drivers/macintosh/adb.c

   1 /*
   2  * Device driver for the Apple Desktop Bus
   3  * and the /dev/adb device on macintoshes.
   4  *
   5  * Copyright (C) 1996 Paul Mackerras.
   6  *
   7  * Modified to declare controllers as structures, added
   8  * client notification of bus reset and handles PowerBook
   9  * sleep, by Benjamin Herrenschmidt.
  10  *
  11  * To do:
  12  *
  13  * - /sys/bus/adb to list the devices and infos
  14  * - more /dev/adb to allow userland to receive the
  15  *   flow of auto-polling datas from a given device.
  16  * - move bus probe to a kernel thread
  17  */
  18
  19 #include <linux/types.h>
  20 #include <linux/errno.h>
  21 #include <linux/kernel.h>
  22 #include <linux/slab.h>
  23 #include <linux/module.h>
  24 #include <linux/fs.h>
  25 #include <linux/mm.h>
  26 #include <linux/sched.h>
  27 #include <linux/adb.h>
  28 #include <linux/cuda.h>
  29 #include <linux/pmu.h>
  30 #include <linux/notifier.h>
  31 #include <linux/wait.h>
  32 #include <linux/init.h>
  33 #include <linux/delay.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/completion.h>
  36 #include <linux/device.h>
  37 #include <linux/kthread.h>
  38 #include <linux/platform_device.h>
  39 #include <linux/mutex.h>
  40
  41 #include <asm/uaccess.h>
  42 #ifdef CONFIG_PPC
  43 #include <asm/prom.h>
  44 #include <asm/machdep.h>
  45 #endif
  46
  47
  48 EXPORT_SYMBOL(adb_client_list);
  49
  50 extern struct adb_driver via_macii_driver;
  51 extern struct adb_driver via_maciisi_driver;
  52 extern struct adb_driver via_cuda_driver;
  53 extern struct adb_driver adb_iop_driver;
  54 extern struct adb_driver via_pmu_driver;
  55 extern struct adb_driver macio_adb_driver;
  56
  57 static DEFINE_MUTEX(adb_mutex);
  58 static struct adb_driver *adb_driver_list[] = {
  59 #ifdef CONFIG_ADB_MACII
  60         &via_macii_driver,
  61 #endif
  62 #ifdef CONFIG_ADB_MACIISI
  63         &via_maciisi_driver,
  64 #endif
  65 #ifdef CONFIG_ADB_CUDA
  66         &via_cuda_driver,
  67 #endif
  68 #ifdef CONFIG_ADB_IOP
  69         &adb_iop_driver,
  70 #endif
  71 #if defined(CONFIG_ADB_PMU) || defined(CONFIG_ADB_PMU68K)
  72         &via_pmu_driver,
  73 #endif
  74 #ifdef CONFIG_ADB_MACIO
  75         &macio_adb_driver,
  76 #endif
  77         NULL
  78 };
  79
  80 static struct class *adb_dev_class;
  81
  82 static struct adb_driver *adb_controller;
  83 BLOCKING_NOTIFIER_HEAD(adb_client_list);
  84 static int adb_got_sleep;
  85 static int adb_inited;
  86 static DEFINE_SEMAPHORE(adb_probe_mutex);
  87 static int sleepy_trackpad;
  88 static int autopoll_devs;
  89 int __adb_probe_sync;
  90
  91 static int adb_scan_bus(void);
  92 static int do_adb_reset_bus(void);
  93 static void adbdev_init(void);
  94 static int try_handler_change(int, int);
  95
  96 static struct adb_handler {
  97         void (*handler)(unsigned char *, int, int);
  98         int original_address;
  99         int handler_id;
 100         int busy;
 101 } adb_handler[16];
 102
 103 /*
 104  * The adb_handler_mutex mutex protects all accesses to the original_address
 105  * and handler_id fields of adb_handler[i] for all i, and changes to the
 106  * handler field.
 107  * Accesses to the handler field are protected by the adb_handler_lock
 108  * rwlock.  It is held across all calls to any handler, so that by the
 109  * time adb_unregister returns, we know that the old handler isn't being
 110  * called.
