drivers/macintosh/therm_pm72.c

   1 /*
   2  * Device driver for the thermostats & fan controller of  the
   3  * Apple G5 "PowerMac7,2" desktop machines.
   4  *
   5  * (c) Copyright IBM Corp. 2003-2004
   6  *
   7  * Maintained by: Benjamin Herrenschmidt
   8  *                <benh@kernel.crashing.org>
   9  *
  10  *
  11  * The algorithm used is the PID control algorithm, used the same
  12  * way the published Darwin code does, using the same values that
  13  * are present in the Darwin 7.0 snapshot property lists.
  14  *
  15  * As far as the CPUs control loops are concerned, I use the
  16  * calibration & PID constants provided by the EEPROM,
  17  * I do _not_ embed any value from the property lists, as the ones
  18  * provided by Darwin 7.0 seem to always have an older version that
  19  * what I've seen on the actual computers.
  20  * It would be interesting to verify that though. Darwin has a
  21  * version code of 1.0.0d11 for all control loops it seems, while
  22  * so far, the machines EEPROMs contain a dataset versioned 1.0.0f
  23  *
  24  * Darwin doesn't provide source to all parts, some missing
  25  * bits like the AppleFCU driver or the actual scale of some
  26  * of the values returned by sensors had to be "guessed" some
  27  * way... or based on what Open Firmware does.
  28  *
  29  * I didn't yet figure out how to get the slots power consumption
  30  * out of the FCU, so that part has not been implemented yet and
  31  * the slots fan is set to a fixed 50% PWM, hoping this value is
  32  * safe enough ...
  33  *
  34  * Note: I have observed strange oscillations of the CPU control
  35  * loop on a dual G5 here. When idle, the CPU exhaust fan tend to
  36  * oscillates slowly (over several minutes) between the minimum
  37  * of 300RPMs and approx. 1000 RPMs. I don't know what is causing
  38  * this, it could be some incorrect constant or an error in the
  39  * way I ported the algorithm, or it could be just normal. I
  40  * don't have full understanding on the way Apple tweaked the PID
  41  * algorithm for the CPU control, it is definitely not a standard
  42  * implementation...
  43  *
  44  * TODO:  - Check MPU structure version/signature
  45  *        - Add things like /sbin/overtemp for non-critical
  46  *          overtemp conditions so userland can take some policy
  47  *          decisions, like slewing down CPUs
  48  *        - Deal with fan and i2c failures in a better way
  49  *
  50  * History:
  51  *
  52  *  Nov. 13, 2003 : 0.5
  53  *      - First release
  54  *
  55  *  Nov. 14, 2003 : 0.6
  56  *      - Read fan speed from FCU, low level fan routines now deal
  57  *        with errors & check fan status, though higher level don't
  58  *        do much.
  59  *      - Move a bunch of definitions to .h file
  60  *
  61  *  Nov. 18, 2003 : 0.7
  62  *      - Fix build on ppc64 kernel
  63  *      - Move back statics definitions to .c file
  64  *      - Avoid calling schedule_timeout with a negative number
  65  *
  66  *  Dec. 18, 2003 : 0.8
  67  *      - Fix typo when reading back fan speed on 2 CPU machines
  68  *
  69  *  Mar. 11, 2004 : 0.9
  70  *      - Rework code accessing the ADC chips, make it more robust and
  71  *        closer to the chip spec. Also make sure it is configured properly,
  72  *        I've seen yet unexplained cases where on startup, I would have stale
  73  *        values in the configuration register
  74  *      - Switch back to use of target fan speed for PID, thus lowering
  75  *        pressure on i2c
  76  */
  77
  78 #include <linux/config.h>
  79 #include <linux/types.h>
  80 #include <linux/module.h>
  81 #include <linux/errno.h>
  82 #include <linux/kernel.h>
  83 #include <linux/delay.h>
  84 #include <linux/sched.h>
  85 #include <linux/i2c.h>
  86 #include <linux/slab.h>
  87 #include <linux/init.h>
  88 #include <linux/spinlock.h>
  89 #include <linux/smp_lock.h>
  90 #include <linux/wait.h>
  91 #include <linux/reboot.h>
  92 #include <linux/kmod.h>
  93 #include <linux/i2c.h>
  94 #include <linux/i2c-dev.h>
  95 #include <asm/prom.h>
  96 #include <asm/machdep.h>
  97 #include <asm/io.h>
  98 #include <asm/system.h>
  99 #include <asm/sections.h>
 100 #include <asm/of_device.h>
 101
 102 #include "therm_pm72.h"
 103
 104 #define VERSION "0.9"
 105
 106 #undef DEBUG
 107
 108 #ifdef DEBUG
 109 #define DBG(args...)    printk(args)
 110 #else
 111 #define DBG(args...)    do { } while(0)
 112 #endif
 113
 114
 115 /*
 116  * Driver statics
 117  */
 118
 119 static struct of_device *               of_dev;
 120 static struct i2c_adapter *             u3_0;
 121 static struct i2c_adapter *             u3_1;
 122 static struct i2c_client *              fcu;
 123 static struct cpu_pid_state             cpu_state[2];
 124 static struct backside_pid_state        backside_state;
 125 static struct drives_pid_state          drives_state;
 126 static int                              state;
 127 static int                              cpu_count;
 128 static pid_t                            ctrl_task;
 129 static struct completion                ctrl_complete;
 130 static int                              critical_state;
 131 static DECLARE_MUTEX(driver_lock);
 132
 133 /*
 134  * i2c_driver structure to attach to the host i2c controller
 135  */
 136
 137 static int therm_pm72_attach(struct i2c_adapter *adapter);
 138 static int therm_pm72_detach(struct i2c_adapter *adapter);
 139
 140 static struct i2c_driver therm_pm72_driver =
 141 {
 142         .name           = "therm_pm72",
 143         .id             = 0xDEADBEEF,
 144         .flags          = I2C_DF_NOTIFY,
 145         .attach_adapter = therm_pm72_attach,
 146         .detach_adapter = therm_pm72_detach,
 147 };
 148
 149 /*
 150  * Utility function to create an i2c_client structure and
 151  * attach it to one of u3 adapters
 152  */
 153 static struct i2c_client *attach_i2c_chip(int id, const char *name)
 154 {
 155         struct i2c_client *clt;
 156         struct i2c_adapter *adap;
 157
