashing.org>
   6  *
   7  * Released under the term of the GNU GPL v2.
   8  *
   9  * The algorithm used is the PID control algorithm, used the same
  10  * way the published Darwin code does, using the same values that
  11  * are present in the Darwin 8.2 snapshot property lists (note however
  12  * that none of the code has been re-used, it's a complete re-implementation
  13  *
  14  * The various control loops found in Darwin config file are:
  15  *
  16  * PowerMac8,1 and PowerMac8,2
  17  * ===========================
  18  *
  19  * System Fans control loop. Different based on models. In addition to the
  20  * usual PID algorithm, the control loop gets 2 additional pairs of linear
  21  * scaling factors (scale/offsets) expressed as 4.12 fixed point values
  22  * signed offset, unsigned scale)
  23  *
  24  * The targets are modified such as:
  25  *  - the linked control (second control) gets the target value as-is
  26  *    (typically the drive fan)
  27  *  - the main control (first control) gets the target value scaled with
  28  *    the first pair of factors, and is then modified as below
  29  *  - the value of the target of the CPU Fan control loop is retrieved,
  30  *    scaled with the second pair of factors, and the max of that and
  31  *    the scaled target is applied to the main control.
  32  *
  33  * # model_id: 2
  34  *   controls       : system-fan, drive-bay-fan
  35  *   sensors        : hd-temp
  36  *   PID params     : G_d = 0x15400000
  37  *                    G_p = 0x00200000
  38  *                    G_r = 0x000002fd
  39  *                    History = 2 entries
  40  *                    Input target = 0x3a0000
  41  *                    Interval = 5s
  42  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
  43  *                    offset = 0x0208 scale  = 0x07ae
  44  *
  45  * # model_id: 3
  46  *   controls       : system-fan, drive-bay-fan
  47  *   sensors        : hd-temp
  48  *   PID params     : G_d = 0x08e00000
  49  *                    G_p = 0x00566666
  50  *                    G_r = 0x0000072b
  51  *                    History = 2 entries
  52  *                    Input target = 0x350000
  53  *                    Interval = 5s
  54  *   linear-factors : offset = 0xff38 scale  = 0x0ccd
  55  *                    offset = 0x0000 scale  = 0x0000
  56  *
  57  * # model_id: 5
  58  *   controls       : system-fan
  59  *   sensors        : hd-temp
  60  *   PID params     : G_d = 0x15400000
  61  *                    G_p = 0x00233333
  62  *                    G_r = 0x000002fd
  63  *                    History = 2 entries
  64  *                    Input target = 0x3a0000
  65  *                    Interval = 5s
  66  *   linear-factors : offset = 0x0000 scale  = 0x1000
  67  *                    offset = 0x0091 scale  = 0x0bae
  68  *
  69  * CPU Fan control loop. The loop is identical for all models. it
  70  * has an additional pair of scaling factor. This is used to scale the
  71  * systems fan control loop target result (the one before it gets scaled
  72  * by the System Fans control loop itself). Then, the max value of the
  73  * calculated target value and system fan value is sent to the fans
  74  *
  75  *   controls       : cpu-fan
  76  *   sensors        : cpu-temp cpu-power
  77  *   PID params     : From SMU sdb partition
  78  *   linear-factors : offset = 0xfb50 scale  = 0x1000
  79  *
  80  * CPU Slew control loop. Not implemented. The cpufreq driver in linux is
  81  * completely separate for now, though we could find a way to link it, either
  82  * as a client reacting to overtemp notifications, or directling monitoring
