drivers/macintosh/windfarm_fcu_controls.c

   1 /*
   2  * Windfarm PowerMac thermal control. FCU fan control
   3  *
   4  * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
   5  *
   6  * Released under the term of the GNU GPL v2.
   7  */
   8 #undef DEBUG
   9
  10 #include <linux/types.h>
  11 #include <linux/errno.h>
  12 #include <linux/kernel.h>
  13 #include <linux/delay.h>
  14 #include <linux/slab.h>
  15 #include <linux/init.h>
  16 #include <linux/wait.h>
  17 #include <linux/i2c.h>
  18 #include <asm/prom.h>
  19 #include <asm/machdep.h>
  20 #include <asm/io.h>
  21 #include <asm/sections.h>
  22
  23 #include "windfarm.h"
  24 #include "windfarm_mpu.h"
  25
  26 #define VERSION "1.0"
  27
  28 #ifdef DEBUG
  29 #define DBG(args...)    printk(args)
  30 #else
  31 #define DBG(args...)    do { } while(0)
  32 #endif
  33
  34 /*
  35  * This option is "weird" :) Basically, if you define this to 1
  36  * the control loop for the RPMs fans (not PWMs) will apply the
  37  * correction factor obtained from the PID to the actual RPM
  38  * speed read from the FCU.
  39  *
  40  * If you define the below constant to 0, then it will be
  41  * applied to the setpoint RPM speed, that is basically the
  42  * speed we proviously "asked" for.
  43  *
  44  * I'm using 0 for now which is what therm_pm72 used to do and
  45  * what Darwin -apparently- does based on observed behaviour.
  46  */
  47 #define RPM_PID_USE_ACTUAL_SPEED        0
  48
  49 /* Default min/max for pumps */
  50 #define CPU_PUMP_OUTPUT_MAX             3200
  51 #define CPU_PUMP_OUTPUT_MIN             1250
  52
  53 #define FCU_FAN_RPM             0
  54 #define FCU_FAN_PWM             1
  55
  56 struct wf_fcu_priv {
  57         struct kref             ref;
  58         struct i2c_client       *i2c;
  59         struct mutex            lock;
  60         struct list_head        fan_list;
  61         int                     rpm_shift;
  62 };
  63
  64 struct wf_fcu_fan {
  65         struct list_head        link;
  66         int                     id;
  67         s32                     min, max, target;
  68         struct wf_fcu_priv      *fcu_priv;
  69         struct wf_control       ctrl;
  70 };
  71
  72 static void wf_fcu_release(struct kref *ref)
  73 {
  74         struct wf_fcu_priv *pv = container_of(ref, struct wf_fcu_priv, ref);
  75
  76         kfree(pv);
  77 }
  78
  79 static void wf_fcu_fan_release(struct wf_control *ct)
  80 {
  81         struct wf_fcu_fan *fan = ct->priv;
  82
  83         kref_put(&fan->fcu_priv->ref, wf_fcu_release);
  84         kfree(fan);
  85 }
  86
  87 static int wf_fcu_read_reg(struct wf_fcu_priv *pv, int reg,
  88                            unsigned char *buf, int nb)
  89 {
  90         int tries, nr, nw;
  91
  92         mutex_lock(&pv->lock);
  93
  94         buf[0] = reg;
  95         tries = 0;
  96         for (;;) {
  97                 nw = i2c_master_send(pv->i2c, buf, 1);
  98                 if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
  99                         break;
 100                 msleep(10);
 101                 ++tries;
 102         }
 103         if (nw <= 0) {
 104                 pr_err("Failure writing address to FCU: %d", nw);
 105                 nr = nw;
 106                 goto bail;
 107         }
 108         tries = 0;
 109         for (;;) {
 110                 nr = i2c_master_recv(pv->i2c, buf, nb);
 111                 if (nr > 0 || (nr < 0 && nr != -ENODEV) || tries >= 100)
 112                         break;
 113                 msleep(10);
 114                 ++tries;
 115         }
 116         if (nr <= 0)