 111  */
 112 static DEFINE_MUTEX(adb_handler_mutex);
 113 static DEFINE_RWLOCK(adb_handler_lock);
 114
 115 #if 0
 116 static void printADBreply(struct adb_request *req)
 117 {
 118         int i;
 119
 120         printk("adb reply (%d)", req->reply_len);
 121         for(i = 0; i < req->reply_len; i++)
 122                 printk(" %x", req->reply[i]);
 123         printk("\n");
 124
 125 }
 126 #endif
 127
 128 static int adb_scan_bus(void)
 129 {
 130         int i, highFree=0, noMovement;
 131         int devmask = 0;
 132         struct adb_request req;
 133
 134         /* assumes adb_handler[] is all zeroes at this point */
 135         for (i = 1; i < 16; i++) {
 136                 /* see if there is anything at address i */
 137                 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 138                             (i << 4) | 0xf);
 139                 if (req.reply_len > 1)
 140                         /* one or more devices at this address */
 141                         adb_handler[i].original_address = i;
 142                 else if (i > highFree)
 143                         highFree = i;
 144         }
 145
 146         /* Note we reset noMovement to 0 each time we move a device */
 147         for (noMovement = 1; noMovement < 2 && highFree > 0; noMovement++) {
 148                 for (i = 1; i < 16; i++) {
 149                         if (adb_handler[i].original_address == 0)
 150                                 continue;
 151                         /*
 152                          * Send a "talk register 3" command to address i
 153                          * to provoke a collision if there is more than
 154                          * one device at this address.
 155                          */
 156                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 157                                     (i << 4) | 0xf);
 158                         /*
 159                          * Move the device(s) which didn't detect a
 160                          * collision to address `highFree'.  Hopefully
 161                          * this only moves one device.
 162                          */
 163                         adb_request(&req, NULL, ADBREQ_SYNC, 3,
 164                                     (i<< 4) | 0xb, (highFree | 0x60), 0xfe);
 165                         /*
 166                          * See if anybody actually moved. This is suggested
 167                          * by HW TechNote 01:
 168                          *
 169                          * http://developer.apple.com/technotes/hw/hw_01.html
 170                          */
 171                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 172                                     (highFree << 4) | 0xf);
 173                         if (req.reply_len <= 1) continue;
 174                         /*
 175                          * Test whether there are any device(s) left
 176                          * at address i.
 177                          */
 178                         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 179                                     (i << 4) | 0xf);
 180                         if (req.reply_len > 1) {
 181                                 /*
 182                                  * There are still one or more devices
 183                                  * left at address i.  Register the one(s)
 184                                  * we moved to `highFree', and find a new
 185                                  * value for highFree.
 186                                  */
 187                                 adb_handler[highFree].original_address =
 188                                         adb_handler[i].original_address;
 189                                 while (highFree > 0 &&
 190                                        adb_handler[highFree].original_address)
 191                                         highFree--;
 192                                 if (highFree <= 0)
 193                                         break;
 194
 195                                 noMovement = 0;
 196                         }
 197                         else {
 198                                 /*
 199                                  * No devices left at address i; move the
 200                                  * one(s) we moved to `highFree' back to i.
 201                                  */
 202                                 adb_request(&req, NULL, ADBREQ_SYNC, 3,
 203                                             (highFree << 4) | 0xb,
 204                                             (i | 0x60), 0xfe);
 205                         }
 206                 }
 207         }
 208
 209         /* Now fill in the handler_id field of the adb_handler entries. */
 210         printk(KERN_DEBUG "adb devices:");
 211         for (i = 1; i < 16; i++) {
 212                 if (adb_handler[i].original_address == 0)
 213                         continue;
 214                 adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 215                             (i << 4) | 0xf);
 216                 adb_handler[i].handler_id = req.reply[2];
 217                 printk(" [%d]: %d %x", i, adb_handler[i].original_address,
 218                        adb_handler[i].handler_id);
 219                 devmask |= 1 << i;
 220         }
 221         printk("\n");
 222         return devmask;
 223 }
 224
 225 /*
 226  * This kernel task handles ADB probing. It dies once probing is
 227  * completed.