 158         if (id & 0x100)
 159                 adap = u3_1;
 160         else
 161                 adap = u3_0;
 162         if (adap == NULL)
 163                 return NULL;
 164
 165         clt = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
 166         if (clt == NULL)
 167                 return NULL;
 168         memset(clt, 0, sizeof(struct i2c_client));
 169
 170         clt->addr = (id >> 1) & 0x7f;
 171         clt->adapter = adap;
 172         clt->driver = &therm_pm72_driver;
 173         clt->id = 0xDEADBEEF;
 174         strncpy(clt->name, name, I2C_NAME_SIZE-1);
 175
 176         if (i2c_attach_client(clt)) {
 177                 printk(KERN_ERR "therm_pm72: Failed to attach to i2c ID 0x%x\n", id);
 178                 kfree(clt);
 179                 return NULL;
 180         }
 181         return clt;
 182 }
 183
 184 /*
 185  * Utility function to get rid of the i2c_client structure
 186  * (will also detach from the adapter hopepfully)
 187  */
 188 static void detach_i2c_chip(struct i2c_client *clt)
 189 {
 190         i2c_detach_client(clt);
 191         kfree(clt);
 192 }
 193
 194 /*
 195  * Here are the i2c chip access wrappers
 196  */
 197
 198 static void initialize_adc(struct cpu_pid_state *state)
 199 {
 200         int rc;
 201         u8 buf[2];
 202
 203         /* Read ADC the configuration register and cache it. We
 204          * also make sure Config2 contains proper values, I've seen
 205          * cases where we got stale grabage in there, thus preventing
 206          * proper reading of conv. values
 207          */
 208
 209         /* Clear Config2 */
 210         buf[0] = 5;
 211         buf[1] = 0;
 212         i2c_master_send(state->monitor, buf, 2);
 213
 214         /* Read & cache Config1 */
 215         buf[0] = 1;
 216         rc = i2c_master_send(state->monitor, buf, 1);
 217         if (rc > 0) {
 218                 rc = i2c_master_recv(state->monitor, buf, 1);
 219                 if (rc > 0) {
 220                         state->adc_config = buf[0];
 221                         DBG("ADC config reg: %02x\n", state->adc_config);
 222                         /* Disable shutdown mode */
 223                         state->adc_config &= 0xfe;
 224                         buf[0] = 1;
 225                         buf[1] = state->adc_config;
 226                         rc = i2c_master_send(state->monitor, buf, 2);
 227                 }
 228         }
 229         if (rc <= 0)
 230                 printk(KERN_ERR "therm_pm72: Error reading ADC config"
 231                        " register !\n");
 232 }
 233
 234 static int read_smon_adc(struct cpu_pid_state *state, int chan)
 235 {
 236         int rc, data, tries = 0;
 237         u8 buf[2];
 238
 239         for (;;) {
 240                 /* Set channel */
 241                 buf[0] = 1;
 242                 buf[1] = (state->adc_config & 0x1f) | (chan << 5);
 243                 rc = i2c_master_send(state->monitor, buf, 2);
 244                 if (rc <= 0)
 245                         goto error;
 246                 /* Wait for convertion */
 247                 msleep(1);
 248                 /* Switch to data register */
 249                 buf[0] = 4;
 250                 rc = i2c_master_send(state->monitor, buf, 1);
 251                 if (rc <= 0)
 252                         goto error;
 253                 /* Read result */
 254                 rc = i2c_master_recv(state->monitor, buf, 2);
 255                 if (rc < 0)
 256                         goto error;
 257                 data = ((u16)buf[0]) << 8 | (u16)buf[1];
 258                 return data >> 6;
 259         error:
 260                 DBG("Error reading ADC, retrying...\n");
 261                 if (++tries > 10) {
 262                         printk(KERN_ERR "therm_pm72: Error reading ADC !\n");
 263                         return -1;
 264                 }
 265                 msleep(10);
 266         }
 267 }
 268
 269 static int fan_read_reg(int reg, unsigned char *buf, int nb)
 270 {
 271         int tries, nr, nw;
 272
 273         buf[0] = reg;
 274         tries = 0;
 275         for (;;) {
 276                 nw = i2c_master_send(fcu, buf, 1);
 277                 if (nw > 0 || (nw < 0 && nw != -EIO) || tries >= 100)
 278                         break;
 279                 msleep(10);
 280                 ++tries;
 281         }
 282         if (nw <= 0) {
 283                 printk(KERN_ERR "Failure writing address to FCU: %d", nw);
 284                 return -EIO;
 285         }
 286         tries = 0;
 287         for (;;) {
 288                 nr = i2c_master_recv(fcu, buf, nb);
 289                 if (nr > 0 || (nr < 0 && nr != ENODEV) || tries >= 100)
 290                         break;
 291                 msleep(10);
 292                 ++tries;
 293         }
 294         if (nr <= 0)
 295                 printk(KERN_ERR "Failure reading data from FCU: %d", nw);
 296         return nr;
 297 }
 298
 299 static int fan_write_reg(int reg, const unsigned char *ptr, int nb)
 300 {
 301         int tries, nw;
 302         unsigned char buf[16];
 303
 304         buf[0] = reg;
 305         memcpy(buf+1, ptr, nb);
 306         ++nb;
 307         tries = 0;
 308         for (;;) {
 309                 nw = i2c_master_send(fcu, buf, nb);
 310                 if (nw > 0 || (nw < 0 && nw != EIO) || tries >= 100)
 311                         break;
 312                 msleep(10);
 313                 ++tries;
 314         }
 315         if (nw < 0)
 316                 printk(KERN_ERR "Failure writing to FCU: %d", nw);
 317         return nw;
 318 }
 319
 320 static int start_fcu(void)
 321 {
 322         unsigned char buf = 0xff;
 323         int rc;
 324
 325         rc = fan_write_reg(0xe, &buf, 1);
 326         if (rc < 0)
 327                 return -EIO;
 328         rc = fan_write_reg(0x2e, &buf, 1);
 329         if (rc < 0)
 330                 return -EIO;
 331         return 0;
 332 }
 333
 334 static int set_rpm_fan(int fan, int rpm)
 335 {
