linux/drivers/macintosh/adb.c
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   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 <linux/uaccess.h>
  42#ifdef CONFIG_PPC
  43#include <asm/prom.h>
  44#include <asm/machdep.h>
  45#endif
  46
  47
  48EXPORT_SYMBOL(adb_client_list);
  49
  50extern struct adb_driver via_macii_driver;
  51extern struct adb_driver via_maciisi_driver;
  52extern struct adb_driver via_cuda_driver;
  53extern struct adb_driver adb_iop_driver;
  54extern struct adb_driver via_pmu_driver;
  55extern struct adb_driver macio_adb_driver;
  56
  57static DEFINE_MUTEX(adb_mutex);
  58static 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
  80static struct class *adb_dev_class;
  81
  82static struct adb_driver *adb_controller;
  83BLOCKING_NOTIFIER_HEAD(adb_client_list);
  84static int adb_got_sleep;
  85static int adb_inited;
  86static DEFINE_SEMAPHORE(adb_probe_mutex);
  87static int sleepy_trackpad;
  88static int autopoll_devs;
  89int __adb_probe_sync;
  90
  91static int adb_scan_bus(void);
  92static int do_adb_reset_bus(void);
  93static void adbdev_init(void);
  94static int try_handler_change(int, int);
  95
  96static 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 */
 112static DEFINE_MUTEX(adb_handler_mutex);
 113static DEFINE_RWLOCK(adb_handler_lock);
 114
 115#if 0
 116static 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
 128static 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                        } else {
 197                                /*
 198                                 * No devices left at address i; move the
 199                                 * one(s) we moved to `highFree' back to i.
 200                                 */
 201                                adb_request(&req, NULL, ADBREQ_SYNC, 3,
 202                                            (highFree << 4) | 0xb,
 203                                            (i | 0x60), 0xfe);
 204                        }
 205                }       
 206        }
 207
 208        /* Now fill in the handler_id field of the adb_handler entries. */
 209        printk(KERN_DEBUG "adb devices:");
 210        for (i = 1; i < 16; i++) {
 211                if (adb_handler[i].original_address == 0)
 212                        continue;
 213                adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 214                            (i << 4) | 0xf);
 215                adb_handler[i].handler_id = req.reply[2];
 216                printk(" [%d]: %d %x", i, adb_handler[i].original_address,
 217                       adb_handler[i].handler_id);
 218                devmask |= 1 << i;
 219        }
 220        printk("\n");
 221        return devmask;
 222}
 223
 224/*
 225 * This kernel task handles ADB probing. It dies once probing is
 226 * completed.
 227 */
 228static int
 229adb_probe_task(void *x)
 230{
 231        printk(KERN_INFO "adb: starting probe task...\n");
 232        do_adb_reset_bus();
 233        printk(KERN_INFO "adb: finished probe task...\n");
 234
 235        up(&adb_probe_mutex);
 236
 237        return 0;
 238}
 239
 240static void
 241__adb_probe_task(struct work_struct *bullshit)
 242{
 243        kthread_run(adb_probe_task, NULL, "kadbprobe");
 244}
 245
 246static DECLARE_WORK(adb_reset_work, __adb_probe_task);
 247
 248int
 249adb_reset_bus(void)
 250{
 251        if (__adb_probe_sync) {
 252                do_adb_reset_bus();
 253                return 0;
 254        }
 255
 256        down(&adb_probe_mutex);
 257        schedule_work(&adb_reset_work);
 258        return 0;
 259}
 260
 261#ifdef CONFIG_PM
 262/*
 263 * notify clients before sleep
 264 */
 265static int __adb_suspend(struct platform_device *dev, pm_message_t state)
 266{
 267        adb_got_sleep = 1;
 268        /* We need to get a lock on the probe thread */
 269        down(&adb_probe_mutex);
 270        /* Stop autopoll */
 271        if (adb_controller->autopoll)
 272                adb_controller->autopoll(0);
 273        blocking_notifier_call_chain(&adb_client_list, ADB_MSG_POWERDOWN, NULL);
 274
 275        return 0;
 276}
 277
 278static int adb_suspend(struct device *dev)
