drivers/macintosh/therm_adt746x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Device driver for the i2c thermostat found on the iBook G4, Albook G4
   4  *
   5  * Copyright (C) 2003, 2004 Colin Leroy, Rasmus Rohde, Benjamin Herrenschmidt
   6  *
   7  * Documentation from 115254175ADT7467_pra.pdf and 3686221171167ADT7460_b.pdf
   8  * https://www.onsemi.com/PowerSolutions/product.do?id=ADT7467
   9  * https://www.onsemi.com/PowerSolutions/product.do?id=ADT7460
  10  *
  11  */
  12
  13 #include <linux/types.h>
  14 #include <linux/module.h>
  15 #include <linux/errno.h>
  16 #include <linux/kernel.h>
  17 #include <linux/delay.h>
  18 #include <linux/sched.h>
  19 #include <linux/i2c.h>
  20 #include <linux/slab.h>
  21 #include <linux/init.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/wait.h>
  24 #include <linux/suspend.h>
  25 #include <linux/kthread.h>
  26 #include <linux/moduleparam.h>
  27 #include <linux/freezer.h>
  28 #include <linux/of.h>
  29 #include <linux/of_platform.h>
  30 #include <linux/platform_device.h>
  31
  32 #include <asm/machdep.h>
  33 #include <asm/io.h>
  34 #include <asm/sections.h>
  35
  36 #undef DEBUG
  37
  38 #define CONFIG_REG   0x40
  39 #define MANUAL_MASK  0xe0
  40 #define AUTO_MASK    0x20
  41 #define INVERT_MASK  0x10
  42
  43 static u8 TEMP_REG[3]    = {0x26, 0x25, 0x27}; /* local, sensor1, sensor2 */
  44 static u8 LIMIT_REG[3]   = {0x6b, 0x6a, 0x6c}; /* local, sensor1, sensor2 */
  45 static u8 MANUAL_MODE[2] = {0x5c, 0x5d};
  46 static u8 REM_CONTROL[2] = {0x00, 0x40};
  47 static u8 FAN_SPEED[2]   = {0x28, 0x2a};
  48 static u8 FAN_SPD_SET[2] = {0x30, 0x31};
  49
  50 static u8 default_limits_local[3] = {70, 50, 70};    /* local, sensor1, sensor2 */
  51 static u8 default_limits_chip[3] = {80, 65, 80};    /* local, sensor1, sensor2 */
  52 static const char *sensor_location[3] = { "?", "?", "?" };
  53
  54 static int limit_adjust;
  55 static int fan_speed = -1;
  56 static bool verbose;
  57
  58 MODULE_AUTHOR("Colin Leroy <colin@colino.net>");
  59 MODULE_DESCRIPTION("Driver for ADT746x thermostat in iBook G4 and "
  60                    "Powerbook G4 Alu");
  61 MODULE_LICENSE("GPL");
  62
  63 module_param(limit_adjust, int, 0644);
  64 MODULE_PARM_DESC(limit_adjust,"Adjust maximum temperatures (50 sensor1, 70 sensor2) "
  65                  "by N degrees.");
  66
  67 module_param(fan_speed, int, 0644);
  68 MODULE_PARM_DESC(fan_speed,"Specify starting fan speed (0-255) "
  69                  "(default 64)");
  70
  71 module_param(verbose, bool, 0);
  72 MODULE_PARM_DESC(verbose,"Verbose log operations "
  73                  "(default 0)");
  74
  75 struct thermostat {
  76         struct i2c_client       *clt;
  77         u8                      temps[3];
  78         u8                      cached_temp[3];
  79         u8                      initial_limits[3];
  80         u8                      limits[3];
  81         int                     last_speed[2];
  82         int                     last_var[2];
  83         int                     pwm_inv[2];
  84         struct task_struct      *thread;
  85         struct platform_device  *pdev;
  86         enum {
  87                 ADT7460,
  88                 ADT7467
  89         }                       type;
  90 };
  91
  92 static void write_both_fan_speed(struct thermostat *th, int speed);
  93 static void write_fan_speed(struct thermostat *th, int speed, int fan);
  94
  95 static int
  96 write_reg(struct thermostat* th, int reg, u8 data)
  97 {
  98         u8 tmp[2];
  99         int rc;
 100
 101         tmp[0] = reg;
 102         tmp[1] = data;
 103         rc = i2c_master_send(th->clt, (const char *)tmp, 2);
 104         if (rc < 0)
 105                 return rc;
 106         if (rc != 2)
 107                 return -ENODEV;
 108         return 0;
 109 }
 110
 111 static int
 112 read_reg(struct thermostat* th, int reg)
 113 {
 114         u8 reg_addr, data;
 115         int rc;
 116
 117         reg_addr = (u8)reg;
 118         rc = i2c_master_send(th->clt, &reg_addr, 1);
 119         if (rc < 0)
 120                 return rc;
 121         if (rc != 1)
 122                 return -ENODEV;