  83  * the CPU temperature
  84  *
  85  * WARNING ! The CPU control loop requires the CPU tmax for the current
  86  * operating point. However, we currently are completely separated from
  87  * the cpufreq driver and thus do not know what the current operating
  88  * point is. Fortunately, we also do not have any hardware supporting anything
  89  * but operating point 0 at the moment, thus we just peek that value directly
  90  * from the SDB partition. If we ever end up with actually slewing the system
  91  * clock and thus changing operating points, we'll have to find a way to
  92  * communicate with the CPU freq driver;
  93  *
  94  */
  95
  96 #include <linux/types.h>
  97 #include <linux/errno.h>
  98 #include <linux/kernel.h>
  99 #include <linux/delay.h>
 100 #include <linux/slab.h>
 101 #include <linux/init.h>
 102 #include <linux/spinlock.h>
 103 #include <linux/wait.h>
 104 #include <linux/kmod.h>
 105 #include <linux/device.h>
 106 #include <linux/platform_device.h>
 107 #include <asm/prom.h>
 108 #include <asm/machdep.h>
 109 #include <asm/io.h>
 110 #include <asm/system.h>
 111 #include <asm/sections.h>
 112 #include <asm/smu.h>
 113
 114 #include "windfarm.h"
 115 #include "windfarm_pid.h"
 116
 117 #define VERSION "0.4"
 118
 119 #undef DEBUG
 120
 121 #ifdef DEBUG
 122 #define DBG(args...)    printk(args)
 123 #else
 124 #define DBG(args...)    do { } while(0)
 125 #endif
 126
 127 /* define this to force CPU overtemp to 74 degree, useful for testing
 128  * the overtemp code
 129  */
 130 #undef HACKED_OVERTEMP
 131
 132 static int wf_smu_mach_model;   /* machine model id */
 133
 134 static struct device *wf_smu_dev;
 135
 136 /* Controls & sensors */
 137 static struct wf_sensor *sensor_cpu_power;
 138 static struct wf_sensor *sensor_cpu_temp;
 139 static struct wf_sensor *sensor_hd_temp;
 140 static struct wf_control *fan_cpu_main;
 141 static struct wf_control *fan_hd;
 142 static struct wf_control *fan_system;
 143 static struct wf_control *cpufreq_clamp;
 144
 145 /* Set to kick the control loop into life */
 146 static int wf_smu_all_controls_ok, wf_smu_all_sensors_ok, wf_smu_started;
 147
 148 /* Failure handling.. could be nicer */
 149 #define FAILURE_FAN             0x01
 150 #define FAILURE_SENSOR          0x02
 151 #define FAILURE_OVERTEMP        0x04
 152
 153 static unsigned int wf_smu_failure_state;
 154 static int wf_smu_readjust, wf_smu_skipping;
 155
 156 /*
 157  * ****** System Fans Control Loop ******
 158  *
 159  */
 160
 161 /* Parameters for the System Fans control loop. Parameters
 162  * not in this table such as interval, history size, ...
 163  * are common to all versions and thus hard coded for now.
 164  */
 165 struct wf_smu_sys_fans_param {
 166         int     model_id;
 167         s32     itarget;
 168         s32     gd, gp, gr;
 169
 170         s16     offset0;
 171         u16     scale0;
 172         s16     offset1;
 173         u16     scale1;
 174 };
 175
 176 #define WF_SMU_SYS_FANS_INTERVAL        5
 177 #define WF_SMU_SYS_FANS_HISTORY_SIZE    2
 178
 179 /* State data used by the system fans control loop
 180  */
 181 struct wf_smu_sys_fans_state {
 182         int                     ticks;
 183         s32                     sys_setpoint;
 184         s32                     hd_setpoint;
 185         s16                     offset0;
 186         u16                     scale0;
 187         s16                     offset1;
 188         u16                     scale1;
 189         struct wf_pid_state     pid;
 190 };
 191
 192 /*
 193  * Configs for SMU Sytem Fan control loop
 194  */
 195 static struct wf_smu_sys_fans_param wf_smu_sys_all_params[] = {