 336         unsigned char buf[2];
 337         int rc;
 338
 339         if (rpm < 300)
 340                 rpm = 300;
 341         else if (rpm > 8191)
 342                 rpm = 8191;
 343         buf[0] = rpm >> 5;
 344         buf[1] = rpm << 3;
 345         rc = fan_write_reg(0x10 + (fan * 2), buf, 2);
 346         if (rc < 0)
 347                 return -EIO;
 348         return 0;
 349 }
 350
 351 static int get_rpm_fan(int fan, int programmed)
 352 {
 353         unsigned char failure;
 354         unsigned char active;
 355         unsigned char buf[2];
 356         int rc, reg_base;
 357
 358         rc = fan_read_reg(0xb, &failure, 1);
 359         if (rc != 1)
 360                 return -EIO;
 361         if ((failure & (1 << fan)) != 0)
 362                 return -EFAULT;
 363         rc = fan_read_reg(0xd, &active, 1);
 364         if (rc != 1)
 365                 return -EIO;
 366         if ((active & (1 << fan)) == 0)
 367                 return -ENXIO;
 368
 369         /* Programmed value or real current speed */
 370         reg_base = programmed ? 0x10 : 0x11;
 371         rc = fan_read_reg(reg_base + (fan * 2), buf, 2);
 372         if (rc != 2)
 373                 return -EIO;
 374
 375         return (buf[0] << 5) | buf[1] >> 3;
 376 }
 377
 378 static int set_pwm_fan(int fan, int pwm)
 379 {
 380         unsigned char buf[2];
 381         int rc;
 382
 383         if (pwm < 10)
 384                 pwm = 10;
 385         else if (pwm > 100)
 386                 pwm = 100;
 387         pwm = (pwm * 2559) / 1000;
 388         buf[0] = pwm;
 389         rc = fan_write_reg(0x30 + (fan * 2), buf, 1);
 390         if (rc < 0)
 391                 return rc;
 392         return 0;
 393 }
 394
 395 static int get_pwm_fan(int fan)
 396 {
 397         unsigned char failure;
 398         unsigned char active;
 399         unsigned char buf[2];
 400         int rc;
 401
 402         rc = fan_read_reg(0x2b, &failure, 1);
 403         if (rc != 1)
 404                 return -EIO;
 405         if ((failure & (1 << fan)) != 0)
 406                 return -EFAULT;
 407         rc = fan_read_reg(0x2d, &active, 1);
 408         if (rc != 1)
 409                 return -EIO;
 410         if ((active & (1 << fan)) == 0)
 411                 return -ENXIO;
 412
 413         /* Programmed value or real current speed */
 414         rc = fan_read_reg(0x30 + (fan * 2), buf, 1);
 415         if (rc != 1)
 416                 return -EIO;
 417
 418         return (buf[0] * 1000) / 2559;
 419 }
 420
 421 /*
 422  * Utility routine to read the CPU calibration EEPROM data
 423  * from the device-tree
 424  */
 425 static int read_eeprom(int cpu, struct mpu_data *out)
 426 {
 427         struct device_node *np;
 428         char nodename[64];
 429         u8 *data;
 430         int len;
 431
 432         /* prom.c routine for finding a node by path is a bit brain dead
 433          * and requires exact @xxx unit numbers. This is a bit ugly but
 434          * will work for these machines
 435          */
 436         sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
 437         np = of_find_node_by_path(nodename);
 438         if (np == NULL) {
 439                 printk(KERN_ERR "therm_pm72: Failed to retreive cpuid node from device-tree\n");
 440                 return -ENODEV;
 441         }
 442         data = (u8 *)get_property(np, "cpuid", &len);
 443         if (data == NULL) {
 444                 printk(KERN_ERR "therm_pm72: Failed to retreive cpuid property from device-tree\n");
 445                 of_node_put(np);
 446                 return -ENODEV;
 447         }
 448         memcpy(out, data, sizeof(struct mpu_data));
 449         of_node_put(np);
 450
 451         return 0;
 452 }
 453
 454 /*
 455  * Now, unfortunately, sysfs doesn't give us a nice void * we could
 456  * pass around to the attribute functions, so we don't really have
 457  * choice but implement a bunch of them...
 458  *
 459  * That sucks a bit, we take the lock because FIX32TOPRINT evaluates
 460  * the input twice... I accept patches :)
 461  */
 462 #define BUILD_SHOW_FUNC_FIX(name, data)                         \
 463 static ssize_t show_##name(struct device *dev, char *buf)       \
 464 {                                                               \
 465         ssize_t r;                                              \
 466         down(&driver_lock);                                     \
 467         r = sprintf(buf, "%d.%03d", FIX32TOPRINT(data));        \
 468         up(&driver_lock);                                       \
 469         return r;                                               \
 470 }
 471 #define BUILD_SHOW_FUNC_INT(name, data)                         \
 472 static ssize_t show_##name(struct device *dev, char *buf)       \
 473 {                                                               \
 474         return sprintf(buf, "%d", data);                        \
 475 }
 476
 477 BUILD_SHOW_FUNC_FIX(cpu0_temperature, cpu_state[0].last_temp)
 478 BUILD_SHOW_FUNC_FIX(cpu0_voltage, cpu_state[0].voltage)
 479 BUILD_SHOW_FUNC_FIX(cpu0_current, cpu_state[0].current_a)
 480 BUILD_SHOW_FUNC_INT(cpu0_exhaust_fan_rpm, cpu_state[0].rpm)
 481 BUILD_SHOW_FUNC_INT(cpu0_intake_fan_rpm, cpu_state[0].intake_rpm)
 482
 483 BUILD_SHOW_FUNC_FIX(cpu1_temperature, cpu_state[1].last_temp)
 484 BUILD_SHOW_FUNC_FIX(cpu1_voltage, cpu_state[1].voltage)
 485 BUILD_SHOW_FUNC_FIX(cpu1_current, cpu_state[1].current_a)
 486 BUILD_SHOW_FUNC_INT(cpu1_exhaust_fan_rpm, cpu_state[1].rpm)
 487 BUILD_SHOW_FUNC_INT(cpu1_intake_fan_rpm, cpu_state[1].intake_rpm)
 488
 489 BUILD_SHOW_FUNC_FIX(backside_temperature, backside_state.last_temp)
 490 BUILD_SHOW_FUNC_INT(backside_fan_pwm, backside_state.pwm)
 491
 492 BUILD_SHOW_FUNC_FIX(drives_temperature, drives_state.last_temp)
 493 BUILD_SHOW_FUNC_INT(drives_fan_rpm, drives_state.rpm)
 494
 495 static DEVICE_ATTR(cpu0_temperature,S_IRUGO,show_cpu0_temperature,NULL);
 496 static DEVICE_ATTR(cpu0_voltage,S_IRUGO,show_cpu0_voltage,NULL);
