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 set_rpm_fan(int fan, int rpm)
 321 {
 322         unsigned char buf[2];
 323         int rc;
 324
 325         if (rpm < 300)
 326                 rpm = 300;
 327         else if (rpm > 8191)
 328                 rpm = 8191;
 329         buf[0] = rpm >> 5;
 330         buf[1] = rpm << 3;
 331         rc = fan_write_reg(0x10 + (fan * 2), buf, 2);
 332         if (rc < 0)
 333                 return -EIO;
 334         return 0;
 335 }
 336
 337 static int get_rpm_fan(int fan, int programmed)
 338 {
 339         unsigned char failure;
 340         unsigned char active;
 341         unsigned char buf[2];
 342         int rc, reg_base;
 343
 344         rc = fan_read_reg(0xb, &failure, 1);
 345         if (rc != 1)
 346                 return -EIO;
 347         if ((failure & (1 << fan)) != 0)
 348                 return -EFAULT;
 349         rc = fan_read_reg(0xd, &active, 1);
 350         if (rc != 1)
 351                 return -EIO;
 352         if ((active & (1 << fan)) == 0)
 353                 return -ENXIO;
 354
 355         /* Programmed value or real current speed */
 356         reg_base = programmed ? 0x10 : 0x11;
 357         rc = fan_read_reg(reg_base + (fan * 2), buf, 2);
 358         if (rc != 2)
 359                 return -EIO;
 360
 361         return (buf[0] << 5) | buf[1] >> 3;
 362 }
 363
 364 static int set_pwm_fan(int fan, int pwm)
 365 {
 366         unsigned char buf[2];
 367         int rc;
 368
 369         if (pwm < 10)
 370                 pwm = 10;
 371         else if (pwm > 100)
 372                 pwm = 100;
 373         pwm = (pwm * 2559) / 1000;
 374         buf[0] = pwm;
 375         rc = fan_write_reg(0x30 + (fan * 2), buf, 1);
 376         if (rc < 0)
 377                 return rc;
 378         return 0;
 379 }
 380
 381 static int get_pwm_fan(int fan)
 382 {
 383         unsigned char failure;
 384         unsigned char active;
 385         unsigned char buf[2];
 386         int rc;
 387
 388         rc = fan_read_reg(0x2b, &failure, 1);
 389         if (rc != 1)
 390                 return -EIO;
 391         if ((failure & (1 << fan)) != 0)
 392                 return -EFAULT;
 393         rc = fan_read_reg(0x2d, &active, 1);
 394         if (rc != 1)
 395                 return -EIO;
 396         if ((active & (1 << fan)) == 0)
 397                 return -ENXIO;
 398
 399         /* Programmed value or real current speed */
 400         rc = fan_read_reg(0x30 + (fan * 2), buf, 1);
 401         if (rc != 1)
 402                 return -EIO;
 403
 404         return (buf[0] * 1000) / 2559;
 405 }
 406
 407 /*
 408  * Utility routine to read the CPU calibration EEPROM data
 409  * from the device-tree
 410  */
 411 static int read_eeprom(int cpu, struct mpu_data *out)
 412 {
 413         struct device_node *np;
 414         char nodename[64];
 415         u8 *data;
 416         int len;
 417
 418         /* prom.c routine for finding a node by path is a bit brain dead
 419          * and requires exact @xxx unit numbers. This is a bit ugly but
 420          * will work for these machines
 421          */
 422         sprintf(nodename, "/u3@0,f8000000/i2c@f8001000/cpuid@a%d", cpu ? 2 : 0);
 423         np = of_find_node_by_path(nodename);
 424         if (np == NULL) {
 425                 printk(KERN_ERR "therm_pm72: Failed to retreive cpuid node from device-tree\n");
 426                 return -ENODEV;
 427         }
 428         data = (u8 *)get_property(np, "cpuid", &len);
 429         if (data == NULL) {
 430                 printk(KERN_ERR "therm_pm72: Failed to retreive cpuid property from device-tree\n");
 431                 of_node_put(np);
 432                 return -ENODEV;
 433         }
 434         memcpy(out, data, sizeof(struct mpu_data));
 435         of_node_put(np);
 436
 437         return 0;
 438 }
 439
 440 /*
 441  * Now, unfortunately, sysfs doesn't give us a nice void * we could
 442  * pass around to the attribute functions, so we don't really have
 443  * choice but implement a bunch of them...