 228  */
 229 static int
 230 adb_probe_task(void *x)
 231 {
 232         printk(KERN_INFO "adb: starting probe task...\n");
 233         do_adb_reset_bus();
 234         printk(KERN_INFO "adb: finished probe task...\n");
 235
 236         up(&adb_probe_mutex);
 237
 238         return 0;
 239 }
 240
 241 static void
 242 __adb_probe_task(struct work_struct *bullshit)
 243 {
 244         kthread_run(adb_probe_task, NULL, "kadbprobe");
 245 }
 246
 247 static DECLARE_WORK(adb_reset_work, __adb_probe_task);
 248
 249 int
 250 adb_reset_bus(void)
 251 {
 252         if (__adb_probe_sync) {
 253                 do_adb_reset_bus();
 254                 return 0;
 255         }
 256
 257         down(&adb_probe_mutex);
 258         schedule_work(&adb_reset_work);
 259         return 0;
 260 }
 261
 262 #ifdef CONFIG_PM
 263 /*
 264  * notify clients before sleep
 265  */
 266 static int adb_suspend(struct platform_device *dev, pm_message_t state)
 267 {
 268         adb_got_sleep = 1;
 269         /* We need to get a lock on the probe thread */
 270         down(&adb_probe_mutex);
 271         /* Stop autopoll */
 272         if (adb_controller->autopoll)
 273                 adb_controller->autopoll(0);
 274         blocking_notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * reset bus after sleep
 281  */
 282 static int adb_resume(struct platform_device *dev)
 283 {
 284         adb_got_sleep = 0;
 285         up(&adb_probe_mutex);
 286         adb_reset_bus();
 287
 288         return 0;
 289 }
 290 #endif /* CONFIG_PM */
 291
 292 static int __init adb_init(void)
 293 {
 294         struct adb_driver *driver;
 295         int i;
 296
 297 #ifdef CONFIG_PPC32
 298         if (!machine_is(chrp) && !machine_is(powermac))
 299                 return 0;
 300 #endif
 301 #ifdef CONFIG_PPC64
 302         if (!machine_is(powermac))
 303                 return 0;
 304 #endif
 305 #ifdef CONFIG_MAC
 306         if (!MACH_IS_MAC)
 307                 return 0;
 308 #endif
 309
 310         /* xmon may do early-init */
 311         if (adb_inited)
 312                 return 0;
 313         adb_inited = 1;
 314
 315         adb_controller = NULL;
 316
 317         i = 0;
 318         while ((driver = adb_driver_list[i++]) != NULL) {
 319                 if (!driver->probe()) {
 320                         adb_controller = driver;
 321                         break;
 322                 }
 323         }
 324         if (adb_controller != NULL && adb_controller->init &&
 325             adb_controller->init())
 326                 adb_controller = NULL;
 327         if (adb_controller == NULL) {
 328                 printk(KERN_WARNING "Warning: no ADB interface detected\n");
 329         } else {
 330 #ifdef CONFIG_PPC
 331                 if (of_machine_is_compatible("AAPL,PowerBook1998") ||
 332                         of_machine_is_compatible("PowerBook1,1"))
 333                         sleepy_trackpad = 1;
 334 #endif /* CONFIG_PPC */
 335
 336                 adbdev_init();
 337                 adb_reset_bus();
 338         }
 339         return 0;
 340 }
 341
 342 device_initcall(adb_init);
 343
 344 static int
 345 do_adb_reset_bus(void)
 346 {
 347         int ret;
 348
 349         if (adb_controller == NULL)
 350                 return -ENXIO;
 351
 352         if (adb_controller->autopoll)
 353                 adb_controller->autopoll(0);
 354
 355         blocking_notifier_call_chain(&adb_client_list,
 356                 ADB_MSG_PRE_RESET, NULL);
 357
 358         if (sleepy_trackpad) {
 359                 /* Let the trackpad settle down */
 360                 msleep(500);
 361         }
 362
 363         mutex_lock(&adb_handler_mutex);
 364         write_lock_irq(&adb_handler_lock);
 365         memset(adb_handler, 0, sizeof(adb_handler));
 366         write_unlock_irq(&adb_handler_lock);
 367
 368         /* That one is still a bit synchronous, oh well... */
 369         if (adb_controller->reset_bus)
 370                 ret = adb_controller->reset_bus();
 371         else
 372                 ret = 0;
 373
 374         if (sleepy_trackpad) {
 375                 /* Let the trackpad settle down */
 376                 msleep(1500);
 377         }
 378
 379         if (!ret) {
 380                 autopoll_devs = adb_scan_bus();
 381                 if (adb_controller->autopoll)
 382                         adb_controller->autopoll(autopoll_devs);
 383         }
 384         mutex_unlock(&adb_handler_mutex);
 385
 386         blocking_notifier_call_chain(&adb_client_list,
 387                 ADB_MSG_POST_RESET, NULL);
 388
 389         return ret;
 390 }
 391
 392 void
 393 adb_poll(void)
 394 {
 395         if ((adb_controller == NULL)||(adb_controller->poll == NULL))
 396                 return;
 397         adb_controller->poll();
 398 }
 399
 400 static void adb_sync_req_done(struct adb_request *req)
 401 {
 402         struct completion *comp = req->arg;
 403
 404         complete(comp);
 405 }
 406
 407 int
 408 adb_request(struct adb_request *req, void (*done)(struct adb_request *),
 409             int flags, int nbytes, ...)