 123         rc = i2c_master_recv(th->clt, (char *)&data, 1);
 124         if (rc < 0)
 125                 return rc;
 126         return data;
 127 }
 128
 129 static int read_fan_speed(struct thermostat *th, u8 addr)
 130 {
 131         u8 tmp[2];
 132         u16 res;
 133
 134         /* should start with low byte */
 135         tmp[1] = read_reg(th, addr);
 136         tmp[0] = read_reg(th, addr + 1);
 137
 138         res = tmp[1] + (tmp[0] << 8);
 139         /* "a value of 0xffff means that the fan has stopped" */
 140         return (res == 0xffff ? 0 : (90000*60)/res);
 141 }
 142
 143 static void write_both_fan_speed(struct thermostat *th, int speed)
 144 {
 145         write_fan_speed(th, speed, 0);
 146         if (th->type == ADT7460)
 147                 write_fan_speed(th, speed, 1);
 148 }
 149
 150 static void write_fan_speed(struct thermostat *th, int speed, int fan)
 151 {
 152         u8 manual;
 153
 154         if (speed > 0xff)
 155                 speed = 0xff;
 156         else if (speed < -1)
 157                 speed = 0;
 158
 159         if (th->type == ADT7467 && fan == 1)
 160                 return;
 161
 162         if (th->last_speed[fan] != speed) {
 163                 if (verbose) {
 164                         if (speed == -1)
 165                                 printk(KERN_DEBUG "adt746x: Setting speed to automatic "
 166                                         "for %s fan.\n", sensor_location[fan+1]);
 167                         else
 168                                 printk(KERN_DEBUG "adt746x: Setting speed to %d "
 169                                         "for %s fan.\n", speed, sensor_location[fan+1]);
 170                 }
 171         } else
 172                 return;
 173
 174         if (speed >= 0) {
 175                 manual = read_reg(th, MANUAL_MODE[fan]);
 176                 manual &= ~INVERT_MASK;
 177                 write_reg(th, MANUAL_MODE[fan],
 178                         manual | MANUAL_MASK | th->pwm_inv[fan]);
 179                 write_reg(th, FAN_SPD_SET[fan], speed);
 180         } else {
 181                 /* back to automatic */
 182                 if(th->type == ADT7460) {
 183                         manual = read_reg(th,
 184                                 MANUAL_MODE[fan]) & (~MANUAL_MASK);
 185                         manual &= ~INVERT_MASK;
 186                         manual |= th->pwm_inv[fan];
 187                         write_reg(th,
 188                                 MANUAL_MODE[fan], manual|REM_CONTROL[fan]);
 189                 } else {
 190                         manual = read_reg(th, MANUAL_MODE[fan]);
 191                         manual &= ~INVERT_MASK;
 192                         manual |= th->pwm_inv[fan];
 193                         write_reg(th, MANUAL_MODE[fan], manual&(~AUTO_MASK));
 194                 }
 195         }
 196
 197         th->last_speed[fan] = speed;
 198 }
 199
 200 static void read_sensors(struct thermostat *th)
 201 {
 202         int i = 0;
 203
 204         for (i = 0; i < 3; i++)
 205                 th->temps[i]  = read_reg(th, TEMP_REG[i]);
 206 }
 207
 208 #ifdef DEBUG
 209 static void display_stats(struct thermostat *th)
 210 {
 211         if (th->temps[0] != th->cached_temp[0]
 212         ||  th->temps[1] != th->cached_temp[1]
 213         ||  th->temps[2] != th->cached_temp[2]) {
 214                 printk(KERN_INFO "adt746x: Temperature infos:"
 215                                  " thermostats: %d,%d,%d;"
 216                                  " limits: %d,%d,%d;"
 217                                  " fan speed: %d RPM\n",
 218                                  th->temps[0], th->temps[1], th->temps[2],
 219                                  th->limits[0],  th->limits[1],  th->limits[2],
 220                                  read_fan_speed(th, FAN_SPEED[0]));
 221         }
 222         th->cached_temp[0] = th->temps[0];
 223         th->cached_temp[1] = th->temps[1];
 224         th->cached_temp[2] = th->temps[2];
 225 }
 226 #endif
 227
 228 static void update_fans_speed (struct thermostat *th)
 229 {
 230         int lastvar = 0; /* last variation, for iBook */
 231         int i = 0;
 232
