drivers/sh/maple/maple.c

   1 /*
   2  * Core maple bus functionality
   3  *
   4  *  Copyright (C) 2007 - 2009 Adrian McMenamin
   5  *  Copyright (C) 2001 - 2008 Paul Mundt
   6  *  Copyright (C) 2000 - 2001 YAEGASHI Takeshi
   7  *  Copyright (C) 2001 M. R. Brown
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/device.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/list.h>
  18 #include <linux/io.h>
  19 #include <linux/slab.h>
  20 #include <linux/maple.h>
  21 #include <linux/dma-mapping.h>
  22 #include <linux/delay.h>
  23 #include <linux/module.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/dma.h>
  26 #include <asm/io.h>
  27 #include <mach/dma.h>
  28 #include <mach/sysasic.h>
  29
  30 MODULE_AUTHOR("Adrian McMenamin <[email protected]>");
  31 MODULE_DESCRIPTION("Maple bus driver for Dreamcast");
  32 MODULE_LICENSE("GPL v2");
  33
  34 static void maple_dma_handler(struct work_struct *work);
  35 static void maple_vblank_handler(struct work_struct *work);
  36
  37 static DECLARE_WORK(maple_dma_process, maple_dma_handler);
  38 static DECLARE_WORK(maple_vblank_process, maple_vblank_handler);
  39
  40 static LIST_HEAD(maple_waitq);
  41 static LIST_HEAD(maple_sentq);
  42
  43 /* mutex to protect queue of waiting packets */
  44 static DEFINE_MUTEX(maple_wlist_lock);
  45
  46 static struct maple_driver maple_unsupported_device;
  47 static struct device maple_bus;
  48 static int subdevice_map[MAPLE_PORTS];
  49 static unsigned long *maple_sendbuf, *maple_sendptr, *maple_lastptr;
  50 static unsigned long maple_pnp_time;
  51 static int started, scanning, fullscan;
  52 static struct kmem_cache *maple_queue_cache;
  53
  54 struct maple_device_specify {
  55         int port;
  56         int unit;
  57 };
  58
  59 static bool checked[MAPLE_PORTS];
  60 static bool empty[MAPLE_PORTS];
  61 static struct maple_device *baseunits[MAPLE_PORTS];
  62
  63 /**
  64  * maple_driver_register - register a maple driver
  65  * @drv: maple driver to be registered.
  66  *
  67  * Registers the passed in @drv, while updating the bus type.
  68  * Devices with matching function IDs will be automatically probed.
  69  */
  70 int maple_driver_register(struct maple_driver *drv)
  71 {
  72         if (!drv)
  73                 return -EINVAL;
  74
  75         drv->drv.bus = &maple_bus_type;
  76
  77         return driver_register(&drv->drv);
  78 }
  79 EXPORT_SYMBOL_GPL(maple_driver_register);
  80
  81 /**
  82  * maple_driver_unregister - unregister a maple driver.
  83  * @drv: maple driver to unregister.
  84  *
  85  * Cleans up after maple_driver_register(). To be invoked in the exit
  86  * path of any module drivers.