 117                 pr_err("wf_fcu: Failure reading data from FCU: %d", nw);
 118  bail:
 119         mutex_unlock(&pv->lock);
 120         return nr;
 121 }
 122
 123 static int wf_fcu_write_reg(struct wf_fcu_priv *pv, int reg,
 124                             const unsigned char *ptr, int nb)
 125 {
 126         int tries, nw;
 127         unsigned char buf[16];
 128
 129         buf[0] = reg;
 130         memcpy(buf+1, ptr, nb);
 131         ++nb;
 132         tries = 0;
 133         for (;;) {
 134                 nw = i2c_master_send(pv->i2c, buf, nb);
 135                 if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
 136                         break;
 137                 msleep(10);
 138                 ++tries;
 139         }
 140         if (nw < 0)
 141                 pr_err("wf_fcu: Failure writing to FCU: %d", nw);
 142         return nw;
 143 }
 144
 145 static int wf_fcu_fan_set_rpm(struct wf_control *ct, s32 value)
 146 {
 147         struct wf_fcu_fan *fan = ct->priv;
 148         struct wf_fcu_priv *pv = fan->fcu_priv;
 149         int rc, shift = pv->rpm_shift;
 150         unsigned char buf[2];
 151
 152         if (value < fan->min)
 153                 value = fan->min;
 154         if (value > fan->max)
 155                 value = fan->max;
 156
 157         fan->target = value;
 158
 159         buf[0] = value >> (8 - shift);
 160         buf[1] = value << shift;
 161         rc = wf_fcu_write_reg(pv, 0x10 + (fan->id * 2), buf, 2);
 162         if (rc < 0)
 163                 return -EIO;
 164         return 0;
 165 }
 166
 167 static int wf_fcu_fan_get_rpm(struct wf_control *ct, s32 *value)
 168 {
 169         struct wf_fcu_fan *fan = ct->priv;
 170         struct wf_fcu_priv *pv = fan->fcu_priv;
 171         int rc, reg_base, shift = pv->rpm_shift;
 172         unsigned char failure;
 173         unsigned char active;
 174         unsigned char buf[2];
 175
 176         rc = wf_fcu_read_reg(pv, 0xb, &failure, 1);
 177         if (rc != 1)
 178                 return -EIO;
 179         if ((failure & (1 << fan->id)) != 0)
 180                 return -EFAULT;
 181         rc = wf_fcu_read_reg(pv, 0xd, &active, 1);
 182         if (rc != 1)
 183                 return -EIO;
 184         if ((active & (1 << fan->id)) == 0)
 185                 return -ENXIO;
 186
 187         /* Programmed value or real current speed */
 188 #if RPM_PID_USE_ACTUAL_SPEED
 189         reg_base = 0x11;
 190 #else
 191         reg_base = 0x10;
 192 #endif
 193         rc = wf_fcu_read_reg(pv, reg_base + (fan->id * 2), buf, 2);
 194         if (rc != 2)
 195                 return -EIO;
 196
 197         *value = (buf[0] << (8 - shift)) | buf[1] >> shift;
 198
 199         return 0;
 200 }
 201
 202 static int wf_fcu_fan_set_pwm(struct wf_control *ct, s32 value)
 203 {
 204         struct wf_fcu_fan *fan = ct->priv;
 205         struct wf_fcu_priv *pv = fan->fcu_priv;
 206         unsigned char buf[2];
 207         int rc;
 208
 209         if (value < fan->min)
 210                 value = fan->min;
 211         if (value > fan->max)
 212                 value = fan->max;
 213
 214         fan->target = value;
 215
 216         value = (value * 2559) / 1000;
 217         buf[0] = value;
 218         rc = wf_fcu_write_reg(pv, 0x30 + (fan->id * 2), buf, 1);
 219         if (rc < 0)
 220                 return -EIO;
 221         return 0;
 222 }
 223
 224 static int wf_fcu_fan_get_pwm(struct wf_control *ct, s32 *value)
 225 {
 226         struct wf_fcu_fan *fan = ct->priv;
 227         struct wf_fcu_priv *pv = fan->fcu_priv;
 228         unsigned char failure;
 229         unsigned char active;