 233         /* we don't care about local sensor, so we start at sensor 1 */
 234         for (i = 1; i < 3; i++) {
 235                 bool started = false;
 236                 int fan_number = (th->type == ADT7460 && i == 2);
 237                 int var = th->temps[i] - th->limits[i];
 238
 239                 if (var > -1) {
 240                         int step = (255 - fan_speed) / 7;
 241                         int new_speed = 0;
 242
 243                         /* hysteresis : change fan speed only if variation is
 244                          * more than two degrees */
 245                         if (abs(var - th->last_var[fan_number]) < 2)
 246                                 continue;
 247
 248                         started = true;
 249                         new_speed = fan_speed + ((var-1)*step);
 250
 251                         if (new_speed < fan_speed)
 252                                 new_speed = fan_speed;
 253                         if (new_speed > 255)
 254                                 new_speed = 255;
 255
 256                         if (verbose)
 257                                 printk(KERN_DEBUG "adt746x: Setting fans speed to %d "
 258                                                  "(limit exceeded by %d on %s)\n",
 259                                                 new_speed, var,
 260                                                 sensor_location[fan_number+1]);
 261                         write_both_fan_speed(th, new_speed);
 262                         th->last_var[fan_number] = var;
 263                 } else if (var < -2) {
 264                         /* don't stop fan if sensor2 is cold and sensor1 is not
 265                          * so cold (lastvar >= -1) */
 266                         if (i == 2 && lastvar < -1) {
 267                                 if (th->last_speed[fan_number] != 0)
 268                                         if (verbose)
 269                                                 printk(KERN_DEBUG "adt746x: Stopping "
 270                                                         "fans.\n");
 271                                 write_both_fan_speed(th, 0);
 272                         }
 273                 }
 274
 275                 lastvar = var;
 276
 277                 if (started)
 278                         return; /* we don't want to re-stop the fan
 279                                 * if sensor1 is heating and sensor2 is not */
 280         }
 281 }
 282
 283 static int monitor_task(void *arg)
 284 {
 285         struct thermostat* th = arg;
 286
 287         set_freezable();
 288         while(!kthread_should_stop()) {
 289                 try_to_freeze();
 290                 msleep_interruptible(2000);
 291
 292 #ifndef DEBUG
 293                 if (fan_speed != -1)
 294                         read_sensors(th);
 295 #else
 296                 read_sensors(th);
 297 #endif
 298
 299                 if (fan_speed != -1)
 300                         update_fans_speed(th);
 301
 302 #ifdef DEBUG
 303                 display_stats(th);
 304 #endif
 305
 306         }
 307
 308         return 0;
 309 }
 310
 311 static void set_limit(struct thermostat *th, int i)
 312 {
 313         /* Set sensor1 limit higher to avoid powerdowns */
 314         th->limits[i] = default_limits_chip[i] + limit_adjust;
 315         write_reg(th, LIMIT_REG[i], th->limits[i]);
 316
 317         /* set our limits to normal */
 318         th->limits[i] = default_limits_local[i] + limit_adjust;
 319 }
 320
 321 #define BUILD_SHOW_FUNC_INT(name, data)                         \
 322 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)        \
 323 {                                                               \
 324         struct thermostat *th = dev_get_drvdata(dev);           \
 325         return sprintf(buf, "%d\n", data);                      \
 326 }
 327
 328 #define BUILD_SHOW_FUNC_INT_LITE(name, data)                            \
 329 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)        \
 330 {                                                               \
 331         return sprintf(buf, "%d\n", data);                      \
 332 }
 333