 279{
 280        return __adb_suspend(to_platform_device(dev), PMSG_SUSPEND);
 281}
 282
 283static int adb_freeze(struct device *dev)
 284{
 285        return __adb_suspend(to_platform_device(dev), PMSG_FREEZE);
 286}
 287
 288static int adb_poweroff(struct device *dev)
 289{
 290        return __adb_suspend(to_platform_device(dev), PMSG_HIBERNATE);
 291}
 292
 293/*
 294 * reset bus after sleep
 295 */
 296static int __adb_resume(struct platform_device *dev)
 297{
 298        adb_got_sleep = 0;
 299        up(&adb_probe_mutex);
 300        adb_reset_bus();
 301
 302        return 0;
 303}
 304
 305static int adb_resume(struct device *dev)
 306{
 307        return __adb_resume(to_platform_device(dev));
 308}
 309#endif /* CONFIG_PM */
 310
 311static int __init adb_init(void)
 312{
 313        struct adb_driver *driver;
 314        int i;
 315
 316#ifdef CONFIG_PPC32
 317        if (!machine_is(chrp) && !machine_is(powermac))
 318                return 0;
 319#endif
 320#ifdef CONFIG_MAC
 321        if (!MACH_IS_MAC)
 322                return 0;
 323#endif
 324
 325        /* xmon may do early-init */
 326        if (adb_inited)
 327                return 0;
 328        adb_inited = 1;
 329                
 330        adb_controller = NULL;
 331
 332        i = 0;
 333        while ((driver = adb_driver_list[i++]) != NULL) {
 334                if (!driver->probe()) {
 335                        adb_controller = driver;
 336                        break;
 337                }
 338        }
 339        if (adb_controller != NULL && adb_controller->init &&
 340            adb_controller->init())
 341                adb_controller = NULL;
 342        if (adb_controller == NULL) {
 343                printk(KERN_WARNING "Warning: no ADB interface detected\n");
 344        } else {
 345#ifdef CONFIG_PPC
 346                if (of_machine_is_compatible("AAPL,PowerBook1998") ||
 347                        of_machine_is_compatible("PowerBook1,1"))
 348                        sleepy_trackpad = 1;
 349#endif /* CONFIG_PPC */
 350
 351                adbdev_init();
 352                adb_reset_bus();
 353        }
 354        return 0;
 355}
 356
 357device_initcall(adb_init);
 358
 359static int
 360do_adb_reset_bus(void)
 361{
 362        int ret;
 363        
 364        if (adb_controller == NULL)
 365                return -ENXIO;
 366                
 367        if (adb_controller->autopoll)
 368                adb_controller->autopoll(0);
 369
 370        blocking_notifier_call_chain(&adb_client_list,
 371                ADB_MSG_PRE_RESET, NULL);
 372
 373        if (sleepy_trackpad) {
 374                /* Let the trackpad settle down */
 375                msleep(500);
 376        }
 377
 378        mutex_lock(&adb_handler_mutex);
 379        write_lock_irq(&adb_handler_lock);
 380        memset(adb_handler, 0, sizeof(adb_handler));
 381        write_unlock_irq(&adb_handler_lock);
 382
 383        /* That one is still a bit synchronous, oh well... */
 384        if (adb_controller->reset_bus)
 385                ret = adb_controller->reset_bus();
 386        else
 387                ret = 0;
 388
 389        if (sleepy_trackpad) {
 390                /* Let the trackpad settle down */
 391                msleep(1500);
 392        }
 393
 394        if (!ret) {
 395                autopoll_devs = adb_scan_bus();
 396                if (adb_controller->autopoll)
 397                        adb_controller->autopoll(autopoll_devs);
 398        }
 399        mutex_unlock(&adb_handler_mutex);
 400
 401        blocking_notifier_call_chain(&adb_client_list,
 402                ADB_MSG_POST_RESET, NULL);
 403        
 404        return ret;
 405}
 406
 407void
 408adb_poll(void)
 409{
 410        if ((adb_controller == NULL)||(adb_controller->poll == NULL))
 411                return;
 412        adb_controller->poll();
 413}
 414
 415static void adb_sync_req_done(struct adb_request *req)
 416{
 417        struct completion *comp = req->arg;
 418
 419        complete(comp);
 420}
 421
 422int
 423adb_request(struct adb_request *req, void (*done)(struct adb_request *),
 424            int flags, int nbytes, ...)