 230         unsigned char buf[2];
 231         int rc;
 232
 233         rc = wf_fcu_read_reg(pv, 0x2b, &failure, 1);
 234         if (rc != 1)
 235                 return -EIO;
 236         if ((failure & (1 << fan->id)) != 0)
 237                 return -EFAULT;
 238         rc = wf_fcu_read_reg(pv, 0x2d, &active, 1);
 239         if (rc != 1)
 240                 return -EIO;
 241         if ((active & (1 << fan->id)) == 0)
 242                 return -ENXIO;
 243
 244         rc = wf_fcu_read_reg(pv, 0x30 + (fan->id * 2), buf, 1);
 245         if (rc != 1)
 246                 return -EIO;
 247
 248         *value = (((s32)buf[0]) * 1000) / 2559;
 249
 250         return 0;
 251 }
 252
 253 static s32 wf_fcu_fan_min(struct wf_control *ct)
 254 {
 255         struct wf_fcu_fan *fan = ct->priv;
 256
 257         return fan->min;
 258 }
 259
 260 static s32 wf_fcu_fan_max(struct wf_control *ct)
 261 {
 262         struct wf_fcu_fan *fan = ct->priv;
 263
 264         return fan->max;
 265 }
 266
 267 static const struct wf_control_ops wf_fcu_fan_rpm_ops = {
 268         .set_value      = wf_fcu_fan_set_rpm,
 269         .get_value      = wf_fcu_fan_get_rpm,
 270         .get_min        = wf_fcu_fan_min,
 271         .get_max        = wf_fcu_fan_max,
 272         .release        = wf_fcu_fan_release,
 273         .owner          = THIS_MODULE,
 274 };
 275
 276 static const struct wf_control_ops wf_fcu_fan_pwm_ops = {
 277         .set_value      = wf_fcu_fan_set_pwm,
 278         .get_value      = wf_fcu_fan_get_pwm,
 279         .get_min        = wf_fcu_fan_min,
 280         .get_max        = wf_fcu_fan_max,
 281         .release        = wf_fcu_fan_release,
 282         .owner          = THIS_MODULE,
 283 };
 284
 285 static void wf_fcu_get_pump_minmax(struct wf_fcu_fan *fan)
 286 {
 287         const struct mpu_data *mpu = wf_get_mpu(0);
 288         u16 pump_min = 0, pump_max = 0xffff;
 289         u16 tmp[4];
 290
 291         /* Try to fetch pumps min/max infos from eeprom */
 292         if (mpu) {
 293                 memcpy(&tmp, mpu->processor_part_num, 8);
 294                 if (tmp[0] != 0xffff && tmp[1] != 0xffff) {
 295                         pump_min = max(pump_min, tmp[0]);
 296                         pump_max = min(pump_max, tmp[1]);
 297                 }
 298                 if (tmp[2] != 0xffff && tmp[3] != 0xffff) {
 299                         pump_min = max(pump_min, tmp[2]);
 300                         pump_max = min(pump_max, tmp[3]);
 301                 }
 302         }
 303
 304         /* Double check the values, this _IS_ needed as the EEPROM on
 305          * some dual 2.5Ghz G5s seem, at least, to have both min & max
 306          * same to the same value ... (grrrr)
 307          */
 308         if (pump_min == pump_max || pump_min == 0 || pump_max == 0xffff) {
 309                 pump_min = CPU_PUMP_OUTPUT_MIN;
 310                 pump_max = CPU_PUMP_OUTPUT_MAX;
 311         }
 312
 313         fan->min = pump_min;
 314         fan->max = pump_max;
 315
 316         DBG("wf_fcu: pump min/max for %s set to: [%d..%d] RPM\n",
 317             fan->ctrl.name, pump_min, pump_max);
 318 }
 319
 320 static void wf_fcu_get_rpmfan_minmax(struct wf_fcu_fan *fan)
 321 {
 322         struct wf_fcu_priv *pv = fan->fcu_priv;
 323         const struct mpu_data *mpu0 = wf_get_mpu(0);
 324         const struct mpu_data *mpu1 = wf_get_mpu(1);
 325
 326         /* Default */
 327         fan->min = 2400 >> pv->rpm_shift;
 328         fan->max = 56000 >> pv->rpm_shift;
 329
 330         /* CPU fans have min/max in MPU */
 331         if (mpu0 && !strcmp(fan->ctrl.name, "cpu-front-fan-0")) {