 410 {
 411         va_list list;
 412         int i;
 413         int rc;
 414         struct completion comp;
 415
 416         if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
 417                 return -ENXIO;
 418         if (nbytes < 1)
 419                 return -EINVAL;
 420
 421         req->nbytes = nbytes+1;
 422         req->done = done;
 423         req->reply_expected = flags & ADBREQ_REPLY;
 424         req->data[0] = ADB_PACKET;
 425         va_start(list, nbytes);
 426         for (i = 0; i < nbytes; ++i)
 427                 req->data[i+1] = va_arg(list, int);
 428         va_end(list);
 429
 430         if (flags & ADBREQ_NOSEND)
 431                 return 0;
 432
 433         /* Synchronous requests block using an on-stack completion */
 434         if (flags & ADBREQ_SYNC) {
 435                 WARN_ON(done);
 436                 req->done = adb_sync_req_done;
 437                 req->arg = &comp;
 438                 init_completion(&comp);
 439         }
 440
 441         rc = adb_controller->send_request(req, 0);
 442
 443         if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
 444                 wait_for_completion(&comp);
 445
 446         return rc;
 447 }
 448
 449  /* Ultimately this should return the number of devices with
 450     the given default id.
 451     And it does it now ! Note: changed behaviour: This function
 452     will now register if default_id _and_ handler_id both match
 453     but handler_id can be left to 0 to match with default_id only.
 454     When handler_id is set, this function will try to adjust
 455     the handler_id id it doesn't match. */
 456 int
 457 adb_register(int default_id, int handler_id, struct adb_ids *ids,
 458              void (*handler)(unsigned char *, int, int))
 459 {
 460         int i;
 461
 462         mutex_lock(&adb_handler_mutex);
 463         ids->nids = 0;
 464         for (i = 1; i < 16; i++) {
 465                 if ((adb_handler[i].original_address == default_id) &&
 466                     (!handler_id || (handler_id == adb_handler[i].handler_id) ||
 467                     try_handler_change(i, handler_id))) {
 468                         if (adb_handler[i].handler != 0) {
 469                                 printk(KERN_ERR
 470                                        "Two handlers for ADB device %d\n",
 471                                        default_id);
 472                                 continue;
 473                         }
 474                         write_lock_irq(&adb_handler_lock);
 475                         adb_handler[i].handler = handler;
 476                         write_unlock_irq(&adb_handler_lock);
 477                         ids->id[ids->nids++] = i;
 478                 }
 479         }
 480         mutex_unlock(&adb_handler_mutex);
 481         return ids->nids;
 482 }
 483
 484 int
 485 adb_unregister(int index)
 486 {
 487         int ret = -ENODEV;
 488
 489         mutex_lock(&adb_handler_mutex);
 490         write_lock_irq(&adb_handler_lock);
 491         if (adb_handler[index].handler) {