 425{
 426        va_list list;
 427        int i;
 428        int rc;
 429        struct completion comp;
 430
 431        if ((adb_controller == NULL) || (adb_controller->send_request == NULL))
 432                return -ENXIO;
 433        if (nbytes < 1)
 434                return -EINVAL;
 435
 436        req->nbytes = nbytes+1;
 437        req->done = done;
 438        req->reply_expected = flags & ADBREQ_REPLY;
 439        req->data[0] = ADB_PACKET;
 440        va_start(list, nbytes);
 441        for (i = 0; i < nbytes; ++i)
 442                req->data[i+1] = va_arg(list, int);
 443        va_end(list);
 444
 445        if (flags & ADBREQ_NOSEND)
 446                return 0;
 447
 448        /* Synchronous requests block using an on-stack completion */
 449        if (flags & ADBREQ_SYNC) {
 450                WARN_ON(done);
 451                req->done = adb_sync_req_done;
 452                req->arg = &comp;
 453                init_completion(&comp);
 454        }
 455
 456        rc = adb_controller->send_request(req, 0);
 457
 458        if ((flags & ADBREQ_SYNC) && !rc && !req->complete)
 459                wait_for_completion(&comp);
 460
 461        return rc;
 462}
 463
 464 /* Ultimately this should return the number of devices with
 465    the given default id.
 466    And it does it now ! Note: changed behaviour: This function
 467    will now register if default_id _and_ handler_id both match
 468    but handler_id can be left to 0 to match with default_id only.
 469    When handler_id is set, this function will try to adjust
 470    the handler_id id it doesn't match. */
 471int
 472adb_register(int default_id, int handler_id, struct adb_ids *ids,
 473             void (*handler)(unsigned char *, int, int))
 474{
 475        int i;
 476
 477        mutex_lock(&adb_handler_mutex);
 478        ids->nids = 0;
 479        for (i = 1; i < 16; i++) {
 480                if ((adb_handler[i].original_address == default_id) &&
 481                    (!handler_id || (handler_id == adb_handler[i].handler_id) || 
 482                    try_handler_change(i, handler_id))) {
 483                        if (adb_handler[i].handler != 0) {
 484                                printk(KERN_ERR
 485                                       "Two handlers for ADB device %d\n",
 486                                       default_id);
 487                                continue;
 488                        }
 489                        write_lock_irq(&adb_handler_lock);
 490                        adb_handler[i].handler = handler;
 491                        write_unlock_irq(&adb_handler_lock);
 492                        ids->id[ids->nids++] = i;
 493                }
 494        }
 495        mutex_unlock(&adb_handler_mutex);
 496        return ids->nids;
 497}
 498
 499int
 500adb_unregister(int index)
 501{
 502        int ret = -ENODEV;
 503
 504        mutex_lock(&adb_handler_mutex);
 505        write_lock_irq(&adb_handler_lock);
 506        if (adb_handler[index].handler) {
 507                while(adb_handler[index].busy) {
 508                        write_unlock_irq(&adb_handler_lock);
 509                        yield();
 510                        write_lock_irq(&adb_handler_lock);
 511                }
 512                ret = 0;
 513                adb_handler[index].handler = NULL;
 514        }
 515        write_unlock_irq(&adb_handler_lock);
 516        mutex_unlock(&adb_handler_mutex);
 517        return ret;
 518}
 519
 520void
 521adb_input(unsigned char *buf, int nb, int autopoll)
 522{
 523        int i, id;
 524        static int dump_adb_input;
 525        unsigned long flags;
 526        
 527        void (*handler)(unsigned char *, int, int);
 528
 529        /* We skip keystrokes and mouse moves when the sleep process
 530         * has been started. We stop autopoll, but this is another security
 531         */
 532        if (adb_got_sleep)
 533                return;
 534                
 535        id = buf[0] >> 4;
 536        if (dump_adb_input) {