 332                 fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);
 333                 fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);
 334                 goto bail;
 335         }
 336         if (mpu1 && !strcmp(fan->ctrl.name, "cpu-front-fan-1")) {
 337                 fan->min = max(fan->min, (s32)mpu1->rminn_intake_fan);
 338                 fan->max = min(fan->max, (s32)mpu1->rmaxn_intake_fan);
 339                 goto bail;
 340         }
 341         if (mpu0 && !strcmp(fan->ctrl.name, "cpu-rear-fan-0")) {
 342                 fan->min = max(fan->min, (s32)mpu0->rminn_exhaust_fan);
 343                 fan->max = min(fan->max, (s32)mpu0->rmaxn_exhaust_fan);
 344                 goto bail;
 345         }
 346         if (mpu1 && !strcmp(fan->ctrl.name, "cpu-rear-fan-1")) {
 347                 fan->min = max(fan->min, (s32)mpu1->rminn_exhaust_fan);
 348                 fan->max = min(fan->max, (s32)mpu1->rmaxn_exhaust_fan);
 349                 goto bail;
 350         }
 351         /* Rackmac variants, we just use mpu0 intake */
 352         if (!strncmp(fan->ctrl.name, "cpu-fan", 7)) {
 353                 fan->min = max(fan->min, (s32)mpu0->rminn_intake_fan);
 354                 fan->max = min(fan->max, (s32)mpu0->rmaxn_intake_fan);
 355                 goto bail;
 356         }
 357  bail:
 358         DBG("wf_fcu: fan min/max for %s set to: [%d..%d] RPM\n",
 359             fan->ctrl.name, fan->min, fan->max);
 360 }
 361
 362 static void wf_fcu_add_fan(struct wf_fcu_priv *pv, const char *name,
 363                            int type, int id)
 364 {
 365         struct wf_fcu_fan *fan;
 366
 367         fan = kzalloc(sizeof(*fan), GFP_KERNEL);
 368         if (!fan)
 369                 return;
 370         fan->fcu_priv = pv;
 371         fan->id = id;
 372         fan->ctrl.name = name;
 373         fan->ctrl.priv = fan;
 374
 375         /* min/max is oddball but the code comes from
 376          * therm_pm72 which seems to work so ...
 377          */
 378         if (type == FCU_FAN_RPM) {
 379                 if (!strncmp(name, "cpu-pump", strlen("cpu-pump")))
 380                         wf_fcu_get_pump_minmax(fan);
 381                 else
 382                         wf_fcu_get_rpmfan_minmax(fan);
 383                 fan->ctrl.type = WF_CONTROL_RPM_FAN;
 384                 fan->ctrl.ops = &wf_fcu_fan_rpm_ops;
 385         } else {
 386                 fan->min = 10;
 387                 fan->max = 100;
 388                 fan->ctrl.type = WF_CONTROL_PWM_FAN;
 389                 fan->ctrl.ops = &wf_fcu_fan_pwm_ops;
 390         }
 391
 392         if (wf_register_control(&fan->ctrl)) {
 393                 pr_err("wf_fcu: Failed to register fan %s\n", name);
 394                 kfree(fan);
 395                 return;
 396         }
 397         list_add(&fan->link, &pv->fan_list);
 398         kref_get(&pv->ref);
 399 }
 400
 401 static void wf_fcu_lookup_fans(struct wf_fcu_priv *pv)
 402 {
 403         /* Translation of device-tree location properties to
 404          * windfarm fan names
 405          */
 406         static const struct {
 407                 const char *dt_name;    /* Device-tree name */
 408                 const char *ct_name;    /* Control name */
 409         } loc_trans[] = {
 410                 { "BACKSIDE",           "backside-fan",         },
 411                 { "SYS CTRLR FAN",      "backside-fan",         },
 412                 { "DRIVE BAY",          "drive-bay-fan",        },
 413                 { "SLOT",               "slots-fan",            },
 414                 { "PCI FAN",            "slots-fan",            },