 497 static DEVICE_ATTR(cpu0_current,S_IRUGO,show_cpu0_current,NULL);
 498 static DEVICE_ATTR(cpu0_exhaust_fan_rpm,S_IRUGO,show_cpu0_exhaust_fan_rpm,NULL);
 499 static DEVICE_ATTR(cpu0_intake_fan_rpm,S_IRUGO,show_cpu0_intake_fan_rpm,NULL);
 500
 501 static DEVICE_ATTR(cpu1_temperature,S_IRUGO,show_cpu1_temperature,NULL);
 502 static DEVICE_ATTR(cpu1_voltage,S_IRUGO,show_cpu1_voltage,NULL);
 503 static DEVICE_ATTR(cpu1_current,S_IRUGO,show_cpu1_current,NULL);
 504 static DEVICE_ATTR(cpu1_exhaust_fan_rpm,S_IRUGO,show_cpu1_exhaust_fan_rpm,NULL);
 505 static DEVICE_ATTR(cpu1_intake_fan_rpm,S_IRUGO,show_cpu1_intake_fan_rpm,NULL);
 506
 507 static DEVICE_ATTR(backside_temperature,S_IRUGO,show_backside_temperature,NULL);
 508 static DEVICE_ATTR(backside_fan_pwm,S_IRUGO,show_backside_fan_pwm,NULL);
 509
 510 static DEVICE_ATTR(drives_temperature,S_IRUGO,show_drives_temperature,NULL);
 511 static DEVICE_ATTR(drives_fan_rpm,S_IRUGO,show_drives_fan_rpm,NULL);
 512
 513 /*
 514  * CPUs fans control loop
 515  */
 516 static void do_monitor_cpu(struct cpu_pid_state *state)
 517 {
 518         s32 temp, voltage, current_a, power, power_target;
 519         s32 integral, derivative, proportional, adj_in_target, sval;
 520         s64 integ_p, deriv_p, prop_p, sum;
 521         int i, intake, rc;
 522
 523         DBG("cpu %d:\n", state->index);
 524
 525         /* Read current fan status */
 526         if (state->index == 0)
 527                 rc = get_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 528         else
 529                 rc = get_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 530         if (rc < 0) {
 531                 printk(KERN_WARNING "Error %d reading CPU %d exhaust fan !\n",
 532                        rc, state->index);
 533                 /* XXX What do we do now ? */
 534         } else
 535                 state->rpm = rc;
 536         DBG("  current rpm: %d\n", state->rpm);
 537
 538         /* Get some sensor readings and scale it */
 539         temp = read_smon_adc(state, 1);
 540         if (temp == -1) {
 541                 state->overtemp++;
 542                 return;
 543         }
 544         voltage = read_smon_adc(state, 3);
 545         current_a = read_smon_adc(state, 4);
 546
 547         /* Fixup temperature according to diode calibration
 548          */
 549         DBG("  temp raw: %04x, m_diode: %04x, b_diode: %04x\n",
 550             temp, state->mpu.mdiode, state->mpu.bdiode);
 551         temp = ((s32)temp * (s32)state->mpu.mdiode + ((s32)state->mpu.bdiode << 12)) >> 2;
 552         state->last_temp = temp;
 553         DBG("  temp: %d.%03d\n", FIX32TOPRINT(temp));
 554
 555         /* Check tmax, increment overtemp if we are there. At tmax+8, we go
 556          * full blown immediately and try to trigger a shutdown
 557          */
 558         if (temp >= ((state->mpu.tmax + 8) << 16)) {
 559                 printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum"
 560                        " (%d) !\n",
 561                        state->index, temp >> 16);
 562                 state->overtemp = CPU_MAX_OVERTEMP;
 563         } else if (temp > (state->mpu.tmax << 16))
 564                 state->overtemp++;
 565         else
 566                 state->overtemp = 0;
 567         if (state->overtemp >= CPU_MAX_OVERTEMP)
 568                 critical_state = 1;
 569         if (state->overtemp > 0) {
 570                 state->rpm = state->mpu.rmaxn_exhaust_fan;
 571                 state->intake_rpm = intake = state->mpu.rmaxn_intake_fan;
 572                 goto do_set_fans;
 573         }
 574
 575         /* Scale other sensor values according to fixed scales
 576          * obtained in Darwin and calculate power from I and V
 577          */
 578         state->voltage = voltage *= ADC_CPU_VOLTAGE_SCALE;
 579         state->current_a = current_a *= ADC_CPU_CURRENT_SCALE;
 580         power = (((u64)current_a) * ((u64)voltage)) >> 16;
 581
 582         /* Calculate power target value (could be done once for all)
 583          * and convert to a 16.16 fp number
 584          */
 585         power_target = ((u32)(state->mpu.pmaxh - state->mpu.padjmax)) << 16;
 586
 587         DBG("  current: %d.%03d, voltage: %d.%03d\n",
 588             FIX32TOPRINT(current_a), FIX32TOPRINT(voltage));
 589         DBG("  power: %d.%03d W, target: %d.%03d, error: %d.%03d\n", FIX32TOPRINT(power),
 590             FIX32TOPRINT(power_target), FIX32TOPRINT(power_target - power));
 591
 592         /* Store temperature and power in history array */
 593         state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
 594         state->temp_history[state->cur_temp] = temp;
 595         state->cur_power = (state->cur_power + 1) % state->count_power;
 596         state->power_history[state->cur_power] = power;
 597         state->error_history[state->cur_power] = power_target - power;
 598
 599         /* If first loop, fill the history table */
 600         if (state->first) {
 601                 for (i = 0; i < (state->count_power - 1); i++) {
 602                         state->cur_power = (state->cur_power + 1) % state->count_power;
 603                         state->power_history[state->cur_power] = power;
 604                         state->error_history[state->cur_power] = power_target - power;
 605                 }
 606                 for (i = 0; i < (CPU_TEMP_HISTORY_SIZE - 1); i++) {
 607                         state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
 608                         state->temp_history[state->cur_temp] = temp;
 609                 }
 610                 state->first = 0;
 611         }
 612
 613         /* Calculate the integral term normally based on the "power" values */
 614         sum = 0;
 615         integral = 0;
 616         for (i = 0; i < state->count_power; i++)
 617                 integral += state->error_history[i];
 618         integral *= CPU_PID_INTERVAL;
 619         DBG("  integral: %08x\n", integral);
 620
 621         /* Calculate the adjusted input (sense value).