 444  *
 445  * That sucks a bit, we take the lock because FIX32TOPRINT evaluates
 446  * the input twice... I accept patches :)
 447  */
 448 #define BUILD_SHOW_FUNC_FIX(name, data)                         \
 449 static ssize_t show_##name(struct device *dev, char *buf)       \
 450 {                                                               \
 451         ssize_t r;                                              \
 452         down(&driver_lock);                                     \
 453         r = sprintf(buf, "%d.%03d", FIX32TOPRINT(data));        \
 454         up(&driver_lock);                                       \
 455         return r;                                               \
 456 }
 457 #define BUILD_SHOW_FUNC_INT(name, data)                         \
 458 static ssize_t show_##name(struct device *dev, char *buf)       \
 459 {                                                               \
 460         return sprintf(buf, "%d", data);                        \
 461 }
 462
 463 BUILD_SHOW_FUNC_FIX(cpu0_temperature, cpu_state[0].last_temp)
 464 BUILD_SHOW_FUNC_FIX(cpu0_voltage, cpu_state[0].voltage)
 465 BUILD_SHOW_FUNC_FIX(cpu0_current, cpu_state[0].current_a)
 466 BUILD_SHOW_FUNC_INT(cpu0_exhaust_fan_rpm, cpu_state[0].rpm)
 467 BUILD_SHOW_FUNC_INT(cpu0_intake_fan_rpm, cpu_state[0].intake_rpm)
 468
 469 BUILD_SHOW_FUNC_FIX(cpu1_temperature, cpu_state[1].last_temp)
 470 BUILD_SHOW_FUNC_FIX(cpu1_voltage, cpu_state[1].voltage)
 471 BUILD_SHOW_FUNC_FIX(cpu1_current, cpu_state[1].current_a)
 472 BUILD_SHOW_FUNC_INT(cpu1_exhaust_fan_rpm, cpu_state[1].rpm)
 473 BUILD_SHOW_FUNC_INT(cpu1_intake_fan_rpm, cpu_state[1].intake_rpm)
 474
 475 BUILD_SHOW_FUNC_FIX(backside_temperature, backside_state.last_temp)
 476 BUILD_SHOW_FUNC_INT(backside_fan_pwm, backside_state.pwm)
 477
 478 BUILD_SHOW_FUNC_FIX(drives_temperature, drives_state.last_temp)
 479 BUILD_SHOW_FUNC_INT(drives_fan_rpm, drives_state.rpm)
 480
 481 static DEVICE_ATTR(cpu0_temperature,S_IRUGO,show_cpu0_temperature,NULL);
 482 static DEVICE_ATTR(cpu0_voltage,S_IRUGO,show_cpu0_voltage,NULL);
 483 static DEVICE_ATTR(cpu0_current,S_IRUGO,show_cpu0_current,NULL);
 484 static DEVICE_ATTR(cpu0_exhaust_fan_rpm,S_IRUGO,show_cpu0_exhaust_fan_rpm,NULL);
 485 static DEVICE_ATTR(cpu0_intake_fan_rpm,S_IRUGO,show_cpu0_intake_fan_rpm,NULL);
 486
 487 static DEVICE_ATTR(cpu1_temperature,S_IRUGO,show_cpu1_temperature,NULL);
 488 static DEVICE_ATTR(cpu1_voltage,S_IRUGO,show_cpu1_voltage,NULL);
 489 static DEVICE_ATTR(cpu1_current,S_IRUGO,show_cpu1_current,NULL);
 490 static DEVICE_ATTR(cpu1_exhaust_fan_rpm,S_IRUGO,show_cpu1_exhaust_fan_rpm,NULL);
 491 static DEVICE_ATTR(cpu1_intake_fan_rpm,S_IRUGO,show_cpu1_intake_fan_rpm,NULL);
 492
 493 static DEVICE_ATTR(backside_temperature,S_IRUGO,show_backside_temperature,NULL);
 494 static DEVICE_ATTR(backside_fan_pwm,S_IRUGO,show_backside_fan_pwm,NULL);
 495
 496 static DEVICE_ATTR(drives_temperature,S_IRUGO,show_drives_temperature,NULL);
 497 static DEVICE_ATTR(drives_fan_rpm,S_IRUGO,show_drives_fan_rpm,NULL);
 498
 499 /*
 500  * CPUs fans control loop
 501  */
 502 static void do_monitor_cpu(struct cpu_pid_state *state)
 503 {
 504         s32 temp, voltage, current_a, power, power_target;
 505         s32 integral, derivative, proportional, adj_in_target, sval;
 506         s64 integ_p, deriv_p, prop_p, sum;
 507         int i, intake, rc;
 508
 509         DBG("cpu %d:\n", state->index);
 510
 511         /* Read current fan status */
 512         if (state->index == 0)
 513                 rc = get_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 514         else
 515                 rc = get_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 516         if (rc < 0) {
 517                 printk(KERN_WARNING "Error %d reading CPU %d exhaust fan !\n",
 518                        rc, state->index);
 519                 /* XXX What do we do now ? */
 520         } else
 521                 state->rpm = rc;
 522         DBG("  current rpm: %d\n", state->rpm);
 523
 524         /* Get some sensor readings and scale it */
 525         temp = read_smon_adc(state, 1);
 526         if (temp == -1) {
 527                 state->overtemp++;
 528                 return;
 529         }
 530         voltage = read_smon_adc(state, 3);
 531         current_a = read_smon_adc(state, 4);
 532
 533         /* Fixup temperature according to diode calibration
 534          */
 535         DBG("  temp raw: %04x, m_diode: %04x, b_diode: %04x\n",
 536             temp, state->mpu.mdiode, state->mpu.bdiode);
 537         temp = ((s32)temp * (s32)state->mpu.mdiode + ((s32)state->mpu.bdiode << 12)) >> 2;
 538         state->last_temp = temp;
 539         DBG("  temp: %d.%03d\n", FIX32TOPRINT(temp));
 540
 541         /* Check tmax, increment overtemp if we are there. At tmax+8, we go
 542          * full blown immediately and try to trigger a shutdown
 543          */
 544         if (temp >= ((state->mpu.tmax + 8) << 16)) {
 545                 printk(KERN_WARNING "Warning ! CPU %d temperature way above maximum"
 546                        " (%d) !\n",
 547                        state->index, temp >> 16);
 548                 state->overtemp = CPU_MAX_OVERTEMP;
 549         } else if (temp > (state->mpu.tmax << 16))
 550                 state->overtemp++;
 551         else
 552                 state->overtemp = 0;