 196         /* Model ID 2 */
 197         {
 198                 .model_id       = 2,
 199                 .itarget        = 0x3a0000,
 200                 .gd             = 0x15400000,
 201                 .gp             = 0x00200000,
 202                 .gr             = 0x000002fd,
 203                 .offset0        = 0xff38,
 204                 .scale0         = 0x0ccd,
 205                 .offset1        = 0x0208,
 206                 .scale1         = 0x07ae,
 207         },
 208         /* Model ID 3 */
 209         {
 210                 .model_id       = 3,
 211                 .itarget        = 0x350000,
 212                 .gd             = 0x08e00000,
 213                 .gp             = 0x00566666,
 214                 .gr             = 0x0000072b,
 215                 .offset0        = 0xff38,
 216                 .scale0         = 0x0ccd,
 217                 .offset1        = 0x0000,
 218                 .scale1         = 0x0000,
 219         },
 220         /* Model ID 5 */
 221         {
 222                 .model_id       = 5,
 223                 .itarget        = 0x3a0000,
 224                 .gd             = 0x15400000,
 225                 .gp             = 0x00233333,
 226                 .gr             = 0x000002fd,
 227                 .offset0        = 0x0000,
 228                 .scale0         = 0x1000,
 229                 .offset1        = 0x0091,
 230                 .scale1         = 0x0bae,
 231         },
 232 };
 233 #define WF_SMU_SYS_FANS_NUM_CONFIGS ARRAY_SIZE(wf_smu_sys_all_params)
 234
 235 static struct wf_smu_sys_fans_state *wf_smu_sys_fans;
 236
 237 /*
 238  * ****** CPU Fans Control Loop ******
 239  *
 240  */
 241
 242
 243 #define WF_SMU_CPU_FANS_INTERVAL        1
 244 #define WF_SMU_CPU_FANS_MAX_HISTORY     16
 245 #define WF_SMU_CPU_FANS_SIBLING_SCALE   0x00001000
 246 #define WF_SMU_CPU_FANS_SIBLING_OFFSET  0xfffffb50
 247
 248 /* State data used by the cpu fans control loop
 249  */
 250 struct wf_smu_cpu_fans_state {
 251         int                     ticks;
 252         s32                     cpu_setpoint;
 253         s32                     scale;
 254         s32                     offset;
 255         struct wf_cpu_pid_state pid;
 256 };
 257
 258 static struct wf_smu_cpu_fans_state *wf_smu_cpu_fans;
 259
 260
 261
 262 /*
 263  * ***** Implementation *****
 264  *
 265  */
 266
 267 static void wf_smu_create_sys_fans(void)
 268 {
 269         struct wf_smu_sys_fans_param *param = NULL;
 270         struct wf_pid_param pid_param;
 271         int i;
 272
 273         /* First, locate the params for this model */
 274         for (i = 0; i < WF_SMU_SYS_FANS_NUM_CONFIGS; i++)
 275                 if (wf_smu_sys_all_params[i].model_id == wf_smu_mach_model) {
 276                         param = &wf_smu_sys_all_params[i];
 277                         break;
 278                 }
 279
 280         /* No params found, put fans to max */
 281         if (param == NULL) {
 282                 printk(KERN_WARNING "windfarm: System fan config not found "
 283                        "for this machine model, max fan speed\n");
 284                 goto fail;
 285         }
 286
 287         /* Alloc & initialize state */
 288         wf_smu_sys_fans = kmalloc(sizeof(struct wf_smu_sys_fans_state),
 289                                   GFP_KERNEL);
 290         if (wf_smu_sys_fans == NULL) {
 291                 printk(KERN_WARNING "windfarm: Memory allocation error"
 292                        " max fan speed\n");
 293                 goto fail;
 294         }
 295         wf_smu_sys_fans->ticks = 1;
 296         wf_smu_sys_fans->scale0 = param->scale0;