 622          *   G_r is 12.20
 623          *   integ is 16.16
 624          *   so the result is 28.36
 625          *
 626          * input target is mpu.ttarget, input max is mpu.tmax
 627          */
 628         integ_p = ((s64)state->mpu.pid_gr) * (s64)integral;
 629         DBG("   integ_p: %d\n", (int)(deriv_p >> 36));
 630         sval = (state->mpu.tmax << 16) - ((integ_p >> 20) & 0xffffffff);
 631         adj_in_target = (state->mpu.ttarget << 16);
 632         if (adj_in_target > sval)
 633                 adj_in_target = sval;
 634         DBG("   adj_in_target: %d.%03d, ttarget: %d\n", FIX32TOPRINT(adj_in_target),
 635             state->mpu.ttarget);
 636
 637         /* Calculate the derivative term */
 638         derivative = state->temp_history[state->cur_temp] -
 639                 state->temp_history[(state->cur_temp + CPU_TEMP_HISTORY_SIZE - 1)
 640                                     % CPU_TEMP_HISTORY_SIZE];
 641         derivative /= CPU_PID_INTERVAL;
 642         deriv_p = ((s64)state->mpu.pid_gd) * (s64)derivative;
 643         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 644         sum += deriv_p;
 645
 646         /* Calculate the proportional term */
 647         proportional = temp - adj_in_target;
 648         prop_p = ((s64)state->mpu.pid_gp) * (s64)proportional;
 649         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 650         sum += prop_p;
 651
 652         /* Scale sum */
 653         sum >>= 36;
 654
 655         DBG("   sum: %d\n", (int)sum);
 656         state->rpm += (s32)sum;
 657
 658         if (state->rpm < state->mpu.rminn_exhaust_fan)
 659                 state->rpm = state->mpu.rminn_exhaust_fan;
 660         if (state->rpm > state->mpu.rmaxn_exhaust_fan)
 661                 state->rpm = state->mpu.rmaxn_exhaust_fan;
 662
 663         intake = (state->rpm * CPU_INTAKE_SCALE) >> 16;
 664         if (intake < state->mpu.rminn_intake_fan)
 665                 intake = state->mpu.rminn_intake_fan;
 666         if (intake > state->mpu.rmaxn_intake_fan)
 667                 intake = state->mpu.rmaxn_intake_fan;
 668         state->intake_rpm = intake;
 669
 670  do_set_fans:
 671         DBG("** CPU %d RPM: %d Ex, %d In, overtemp: %d\n",
 672             state->index, (int)state->rpm, intake, state->overtemp);
 673
 674         /* We should check for errors, shouldn't we ? But then, what
 675          * do we do once the error occurs ? For FCU notified fan
 676          * failures (-EFAULT) we probably want to notify userland
 677          * some way...
 678          */
 679         if (state->index == 0) {
 680                 set_rpm_fan(CPUA_INTAKE_FAN_RPM_ID, intake);
 681                 set_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, state->rpm);
 682         } else {
 683                 set_rpm_fan(CPUB_INTAKE_FAN_RPM_ID, intake);
 684                 set_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, state->rpm);
 685         }
 686 }
 687
 688 /*
 689  * Initialize the state structure for one CPU control loop
 690  */
 691 static int init_cpu_state(struct cpu_pid_state *state, int index)
 692 {
 693         state->index = index;
 694         state->first = 1;
 695         state->rpm = 1000;
 696         state->overtemp = 0;
 697         state->adc_config = 0x00;
 698
 699         if (index == 0)
 700                 state->monitor = attach_i2c_chip(SUPPLY_MONITOR_ID, "CPU0_monitor");
 701         else if (index == 1)
 702                 state->monitor = attach_i2c_chip(SUPPLY_MONITORB_ID, "CPU1_monitor");
 703         if (state->monitor == NULL)
 704                 goto fail;
 705
 706         if (read_eeprom(index, &state->mpu))
 707                 goto fail;
 708
 709         state->count_power = state->mpu.tguardband;
 710         if (state->count_power > CPU_POWER_HISTORY_SIZE) {
 711                 printk(KERN_WARNING "Warning ! too many power history slots\n");
 712                 state->count_power = CPU_POWER_HISTORY_SIZE;
 713         }
 714         DBG("CPU %d Using %d power history entries\n", index, state->count_power);
 715
 716         if (index == 0) {
 717                 device_create_file(&of_dev->dev, &dev_attr_cpu0_temperature);
 718                 device_create_file(&of_dev->dev, &dev_attr_cpu0_voltage);
 719                 device_create_file(&of_dev->dev, &dev_attr_cpu0_current);
 720                 device_create_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
 721                 device_create_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
 722         } else {
 723                 device_create_file(&of_dev->dev, &dev_attr_cpu1_temperature);
 724                 device_create_file(&of_dev->dev, &dev_attr_cpu1_voltage);
 725                 device_create_file(&of_dev->dev, &dev_attr_cpu1_current);
 726                 device_create_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
 727                 device_create_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
 728         }
 729
 730         return 0;
 731  fail:
 732         if (state->monitor)
 733                 detach_i2c_chip(state->monitor);
 734         state->monitor = NULL;
 735
 736         return -ENODEV;
 737 }
 738
 739 /*
 740  * Dispose of the state data for one CPU control loop
 741  */
 742 static void dispose_cpu_state(struct cpu_pid_state *state)
 743 {
 744         if (state->monitor == NULL)
 745                 return;
 746
 747         if (state->index == 0) {
 748                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_temperature);
 749                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_voltage);
 750                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_current);
 751                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
 752                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
 753         } else {
 754                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_temperature);
 755                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_voltage);
 756                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_current);
 757                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
 758                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
 759         }
 760
 761         detach_i2c_chip(state->monitor);
 762         state->monitor = NULL;
 763 }
 764
 765 /*
 766  * Motherboard backside & U3 heatsink fan control loop
 767  */
 768 static void do_monitor_backside(struct backside_pid_state *state)
 769 {
 770         s32 temp, integral, derivative;
 771         s64 integ_p, deriv_p, prop_p, sum;
