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