 553         if (state->overtemp >= CPU_MAX_OVERTEMP)
 554                 critical_state = 1;
 555         if (state->overtemp > 0) {
 556                 state->rpm = state->mpu.rmaxn_exhaust_fan;
 557                 state->intake_rpm = intake = state->mpu.rmaxn_intake_fan;
 558                 goto do_set_fans;
 559         }
 560
 561         /* Scale other sensor values according to fixed scales
 562          * obtained in Darwin and calculate power from I and V
 563          */
 564         state->voltage = voltage *= ADC_CPU_VOLTAGE_SCALE;
 565         state->current_a = current_a *= ADC_CPU_CURRENT_SCALE;
 566         power = (((u64)current_a) * ((u64)voltage)) >> 16;
 567
 568         /* Calculate power target value (could be done once for all)
 569          * and convert to a 16.16 fp number
 570          */
 571         power_target = ((u32)(state->mpu.pmaxh - state->mpu.padjmax)) << 16;
 572
 573         DBG("  current: %d.%03d, voltage: %d.%03d\n",
 574             FIX32TOPRINT(current_a), FIX32TOPRINT(voltage));
 575         DBG("  power: %d.%03d W, target: %d.%03d, error: %d.%03d\n", FIX32TOPRINT(power),
 576             FIX32TOPRINT(power_target), FIX32TOPRINT(power_target - power));
 577
 578         /* Store temperature and power in history array */
 579         state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
 580         state->temp_history[state->cur_temp] = temp;
 581         state->cur_power = (state->cur_power + 1) % state->count_power;
 582         state->power_history[state->cur_power] = power;
 583         state->error_history[state->cur_power] = power_target - power;
 584
 585         /* If first loop, fill the history table */
 586         if (state->first) {
 587                 for (i = 0; i < (state->count_power - 1); i++) {
 588                         state->cur_power = (state->cur_power + 1) % state->count_power;
 589                         state->power_history[state->cur_power] = power;
 590                         state->error_history[state->cur_power] = power_target - power;
 591                 }
 592                 for (i = 0; i < (CPU_TEMP_HISTORY_SIZE - 1); i++) {
 593                         state->cur_temp = (state->cur_temp + 1) % CPU_TEMP_HISTORY_SIZE;
 594                         state->temp_history[state->cur_temp] = temp;
 595                 }
 596                 state->first = 0;
 597         }
 598
 599         /* Calculate the integral term normally based on the "power" values */
 600         sum = 0;
 601         integral = 0;
 602         for (i = 0; i < state->count_power; i++)
 603                 integral += state->error_history[i];
 604         integral *= CPU_PID_INTERVAL;
 605         DBG("  integral: %08x\n", integral);
 606
 607         /* Calculate the adjusted input (sense value).
 608          *   G_r is 12.20
 609          *   integ is 16.16
 610          *   so the result is 28.36
 611          *
 612          * input target is mpu.ttarget, input max is mpu.tmax
 613          */
 614         integ_p = ((s64)state->mpu.pid_gr) * (s64)integral;
 615         DBG("   integ_p: %d\n", (int)(deriv_p >> 36));
 616         sval = (state->mpu.tmax << 16) - ((integ_p >> 20) & 0xffffffff);
 617         adj_in_target = (state->mpu.ttarget << 16);
 618         if (adj_in_target > sval)
 619                 adj_in_target = sval;
 620         DBG("   adj_in_target: %d.%03d, ttarget: %d\n", FIX32TOPRINT(adj_in_target),
 621             state->mpu.ttarget);
 622
 623         /* Calculate the derivative term */
 624         derivative = state->temp_history[state->cur_temp] -
 625                 state->temp_history[(state->cur_temp + CPU_TEMP_HISTORY_SIZE - 1)
 626                                     % CPU_TEMP_HISTORY_SIZE];
 627         derivative /= CPU_PID_INTERVAL;
 628         deriv_p = ((s64)state->mpu.pid_gd) * (s64)derivative;
 629         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 630         sum += deriv_p;
 631
 632         /* Calculate the proportional term */
 633         proportional = temp - adj_in_target;
 634         prop_p = ((s64)state->mpu.pid_gp) * (s64)proportional;
 635         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 636         sum += prop_p;
 637
 638         /* Scale sum */
 639         sum >>= 36;
 640
 641         DBG("   sum: %d\n", (int)sum);
 642         state->rpm += (s32)sum;
 643
 644         if (state->rpm < state->mpu.rminn_exhaust_fan)
 645                 state->rpm = state->mpu.rminn_exhaust_fan;
 646         if (state->rpm > state->mpu.rmaxn_exhaust_fan)
 647                 state->rpm = state->mpu.rmaxn_exhaust_fan;
 648
 649         intake = (state->rpm * CPU_INTAKE_SCALE) >> 16;
 650         if (intake < state->mpu.rminn_intake_fan)
 651                 intake = state->mpu.rminn_intake_fan;
 652         if (intake > state->mpu.rmaxn_intake_fan)
 653                 intake = state->mpu.rmaxn_intake_fan;
 654         state->intake_rpm = intake;
 655
 656  do_set_fans:
 657         DBG("** CPU %d RPM: %d Ex, %d In, overtemp: %d\n",
 658             state->index, (int)state->rpm, intake, state->overtemp);
 659
 660         /* We should check for errors, shouldn't we ? But then, what
 661          * do we do once the error occurs ? For FCU notified fan
 662          * failures (-EFAULT) we probably want to notify userland
 663          * some way...