  87  */
  88 void maple_driver_unregister(struct maple_driver *drv)
  89 {
  90         driver_unregister(&drv->drv);
  91 }
  92 EXPORT_SYMBOL_GPL(maple_driver_unregister);
  93
  94 /* set hardware registers to enable next round of dma */
  95 static void maple_dma_reset(void)
  96 {
  97         __raw_writel(MAPLE_MAGIC, MAPLE_RESET);
  98         /* set trig type to 0 for software trigger, 1 for hardware (VBLANK) */
  99         __raw_writel(1, MAPLE_TRIGTYPE);
 100         /*
 101         * Maple system register
 102         * bits 31 - 16  timeout in units of 20nsec
 103         * bit 12        hard trigger - set 0 to keep responding to VBLANK
 104         * bits 9 - 8    set 00 for 2 Mbps, 01 for 1 Mbps
 105         * bits 3 - 0    delay (in 1.3ms) between VBLANK and start of DMA
 106         * max delay is 11
 107         */
 108         __raw_writel(MAPLE_2MBPS | MAPLE_TIMEOUT(0xFFFF), MAPLE_SPEED);
 109         __raw_writel(virt_to_phys(maple_sendbuf), MAPLE_DMAADDR);
 110         __raw_writel(1, MAPLE_ENABLE);
 111 }
 112
 113 /**
 114  * maple_getcond_callback - setup handling MAPLE_COMMAND_GETCOND
 115  * @dev: device responding
 116  * @callback: handler callback
 117  * @interval: interval in jiffies between callbacks
 118  * @function: the function code for the device
 119  */
 120 void maple_getcond_callback(struct maple_device *dev,
 121                         void (*callback) (struct mapleq *mq),
 122                         unsigned long interval, unsigned long function)
 123 {
 124         dev->callback = callback;
 125         dev->interval = interval;
 126         dev->function = cpu_to_be32(function);
 127         dev->when = jiffies;
 128 }
 129 EXPORT_SYMBOL_GPL(maple_getcond_callback);
 130
 131 static int maple_dma_done(void)
 132 {
 133         return (__raw_readl(MAPLE_STATE) & 1) == 0;
 134 }
 135
 136 static void maple_release_device(struct device *dev)
 137 {
 138         struct maple_device *mdev;
 139         struct mapleq *mq;
 140
 141         mdev = to_maple_dev(dev);
 142         mq = mdev->mq;
 143         kmem_cache_free(maple_queue_cache, mq->recvbuf);
 144         kfree(mq);
 145         kfree(mdev);
 146 }
 147
 148 /**
 149  * maple_add_packet - add a single instruction to the maple bus queue
 150  * @mdev: maple device
 151  * @function: function on device being queried
 152  * @command: maple command to add
 153  * @length: length of command string (in 32 bit words)
 154  * @data: remainder of command string
 155  */
 156 int maple_add_packet(struct maple_device *mdev, u32 function, u32 command,
 157         size_t length, void *data)
 158 {
 159         int ret = 0;
 160         void *sendbuf = NULL;
 161
 162         if (length) {
 163                 sendbuf = kcalloc(length, 4, GFP_KERNEL);
 164                 if (!sendbuf) {
 165                         ret = -ENOMEM;
 166                         goto out;
 167                 }
 168                 ((__be32 *)sendbuf)[0] = cpu_to_be32(function);
 169         }
 170
 171         mdev->mq->command = command;
 172         mdev->mq->length = length;
 173         if (length > 1)
 174                 memcpy(sendbuf + 4, data, (length - 1) * 4);
 175         mdev->mq->sendbuf = sendbuf;
 176
 177         mutex_lock(&maple_wlist_lock);
 178         list_add_tail(&mdev->mq->list, &maple_waitq);
 179         mutex_unlock(&maple_wlist_lock);
 180 out:
 181         return ret;
 182 }
 183 EXPORT_SYMBOL_GPL(maple_add_packet);
 184
 185 static struct mapleq *maple_allocq(struct maple_device *mdev)
 186 {
 187         struct mapleq *mq;
 188
 189         mq = kzalloc(sizeof(*mq), GFP_KERNEL);
 190         if (!mq)
 191                 goto failed_nomem;
 192
 193         INIT_LIST_HEAD(&mq->list);
 194         mq->dev = mdev;
 195         mq->recvbuf = kmem_cache_zalloc(maple_queue_cache, GFP_KERNEL);
 196         if (!mq->recvbuf)
 197                 goto failed_p2;
 198         mq->recvbuf->buf = &((mq->recvbuf->bufx)[0]);
 199
 200         return mq;
 201
 202 failed_p2:
 203         kfree(mq);
 204 failed_nomem:
 205         dev_err(&mdev->dev, "could not allocate memory for device (%d, %d)\n",
 206                 mdev->port, mdev->unit);
 207         return NULL;
 208 }
 209
 210 static struct maple_device *maple_alloc_dev(int port, int unit)
 211 {
 212         struct maple_device *mdev;
 213
 214         /* zero this out to avoid kobj subsystem