 772         int i, rc;
 773
 774         if (--state->ticks != 0)
 775                 return;
 776         state->ticks = BACKSIDE_PID_INTERVAL;
 777
 778         DBG("backside:\n");
 779
 780         /* Check fan status */
 781         rc = get_pwm_fan(BACKSIDE_FAN_PWM_ID);
 782         if (rc < 0) {
 783                 printk(KERN_WARNING "Error %d reading backside fan !\n", rc);
 784                 /* XXX What do we do now ? */
 785         } else
 786                 state->pwm = rc;
 787         DBG("  current pwm: %d\n", state->pwm);
 788
 789         /* Get some sensor readings */
 790         temp = i2c_smbus_read_byte_data(state->monitor, MAX6690_EXT_TEMP) << 16;
 791         state->last_temp = temp;
 792         DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
 793             FIX32TOPRINT(BACKSIDE_PID_INPUT_TARGET));
 794
 795         /* Store temperature and error in history array */
 796         state->cur_sample = (state->cur_sample + 1) % BACKSIDE_PID_HISTORY_SIZE;
 797         state->sample_history[state->cur_sample] = temp;
 798         state->error_history[state->cur_sample] = temp - BACKSIDE_PID_INPUT_TARGET;
 799
 800         /* If first loop, fill the history table */
 801         if (state->first) {
 802                 for (i = 0; i < (BACKSIDE_PID_HISTORY_SIZE - 1); i++) {
 803                         state->cur_sample = (state->cur_sample + 1) %
 804                                 BACKSIDE_PID_HISTORY_SIZE;
 805                         state->sample_history[state->cur_sample] = temp;
 806                         state->error_history[state->cur_sample] =
 807                                 temp - BACKSIDE_PID_INPUT_TARGET;
 808                 }
 809                 state->first = 0;
 810         }
 811
 812         /* Calculate the integral term */
 813         sum = 0;
 814         integral = 0;
 815         for (i = 0; i < BACKSIDE_PID_HISTORY_SIZE; i++)
 816                 integral += state->error_history[i];
 817         integral *= BACKSIDE_PID_INTERVAL;
 818         DBG("  integral: %08x\n", integral);
 819         integ_p = ((s64)BACKSIDE_PID_G_r) * (s64)integral;
 820         DBG("   integ_p: %d\n", (int)(integ_p >> 36));
 821         sum += integ_p;
 822
 823         /* Calculate the derivative term */
 824         derivative = state->error_history[state->cur_sample] -
 825                 state->error_history[(state->cur_sample + BACKSIDE_PID_HISTORY_SIZE - 1)
 826                                     % BACKSIDE_PID_HISTORY_SIZE];
 827         derivative /= BACKSIDE_PID_INTERVAL;
 828         deriv_p = ((s64)BACKSIDE_PID_G_d) * (s64)derivative;
 829         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 830         sum += deriv_p;
 831
 832         /* Calculate the proportional term */
 833         prop_p = ((s64)BACKSIDE_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
 834         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 835         sum += prop_p;
 836
 837         /* Scale sum */
 838         sum >>= 36;
 839
 840         DBG("   sum: %d\n", (int)sum);
 841         state->pwm += (s32)sum;
 842         if (state->pwm < BACKSIDE_PID_OUTPUT_MIN)
 843                 state->pwm = BACKSIDE_PID_OUTPUT_MIN;
 844         if (state->pwm > BACKSIDE_PID_OUTPUT_MAX)
 845                 state->pwm = BACKSIDE_PID_OUTPUT_MAX;
 846
 847         DBG("** BACKSIDE PWM: %d\n", (int)state->pwm);
 848         set_pwm_fan(BACKSIDE_FAN_PWM_ID, state->pwm);
 849 }
 850
 851 /*
 852  * Initialize the state structure for the backside fan control loop
 853  */
 854 static int init_backside_state(struct backside_pid_state *state)
 855 {
 856         state->ticks = 1;
 857         state->first = 1;
 858         state->pwm = 50;
 859
 860         state->monitor = attach_i2c_chip(BACKSIDE_MAX_ID, "backside_temp");
 861         if (state->monitor == NULL)
 862                 return -ENODEV;
 863
 864         device_create_file(&of_dev->dev, &dev_attr_backside_temperature);
 865         device_create_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
 866
 867         return 0;
 868 }
 869
 870 /*
 871  * Dispose of the state data for the backside control loop
 872  */
 873 static void dispose_backside_state(struct backside_pid_state *state)
 874 {
 875         if (state->monitor == NULL)
 876                 return;
 877
 878         device_remove_file(&of_dev->dev, &dev_attr_backside_temperature);
 879         device_remove_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
 880
 881         detach_i2c_chip(state->monitor);
 882         state->monitor = NULL;
 883 }
 884
 885 /*
 886  * Drives bay fan control loop
 887  */
 888 static void do_monitor_drives(struct drives_pid_state *state)
 889 {
 890         s32 temp, integral, derivative;
 891         s64 integ_p, deriv_p, prop_p, sum;
 892         int i, rc;
 893
 894         if (--state->ticks != 0)
 895                 return;
 896         state->ticks = DRIVES_PID_INTERVAL;
 897
 898         DBG("drives:\n");
 899
 900         /* Check fan status */
 901         rc = get_rpm_fan(DRIVES_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 902         if (rc < 0) {
 903                 printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
 904                 /* XXX What do we do now ? */
 905         } else
 906                 state->rpm = rc;
 907         DBG("  current rpm: %d\n", state->rpm);
 908
 909         /* Get some sensor readings */
 910         temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor, DS1775_TEMP)) << 8;
 911         state->last_temp = temp;
 912         DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
 913             FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));
 914
 915         /* Store temperature and error in history array */
 916         state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
 917         state->sample_history[state->cur_sample] = temp;
 918         state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
 919
 920         /* If first loop, fill the history table */
 921         if (state->first) {
 922                 for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
 923                         state->cur_sample = (state->cur_sample + 1) %
 924                                 DRIVES_PID_HISTORY_SIZE;
 925                         state->sample_history[state->cur_sample] = temp;
 926                         state->error_history[state->cur_sample] =
 927                                 temp - DRIVES_PID_INPUT_TARGET;
 928                 }
 929                 state->first = 0;
 930         }
 931
 932         /* Calculate the integral term */
 933         sum = 0;
 934         integral = 0;