 664          */
 665         if (state->index == 0) {
 666                 set_rpm_fan(CPUA_INTAKE_FAN_RPM_ID, intake);
 667                 set_rpm_fan(CPUA_EXHAUST_FAN_RPM_ID, state->rpm);
 668         } else {
 669                 set_rpm_fan(CPUB_INTAKE_FAN_RPM_ID, intake);
 670                 set_rpm_fan(CPUB_EXHAUST_FAN_RPM_ID, state->rpm);
 671         }
 672 }
 673
 674 /*
 675  * Initialize the state structure for one CPU control loop
 676  */
 677 static int init_cpu_state(struct cpu_pid_state *state, int index)
 678 {
 679         state->index = index;
 680         state->first = 1;
 681         state->rpm = 1000;
 682         state->overtemp = 0;
 683         state->adc_config = 0x00;
 684
 685         if (index == 0)
 686                 state->monitor = attach_i2c_chip(SUPPLY_MONITOR_ID, "CPU0_monitor");
 687         else if (index == 1)
 688                 state->monitor = attach_i2c_chip(SUPPLY_MONITORB_ID, "CPU1_monitor");
 689         if (state->monitor == NULL)
 690                 goto fail;
 691
 692         if (read_eeprom(index, &state->mpu))
 693                 goto fail;
 694
 695         state->count_power = state->mpu.tguardband;
 696         if (state->count_power > CPU_POWER_HISTORY_SIZE) {
 697                 printk(KERN_WARNING "Warning ! too many power history slots\n");
 698                 state->count_power = CPU_POWER_HISTORY_SIZE;
 699         }
 700         DBG("CPU %d Using %d power history entries\n", index, state->count_power);
 701
 702         if (index == 0) {
 703                 device_create_file(&of_dev->dev, &dev_attr_cpu0_temperature);
 704                 device_create_file(&of_dev->dev, &dev_attr_cpu0_voltage);
 705                 device_create_file(&of_dev->dev, &dev_attr_cpu0_current);
 706                 device_create_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
 707                 device_create_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
 708         } else {
 709                 device_create_file(&of_dev->dev, &dev_attr_cpu1_temperature);
 710                 device_create_file(&of_dev->dev, &dev_attr_cpu1_voltage);
 711                 device_create_file(&of_dev->dev, &dev_attr_cpu1_current);
 712                 device_create_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
 713                 device_create_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
 714         }
 715
 716         return 0;
 717  fail:
 718         if (state->monitor)
 719                 detach_i2c_chip(state->monitor);
 720         state->monitor = NULL;
 721
 722         return -ENODEV;
 723 }
 724
 725 /*
 726  * Dispose of the state data for one CPU control loop
 727  */
 728 static void dispose_cpu_state(struct cpu_pid_state *state)
 729 {
 730         if (state->monitor == NULL)
 731                 return;
 732
 733         if (state->index == 0) {
 734                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_temperature);
 735                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_voltage);
 736                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_current);
 737                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_exhaust_fan_rpm);
 738                 device_remove_file(&of_dev->dev, &dev_attr_cpu0_intake_fan_rpm);
 739         } else {
 740                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_temperature);
 741                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_voltage);
 742                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_current);
 743                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_exhaust_fan_rpm);
 744                 device_remove_file(&of_dev->dev, &dev_attr_cpu1_intake_fan_rpm);
 745         }
 746
 747         detach_i2c_chip(state->monitor);
 748         state->monitor = NULL;
 749 }
 750
 751 /*
 752  * Motherboard backside & U3 heatsink fan control loop
 753  */
 754 static void do_monitor_backside(struct backside_pid_state *state)
 755 {
 756         s32 temp, integral, derivative;
 757         s64 integ_p, deriv_p, prop_p, sum;
 758         int i, rc;
 759
 760         if (--state->ticks != 0)
 761                 return;
 762         state->ticks = BACKSIDE_PID_INTERVAL;
 763
 764         DBG("backside:\n");
 765
 766         /* Check fan status */
 767         rc = get_pwm_fan(BACKSIDE_FAN_PWM_ID);
 768         if (rc < 0) {
 769                 printk(KERN_WARNING "Error %d reading backside fan !\n", rc);
 770                 /* XXX What do we do now ? */
 771         } else
 772                 state->pwm = rc;
 773         DBG("  current pwm: %d\n", state->pwm);
 774
 775         /* Get some sensor readings */
 776         temp = i2c_smbus_read_byte_data(state->monitor, MAX6690_EXT_TEMP) << 16;