 215         * thinking it has already been registered */
 216
 217         mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
 218         if (!mdev)
 219                 return NULL;
 220
 221         mdev->port = port;
 222         mdev->unit = unit;
 223
 224         mdev->mq = maple_allocq(mdev);
 225
 226         if (!mdev->mq) {
 227                 kfree(mdev);
 228                 return NULL;
 229         }
 230         mdev->dev.bus = &maple_bus_type;
 231         mdev->dev.parent = &maple_bus;
 232         init_waitqueue_head(&mdev->maple_wait);
 233         return mdev;
 234 }
 235
 236 static void maple_free_dev(struct maple_device *mdev)
 237 {
 238         kmem_cache_free(maple_queue_cache, mdev->mq->recvbuf);
 239         kfree(mdev->mq);
 240         kfree(mdev);
 241 }
 242
 243 /* process the command queue into a maple command block
 244  * terminating command has bit 32 of first long set to 0
 245  */
 246 static void maple_build_block(struct mapleq *mq)
 247 {
 248         int port, unit, from, to, len;
 249         unsigned long *lsendbuf = mq->sendbuf;
 250
 251         port = mq->dev->port & 3;
 252         unit = mq->dev->unit;
 253         len = mq->length;
 254         from = port << 6;
 255         to = (port << 6) | (unit > 0 ? (1 << (unit - 1)) & 0x1f : 0x20);
 256
 257         *maple_lastptr &= 0x7fffffff;
 258         maple_lastptr = maple_sendptr;
 259
 260         *maple_sendptr++ = (port << 16) | len | 0x80000000;
 261         *maple_sendptr++ = virt_to_phys(mq->recvbuf->buf);
 262         *maple_sendptr++ =
 263             mq->command | (to << 8) | (from << 16) | (len << 24);
 264         while (len-- > 0)
 265                 *maple_sendptr++ = *lsendbuf++;
 266 }
 267
 268 /* build up command queue */
 269 static void maple_send(void)
 270 {
 271         int i, maple_packets = 0;
 272         struct mapleq *mq, *nmq;
 273
 274         if (!maple_dma_done())
 275                 return;
 276
 277         /* disable DMA */
 278         __raw_writel(0, MAPLE_ENABLE);
 279
 280         if (!list_empty(&maple_sentq))
 281                 goto finish;
 282
 283         mutex_lock(&maple_wlist_lock);
 284         if (list_empty(&maple_waitq)) {
 285                 mutex_unlock(&maple_wlist_lock);
 286                 goto finish;
 287         }
 288
 289         maple_lastptr = maple_sendbuf;
 290         maple_sendptr = maple_sendbuf;
 291
 292         list_for_each_entry_safe(mq, nmq, &maple_waitq, list) {
 293                 maple_build_block(mq);
 294                 list_del_init(&mq->list);
 295                 list_add_tail(&mq->list, &maple_sentq);
 296                 if (maple_packets++ > MAPLE_MAXPACKETS)
 297                         break;
 298         }
 299         mutex_unlock(&maple_wlist_lock);
 300         if (maple_packets > 0) {
 301                 for (i = 0; i < (1 << MAPLE_DMA_PAGES); i++)
 302                         __flush_purge_region(maple_sendbuf + i * PAGE_SIZE,
 303                                         PAGE_SIZE);
 304         }
 305
 306 finish:
 307         maple_dma_reset();
 308 }
 309
 310 /* check if there is a driver registered likely to match this device */
 311 static int maple_check_matching_driver(struct device_driver *driver,
 312                                         void *devptr)
 313 {
 314         struct maple_driver *maple_drv;
 315         struct maple_device *mdev;
 316
 317         mdev = devptr;
 318         maple_drv = to_maple_driver(driver);
 319         if (mdev->devinfo.function & cpu_to_be32(maple_drv->function))
 320                 return 1;
 321         return 0;
 322 }
 323
 324 static void maple_detach_driver(struct maple_device *mdev)
 325 {
 326         device_unregister(&mdev->dev);
 327 }
 328
 329 /* process initial MAPLE_COMMAND_DEVINFO for each device or port */
 330 static void maple_attach_driver(struct maple_device *mdev)
 331 {
 332         char *p, *recvbuf;
 333         unsigned long function;
 334         int matched, error;
 335
 336         recvbuf = mdev->mq->recvbuf->buf;
 337         /* copy the data as individual elements in
 338         * case of memory optimisation */
 339         memcpy(&mdev->devinfo.function, recvbuf + 4, 4);
 340         memcpy(&mdev->devinfo.function_data[0], recvbuf + 8, 12);
 341         memcpy(&mdev->devinfo.area_code, recvbuf + 20, 1);
 342         memcpy(&mdev->devinfo.connector_direction, recvbuf + 21, 1);