 935         for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
 936                 integral += state->error_history[i];
 937         integral *= DRIVES_PID_INTERVAL;
 938         DBG("  integral: %08x\n", integral);
 939         integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
 940         DBG("   integ_p: %d\n", (int)(integ_p >> 36));
 941         sum += integ_p;
 942
 943         /* Calculate the derivative term */
 944         derivative = state->error_history[state->cur_sample] -
 945                 state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
 946                                     % DRIVES_PID_HISTORY_SIZE];
 947         derivative /= DRIVES_PID_INTERVAL;
 948         deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
 949         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 950         sum += deriv_p;
 951
 952         /* Calculate the proportional term */
 953         prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
 954         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 955         sum += prop_p;
 956
 957         /* Scale sum */
 958         sum >>= 36;
 959
 960         DBG("   sum: %d\n", (int)sum);
 961         state->rpm += (s32)sum;
 962         if (state->rpm < DRIVES_PID_OUTPUT_MIN)
 963                 state->rpm = DRIVES_PID_OUTPUT_MIN;
 964         if (state->rpm > DRIVES_PID_OUTPUT_MAX)
 965                 state->rpm = DRIVES_PID_OUTPUT_MAX;
 966
 967         DBG("** DRIVES RPM: %d\n", (int)state->rpm);
 968         set_rpm_fan(DRIVES_FAN_RPM_ID, state->rpm);
 969 }
 970
 971 /*
 972  * Initialize the state structure for the drives bay fan control loop
 973  */
 974 static int init_drives_state(struct drives_pid_state *state)
 975 {
 976         state->ticks = 1;
 977         state->first = 1;
 978         state->rpm = 1000;
 979
 980         state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
 981         if (state->monitor == NULL)
 982                 return -ENODEV;
 983
 984         device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
 985         device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
 986
 987         return 0;
 988 }
 989
 990 /*
 991  * Dispose of the state data for the drives control loop
 992  */
 993 static void dispose_drives_state(struct drives_pid_state *state)
 994 {
 995         if (state->monitor == NULL)
 996                 return;
 997
 998         device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
 999         device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
1000
1001         detach_i2c_chip(state->monitor);
1002         state->monitor = NULL;
1003 }
1004
1005 static int call_critical_overtemp(void)
1006 {
1007         char *argv[] = { critical_overtemp_path, NULL };
1008         static char *envp[] = { "HOME=/",
1009                                 "TERM=linux",
1010                                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
1011                                 NULL };
1012
1013         return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
1014 }
1015
1016
1017 /*
1018  * Here's the kernel thread that calls the various control loops
1019  */
1020 static int main_control_loop(void *x)
1021 {
1022         daemonize("kfand");
1023
1024         DBG("main_control_loop started\n");
1025
1026         down(&driver_lock);
1027
1028         if (start_fcu() < 0) {
1029                 printk(KERN_ERR "kfand: failed to start FCU\n");
1030                 up(&driver_lock);
1031                 goto out;
1032         }
1033
1034         /* Set the PCI fan once for now */
1035         set_pwm_fan(SLOTS_FAN_PWM_ID, SLOTS_FAN_DEFAULT_PWM);
1036
1037         /* Initialize ADCs */
1038         initialize_adc(&cpu_state[0]);
1039         if (cpu_state[1].monitor != NULL)
1040                 initialize_adc(&cpu_state[1]);
1041
1042         up(&driver_lock);
1043
1044         while (state == state_attached) {
1045                 unsigned long elapsed, start;
1046
1047                 start = jiffies;
1048
1049                 down(&driver_lock);
1050                 do_monitor_cpu(&cpu_state[0]);
1051                 if (cpu_state[1].monitor != NULL)
1052                         do_monitor_cpu(&cpu_state[1]);
1053                 do_monitor_backside(&backside_state);
1054                 do_monitor_drives(&drives_state);
1055                 up(&driver_lock);
1056
1057                 if (critical_state == 1) {
1058                         printk(KERN_WARNING "Temperature control detected a critical condition\n");
1059                         printk(KERN_WARNING "Attempting to shut down...\n");
1060                         if (call_critical_overtemp()) {
1061                                 printk(KERN_WARNING "Can't call %s, power off now!\n",
1062                                        critical_overtemp_path);
1063                                 machine_power_off();
1064                         }
1065                 }
1066                 if (critical_state > 0)
1067                         critical_state++;
1068                 if (critical_state > MAX_CRITICAL_STATE) {
1069                         printk(KERN_WARNING "Shutdown timed out, power off now !\n");
1070                         machine_power_off();
1071                 }
1072
1073                 // FIXME: Deal with signals
1074                 set_current_state(TASK_INTERRUPTIBLE);
1075                 elapsed = jiffies - start;
1076                 if (elapsed < HZ)
1077                         schedule_timeout(HZ - elapsed);
1078         }
1079
1080  out:
1081         DBG("main_control_loop ended\n");
1082
1083         ctrl_task = 0;
1084         complete_and_exit(&ctrl_complete, 0);
1085 }
1086
1087 /*
1088  * Dispose the control loops when tearing down
1089  */
1090 static void dispose_control_loops(void)
1091 {
1092         dispose_cpu_state(&cpu_state[0]);
1093         dispose_cpu_state(&cpu_state[1]);
1094
1095         dispose_backside_state(&backside_state);
1096         dispose_drives_state(&drives_state);
1097 }
1098
1099 /*
1100  * Create the control loops. U3-0 i2c bus is up, so we can now
1101  * get to the various sensors
1102  */
1103 static int create_control_loops(void)
1104 {
1105         struct device_node *np;
1106
1107         /* Count CPUs from the device-tree, we don't care how many are
1108          * actually used by Linux
1109          */
1110         cpu_count = 0;
1111         for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
1112                 cpu_count++;
1113
1114         DBG("counted %d CPUs in the device-tree\n", cpu_count);
1115
1116         /* Create control loops for everything. If any fail, everything