 777         state->last_temp = temp;
 778         DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
 779             FIX32TOPRINT(BACKSIDE_PID_INPUT_TARGET));
 780
 781         /* Store temperature and error in history array */
 782         state->cur_sample = (state->cur_sample + 1) % BACKSIDE_PID_HISTORY_SIZE;
 783         state->sample_history[state->cur_sample] = temp;
 784         state->error_history[state->cur_sample] = temp - BACKSIDE_PID_INPUT_TARGET;
 785
 786         /* If first loop, fill the history table */
 787         if (state->first) {
 788                 for (i = 0; i < (BACKSIDE_PID_HISTORY_SIZE - 1); i++) {
 789                         state->cur_sample = (state->cur_sample + 1) %
 790                                 BACKSIDE_PID_HISTORY_SIZE;
 791                         state->sample_history[state->cur_sample] = temp;
 792                         state->error_history[state->cur_sample] =
 793                                 temp - BACKSIDE_PID_INPUT_TARGET;
 794                 }
 795                 state->first = 0;
 796         }
 797
 798         /* Calculate the integral term */
 799         sum = 0;
 800         integral = 0;
 801         for (i = 0; i < BACKSIDE_PID_HISTORY_SIZE; i++)
 802                 integral += state->error_history[i];
 803         integral *= BACKSIDE_PID_INTERVAL;
 804         DBG("  integral: %08x\n", integral);
 805         integ_p = ((s64)BACKSIDE_PID_G_r) * (s64)integral;
 806         DBG("   integ_p: %d\n", (int)(integ_p >> 36));
 807         sum += integ_p;
 808
 809         /* Calculate the derivative term */
 810         derivative = state->error_history[state->cur_sample] -
 811                 state->error_history[(state->cur_sample + BACKSIDE_PID_HISTORY_SIZE - 1)
 812                                     % BACKSIDE_PID_HISTORY_SIZE];
 813         derivative /= BACKSIDE_PID_INTERVAL;
 814         deriv_p = ((s64)BACKSIDE_PID_G_d) * (s64)derivative;
 815         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 816         sum += deriv_p;
 817
 818         /* Calculate the proportional term */
 819         prop_p = ((s64)BACKSIDE_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
 820         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 821         sum += prop_p;
 822
 823         /* Scale sum */
 824         sum >>= 36;
 825
 826         DBG("   sum: %d\n", (int)sum);
 827         state->pwm += (s32)sum;
 828         if (state->pwm < BACKSIDE_PID_OUTPUT_MIN)
 829                 state->pwm = BACKSIDE_PID_OUTPUT_MIN;
 830         if (state->pwm > BACKSIDE_PID_OUTPUT_MAX)
 831                 state->pwm = BACKSIDE_PID_OUTPUT_MAX;
 832
 833         DBG("** BACKSIDE PWM: %d\n", (int)state->pwm);
 834         set_pwm_fan(BACKSIDE_FAN_PWM_ID, state->pwm);
 835 }
 836
 837 /*
 838  * Initialize the state structure for the backside fan control loop
 839  */
 840 static int init_backside_state(struct backside_pid_state *state)
 841 {
 842         state->ticks = 1;
 843         state->first = 1;
 844         state->pwm = 50;
 845
 846         state->monitor = attach_i2c_chip(BACKSIDE_MAX_ID, "backside_temp");
 847         if (state->monitor == NULL)
 848                 return -ENODEV;
 849
 850         device_create_file(&of_dev->dev, &dev_attr_backside_temperature);
 851         device_create_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
 852
 853         return 0;
 854 }
 855
 856 /*
 857  * Dispose of the state data for the backside control loop
 858  */
 859 static void dispose_backside_state(struct backside_pid_state *state)
 860 {
 861         if (state->monitor == NULL)
 862                 return;
 863
 864         device_remove_file(&of_dev->dev, &dev_attr_backside_temperature);
 865         device_remove_file(&of_dev->dev, &dev_attr_backside_fan_pwm);
 866
 867         detach_i2c_chip(state->monitor);
 868         state->monitor = NULL;
 869 }
 870
 871 /*
 872  * Drives bay fan control loop
 873  */
 874 static void do_monitor_drives(struct drives_pid_state *state)
 875 {
 876         s32 temp, integral, derivative;
 877         s64 integ_p, deriv_p, prop_p, sum;
 878         int i, rc;
 879
 880         if (--state->ticks != 0)
 881                 return;
 882         state->ticks = DRIVES_PID_INTERVAL;
 883
 884         DBG("drives:\n");
 885
 886         /* Check fan status */
 887         rc = get_rpm_fan(DRIVES_FAN_RPM_ID, !RPM_PID_USE_ACTUAL_SPEED);
 888         if (rc < 0) {
 889                 printk(KERN_WARNING "Error %d reading drives fan !\n", rc);
 890                 /* XXX What do we do now ? */
 891         } else
 892                 state->rpm = rc;
 893         DBG("  current rpm: %d\n", state->rpm);
 894
 895         /* Get some sensor readings */