 343         memcpy(&mdev->devinfo.product_name[0], recvbuf + 22, 30);
 344         memcpy(&mdev->devinfo.standby_power, recvbuf + 112, 2);
 345         memcpy(&mdev->devinfo.max_power, recvbuf + 114, 2);
 346         memcpy(mdev->product_name, mdev->devinfo.product_name, 30);
 347         mdev->product_name[30] = '\0';
 348         memcpy(mdev->product_licence, mdev->devinfo.product_licence, 60);
 349         mdev->product_licence[60] = '\0';
 350
 351         for (p = mdev->product_name + 29; mdev->product_name <= p; p--)
 352                 if (*p == ' ')
 353                         *p = '\0';
 354                 else
 355                         break;
 356         for (p = mdev->product_licence + 59; mdev->product_licence <= p; p--)
 357                 if (*p == ' ')
 358                         *p = '\0';
 359                 else
 360                         break;
 361
 362         function = be32_to_cpu(mdev->devinfo.function);
 363
 364         dev_info(&mdev->dev, "detected %s: function 0x%lX: at (%d, %d)\n",
 365                 mdev->product_name, function, mdev->port, mdev->unit);
 366
 367         if (function > 0x200) {
 368                 /* Do this silently - as not a real device */
 369                 function = 0;
 370                 mdev->driver = &maple_unsupported_device;
 371                 dev_set_name(&mdev->dev, "%d:0.port", mdev->port);
 372         } else {
 373                 matched =
 374                         bus_for_each_drv(&maple_bus_type, NULL, mdev,
 375                                 maple_check_matching_driver);
 376
 377                 if (matched == 0) {
 378                         /* Driver does not exist yet */
 379                         dev_info(&mdev->dev, "no driver found\n");
 380                         mdev->driver = &maple_unsupported_device;
 381                 }
 382                 dev_set_name(&mdev->dev, "%d:0%d.%lX", mdev->port,
 383                              mdev->unit, function);
 384         }
 385
 386         mdev->function = function;
 387         mdev->dev.release = &maple_release_device;
 388
 389         atomic_set(&mdev->busy, 0);
 390         error = device_register(&mdev->dev);
 391         if (error) {
 392                 dev_warn(&mdev->dev, "could not register device at"
 393                         " (%d, %d), with error 0x%X\n", mdev->unit,
 394                         mdev->port, error);
 395                 maple_free_dev(mdev);
 396                 mdev = NULL;
 397                 return;
 398         }
 399 }
 400
 401 /*
 402  * if device has been registered for the given
 403  * port and unit then return 1 - allows identification
 404  * of which devices need to be attached or detached
 405  */
 406 static int check_maple_device(struct device *device, void *portptr)
 407 {
 408         struct maple_device_specify *ds;
 409         struct maple_device *mdev;
 410
 411         ds = portptr;
 412         mdev = to_maple_dev(device);
 413         if (mdev->port == ds->port && mdev->unit == ds->unit)
 414                 return 1;
 415         return 0;
 416 }
 417
 418 static int setup_maple_commands(struct device *device, void *ignored)
 419 {
 420         int add;
 421         struct maple_device *mdev = to_maple_dev(device);
 422         if (mdev->interval > 0 && atomic_read(&mdev->busy) == 0 &&
 423                 time_after(jiffies, mdev->when)) {
 424                 /* bounce if we cannot add */
 425                 add = maple_add_packet(mdev,
 426                         be32_to_cpu(mdev->devinfo.function),
 427                         MAPLE_COMMAND_GETCOND, 1, NULL);
 428                 if (!add)
 429                         mdev->when = jiffies + mdev->interval;
 430         } else {
 431                 if (time_after(jiffies, maple_pnp_time))
 432                         /* Ensure we don't have block reads and devinfo
 433                         * calls interfering with one another - so flag the
 434                         * device as busy */
 435                         if (atomic_read(&mdev->busy) == 0) {
 436                                 atomic_set(&mdev->busy, 1);
 437                                 maple_add_packet(mdev, 0,
 438                                         MAPLE_COMMAND_DEVINFO, 0, NULL);
 439                         }
 440         }
 441         return 0;
 442 }
 443
 444 /* VBLANK bottom half - implemented via workqueue */