 334 #define BUILD_SHOW_FUNC_STR(name, data)                         \
 335 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
 336 {                                                               \
 337         return sprintf(buf, "%s\n", data);                      \
 338 }
 339
 340 #define BUILD_SHOW_FUNC_FAN(name, data)                         \
 341 static ssize_t show_##name(struct device *dev, struct device_attribute *attr, char *buf)       \
 342 {                                                               \
 343         struct thermostat *th = dev_get_drvdata(dev);           \
 344         return sprintf(buf, "%d (%d rpm)\n",                    \
 345                 th->last_speed[data],                           \
 346                 read_fan_speed(th, FAN_SPEED[data])             \
 347                 );                                              \
 348 }
 349
 350 #define BUILD_STORE_FUNC_DEG(name, data)                        \
 351 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
 352 {                                                               \
 353         struct thermostat *th = dev_get_drvdata(dev);           \
 354         int val;                                                \
 355         int i;                                                  \
 356         val = simple_strtol(buf, NULL, 10);                     \
 357         printk(KERN_INFO "Adjusting limits by %d degrees\n", val);      \
 358         limit_adjust = val;                                     \
 359         for (i=0; i < 3; i++)                                   \
 360                 set_limit(th, i);                               \
 361         return n;                                               \
 362 }
 363
 364 #define BUILD_STORE_FUNC_INT(name, data)                        \
 365 static ssize_t store_##name(struct device *dev, struct device_attribute *attr, const char *buf, size_t n) \
 366 {                                                               \
 367         int val;                                                \
 368         val = simple_strtol(buf, NULL, 10);                     \
 369         if (val < 0 || val > 255)                               \
 370                 return -EINVAL;                                 \
 371         printk(KERN_INFO "Setting specified fan speed to %d\n", val);   \
 372         data = val;                                             \
 373         return n;                                               \
 374 }
 375
 376 BUILD_SHOW_FUNC_INT(sensor1_temperature,         (read_reg(th, TEMP_REG[1])))
 377 BUILD_SHOW_FUNC_INT(sensor2_temperature,         (read_reg(th, TEMP_REG[2])))
 378 BUILD_SHOW_FUNC_INT(sensor1_limit,               th->limits[1])
 379 BUILD_SHOW_FUNC_INT(sensor2_limit,               th->limits[2])
 380 BUILD_SHOW_FUNC_STR(sensor1_location,            sensor_location[1])
 381 BUILD_SHOW_FUNC_STR(sensor2_location,            sensor_location[2])
 382
 383 BUILD_SHOW_FUNC_INT_LITE(specified_fan_speed, fan_speed)
 384 BUILD_STORE_FUNC_INT(specified_fan_speed,fan_speed)
 385
 386 BUILD_SHOW_FUNC_FAN(sensor1_fan_speed,   0)
 387 BUILD_SHOW_FUNC_FAN(sensor2_fan_speed,   1)
 388
 389 BUILD_SHOW_FUNC_INT_LITE(limit_adjust,   limit_adjust)
 390 BUILD_STORE_FUNC_DEG(limit_adjust,       th)
 391
 392 static DEVICE_ATTR(sensor1_temperature, S_IRUGO,
 393                    show_sensor1_temperature,NULL);
 394 static DEVICE_ATTR(sensor2_temperature, S_IRUGO,
 395                    show_sensor2_temperature,NULL);
 396 static DEVICE_ATTR(sensor1_limit, S_IRUGO,
 397                    show_sensor1_limit,  NULL);
 398 static DEVICE_ATTR(sensor2_limit, S_IRUGO,
 399                    show_sensor2_limit,  NULL);
 400 static DEVICE_ATTR(sensor1_location, S_IRUGO,
 401                    show_sensor1_location, NULL);
 402 static DEVICE_ATTR(sensor2_location, S_IRUGO,
 403                    show_sensor2_location, NULL);
 404
 405 static DEVICE_ATTR(specified_fan_speed, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
 406                    show_specified_fan_speed,store_specified_fan_speed);
 407
 408 static DEVICE_ATTR(sensor1_fan_speed,   S_IRUGO,
 409                    show_sensor1_fan_speed,      NULL);