 896         temp = le16_to_cpu(i2c_smbus_read_word_data(state->monitor, DS1775_TEMP)) << 8;
 897         state->last_temp = temp;
 898         DBG("  temp: %d.%03d, target: %d.%03d\n", FIX32TOPRINT(temp),
 899             FIX32TOPRINT(DRIVES_PID_INPUT_TARGET));
 900
 901         /* Store temperature and error in history array */
 902         state->cur_sample = (state->cur_sample + 1) % DRIVES_PID_HISTORY_SIZE;
 903         state->sample_history[state->cur_sample] = temp;
 904         state->error_history[state->cur_sample] = temp - DRIVES_PID_INPUT_TARGET;
 905
 906         /* If first loop, fill the history table */
 907         if (state->first) {
 908                 for (i = 0; i < (DRIVES_PID_HISTORY_SIZE - 1); i++) {
 909                         state->cur_sample = (state->cur_sample + 1) %
 910                                 DRIVES_PID_HISTORY_SIZE;
 911                         state->sample_history[state->cur_sample] = temp;
 912                         state->error_history[state->cur_sample] =
 913                                 temp - DRIVES_PID_INPUT_TARGET;
 914                 }
 915                 state->first = 0;
 916         }
 917
 918         /* Calculate the integral term */
 919         sum = 0;
 920         integral = 0;
 921         for (i = 0; i < DRIVES_PID_HISTORY_SIZE; i++)
 922                 integral += state->error_history[i];
 923         integral *= DRIVES_PID_INTERVAL;
 924         DBG("  integral: %08x\n", integral);
 925         integ_p = ((s64)DRIVES_PID_G_r) * (s64)integral;
 926         DBG("   integ_p: %d\n", (int)(integ_p >> 36));
 927         sum += integ_p;
 928
 929         /* Calculate the derivative term */
 930         derivative = state->error_history[state->cur_sample] -
 931                 state->error_history[(state->cur_sample + DRIVES_PID_HISTORY_SIZE - 1)
 932                                     % DRIVES_PID_HISTORY_SIZE];
 933         derivative /= DRIVES_PID_INTERVAL;
 934         deriv_p = ((s64)DRIVES_PID_G_d) * (s64)derivative;
 935         DBG("   deriv_p: %d\n", (int)(deriv_p >> 36));
 936         sum += deriv_p;
 937
 938         /* Calculate the proportional term */
 939         prop_p = ((s64)DRIVES_PID_G_p) * (s64)(state->error_history[state->cur_sample]);
 940         DBG("   prop_p: %d\n", (int)(prop_p >> 36));
 941         sum += prop_p;
 942
 943         /* Scale sum */
 944         sum >>= 36;
 945
 946         DBG("   sum: %d\n", (int)sum);
 947         state->rpm += (s32)sum;
 948         if (state->rpm < DRIVES_PID_OUTPUT_MIN)
 949                 state->rpm = DRIVES_PID_OUTPUT_MIN;
 950         if (state->rpm > DRIVES_PID_OUTPUT_MAX)
 951                 state->rpm = DRIVES_PID_OUTPUT_MAX;
 952
 953         DBG("** DRIVES RPM: %d\n", (int)state->rpm);
 954         set_rpm_fan(DRIVES_FAN_RPM_ID, state->rpm);
 955 }
 956
 957 /*
 958  * Initialize the state structure for the drives bay fan control loop
 959  */
 960 static int init_drives_state(struct drives_pid_state *state)
 961 {
 962         state->ticks = 1;
 963         state->first = 1;
 964         state->rpm = 1000;
 965
 966         state->monitor = attach_i2c_chip(DRIVES_DALLAS_ID, "drives_temp");
 967         if (state->monitor == NULL)
 968                 return -ENODEV;
 969
 970         device_create_file(&of_dev->dev, &dev_attr_drives_temperature);
 971         device_create_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
 972
 973         return 0;
 974 }
 975
 976 /*
 977  * Dispose of the state data for the drives control loop
 978  */
 979 static void dispose_drives_state(struct drives_pid_state *state)
 980 {
 981         if (state->monitor == NULL)
 982                 return;
 983
 984         device_remove_file(&of_dev->dev, &dev_attr_drives_temperature);
 985         device_remove_file(&of_dev->dev, &dev_attr_drives_fan_rpm);
 986
 987         detach_i2c_chip(state->monitor);
 988         state->monitor = NULL;
 989 }
 990
 991 static int call_critical_overtemp(void)
 992 {
 993         char *argv[] = { critical_overtemp_path, NULL };
 994         static char *envp[] = { "HOME=/",
 995                                 "TERM=linux",
 996                                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
 997                                 NULL };
 998
 999         return call_usermodehelper(critical_overtemp_path, argv, envp, 0);
1000 }
1001
1002
1003 /*
1004  * Here's the kernel thread that calls the various control loops
1005  */
1006 static int main_control_loop(void *x)
1007 {
1008         daemonize("kfand");
1009
1010         DBG("main_control_loop started\n");
1011
1012         down(&driver_lock);
1013
1014         /* Set the PCI fan once for now */
1015         set_pwm_fan(SLOTS_FAN_PWM_ID, SLOTS_FAN_DEFAULT_PWM);
1016
1017         /* Initialize ADCs */
1018         initialize_adc(&cpu_state[0]);