 445 static void maple_vblank_handler(struct work_struct *work)
 446 {
 447         int x, locking;
 448         struct maple_device *mdev;
 449
 450         if (!maple_dma_done())
 451                 return;
 452
 453         __raw_writel(0, MAPLE_ENABLE);
 454
 455         if (!list_empty(&maple_sentq))
 456                 goto finish;
 457
 458         /*
 459         * Set up essential commands - to fetch data and
 460         * check devices are still present
 461         */
 462         bus_for_each_dev(&maple_bus_type, NULL, NULL,
 463                 setup_maple_commands);
 464
 465         if (time_after(jiffies, maple_pnp_time)) {
 466                 /*
 467                 * Scan the empty ports - bus is flakey and may have
 468                 * mis-reported emptyness
 469                 */
 470                 for (x = 0; x < MAPLE_PORTS; x++) {
 471                         if (checked[x] && empty[x]) {
 472                                 mdev = baseunits[x];
 473                                 if (!mdev)
 474                                         break;
 475                                 atomic_set(&mdev->busy, 1);
 476                                 locking = maple_add_packet(mdev, 0,
 477                                         MAPLE_COMMAND_DEVINFO, 0, NULL);
 478                                 if (!locking)
 479                                         break;
 480                                 }
 481                         }
 482
 483                 maple_pnp_time = jiffies + MAPLE_PNP_INTERVAL;
 484         }
 485
 486 finish:
 487         maple_send();
 488 }
 489
 490 /* handle devices added via hotplugs - placing them on queue for DEVINFO */
 491 static void maple_map_subunits(struct maple_device *mdev, int submask)
 492 {
 493         int retval, k, devcheck;
 494         struct maple_device *mdev_add;
 495         struct maple_device_specify ds;
 496
 497         ds.port = mdev->port;
 498         for (k = 0; k < 5; k++) {
 499                 ds.unit = k + 1;
 500                 retval =
 501                     bus_for_each_dev(&maple_bus_type, NULL, &ds,
 502                                      check_maple_device);
 503                 if (retval) {
 504                         submask = submask >> 1;
 505                         continue;
 506                 }
 507                 devcheck = submask & 0x01;
 508                 if (devcheck) {
 509                         mdev_add = maple_alloc_dev(mdev->port, k + 1);
 510                         if (!mdev_add)
 511                                 return;
 512                         atomic_set(&mdev_add->busy, 1);
 513                         maple_add_packet(mdev_add, 0, MAPLE_COMMAND_DEVINFO,
 514                                 0, NULL);
 515                         /* mark that we are checking sub devices */
 516                         scanning = 1;
 517                 }
 518                 submask = submask >> 1;
 519         }
 520 }
 521
 522 /* mark a device as removed */
 523 static void maple_clean_submap(struct maple_device *mdev)
 524 {
 525         int killbit;
 526
 527         killbit = (mdev->unit > 0 ? (1 << (mdev->unit - 1)) & 0x1f : 0x20);
 528         killbit = ~killbit;
 529         killbit &= 0xFF;
 530         subdevice_map[mdev->port] = subdevice_map[mdev->port] & killbit;
 531 }
 532
 533 /* handle empty port or hotplug removal */
 534 static void maple_response_none(struct maple_device *mdev)
 535 {
 536         maple_clean_submap(mdev);
 537
 538         if (likely(mdev->unit != 0)) {
 539                 /*
 540                 * Block devices play up
 541                 * and give the impression they have
 542                 * been removed even when still in place or
 543                 * trip the mtd layer when they have
 544                 * really gone - this code traps that eventuality
 545                 * and ensures we aren't overloaded with useless
 546                 * error messages
 547                 */
 548                 if (mdev->can_unload) {
 549                         if (!mdev->can_unload(mdev)) {
 550                                 atomic_set(&mdev->busy, 2);
 551                                 wake_up(&mdev->maple_wait);
 552                                 return;
 553                         }
 554                 }
 555
 556                 dev_info(&mdev->dev, "detaching device at (%d, %d)\n",
 557                         mdev->port, mdev->unit);