 415                 { "CPU A INTAKE",       "cpu-front-fan-0",      },
 416                 { "CPU A EXHAUST",      "cpu-rear-fan-0",       },
 417                 { "CPU B INTAKE",       "cpu-front-fan-1",      },
 418                 { "CPU B EXHAUST",      "cpu-rear-fan-1",       },
 419                 { "CPU A PUMP",         "cpu-pump-0",           },
 420                 { "CPU B PUMP",         "cpu-pump-1",           },
 421                 { "CPU A 1",            "cpu-fan-a-0",          },
 422                 { "CPU A 2",            "cpu-fan-b-0",          },
 423                 { "CPU A 3",            "cpu-fan-c-0",          },
 424                 { "CPU B 1",            "cpu-fan-a-1",          },
 425                 { "CPU B 2",            "cpu-fan-b-1",          },
 426                 { "CPU B 3",            "cpu-fan-c-1",          },
 427         };
 428         struct device_node *np = NULL, *fcu = pv->i2c->dev.of_node;
 429         int i;
 430
 431         DBG("Looking up FCU controls in device-tree...\n");
 432
 433         while ((np = of_get_next_child(fcu, np)) != NULL) {
 434                 int id, type = -1;
 435                 const char *loc;
 436                 const char *name;
 437                 const u32 *reg;
 438
 439                 DBG(" control: %s, type: %s\n", np->name, np->type);
 440
 441                 /* Detect control type */
 442                 if (!strcmp(np->type, "fan-rpm-control") ||
 443                     !strcmp(np->type, "fan-rpm"))
 444                         type = FCU_FAN_RPM;
 445                 if (!strcmp(np->type, "fan-pwm-control") ||
 446                     !strcmp(np->type, "fan-pwm"))
 447                         type = FCU_FAN_PWM;
 448                 /* Only care about fans for now */
 449                 if (type == -1)
 450                         continue;
 451
 452                 /* Lookup for a matching location */
 453                 loc = of_get_property(np, "location", NULL);
 454                 reg = of_get_property(np, "reg", NULL);
 455                 if (loc == NULL || reg == NULL)
 456                         continue;
 457                 DBG(" matching location: %s, reg: 0x%08x\n", loc, *reg);
 458
 459                 for (i = 0; i < ARRAY_SIZE(loc_trans); i++) {
 460                         if (strncmp(loc, loc_trans[i].dt_name,
 461                                     strlen(loc_trans[i].dt_name)))
 462                                 continue;
 463                         name = loc_trans[i].ct_name;
 464
 465                         DBG(" location match, name: %s\n", name);
 466
 467                         if (type == FCU_FAN_RPM)
 468                                 id = ((*reg) - 0x10) / 2;
 469                         else
 470                                 id = ((*reg) - 0x30) / 2;
 471                         if (id > 7) {
 472                                 pr_warning("wf_fcu: Can't parse "
 473                                        "fan ID in device-tree for %pOF\n",
 474                                            np);
 475                                 break;
 476                         }
 477                         wf_fcu_add_fan(pv, name, type, id);
 478                         break;
 479                 }
 480         }
 481 }
 482
 483 static void wf_fcu_default_fans(struct wf_fcu_priv *pv)
 484 {
 485         /* We only support the default fans for PowerMac7,2 */
 486         if (!of_machine_is_compatible("PowerMac7,2"))
 487                 return;
 488
 489         wf_fcu_add_fan(pv, "backside-fan",      FCU_FAN_PWM, 1);
 490         wf_fcu_add_fan(pv, "drive-bay-fan",     FCU_FAN_RPM, 2);