1019         if (cpu_state[1].monitor != NULL)
1020                 initialize_adc(&cpu_state[1]);
1021
1022         up(&driver_lock);
1023
1024         while (state == state_attached) {
1025                 unsigned long elapsed, start;
1026
1027                 start = jiffies;
1028
1029                 down(&driver_lock);
1030                 do_monitor_cpu(&cpu_state[0]);
1031                 if (cpu_state[1].monitor != NULL)
1032                         do_monitor_cpu(&cpu_state[1]);
1033                 do_monitor_backside(&backside_state);
1034                 do_monitor_drives(&drives_state);
1035                 up(&driver_lock);
1036
1037                 if (critical_state == 1) {
1038                         printk(KERN_WARNING "Temperature control detected a critical condition\n");
1039                         printk(KERN_WARNING "Attempting to shut down...\n");
1040                         if (call_critical_overtemp()) {
1041                                 printk(KERN_WARNING "Can't call %s, power off now!\n",
1042                                        critical_overtemp_path);
1043                                 machine_power_off();
1044                         }
1045                 }
1046                 if (critical_state > 0)
1047                         critical_state++;
1048                 if (critical_state > MAX_CRITICAL_STATE) {
1049                         printk(KERN_WARNING "Shutdown timed out, power off now !\n");
1050                         machine_power_off();
1051                 }
1052
1053                 // FIXME: Deal with signals
1054                 set_current_state(TASK_INTERRUPTIBLE);
1055                 elapsed = jiffies - start;
1056                 if (elapsed < HZ)
1057                         schedule_timeout(HZ - elapsed);
1058         }
1059
1060         DBG("main_control_loop ended\n");
1061
1062         ctrl_task = 0;
1063         complete_and_exit(&ctrl_complete, 0);
1064 }
1065
1066 /*
1067  * Dispose the control loops when tearing down
1068  */
1069 static void dispose_control_loops(void)
1070 {
1071         dispose_cpu_state(&cpu_state[0]);
1072         dispose_cpu_state(&cpu_state[1]);
1073
1074         dispose_backside_state(&backside_state);
1075         dispose_drives_state(&drives_state);
1076 }
1077
1078 /*
1079  * Create the control loops. U3-0 i2c bus is up, so we can now
1080  * get to the various sensors
1081  */
1082 static int create_control_loops(void)
1083 {
1084         struct device_node *np;
1085
1086         /* Count CPUs from the device-tree, we don't care how many are
1087          * actually used by Linux
1088          */
1089         cpu_count = 0;
1090         for (np = NULL; NULL != (np = of_find_node_by_type(np, "cpu"));)
1091                 cpu_count++;
1092
1093         DBG("counted %d CPUs in the device-tree\n", cpu_count);
1094
1095         /* Create control loops for everything. If any fail, everything
1096          * fails
1097          */
1098         if (init_cpu_state(&cpu_state[0], 0))
1099                 goto fail;
1100         if (cpu_count > 1 && init_cpu_state(&cpu_state[1], 1))
1101                 goto fail;
1102         if (init_backside_state(&backside_state))
1103                 goto fail;
1104         if (init_drives_state(&drives_state))
1105                 goto fail;
1106
1107         DBG("all control loops up !\n");
1108
1109         return 0;
1110
1111  fail:
1112         DBG("failure creating control loops, disposing\n");
1113
1114         dispose_control_loops();
1115
1116         return -ENODEV;
1117 }
1118
1119 /*
1120  * Start the control loops after everything is up, that is create
1121  * the thread that will make them run
1122  */
1123 static void start_control_loops(void)
1124 {
1125         init_completion(&ctrl_complete);
1126
1127         ctrl_task = kernel_thread(main_control_loop, NULL, SIGCHLD | CLONE_KERNEL);
1128 }
1129
1130 /*
1131  * Stop the control loops when tearing down
1132  */
1133 static void stop_control_loops(void)
1134 {
1135         if (ctrl_task != 0)
1136                 wait_for_completion(&ctrl_complete);
1137 }
1138
1139 /*
1140  * Attach to the i2c FCU after detecting U3-1 bus
1141  */
1142 static int attach_fcu(void)
1143 {
1144         fcu = attach_i2c_chip(FAN_CTRLER_ID, "fcu");
1145         if (fcu == NULL)
1146                 return -ENODEV;
1147
1148         DBG("FCU attached\n");
1149
1150         return 0;
1151 }
1152
1153 /*
1154  * Detach from the i2c FCU when tearing down
1155  */
1156 static void detach_fcu(void)
1157 {
1158         if (fcu)
1159                 detach_i2c_chip(fcu);
1160         fcu = NULL;
1161 }
1162
1163 /*
1164  * Attach to the i2c controller. We probe the various chips based
1165  * on the device-tree nodes and build everything for the driver to