 558                 maple_detach_driver(mdev);
 559                 return;
 560         } else {
 561                 if (!started || !fullscan) {
 562                         if (checked[mdev->port] == false) {
 563                                 checked[mdev->port] = true;
 564                                 empty[mdev->port] = true;
 565                                 dev_info(&mdev->dev, "no devices"
 566                                         " to port %d\n", mdev->port);
 567                         }
 568                         return;
 569                 }
 570         }
 571         /* Some hardware devices generate false detach messages on unit 0 */
 572         atomic_set(&mdev->busy, 0);
 573 }
 574
 575 /* preprocess hotplugs or scans */
 576 static void maple_response_devinfo(struct maple_device *mdev,
 577                                    char *recvbuf)
 578 {
 579         char submask;
 580         if (!started || (scanning == 2) || !fullscan) {
 581                 if ((mdev->unit == 0) && (checked[mdev->port] == false)) {
 582                         checked[mdev->port] = true;
 583                         maple_attach_driver(mdev);
 584                 } else {
 585                         if (mdev->unit != 0)
 586                                 maple_attach_driver(mdev);
 587                         if (mdev->unit == 0) {
 588                                 empty[mdev->port] = false;
 589                                 maple_attach_driver(mdev);
 590                         }
 591                 }
 592         }
 593         if (mdev->unit == 0) {
 594                 submask = recvbuf[2] & 0x1F;
 595                 if (submask ^ subdevice_map[mdev->port]) {
 596                         maple_map_subunits(mdev, submask);
 597                         subdevice_map[mdev->port] = submask;
 598                 }
 599         }
 600 }
 601
 602 static void maple_response_fileerr(struct maple_device *mdev, void *recvbuf)
 603 {
 604         if (mdev->fileerr_handler) {
 605                 mdev->fileerr_handler(mdev, recvbuf);
 606                 return;
 607         } else
 608                 dev_warn(&mdev->dev, "device at (%d, %d) reports"
 609                         "file error 0x%X\n", mdev->port, mdev->unit,
 610                         ((int *)recvbuf)[1]);
 611 }
 612
 613 static void maple_port_rescan(void)
 614 {
 615         int i;
 616         struct maple_device *mdev;
 617
 618         fullscan = 1;
 619         for (i = 0; i < MAPLE_PORTS; i++) {
 620                 if (checked[i] == false) {
 621                         fullscan = 0;
 622                         mdev = baseunits[i];
 623                         maple_add_packet(mdev, 0, MAPLE_COMMAND_DEVINFO,
 624                                 0, NULL);
 625                 }
 626         }
 627 }
 628
 629 /* maple dma end bottom half - implemented via workqueue */
 630 static void maple_dma_handler(struct work_struct *work)
 631 {
 632         struct mapleq *mq, *nmq;
 633         struct maple_device *mdev;
 634         char *recvbuf;
 635         enum maple_code code;
 636
 637         if (!maple_dma_done())
 638                 return;
 639         __raw_writel(0, MAPLE_ENABLE);
 640         if (!list_empty(&maple_sentq)) {
 641                 list_for_each_entry_safe(mq, nmq, &maple_sentq, list) {
 642                         mdev = mq->dev;
 643                         recvbuf = mq->recvbuf->buf;
 644                         __flush_invalidate_region(sh_cacheop_vaddr(recvbuf),
 645                                         0x400);
 646                         code = recvbuf[0];
 647                         kfree(mq->sendbuf);
 648                         list_del_init(&mq->list);
 649                         switch (code) {
 650                         case MAPLE_RESPONSE_NONE:
 651                                 maple_response_none(mdev);
 652                                 break;
 653
 654                         case MAPLE_RESPONSE_DEVINFO:
 655                                 maple_response_devinfo(mdev, recvbuf);
 656                                 atomic_set(&mdev->busy, 0);
 657                                 break;
 658
 659                         case MAPLE_RESPONSE_DATATRF:
 660                                 if (mdev->callback)
 661                                         mdev->callback(mq);
 662                                 atomic_set(&mdev->busy, 0);