 537                printk(KERN_INFO "adb packet: ");
 538                for (i = 0; i < nb; ++i)
 539                        printk(" %x", buf[i]);
 540                printk(", id = %d\n", id);
 541        }
 542        write_lock_irqsave(&adb_handler_lock, flags);
 543        handler = adb_handler[id].handler;
 544        if (handler != NULL)
 545                adb_handler[id].busy = 1;
 546        write_unlock_irqrestore(&adb_handler_lock, flags);
 547        if (handler != NULL) {
 548                (*handler)(buf, nb, autopoll);
 549                wmb();
 550                adb_handler[id].busy = 0;
 551        }
 552                
 553}
 554
 555/* Try to change handler to new_id. Will return 1 if successful. */
 556static int try_handler_change(int address, int new_id)
 557{
 558        struct adb_request req;
 559
 560        if (adb_handler[address].handler_id == new_id)
 561            return 1;
 562        adb_request(&req, NULL, ADBREQ_SYNC, 3,
 563            ADB_WRITEREG(address, 3), address | 0x20, new_id);
 564        adb_request(&req, NULL, ADBREQ_SYNC | ADBREQ_REPLY, 1,
 565            ADB_READREG(address, 3));
 566        if (req.reply_len < 2)
 567            return 0;
 568        if (req.reply[2] != new_id)
 569            return 0;
 570        adb_handler[address].handler_id = req.reply[2];
 571
 572        return 1;
 573}
 574
 575int
 576adb_try_handler_change(int address, int new_id)
 577{
 578        int ret;
 579
 580        mutex_lock(&adb_handler_mutex);
 581        ret = try_handler_change(address, new_id);
 582        mutex_unlock(&adb_handler_mutex);
 583        return ret;
 584}
 585
 586int
 587adb_get_infos(int address, int *original_address, int *handler_id)
 588{
 589        mutex_lock(&adb_handler_mutex);
 590        *original_address = adb_handler[address].original_address;
 591        *handler_id = adb_handler[address].handler_id;
 592        mutex_unlock(&adb_handler_mutex);
 593
 594        return (*original_address != 0);
 595}
 596
 597
 598/*
 599 * /dev/adb device driver.
 600 */
 601
 602#define ADB_MAJOR       56      /* major number for /dev/adb */
 603
 604struct adbdev_state {
 605        spinlock_t      lock;
 606        atomic_t        n_pending;
 607        struct adb_request *completed;
 608        wait_queue_head_t wait_queue;
 609        int             inuse;
 610};
 611
 612static void adb_write_done(struct adb_request *req)
 613{
 614        struct adbdev_state *state = (struct adbdev_state *) req->arg;
 615        unsigned long flags;
 616
 617        if (!req->complete) {
 618                req->reply_len = 0;
 619                req->complete = 1;
 620        }
 621        spin_lock_irqsave(&state->lock, flags);
 622        atomic_dec(&state->n_pending);
 623        if (!state->inuse) {
 624                kfree(req);
 625                if (atomic_read(&state->n_pending) == 0) {
 626                        spin_unlock_irqrestore(&state->lock, flags);
 627                        kfree(state);
 628                        return;
 629                }
 630        } else {
 631                struct adb_request **ap = &state->completed;
 632                while (*ap != NULL)
 633                        ap = &(*ap)->next;
 634                req->next = NULL;
 635                *ap = req;
 636                wake_up_interruptible(&state->wait_queue);
 637        }
 638        spin_unlock_irqrestore(&state->lock, flags);
 639}
 640
 641static int
 642do_adb_query(struct adb_request *req)
 643{
 644        int     ret = -EINVAL;
 645
 646        switch(req->data[1]) {
 647        case ADB_QUERY_GETDEVINFO:
 648                if (req->nbytes < 3)
 649                        break;
 650                mutex_lock(&adb_handler_mutex);
 651                req->reply[0] = adb_handler[req->data[2]].original_address;
 652                req->reply[1] = adb_handler[req->data[2]].handler_id;
 653                mutex_unlock(&adb_handler_mutex);
 654                req->complete = 1;
 655                req->reply_len = 2;
 656                adb_write_done(req);