 297         wf_smu_sys_fans->offset0 = param->offset0;
 298         wf_smu_sys_fans->scale1 = param->scale1;
 299         wf_smu_sys_fans->offset1 = param->offset1;
 300
 301         /* Fill PID params */
 302         pid_param.gd = param->gd;
 303         pid_param.gp = param->gp;
 304         pid_param.gr = param->gr;
 305         pid_param.interval = WF_SMU_SYS_FANS_INTERVAL;
 306         pid_param.history_len = WF_SMU_SYS_FANS_HISTORY_SIZE;
 307         pid_param.itarget = param->itarget;
 308         pid_param.min = fan_system->ops->get_min(fan_system);
 309         pid_param.max = fan_system->ops->get_max(fan_system);
 310         if (fan_hd) {
 311                 pid_param.min =
 312                         max(pid_param.min,fan_hd->ops->get_min(fan_hd));
 313                 pid_param.max =
 314                         min(pid_param.max,fan_hd->ops->get_max(fan_hd));
 315         }
 316         wf_pid_init(&wf_smu_sys_fans->pid, &pid_param);
 317
 318         DBG("wf: System Fan control initialized.\n");
 319         DBG("    itarged=%d.%03d, min=%d RPM, max=%d RPM\n",
 320             FIX32TOPRINT(pid_param.itarget), pid_param.min, pid_param.max);
 321         return;
 322
 323  fail:
 324
 325         if (fan_system)
 326                 wf_control_set_max(fan_system);
 327         if (fan_hd)
 328                 wf_control_set_max(fan_hd);
 329 }
 330
 331 static void wf_smu_sys_fans_tick(struct wf_smu_sys_fans_state *st)
 332 {
 333         s32 new_setpoint, temp, scaled, cputarget;
 334         int rc;
 335
 336         if (--st->ticks != 0) {
 337                 if (wf_smu_readjust)
 338                         goto readjust;
 339                 return;
 340         }
 341         st->ticks = WF_SMU_SYS_FANS_INTERVAL;
 342
 343         rc = sensor_hd_temp->ops->get_value(sensor_hd_temp, &temp);
 344         if (rc) {
 345                 printk(KERN_WARNING "windfarm: HD temp sensor error %d\n",
 346                        rc);
 347                 wf_smu_failure_state |= FAILURE_SENSOR;
 348                 return;
 349         }
 350
 351         DBG("wf_smu: System Fans tick ! HD temp: %d.%03d\n",
 352             FIX32TOPRINT(temp));
 353
 354         if (temp > (st->pid.param.itarget + 0x50000))
 355                 wf_smu_failure_state |= FAILURE_OVERTEMP;
 356
 357         new_setpoint = wf_pid_run(&st->pid, temp);
 358
 359         DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
 360
 361         scaled = ((((s64)new_setpoint) * (s64)st->scale0) >> 12) + st->offset0;
 362
 363         DBG("wf_smu: scaled setpoint: %d RPM\n", (int)scaled);
 364
 365         cputarget = wf_smu_cpu_fans ? wf_smu_cpu_fans->pid.target : 0;
 366         cputarget = ((((s64)cputarget) * (s64)st->scale1) >> 12) + st->offset1;
 367         scaled = max(scaled, cputarget);
 368         scaled = max(scaled, st->pid.param.min);
 369         scaled = min(scaled, st->pid.param.max);
 370
 371         DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)scaled);
 372
 373         if (st->sys_setpoint == scaled && new_setpoint == st->hd_setpoint)
 374                 return;
 375         st->sys_setpoint = scaled;
 376         st->hd_setpoint = new_setpoint;
 377  readjust:
 378         if (fan_system && wf_smu_failure_state == 0) {
 379                 rc = fan_system->ops->set_value(fan_system, st->sys_setpoint);
 380                 if (rc) {
 381                         printk(KERN_WARNING "windfarm: Sys fan error %d\n",
 382                                rc);
 383                         wf_smu_failure_state |= FAILURE_FAN;
 384                 }
 385         }
 386         if (fan_hd && wf_smu_failure_state == 0) {