1166  * run, we then kick the driver monitoring thread
1167  */
1168 static int therm_pm72_attach(struct i2c_adapter *adapter)
1169 {
1170         down(&driver_lock);
1171
1172         /* Check state */
1173         if (state == state_detached)
1174                 state = state_attaching;
1175         if (state != state_attaching) {
1176                 up(&driver_lock);
1177                 return 0;
1178         }
1179
1180         /* Check if we are looking for one of these */
1181         if (u3_0 == NULL && !strcmp(adapter->name, "u3 0")) {
1182                 u3_0 = adapter;
1183                 DBG("found U3-0, creating control loops\n");
1184                 if (create_control_loops())
1185                         u3_0 = NULL;
1186         } else if (u3_1 == NULL && !strcmp(adapter->name, "u3 1")) {
1187                 u3_1 = adapter;
1188                 DBG("found U3-1, attaching FCU\n");
1189                 if (attach_fcu())
1190                         u3_1 = NULL;
1191         }
1192         /* We got all we need, start control loops */
1193         if (u3_0 != NULL && u3_1 != NULL) {
1194                 DBG("everything up, starting control loops\n");
1195                 state = state_attached;
1196                 start_control_loops();
1197         }
1198         up(&driver_lock);
1199
1200         return 0;
1201 }
1202
1203 /*
1204  * Called on every adapter when the driver or the i2c controller
1205  * is going away.
1206  */
1207 static int therm_pm72_detach(struct i2c_adapter *adapter)
1208 {
1209         down(&driver_lock);
1210
1211         if (state != state_detached)
1212                 state = state_detaching;
1213
1214         /* Stop control loops if any */
1215         DBG("stopping control loops\n");
1216         up(&driver_lock);
1217         stop_control_loops();
1218         down(&driver_lock);
1219
1220         if (u3_0 != NULL && !strcmp(adapter->name, "u3 0")) {
1221                 DBG("lost U3-0, disposing control loops\n");
1222                 dispose_control_loops();
1223                 u3_0 = NULL;
1224         }
1225
1226         if (u3_1 != NULL && !strcmp(adapter->name, "u3 1")) {
1227                 DBG("lost U3-1, detaching FCU\n");
1228                 detach_fcu();
1229                 u3_1 = NULL;
1230         }
1231         if (u3_0 == NULL && u3_1 == NULL)
1232                 state = state_detached;
1233
1234         up(&driver_lock);
1235
1236         return 0;
1237 }
1238
1239 static int fcu_of_probe(struct of_device* dev, const struct of_match *match)
1240 {
1241         int rc;
1242
1243         state = state_detached;
1244
1245         rc = i2c_add_driver(&therm_pm72_driver);
1246         if (rc < 0)
1247                 return rc;
1248         return 0;
1249 }
1250
1251 static int fcu_of_remove(struct of_device* dev)
1252 {
1253         i2c_del_driver(&therm_pm72_driver);
1254
1255         return 0;
1256 }
1257
1258 static struct of_match fcu_of_match[] =
1259 {
1260         {
1261         .name           = OF_ANY_MATCH,
1262         .type           = "fcu",
1263         .compatible     = OF_ANY_MATCH
1264         },
1265         {},
1266 };
1267
1268 static struct of_platform_driver fcu_of_platform_driver =
1269 {
1270         .name           = "temperature",
1271         .match_table    = fcu_of_match,
1272         .probe          = fcu_of_probe,
1273         .remove         = fcu_of_remove
1274 };
1275
1276 /*
1277  * Check machine type, attach to i2c controller
1278  */
1279 static int __init therm_pm72_init(void)
1280 {
1281         struct device_node *np;
1282
1283         if (!machine_is_compatible("PowerMac7,2"))
1284                 return -ENODEV;
1285
1286         printk(KERN_INFO "PowerMac G5 Thermal control driver %s\n", VERSION);
1287
1288         np = of_find_node_by_type(NULL, "fcu");
1289         if (np == NULL) {
1290                 printk(KERN_ERR "Can't find FCU in device-tree !\n");
1291                 return -ENODEV;
1292         }
1293         of_dev = of_platform_device_create(np, "temperature");
1294         if (of_dev == NULL) {
1295                 printk(KERN_ERR "Can't register FCU platform device !\n");
1296                 return -ENODEV;
1297         }
1298
1299         of_register_driver(&fcu_of_platform_driver);
1300
1301         return 0;
1302 }
1303
1304 static void __exit therm_pm72_exit(void)
1305 {
1306         of_unregister_driver(&fcu_of_platform_driver);
1307
1308         if (of_dev)
1309                 of_device_unregister(of_dev);
1310 }
1311
1312 module_init(therm_pm72_init);
1313 module_exit(therm_pm72_exit);
1314
1315 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
1316 MODULE_DESCRIPTION("Driver for Apple's PowerMac7,2 G5 thermal control");
1317 MODULE_LICENSE("GPL");
1318