 657                ret = 0;
 658                break;
 659        }
 660        return ret;
 661}
 662
 663static int adb_open(struct inode *inode, struct file *file)
 664{
 665        struct adbdev_state *state;
 666        int ret = 0;
 667
 668        mutex_lock(&adb_mutex);
 669        if (iminor(inode) > 0 || adb_controller == NULL) {
 670                ret = -ENXIO;
 671                goto out;
 672        }
 673        state = kmalloc(sizeof(struct adbdev_state), GFP_KERNEL);
 674        if (state == 0) {
 675                ret = -ENOMEM;
 676                goto out;
 677        }
 678        file->private_data = state;
 679        spin_lock_init(&state->lock);
 680        atomic_set(&state->n_pending, 0);
 681        state->completed = NULL;
 682        init_waitqueue_head(&state->wait_queue);
 683        state->inuse = 1;
 684
 685out:
 686        mutex_unlock(&adb_mutex);
 687        return ret;
 688}
 689
 690static int adb_release(struct inode *inode, struct file *file)
 691{
 692        struct adbdev_state *state = file->private_data;
 693        unsigned long flags;
 694
 695        mutex_lock(&adb_mutex);
 696        if (state) {
 697                file->private_data = NULL;
 698                spin_lock_irqsave(&state->lock, flags);
 699                if (atomic_read(&state->n_pending) == 0
 700                    && state->completed == NULL) {
 701                        spin_unlock_irqrestore(&state->lock, flags);
 702                        kfree(state);
 703                } else {
 704                        state->inuse = 0;
 705                        spin_unlock_irqrestore(&state->lock, flags);
 706                }
 707        }
 708        mutex_unlock(&adb_mutex);
 709        return 0;
 710}
 711
 712static ssize_t adb_read(struct file *file, char __user *buf,
 713                        size_t count, loff_t *ppos)
 714{
 715        int ret = 0;
 716        struct adbdev_state *state = file->private_data;
 717        struct adb_request *req;
 718        DECLARE_WAITQUEUE(wait, current);
 719        unsigned long flags;
 720
 721        if (count < 2)
 722                return -EINVAL;
 723        if (count > sizeof(req->reply))
 724                count = sizeof(req->reply);
 725        if (!access_ok(VERIFY_WRITE, buf, count))
 726                return -EFAULT;
 727
 728        req = NULL;
 729        spin_lock_irqsave(&state->lock, flags);
 730        add_wait_queue(&state->wait_queue, &wait);
 731        set_current_state(TASK_INTERRUPTIBLE);
 732
 733        for (;;) {
 734                req = state->completed;
 735                if (req != NULL)
 736                        state->completed = req->next;
 737                else if (atomic_read(&state->n_pending) == 0)
 738                        ret = -EIO;
 739                if (req != NULL || ret != 0)
 740                        break;
 741                
 742                if (file->f_flags & O_NONBLOCK) {
 743                        ret = -EAGAIN;
 744                        break;
 745                }
 746                if (signal_pending(current)) {
 747                        ret = -ERESTARTSYS;
 748                        break;
 749                }
 750                spin_unlock_irqrestore(&state->lock, flags);
 751                schedule();
 752                spin_lock_irqsave(&state->lock, flags);
 753        }
 754
 755        set_current_state(TASK_RUNNING);
 756        remove_wait_queue(&state->wait_queue, &wait);
 757        spin_unlock_irqrestore(&state->lock, flags);
 758        
 759        if (ret)
 760                return ret;
 761
 762        ret = req->reply_len;
 763        if (ret > count)
 764                ret = count;
 765        if (ret > 0 && copy_to_user(buf, req->reply, ret))
 766                ret = -EFAULT;
 767
 768        kfree(req);
 769        return ret;
 770}
 771
 772static ssize_t adb_write(struct file *file, const char __user *buf,
 773                         size_t count, loff_t *ppos)
 774{
 775        int ret/*, i*/;
 776        struct adbdev_state *state = file->private_data;