 492                 while(adb_handler[index].busy) {
 493                         write_unlock_irq(&adb_handler_lock);
 494                         yield();
 495                         write_lock_irq(&adb_handler_lock);
 496                 }
 497                 ret = 0;
 498                 adb_handler[index].handler = NULL;
 499         }
 500         write_unlock_irq(&adb_handler_lock);
 501         mutex_unlock(&adb_handler_mutex);
 502         return ret;
 503 }
 504
 505 void
 506 adb_input(unsigned char *buf, int nb, int autopoll)
 507 {
 508         int i, id;
 509         static int dump_adb_input = 0;
 510         unsigned long flags;
 511
 512         void (*handler)(unsigned char *, int, int);
 513
 514         /* We skip keystrokes and mouse moves when the sleep process
 515          * has been started. We stop autopoll, but this is another security
 516          */
 517         if (adb_got_sleep)
 518                 return;
 519
 520         id = buf[0] >> 4;
 521         if (dump_adb_input) {
 522                 printk(KERN_INFO "adb packet: ");
 523                 for (i = 0; i < nb; ++i)
 524                         printk(" %x", buf[i]);
 525                 printk(", id = %d\n", id);
 526         }
 527         write_lock_irqsave(&adb_handler_lock, flags);
 528         handler = adb_handler[id].handler;
 529         if (handler != NULL)
 530                 adb_handler[id].busy = 1;
 531         write_unlock_irqrestore(&adb_handler_lock, flags);
 532         if (handler != NULL) {
 533                 (*handler)(buf, nb, autopoll);
 534                 wmb();
 535                 adb_handler[id].busy = 0;
 536         }
 537
 538 }
 539
 540 /* Try to change handler to new_id. Will return 1 if successful. */
 541 static int try_handler_change(int address, int new_id)
 542 {
 543         struct adb_request req;
 544
 545         if (adb_handler[address].handler_id == new_id)
 546             return 1;
 547         adb_request(&req, NULL, ADBREQ_SYNC, 3,
 548             ADB_WRITEREG(address, 3), address | 0x20, new_id);
 549         adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 550             ADB_READREG(address, 3));
 551         if (req.reply_len < 2)
 552             return 0;
 553         if (req.reply[2] != new_id)
 554             return 0;
 555         adb_handler[address].handler_id = req.reply[2];
 556
 557         return 1;
 558 }
 559
 560 int
 561 adb_try_handler_change(int address, int new_id)
 562 {
 563         int ret;
 564
 565         mutex_lock(&adb_handler_mutex);
 566         ret = try_handler_change(address, new_id);
 567         mutex_unlock(&adb_handler_mutex);
 568         return ret;
 569 }
 570
 571 int
 572 adb_get_infos(int address, int *original_address, int *handler_id)
 573 {
 574         mutex_lock(&adb_handler_mutex);
 575         *original_address = adb_handler[address].original_address;
 576         *handler_id = adb_handler[address].handler_id;
 577         mutex_unlock(&adb_handler_mutex);
 578
 579         return (*original_address != 0);
 580 }
 581
 582
 583 /*
 584  * /dev/adb device driver.