 410 static DEVICE_ATTR(sensor2_fan_speed,   S_IRUGO,
 411                    show_sensor2_fan_speed,      NULL);
 412
 413 static DEVICE_ATTR(limit_adjust,        S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH,
 414                    show_limit_adjust,   store_limit_adjust);
 415
 416 static void thermostat_create_files(struct thermostat *th)
 417 {
 418         struct device_node *np = th->clt->dev.of_node;
 419         struct device *dev;
 420         int err;
 421
 422         /* To maintain ABI compatibility with userspace, create
 423          * the old style platform driver and attach the attributes
 424          * to it here
 425          */
 426         th->pdev = of_platform_device_create(np, "temperatures", NULL);
 427         if (!th->pdev)
 428                 return;
 429         dev = &th->pdev->dev;
 430         dev_set_drvdata(dev, th);
 431         err = device_create_file(dev, &dev_attr_sensor1_temperature);
 432         err |= device_create_file(dev, &dev_attr_sensor2_temperature);
 433         err |= device_create_file(dev, &dev_attr_sensor1_limit);
 434         err |= device_create_file(dev, &dev_attr_sensor2_limit);
 435         err |= device_create_file(dev, &dev_attr_sensor1_location);
 436         err |= device_create_file(dev, &dev_attr_sensor2_location);
 437         err |= device_create_file(dev, &dev_attr_limit_adjust);
 438         err |= device_create_file(dev, &dev_attr_specified_fan_speed);
 439         err |= device_create_file(dev, &dev_attr_sensor1_fan_speed);
 440         if(th->type == ADT7460)
 441                 err |= device_create_file(dev, &dev_attr_sensor2_fan_speed);
 442         if (err)
 443                 printk(KERN_WARNING
 444                         "Failed to create temperature attribute file(s).\n");
 445 }
 446
 447 static void thermostat_remove_files(struct thermostat *th)
 448 {
 449         struct device *dev;
 450
 451         if (!th->pdev)
 452                 return;
 453         dev = &th->pdev->dev;
 454         device_remove_file(dev, &dev_attr_sensor1_temperature);
 455         device_remove_file(dev, &dev_attr_sensor2_temperature);
 456         device_remove_file(dev, &dev_attr_sensor1_limit);
 457         device_remove_file(dev, &dev_attr_sensor2_limit);
 458         device_remove_file(dev, &dev_attr_sensor1_location);
 459         device_remove_file(dev, &dev_attr_sensor2_location);
 460         device_remove_file(dev, &dev_attr_limit_adjust);
 461         device_remove_file(dev, &dev_attr_specified_fan_speed);
 462         device_remove_file(dev, &dev_attr_sensor1_fan_speed);
 463         if (th->type == ADT7460)
 464                 device_remove_file(dev, &dev_attr_sensor2_fan_speed);
 465         of_device_unregister(th->pdev);
 466
 467 }
 468
 469 static int probe_thermostat(struct i2c_client *client)
 470 {
 471         const struct i2c_device_id *id = i2c_client_get_device_id(client);
 472         struct device_node *np = client->dev.of_node;
 473         struct thermostat* th;
 474         const __be32 *prop;
 475         int i, rc, vers, offset = 0;
 476
 477         if (!np)
 478                 return -ENXIO;
 479         prop = of_get_property(np, "hwsensor-params-version", NULL);
 480         if (!prop)
 481                 return -ENXIO;
 482         vers = be32_to_cpup(prop);
 483         printk(KERN_INFO "adt746x: version %d (%ssupported)\n",
 484                vers, vers == 1 ? "" : "un");
 485         if (vers != 1)
 486                 return -ENXIO;
 487
 488         if (of_property_present(np, "hwsensor-location")) {
 489                 for (i = 0; i < 3; i++) {
 490                         sensor_location[i] = of_get_property(np,
 491                                         "hwsensor-location", NULL) + offset;
 492
 493                         if (sensor_location[i] == NULL)
 494                                 sensor_location[i] = "";
 495
 496                         printk(KERN_INFO "sensor %d: %s\n", i, sensor_location[i]);
 497                         offset += strlen(sensor_location[i]) + 1;
 498                 }
 499         }
 500
 501         th = kzalloc(sizeof(struct thermostat), GFP_KERNEL);