1117          * fails
1118          */
1119         if (init_cpu_state(&cpu_state[0], 0))
1120                 goto fail;
1121         if (cpu_count > 1 && init_cpu_state(&cpu_state[1], 1))
1122                 goto fail;
1123         if (init_backside_state(&backside_state))
1124                 goto fail;
1125         if (init_drives_state(&drives_state))
1126                 goto fail;
1127
1128         DBG("all control loops up !\n");
1129
1130         return 0;
1131
1132  fail:
1133         DBG("failure creating control loops, disposing\n");
1134
1135         dispose_control_loops();
1136
1137         return -ENODEV;
1138 }
1139
1140 /*
1141  * Start the control loops after everything is up, that is create
1142  * the thread that will make them run
1143  */
1144 static void start_control_loops(void)
1145 {
1146         init_completion(&ctrl_complete);
1147
1148         ctrl_task = kernel_thread(main_control_loop, NULL, SIGCHLD | CLONE_KERNEL);
1149 }
1150
1151 /*
1152  * Stop the control loops when tearing down
1153  */
1154 static void stop_control_loops(void)
1155 {
1156         if (ctrl_task != 0)
1157                 wait_for_completion(&ctrl_complete);
1158 }
1159
1160 /*
1161  * Attach to the i2c FCU after detecting U3-1 bus
1162  */
1163 static int attach_fcu(void)
1164 {
1165         fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
1166         if (fcu == NULL)
1167                 return -ENODEV;
1168
1169         DBG("FCU attached\n");
1170
1171         return 0;
1172 }
1173
1174 /*
1175  * Detach from the i2c FCU when tearing down
1176  */
1177 static void detach_fcu(void)
1178 {
1179         if (fcu)
1180                 detach_i2c_chip(fcu);
1181         fcu = NULL;
1182 }
1183
1184 /*
1185  * Attach to the i2c controller. We probe the various chips based
1186  * on the device-tree nodes and build everything for the driver to
1187  * run, we then kick the driver monitoring thread
1188  */
1189 static int therm_pm72_attach(struct i2c_adapter *adapter)
1190 {
1191         down(&driver_lock);
1192
1193         /* Check state */
1194         if (state == state_detached)
1195                 state = state_attaching;
1196         if (state != state_attaching) {
1197                 up(&driver_lock);
1198                 return 0;
1199         }
1200
1201         /* Check if we are looking for one of these */
1202         if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
1203                 u3_0 = adapter;
1204                 DBG("found U3-0, creating control loops\n");
1205                 if (create_control_loops())
1206                         u3_0 = NULL;
1207         } else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
1208                 u3_1 = adapter;
1209                 DBG("found U3-1, attaching FCU\n");
1210                 if (attach_fcu())
1211                         u3_1 = NULL;
1212         }
1213         /* We got all we need, start control loops */
1214         if (u3_0 != NULL && u3_1 != NULL) {
1215                 DBG("everything up, starting control loops\n");
1216                 state = state_attached;
1217                 start_control_loops();
1218         }
1219         up(&driver_lock);
1220
1221         return 0;
1222 }
1223
1224 /*
1225  * Called on every adapter when the driver or the i2c controller
1226  * is going away.
1227  */
1228 static int therm_pm72_detach(struct i2c_adapter *adapter)
1229 {
1230         down(&driver_lock);
1231
1232         if (state != state_detached)
1233                 state = state_detaching;
1234
1235         /* Stop control loops if any */
1236         DBG("stopping control loops\n");
1237         up(&driver_lock);
1238         stop_control_loops();
1239         down(&driver_lock);
1240
1241         if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
1242                 DBG("lost U3-0, disposing control loops\n");
1243                 dispose_control_loops();
1244                 u3_0 = NULL;
1245         }
1246
1247         if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
1248                 DBG("lost U3-1, detaching FCU\n");
1249                 detach_fcu();
1250                 u3_1 = NULL;
1251         }
1252         if (u3_0 == NULL && u3_1 == NULL)
1253                 state = state_detached;
1254
1255         up(&driver_lock);
1256
1257         return 0;
1258 }
1259
1260 static int fcu_of_probe(struct of_device* dev, const struct of_match *match)
1261 {
1262         int rc;
1263
1264         state = state_detached;
1265
1266         rc = i2c_add_driver(&therm_pm72_driver);
1267         if (rc < 0)
1268                 return rc;
1269         return 0;
1270 }
1271
1272 static int fcu_of_remove(struct of_device* dev)
1273 {
1274         i2c_del_driver(&therm_pm72_driver);
1275
1276         return 0;
1277 }
1278
1279 static struct of_match fcu_of_match[] =
1280 {
1281         {
1282         .name           = OF_ANY_MATCH,
1283         .type           = "fcu",
1284         .compatible     = OF_ANY_MATCH
1285         },
1286         {},
1287 };
1288
1289 static struct of_platform_driver fcu_of_platform_driver =
1290 {
1291         .name           = "temperature",
1292         .match_table    = fcu_of_match,
1293         .probe          = fcu_of_probe,
1294         .remove         = fcu_of_remove
1295 };
1296
1297 /*
1298  * Check machine type, attach to i2c controller
1299  */
1300 static int __init therm_pm72_init(void)
1301 {
1302         struct device_node *np;
1303
1304         if (!machine_is_compatible("PowerMac7,2"))
1305                 return -ENODEV;
1306
1307         printk(KERN_INFO "PowerMac G5 Thermal control driver %s\n", VERSION);
1308
1309         np = of_find_node_by_type(NULL, "fcu");
1310         if (np == NULL) {
1311                 printk(KERN_ERR "Can't find FCU in device-tree !\n");
1312                 return -ENODEV;
1313         }
1314         of_dev = of_platform_device_create(np, "temperature");
1315         if (of_dev == NULL) {
1316                 printk(KERN_ERR "Can't register FCU platform device !\n");
1317                 return -ENODEV;
1318         }
1319
1320         of_register_driver(&fcu_of_platform_driver);
1321
1322         return 0;
1323 }
1324
1325 static void __exit therm_pm72_exit(void)
1326 {
1327         of_unregister_driver(&fcu_of_platform_driver);
1328
1329         if (of_dev)
1330                 of_device_unregister(of_dev);
1331 }
1332
1333 module_init(therm_pm72_init);
1334 module_exit(therm_pm72_exit);
1335
1336 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
1337 MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control");
1338 MODULE_LICENSE("GPL");
1339