 585  */
 586
 587 #define ADB_MAJOR       56      /* major number for /dev/adb */
 588
 589 struct adbdev_state {
 590         spinlock_t      lock;
 591         atomic_t        n_pending;
 592         struct adb_request *completed;
 593         wait_queue_head_t wait_queue;
 594         int             inuse;
 595 };
 596
 597 static void adb_write_done(struct adb_request *req)
 598 {
 599         struct adbdev_state *state = (struct adbdev_state *) req->arg;
 600         unsigned long flags;
 601
 602         if (!req->complete) {
 603                 req->reply_len = 0;
 604                 req->complete = 1;
 605         }
 606         spin_lock_irqsave(&state->lock, flags);
 607         atomic_dec(&state->n_pending);
 608         if (!state->inuse) {
 609                 kfree(req);
 610                 if (atomic_read(&state->n_pending) == 0) {
 611                         spin_unlock_irqrestore(&state->lock, flags);
 612                         kfree(state);
 613                         return;
 614                 }
 615         } else {
 616                 struct adb_request **ap = &state->completed;
 617                 while (*ap != NULL)
 618                         ap = &(*ap)->next;
 619                 req->next = NULL;
 620                 *ap = req;
 621                 wake_up_interruptible(&state->wait_queue);
 622         }
 623         spin_unlock_irqrestore(&state->lock, flags);
 624 }
 625
 626 static int
 627 do_adb_query(struct adb_request *req)
 628 {
 629         int     ret = -EINVAL;
 630
 631         switch(req->data[1])
 632         {
 633         case ADB_QUERY_GETDEVINFO:
 634                 if (req->nbytes < 3)
 635                         break;
 636                 mutex_lock(&adb_handler_mutex);
 637                 req->reply[0] = adb_handler[req->data[2]].original_address;
 638                 req->reply[1] = adb_handler[req->data[2]].handler_id;
 639                 mutex_unlock(&adb_handler_mutex);
 640                 req->complete = 1;
 641                 req->reply_len = 2;
 642                 adb_write_done(req);
 643                 ret = 0;
 644                 break;
 645         }
 646         return ret;
 647 }
 648
 649 static int adb_open(struct inode *inode, struct file *file)
 650 {
 651         struct adbdev_state *state;
 652         int ret = 0;
 653
 654         mutex_lock(&adb_mutex);
 655         if (iminor(inode) > 0 || adb_controller == NULL) {
 656                 ret = -ENXIO;
 657                 goto out;
 658         }
 659         state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
 660         if (state == 0) {
 661                 ret = -ENOMEM;
 662                 goto out;
 663         }
 664         file->private_data = state;
 665         spin_lock_init(&state->lock);
 666         atomic_set(&state->n_pending, 0);
 667         state->completed = NULL;
 668         init_waitqueue_head(&state->wait_queue);
 669         state->inuse = 1;
 670
 671 out:
 672         mutex_unlock(&adb_mutex);
 673         return ret;
 674 }
 675
 676 static int adb_release(struct inode *inode, struct file *file)
 677 {
 678         struct adbdev_state *state = file->private_data;
 679         unsigned long flags;
 680
 681         mutex_lock(&adb_mutex);
 682         if (state) {
 683                 file->private_data = NULL;
 684                 spin_lock_irqsave(&state->lock, flags);
 685                 if (atomic_read(&state->n_pending) == 0
 686                     && state->completed == NULL) {
 687                         spin_unlock_irqrestore(&state->lock, flags);
 688                         kfree(state);
 689                 } else {
 690                         state->inuse = 0;
 691                         spin_unlock_irqrestore(&state->lock, flags);
 692                 }
 693         }
 694         mutex_unlock(&adb_mutex);
 695         return 0;
 696 }
 697
 698 static ssize_t adb_read(struct file *file, char __user *buf,
 699                         size_t count, loff_t *ppos)
 700 {
 701         int ret = 0;
 702         struct adbdev_state *state = file->private_data;
 703         struct adb_request *req;
 704         wait_queue_t wait = __WAITQUEUE_INITIALIZER(wait,current);
 705         unsigned long flags;
 706
 707         if (count < 2)
 708                 return -EINVAL;
 709         if (count > sizeof(req->reply))
 710                 count = sizeof(req->reply);
 711         if (!access_ok(VERIFY_WRITE, buf, count))
 712                 return -EFAULT;
 713
 714         req = NULL;
 715         spin_lock_irqsave(&state->lock, flags);
 716         add_wait_queue(&state->wait_queue, &wait);
 717         set_current_state(TASK_INTERRUPTIBLE);
 718
 719         for (;;) {
 720                 req = state->completed;
 721                 if (req != NULL)
 722                         state->completed = req->next;
 723                 else if (atomic_read(&state->n_pending) == 0)
 724                         ret = -EIO;
 725                 if (req != NULL || ret != 0)