 491         wf_fcu_add_fan(pv, "slots-fan",         FCU_FAN_PWM, 2);
 492         wf_fcu_add_fan(pv, "cpu-front-fan-0",   FCU_FAN_RPM, 3);
 493         wf_fcu_add_fan(pv, "cpu-rear-fan-0",    FCU_FAN_RPM, 4);
 494         wf_fcu_add_fan(pv, "cpu-front-fan-1",   FCU_FAN_RPM, 5);
 495         wf_fcu_add_fan(pv, "cpu-rear-fan-1",    FCU_FAN_RPM, 6);
 496 }
 497
 498 static int wf_fcu_init_chip(struct wf_fcu_priv *pv)
 499 {
 500         unsigned char buf = 0xff;
 501         int rc;
 502
 503         rc = wf_fcu_write_reg(pv, 0xe, &buf, 1);
 504         if (rc < 0)
 505                 return -EIO;
 506         rc = wf_fcu_write_reg(pv, 0x2e, &buf, 1);
 507         if (rc < 0)
 508                 return -EIO;
 509         rc = wf_fcu_read_reg(pv, 0, &buf, 1);
 510         if (rc < 0)
 511                 return -EIO;
 512         pv->rpm_shift = (buf == 1) ? 2 : 3;
 513
 514         pr_debug("wf_fcu: FCU Initialized, RPM fan shift is %d\n",
 515                  pv->rpm_shift);
 516
 517         return 0;
 518 }
 519
 520 static int wf_fcu_probe(struct i2c_client *client,
 521                         const struct i2c_device_id *id)
 522 {
 523         struct wf_fcu_priv *pv;
 524
 525         pv = kzalloc(sizeof(*pv), GFP_KERNEL);
 526         if (!pv)
 527                 return -ENOMEM;
 528
 529         kref_init(&pv->ref);
 530         mutex_init(&pv->lock);
 531         INIT_LIST_HEAD(&pv->fan_list);
 532         pv->i2c = client;
 533
 534         /*
 535          * First we must start the FCU which will query the
 536          * shift value to apply to RPMs
 537          */
 538         if (wf_fcu_init_chip(pv)) {
 539                 pr_err("wf_fcu: Initialization failed !\n");
 540                 kfree(pv);
 541                 return -ENXIO;
 542         }
 543
 544         /* First lookup fans in the device-tree */
 545         wf_fcu_lookup_fans(pv);
 546
 547         /*
 548          * Older machines don't have the device-tree entries
 549          * we are looking for, just hard code the list
 550          */
 551         if (list_empty(&pv->fan_list))
 552                 wf_fcu_default_fans(pv);
 553
 554         /* Still no fans ? FAIL */
 555         if (list_empty(&pv->fan_list)) {
 556                 pr_err("wf_fcu: Failed to find fans for your machine\n");
 557                 kfree(pv);
 558                 return -ENODEV;
 559         }
 560
 561         dev_set_drvdata(&client->dev, pv);
 562
 563         return 0;
 564 }
 565
 566 static int wf_fcu_remove(struct i2c_client *client)
 567 {
 568         struct wf_fcu_priv *pv = dev_get_drvdata(&client->dev);
 569         struct wf_fcu_fan *fan;
 570
 571         while (!list_empty(&pv->fan_list)) {
 572                 fan = list_first_entry(&pv->fan_list, struct wf_fcu_fan, link);
 573                 list_del(&fan->link);
 574                 wf_unregister_control(&fan->ctrl);
 575         }
 576         kref_put(&pv->ref, wf_fcu_release);
 577         return 0;
 578 }
 579
 580 static const struct i2c_device_id wf_fcu_id[] = {
 581         { "MAC,fcu", 0 },
 582         { }
 583 };
 584 MODULE_DEVICE_TABLE(i2c, wf_fcu_id);
 585
 586 static struct i2c_driver wf_fcu_driver = {
 587         .driver = {
 588                 .name   = "wf_fcu",
 589         },
 590         .probe          = wf_fcu_probe,
 591         .remove         = wf_fcu_remove,
 592         .id_table       = wf_fcu_id,
 593 };
 594
 595 module_i2c_driver(wf_fcu_driver);
 596
 597 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 598 MODULE_DESCRIPTION("FCU control objects for PowerMacs thermal control");
 599 MODULE_LICENSE("GPL");
 600