 387                 rc = fan_hd->ops->set_value(fan_hd, st->hd_setpoint);
 388                 if (rc) {
 389                         printk(KERN_WARNING "windfarm: HD fan error %d\n",
 390                                rc);
 391                         wf_smu_failure_state |= FAILURE_FAN;
 392                 }
 393         }
 394 }
 395
 396 static void wf_smu_create_cpu_fans(void)
 397 {
 398         struct wf_cpu_pid_param pid_param;
 399         struct smu_sdbp_header *hdr;
 400         struct smu_sdbp_cpupiddata *piddata;
 401         struct smu_sdbp_fvt *fvt;
 402         s32 tmax, tdelta, maxpow, powadj;
 403
 404         /* First, locate the PID params in SMU SBD */
 405         hdr = smu_get_sdb_partition(SMU_SDB_CPUPIDDATA_ID, NULL);
 406         if (hdr == 0) {
 407                 printk(KERN_WARNING "windfarm: CPU PID fan config not found "
 408                        "max fan speed\n");
 409                 goto fail;
 410         }
 411         piddata = (struct smu_sdbp_cpupiddata *)&hdr[1];
 412
 413         /* Get the FVT params for operating point 0 (the only supported one
 414          * for now) in order to get tmax
 415          */
 416         hdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
 417         if (hdr) {
 418                 fvt = (struct smu_sdbp_fvt *)&hdr[1];
 419                 tmax = ((s32)fvt->maxtemp) << 16;
 420         } else
 421                 tmax = 0x5e0000; /* 94 degree default */
 422
 423         /* Alloc & initialize state */
 424         wf_smu_cpu_fans = kmalloc(sizeof(struct wf_smu_cpu_fans_state),
 425                                   GFP_KERNEL);
 426         if (wf_smu_cpu_fans == NULL)
 427                 goto fail;
 428         wf_smu_cpu_fans->ticks = 1;
 429
 430         wf_smu_cpu_fans->scale = WF_SMU_CPU_FANS_SIBLING_SCALE;
 431         wf_smu_cpu_fans->offset = WF_SMU_CPU_FANS_SIBLING_OFFSET;
 432
 433         /* Fill PID params */
 434         pid_param.interval = WF_SMU_CPU_FANS_INTERVAL;
 435         pid_param.history_len = piddata->history_len;
 436         if (pid_param.history_len > WF_CPU_PID_MAX_HISTORY) {
 437                 printk(KERN_WARNING "windfarm: History size overflow on "
 438                        "CPU control loop (%d)\n", piddata->history_len);
 439                 pid_param.history_len = WF_CPU_PID_MAX_HISTORY;
 440         }
 441         pid_param.gd = piddata->gd;
 442         pid_param.gp = piddata->gp;
 443         pid_param.gr = piddata->gr / pid_param.history_len;
 444
 445         tdelta = ((s32)piddata->target_temp_delta) << 16;
 446         maxpow = ((s32)piddata->max_power) << 16;
 447         powadj = ((s32)piddata->power_adj) << 16;
 448
 449         pid_param.tmax = tmax;
 450         pid_param.ttarget = tmax - tdelta;
 451         pid_param.pmaxadj = maxpow - powadj;
 452
 453         pid_param.min = fan_cpu_main->ops->get_min(fan_cpu_main);
 454         pid_param.max = fan_cpu_main->ops->get_max(fan_cpu_main);
 455
 456         wf_cpu_pid_init(&wf_smu_cpu_fans->pid, &pid_param);
 457
 458         DBG("wf: CPU Fan control initialized.\n");
 459         DBG("    ttarged=%d.%03d, tmax=%d.%03d, min=%d RPM, max=%d RPM\n",
 460             FIX32TOPRINT(pid_param.ttarget), FIX32TOPRINT(pid_param.tmax),
 461             pid_param.min, pid_param.max);
 462
 463         return;
 464
 465  fail:
 466         printk(KERN_WARNING "windfarm: CPU fan config not found\n"
 467                "for this machine model, max fan speed\n");
 468
 469         if (cpufreq_clamp)
 470                 wf_control_set_max(cpufreq_clamp);
 471         if (fan_cpu_main)
 472                 wf_control_set_max(fan_cpu_main);
 473 }
 474