 726                         break;
 727
 728                 if (file->f_flags & O_NONBLOCK) {
 729                         ret = -EAGAIN;
 730                         break;
 731                 }
 732                 if (signal_pending(current)) {
 733                         ret = -ERESTARTSYS;
 734                         break;
 735                 }
 736                 spin_unlock_irqrestore(&state->lock, flags);
 737                 schedule();
 738                 spin_lock_irqsave(&state->lock, flags);
 739         }
 740
 741         set_current_state(TASK_RUNNING);
 742         remove_wait_queue(&state->wait_queue, &wait);
 743         spin_unlock_irqrestore(&state->lock, flags);
 744
 745         if (ret)
 746                 return ret;
 747
 748         ret = req->reply_len;
 749         if (ret > count)
 750                 ret = count;
 751         if (ret > 0 && copy_to_user(buf, req->reply, ret))
 752                 ret = -EFAULT;
 753
 754         kfree(req);
 755         return ret;
 756 }
 757
 758 static ssize_t adb_write(struct file *file, const char __user *buf,
 759                          size_t count, loff_t *ppos)
 760 {
 761         int ret/*, i*/;
 762         struct adbdev_state *state = file->private_data;
 763         struct adb_request *req;
 764
 765         if (count < 2 || count > sizeof(req->data))
 766                 return -EINVAL;
 767         if (adb_controller == NULL)
 768                 return -ENXIO;
 769         if (!access_ok(VERIFY_READ, buf, count))
 770                 return -EFAULT;
 771
 772         req = kmalloc(sizeof(struct adb_request),
 773                                              GFP_KERNEL);
 774         if (req == NULL)
 775                 return -ENOMEM;
 776
 777         req->nbytes = count;
 778         req->done = adb_write_done;
 779         req->arg = (void *) state;
 780         req->complete = 0;
 781
 782         ret = -EFAULT;
 783         if (copy_from_user(req->data, buf, count))
 784                 goto out;
 785
 786         atomic_inc(&state->n_pending);
 787
 788         /* If a probe is in progress or we are sleeping, wait for it to complete */
 789         down(&adb_probe_mutex);
 790
 791         /* Queries are special requests sent to the ADB driver itself */
 792         if (req->data[0] == ADB_QUERY) {
 793                 if (count > 1)
 794                         ret = do_adb_query(req);
 795                 else
 796                         ret = -EINVAL;
 797                 up(&adb_probe_mutex);
 798         }
 799         /* Special case for ADB_BUSRESET request, all others are sent to
 800            the controller */
 801         else if ((req->data[0] == ADB_PACKET)&&(count > 1)
 802                 &&(req->data[1] == ADB_BUSRESET)) {
 803                 ret = do_adb_reset_bus();
 804                 up(&adb_probe_mutex);
 805                 atomic_dec(&state->n_pending);
 806                 if (ret == 0)
 807                         ret = count;
 808                 goto out;
 809         } else {
 810                 req->reply_expected = ((req->data[1] & 0xc) == 0xc);
 811                 if (adb_controller && adb_controller->send_request)
 812                         ret = adb_controller->send_request(req, 0);
 813                 else
 814                         ret = -ENXIO;
 815                 up(&adb_probe_mutex);
 816         }
 817
 818         if (ret != 0) {
 819                 atomic_dec(&state->n_pending);
 820                 goto out;
 821         }
 822         return count;
 823
 824 out:
 825         kfree(req);
 826         return ret;
 827 }
 828
 829 static const struct file_operations adb_fops = {
 830         .owner          = THIS_MODULE,
 831         .llseek         = no_llseek,
 832         .read           = adb_read,
 833         .write          = adb_write,
 834         .open           = adb_open,
 835         .release        = adb_release,
 836 };
 837
 838 static struct platform_driver adb_pfdrv = {
 839         .driver = {
 840                 .name = "adb",
 841         },
 842 #ifdef CONFIG_PM
 843         .suspend = adb_suspend,
 844         .resume = adb_resume,
 845 #endif
 846 };
 847
 848 static struct platform_device adb_pfdev = {
 849         .name = "adb",
 850 };
 851
 852 static int __init
 853 adb_dummy_probe(struct platform_device *dev)
 854 {
 855         if (dev == &adb_pfdev)
 856                 return 0;
 857         return -ENODEV;
 858 }
 859
 860 static void __init
 861 adbdev_init(void)
 862 {
 863         if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
 864                 printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
 865                 return;
 866         }
 867
 868         adb_dev_class = class_create(THIS_MODULE, "adb");
 869         if (IS_ERR(adb_dev_class))
 870                 return;
 871         device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
 872
 873         platform_device_register(&adb_pfdev);
 874         platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
 875 }