 502         if (!th)
 503                 return -ENOMEM;
 504
 505         i2c_set_clientdata(client, th);
 506         th->clt = client;
 507         th->type = id->driver_data;
 508
 509         rc = read_reg(th, CONFIG_REG);
 510         if (rc < 0) {
 511                 dev_err(&client->dev, "Thermostat failed to read config!\n");
 512                 kfree(th);
 513                 return -ENODEV;
 514         }
 515
 516         /* force manual control to start the fan quieter */
 517         if (fan_speed == -1)
 518                 fan_speed = 64;
 519
 520         if (th->type == ADT7460) {
 521                 printk(KERN_INFO "adt746x: ADT7460 initializing\n");
 522                 /* The 7460 needs to be started explicitly */
 523                 write_reg(th, CONFIG_REG, 1);
 524         } else
 525                 printk(KERN_INFO "adt746x: ADT7467 initializing\n");
 526
 527         for (i = 0; i < 3; i++) {
 528                 th->initial_limits[i] = read_reg(th, LIMIT_REG[i]);
 529                 set_limit(th, i);
 530         }
 531
 532         printk(KERN_INFO "adt746x: Lowering max temperatures from %d, %d, %d"
 533                          " to %d, %d, %d\n",
 534                          th->initial_limits[0], th->initial_limits[1],
 535                          th->initial_limits[2], th->limits[0], th->limits[1],
 536                          th->limits[2]);
 537
 538         /* record invert bit status because fw can corrupt it after suspend */
 539         th->pwm_inv[0] = read_reg(th, MANUAL_MODE[0]) & INVERT_MASK;
 540         th->pwm_inv[1] = read_reg(th, MANUAL_MODE[1]) & INVERT_MASK;
 541
 542         /* be sure to really write fan speed the first time */
 543         th->last_speed[0] = -2;
 544         th->last_speed[1] = -2;
 545         th->last_var[0] = -80;
 546         th->last_var[1] = -80;
 547
 548         if (fan_speed != -1) {
 549                 /* manual mode, stop fans */
 550                 write_both_fan_speed(th, 0);
 551         } else {
 552                 /* automatic mode */
 553                 write_both_fan_speed(th, -1);
 554         }
 555
 556         th->thread = kthread_run(monitor_task, th, "kfand");
 557         if (th->thread == ERR_PTR(-ENOMEM)) {
 558                 printk(KERN_INFO "adt746x: Kthread creation failed\n");
 559                 th->thread = NULL;
 560                 return -ENOMEM;
 561         }
 562
 563         thermostat_create_files(th);
 564
 565         return 0;
 566 }
 567
 568 static void remove_thermostat(struct i2c_client *client)
 569 {
 570         struct thermostat *th = i2c_get_clientdata(client);
 571         int i;
 572
 573         thermostat_remove_files(th);
 574
 575         if (th->thread != NULL)
 576                 kthread_stop(th->thread);
 577
 578         printk(KERN_INFO "adt746x: Putting max temperatures back from "
 579                          "%d, %d, %d to %d, %d, %d\n",
 580                 th->limits[0], th->limits[1], th->limits[2],
 581                 th->initial_limits[0], th->initial_limits[1],
 582                 th->initial_limits[2]);
 583
 584         for (i = 0; i < 3; i++)
 585                 write_reg(th, LIMIT_REG[i], th->initial_limits[i]);
 586
 587         write_both_fan_speed(th, -1);
 588
 589         kfree(th);
 590 }
 591
 592 static const struct i2c_device_id therm_adt746x_id[] = {
 593         { "MAC,adt7460", ADT7460 },
 594         { "MAC,adt7467", ADT7467 },
 595         { }
 596 };
 597 MODULE_DEVICE_TABLE(i2c, therm_adt746x_id);
 598
 599 static struct i2c_driver thermostat_driver = {
 600         .driver = {
 601                 .name   = "therm_adt746x",
 602         },
 603         .probe = probe_thermostat,
 604         .remove = remove_thermostat,
 605         .id_table = therm_adt746x_id,
 606 };
 607
 608 static int __init thermostat_init(void)
 609 {
 610 #ifndef CONFIG_I2C_POWERMAC
 611         request_module("i2c-powermac");
 612 #endif
 613
 614         return i2c_add_driver(&thermostat_driver);
 615 }
 616
 617 static void __exit thermostat_exit(void)
 618 {
 619         i2c_del_driver(&thermostat_driver);
 620 }
 621
 622 module_init(thermostat_init);
 623 module_exit(thermostat_exit);