 475 static void wf_smu_cpu_fans_tick(struct wf_smu_cpu_fans_state *st)
 476 {
 477         s32 new_setpoint, temp, power, systarget;
 478         int rc;
 479
 480         if (--st->ticks != 0) {
 481                 if (wf_smu_readjust)
 482                         goto readjust;
 483                 return;
 484         }
 485         st->ticks = WF_SMU_CPU_FANS_INTERVAL;
 486
 487         rc = sensor_cpu_temp->ops->get_value(sensor_cpu_temp, &temp);
 488         if (rc) {
 489                 printk(KERN_WARNING "windfarm: CPU temp sensor error %d\n",
 490                        rc);
 491                 wf_smu_failure_state |= FAILURE_SENSOR;
 492                 return;
 493         }
 494
 495         rc = sensor_cpu_power->ops->get_value(sensor_cpu_power, &power);
 496         if (rc) {
 497                 printk(KERN_WARNING "windfarm: CPU power sensor error %d\n",
 498                        rc);
 499                 wf_smu_failure_state |= FAILURE_SENSOR;
 500                 return;
 501         }
 502
 503         DBG("wf_smu: CPU Fans tick ! CPU temp: %d.%03d, power: %d.%03d\n",
 504             FIX32TOPRINT(temp), FIX32TOPRINT(power));
 505
 506 #ifdef HACKED_OVERTEMP
 507         if (temp > 0x4a0000)
 508                 wf_smu_failure_state |= FAILURE_OVERTEMP;
 509 #else
 510         if (temp > st->pid.param.tmax)
 511                 wf_smu_failure_state |= FAILURE_OVERTEMP;
 512 #endif
 513         new_setpoint = wf_cpu_pid_run(&st->pid, power, temp);
 514
 515         DBG("wf_smu: new_setpoint: %d RPM\n", (int)new_setpoint);
 516
 517         systarget = wf_smu_sys_fans ? wf_smu_sys_fans->pid.target : 0;
 518         systarget = ((((s64)systarget) * (s64)st->scale) >> 12)
 519                 + st->offset;
 520         new_setpoint = max(new_setpoint, systarget);
 521         new_setpoint = max(new_setpoint, st->pid.param.min);
 522         new_setpoint = min(new_setpoint, st->pid.param.max);
 523
 524         DBG("wf_smu: adjusted setpoint: %d RPM\n", (int)new_setpoint);
 525
 526         if (st->cpu_setpoint == new_setpoint)
 527                 return;
 528         st->cpu_setpoint = new_setpoint;
 529  readjust:
 530         if (fan_cpu_main && wf_smu_failure_state == 0) {
 531                 rc = fan_cpu_main->ops->set_value(fan_cpu_main,
 532                                                   st->cpu_setpoint);
 533                 if (rc) {
 534                         printk(KERN_WARNING "windfarm: CPU main fan"
 535                                " error %d\n", rc);
 536                         wf_smu_failure_state |= FAILURE_FAN;
 537                 }
 538         }
 539 }
 540
 541 /*
 542  * ****** Setup / Init / Misc ... ******
 543  *
 544  */
 545
 546 static void wf_smu_tick(void)
 547 {
 548         unsigned int last_failure = wf_smu_failure_state;
 549         unsigned int new_failure;
 550
 551         if (!wf_smu_started) {
 552                 DBG("wf: creating control loops !\n");
 553                 wf_smu_create_sys_fans();
 554                 wf_smu_create_cpu_fans();
 555                 wf_smu_started = 1;
 556         }
 557
 558         /* Skipping ticks */
 559         if (wf_smu_skipping && --wf_smu_skipping)
 560                 return;
 561
 562         wf_smu_failure_state = 0;
 563         if (wf_smu_sys_fans)
 564                 wf_smu_sys_fans_tick(wf_smu_sys_fans);
 565         if (wf_smu_cpu_fans)
 566                 wf_smu_cpu_fans_tick(wf_smu_cpu_fans);
 567
 568         wf_smu_readjust = 0;
 569         new_failure = wf_smu_failure_state & ~last_failure;
 570
 571         /* If entering failure mode, clamp cpufreq and ramp all
 572          * fans to full speed.