 777        struct adb_request *req;
 778
 779        if (count < 2 || count > sizeof(req->data))
 780                return -EINVAL;
 781        if (adb_controller == NULL)
 782                return -ENXIO;
 783        if (!access_ok(VERIFY_READ, buf, count))
 784                return -EFAULT;
 785
 786        req = kmalloc(sizeof(struct adb_request),
 787                                             GFP_KERNEL);
 788        if (req == NULL)
 789                return -ENOMEM;
 790
 791        req->nbytes = count;
 792        req->done = adb_write_done;
 793        req->arg = (void *) state;
 794        req->complete = 0;
 795        
 796        ret = -EFAULT;
 797        if (copy_from_user(req->data, buf, count))
 798                goto out;
 799
 800        atomic_inc(&state->n_pending);
 801
 802        /* If a probe is in progress or we are sleeping, wait for it to complete */
 803        down(&adb_probe_mutex);
 804
 805        /* Queries are special requests sent to the ADB driver itself */
 806        if (req->data[0] == ADB_QUERY) {
 807                if (count > 1)
 808                        ret = do_adb_query(req);
 809                else
 810                        ret = -EINVAL;
 811                up(&adb_probe_mutex);
 812        }
 813        /* Special case for ADB_BUSRESET request, all others are sent to
 814           the controller */
 815        else if ((req->data[0] == ADB_PACKET) && (count > 1)
 816                && (req->data[1] == ADB_BUSRESET)) {
 817                ret = do_adb_reset_bus();
 818                up(&adb_probe_mutex);
 819                atomic_dec(&state->n_pending);
 820                if (ret == 0)
 821                        ret = count;
 822                goto out;
 823        } else {        
 824                req->reply_expected = ((req->data[1] & 0xc) == 0xc);
 825                if (adb_controller && adb_controller->send_request)
 826                        ret = adb_controller->send_request(req, 0);
 827                else
 828                        ret = -ENXIO;
 829                up(&adb_probe_mutex);
 830        }
 831
 832        if (ret != 0) {
 833                atomic_dec(&state->n_pending);
 834                goto out;
 835        }
 836        return count;
 837
 838out:
 839        kfree(req);
 840        return ret;
 841}
 842
 843static const struct file_operations adb_fops = {
 844        .owner          = THIS_MODULE,
 845        .llseek         = no_llseek,
 846        .read           = adb_read,
 847        .write          = adb_write,
 848        .open           = adb_open,
 849        .release        = adb_release,
 850};
 851
 852#ifdef CONFIG_PM
 853static const struct dev_pm_ops adb_dev_pm_ops = {
 854        .suspend = adb_suspend,
 855        .resume = adb_resume,
 856        /* Hibernate hooks */
 857        .freeze = adb_freeze,
 858        .thaw = adb_resume,
 859        .poweroff = adb_poweroff,
 860        .restore = adb_resume,
 861};
 862#endif
 863
 864static struct platform_driver adb_pfdrv = {
 865        .driver = {
 866                .name = "adb",
 867#ifdef CONFIG_PM
 868                .pm = &adb_dev_pm_ops,
 869#endif
 870        },
 871};
 872
 873static struct platform_device adb_pfdev = {
 874        .name = "adb",
 875};
 876
 877static int __init
 878adb_dummy_probe(struct platform_device *dev)
 879{
 880        if (dev == &adb_pfdev)
 881                return 0;
 882        return -ENODEV;
 883}
 884
 885static void __init
 886adbdev_init(void)
 887{
 888        if (register_chrdev(ADB_MAJOR, "adb", &adb_fops)) {
 889                printk(KERN_ERR "adb: unable to get major %d\n", ADB_MAJOR);
 890                return;
 891        }
 892
 893        adb_dev_class = class_create(THIS_MODULE, "adb");
 894        if (IS_ERR(adb_dev_class))
 895                return;
 896        device_create(adb_dev_class, NULL, MKDEV(ADB_MAJOR, 0), NULL, "adb");
 897
 898        platform_device_register(&adb_pfdev);
 899        platform_driver_probe(&adb_pfdrv, adb_dummy_probe);
 900}
 901