 573          */
 574         if (wf_smu_failure_state && !last_failure) {
 575                 if (cpufreq_clamp)
 576                         wf_control_set_max(cpufreq_clamp);
 577                 if (fan_system)
 578                         wf_control_set_max(fan_system);
 579                 if (fan_cpu_main)
 580                         wf_control_set_max(fan_cpu_main);
 581                 if (fan_hd)
 582                         wf_control_set_max(fan_hd);
 583         }
 584
 585         /* If leaving failure mode, unclamp cpufreq and readjust
 586          * all fans on next iteration
 587          */
 588         if (!wf_smu_failure_state && last_failure) {
 589                 if (cpufreq_clamp)
 590                         wf_control_set_min(cpufreq_clamp);
 591                 wf_smu_readjust = 1;
 592         }
 593
 594         /* Overtemp condition detected, notify and start skipping a couple
 595          * ticks to let the temperature go down
 596          */
 597         if (new_failure & FAILURE_OVERTEMP) {
 598                 wf_set_overtemp();
 599                 wf_smu_skipping = 2;
 600         }
 601
 602         /* We only clear the overtemp condition if overtemp is cleared
 603          * _and_ no other failure is present. Since a sensor error will
 604          * clear the overtemp condition (can't measure temperature) at
 605          * the control loop levels, but we don't want to keep it clear
 606          * here in this case
 607          */
 608         if (new_failure == 0 && last_failure & FAILURE_OVERTEMP)
 609                 wf_clear_overtemp();
 610 }
 611
 612 static void wf_smu_new_control(struct wf_control *ct)
 613 {
 614         if (wf_smu_all_controls_ok)
 615                 return;
 616
 617         if (fan_cpu_main == NULL && !strcmp(ct->name, "cpu-fan")) {
 618                 if (wf_get_control(ct) == 0)
 619                         fan_cpu_main = ct;
 620         }
 621
 622         if (fan_system == NULL && !strcmp(ct->name, "system-fan")) {
 623                 if (wf_get_control(ct) == 0)
 624                         fan_system = ct;
 625         }
 626
 627         if (cpufreq_clamp == NULL && !strcmp(ct->name, "cpufreq-clamp")) {
 628                 if (wf_get_control(ct) == 0)
 629                         cpufreq_clamp = ct;
 630         }
 631
 632         /* Darwin property list says the HD fan is only for model ID
 633          * 0, 1, 2 and 3
 634          */
 635
 636         if (wf_smu_mach_model > 3) {
 637                 if (fan_system && fan_cpu_main && cpufreq_clamp)
 638                         wf_smu_all_controls_ok = 1;
 639                 return;
 640         }
 641
 642         if (fan_hd == NULL && !strcmp(ct->name, "drive-bay-fan")) {
 643                 if (wf_get_control(ct) == 0)
 644                         fan_hd = ct;
 645         }
 646
 647         if (fan_system && fan_hd && fan_cpu_main && cpufreq_clamp)
 648                 wf_smu_all_controls_ok = 1;
 649 }
 650
 651 static void wf_smu_new_sensor(struct wf_sensor *sr)
 652 {
 653         if (wf_smu_all_sensors_ok)
 654                 return;
 655
 656         if (sensor_cpu_power == NULL && !strcmp(sr->name, "cpu-power")) {
 657                 if (wf_get_sensor(sr) == 0)
 658                         sensor_cpu_power = sr;
 659         }
 660
 661         if (sensor_cpu_temp == NULL && !strcmp(sr->name, "cpu-temp")) {
 662                 if (wf_get_sensor(sr) == 0)
 663                         sensor_cpu_temp = sr;
 664         }
 665
 666         if (sensor_hd_temp == NULL && !strcmp(sr->name, "hd-temp")) {
 667                 if (wf_get_sensor(sr) == 0)
 668                         sensor_hd_temp = sr;
 669         }
 670
 671         if (sensor_cpu_power && sensor_cpu_temp && sensor_hd_temp)
 672                 wf_smu_all_sensors_ok = 1;
 673 }
 674
 675
 676 static int wf_smu_notify(struct notifier_block *self,
 677                                unsigned long event, void *data)
 678 {
 679         switch(event) {
 680         case WF_EVENT_NEW_CONTROL:
 681                 DBG("wf: new control %s detected\n",
 682                     ((struct wf_control *)data)->name);
 683                 wf_smu_new_control(data);
 684                 wf_smu_readjust = 1;
 685                 break;
 686         case WF_EVENT_NEW_SENSOR:
 687                 DBG("wf: new sensor %s detected\n",
 688                     ((struct wf_sensor *)data)->name);
 689                 wf_smu_new_sensor(data);
 690                 break;
 691         case WF_EVENT_TICK:
 692                 if (wf_smu_all_controls_ok && wf_smu_all_sensors_ok)
 693                         wf_smu_tick();
 694         }
 695
 696         return 0;
 697 }
 698
 699 static struct notifier_block wf_smu_events = {
 700         .notifier_call  = wf_smu_notify,
 701 };
 702
 703 static int wf_init_pm(void)
 704 {
 705         struct smu_sdbp_header *hdr;
 706
 707         hdr = smu_get_sdb_partition(SMU_SDB_SENSORTREE_ID, NULL);
 708         if (hdr != 0) {
 709                 struct smu_sdbp_sensortree *st =
 710                         (struct smu_sdbp_sensortree *)&hdr[1];
 711                 wf_smu_mach_model = st->model_id;
 712         }
 713
 714         printk(KERN_INFO "windfarm: Initializing for iMacG5 model ID %d\n",
 715                wf_smu_mach_model);
 716
 717         return 0;
 718 }
 719
 720 static int wf_smu_probe(struct device *ddev)
 721 {
 722         wf_smu_dev = ddev;
 723
 724         wf_register_client(&wf_smu_events);
 725
 726         return 0;
 727 }
 728
 729 static int wf_smu_remove(struct device *ddev)
 730 {
 731         wf_unregister_client(&wf_smu_events);
 732
 733         /* XXX We don't have yet a guarantee that our callback isn't
 734          * in progress when returning from wf_unregister_client, so
 735          * we add an arbitrary delay. I'll have to fix that in the core
 736          */
 737         msleep(1000);
 738
 739         /* Release all sensors */
 740         /* One more crappy race: I don't think we have any guarantee here
 741          * that the attribute callback won't race with the sensor beeing
 742          * disposed of, and I'm not 100% certain what best way to deal
 743          * with that except by adding locks all over... I'll do that
 744          * eventually but heh, who ever rmmod this module anyway ?
 745          */
 746         if (sensor_cpu_power)
 747                 wf_put_sensor(sensor_cpu_power);
 748         if (sensor_cpu_temp)
 749                 wf_put_sensor(sensor_cpu_temp);
 750         if (sensor_hd_temp)
 751                 wf_put_sensor(sensor_hd_temp);
 752
 753         /* Release all controls */
 754         if (fan_cpu_main)
 755                 wf_put_control(fan_cpu_main);
 756         if (fan_hd)
 757                 wf_put_control(fan_hd);
 758         if (fan_system)
 759                 wf_put_control(fan_system);
 760         if (cpufreq_clamp)
 761                 wf_put_control(cpufreq_clamp);
 762
 763         /* Destroy control loops state structures */
 764         if (wf_smu_sys_fans)
 765                 kfree(wf_smu_sys_fans);
 766         if (wf_smu_cpu_fans)
 767                 kfree(wf_smu_cpu_fans);
 768
 769         wf_smu_dev = NULL;
 770
 771         return 0;
 772 }
 773
 774 static struct device_driver wf_smu_driver = {
 775         .name = "windfarm",
 776         .bus = &platform_bus_type,
 777         .probe = wf_smu_probe,
 778         .remove = wf_smu_remove,
 779 };
 780
 781
 782 static int __init wf_smu_init(void)
 783 {
 784         int rc = -ENODEV;
 785
 786         if (machine_is_compatible("PowerMac8,1") ||
 787             machine_is_compatible("PowerMac8,2"))
 788                 rc = wf_init_pm();
 789
 790         if (rc == 0) {
 791 #ifdef MODULE
 792                 request_module("windfarm_smu_controls");
 793                 request_module("windfarm_smu_sensors");
 794                 request_module("windfarm_lm75_sensor");
 795
 796 #endif /* MODULE */
 797                 driver_register(&wf_smu_driver);
 798         }
 799
 800         return rc;
 801 }
 802
 803 static void __exit wf_smu_exit(void)
 804 {
 805
 806         driver_unregister(&wf_smu_driver);
 807 }
 808
 809
 810 module_init(wf_smu_init);
 811 module_exit(wf_smu_exit);
 812
 813 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 814 MODULE_DESCRIPTION("Thermal control logic for iMac G5");
 815 MODULE_LICENSE("GPL");
 816