 663                                 wake_up(&mdev->maple_wait);
 664                                 break;
 665
 666                         case MAPLE_RESPONSE_FILEERR:
 667                                 maple_response_fileerr(mdev, recvbuf);
 668                                 atomic_set(&mdev->busy, 0);
 669                                 wake_up(&mdev->maple_wait);
 670                                 break;
 671
 672                         case MAPLE_RESPONSE_AGAIN:
 673                         case MAPLE_RESPONSE_BADCMD:
 674                         case MAPLE_RESPONSE_BADFUNC:
 675                                 dev_warn(&mdev->dev, "non-fatal error"
 676                                         " 0x%X at (%d, %d)\n", code,
 677                                         mdev->port, mdev->unit);
 678                                 atomic_set(&mdev->busy, 0);
 679                                 break;
 680
 681                         case MAPLE_RESPONSE_ALLINFO:
 682                                 dev_notice(&mdev->dev, "extended"
 683                                 " device information request for (%d, %d)"
 684                                 " but call is not supported\n", mdev->port,
 685                                 mdev->unit);
 686                                 atomic_set(&mdev->busy, 0);
 687                                 break;
 688
 689                         case MAPLE_RESPONSE_OK:
 690                                 atomic_set(&mdev->busy, 0);
 691                                 wake_up(&mdev->maple_wait);
 692                                 break;
 693
 694                         default:
 695                                 break;
 696                         }
 697                 }
 698                 /* if scanning is 1 then we have subdevices to check */
 699                 if (scanning == 1) {
 700                         maple_send();
 701                         scanning = 2;
 702                 } else
 703                         scanning = 0;
 704                 /*check if we have actually tested all ports yet */
 705                 if (!fullscan)
 706                         maple_port_rescan();
 707                 /* mark that we have been through the first scan */
 708                 started = 1;
 709         }
 710         maple_send();
 711 }
 712
 713 static irqreturn_t maple_dma_interrupt(int irq, void *dev_id)
 714 {
 715         /* Load everything into the bottom half */
 716         schedule_work(&maple_dma_process);
 717         return IRQ_HANDLED;
 718 }
 719
 720 static irqreturn_t maple_vblank_interrupt(int irq, void *dev_id)
 721 {
 722         schedule_work(&maple_vblank_process);
 723         return IRQ_HANDLED;
 724 }
 725
 726 static int maple_set_dma_interrupt_handler(void)
 727 {
 728         return request_irq(HW_EVENT_MAPLE_DMA, maple_dma_interrupt,
 729                 IRQF_SHARED, "maple bus DMA", &maple_unsupported_device);
 730 }
 731
 732 static int maple_set_vblank_interrupt_handler(void)
 733 {
 734         return request_irq(HW_EVENT_VSYNC, maple_vblank_interrupt,
 735                 IRQF_SHARED, "maple bus VBLANK", &maple_unsupported_device);
 736 }
 737
 738 static int maple_get_dma_buffer(void)
 739 {
 740         maple_sendbuf =
 741             (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
 742                                       MAPLE_DMA_PAGES);
 743         if (!maple_sendbuf)
 744                 return -ENOMEM;
 745         return 0;
 746 }
 747
 748 static int maple_match_bus_driver(struct device *devptr,
 749                                   struct device_driver *drvptr)
 750 {
 751         struct maple_driver *maple_drv = to_maple_driver(drvptr);
 752         struct maple_device *maple_dev = to_maple_dev(devptr);
 753
 754         /* Trap empty port case */
 755         if (maple_dev->devinfo.function == 0xFFFFFFFF)
 756                 return 0;
 757         else if (maple_dev->devinfo.function &
 758                  cpu_to_be32(maple_drv->function))
 759                 return 1;
 760         return 0;
 761 }
 762
 763 static int maple_bus_uevent(struct device *dev,
 764                             struct kobj_uevent_env *env)
 765 {
 766         return 0;
 767 }
 768
 769 static void maple_bus_release(struct device *dev)
 770 {
 771 }
 772
 773 static struct maple_driver maple_unsupported_device = {
 774         .drv = {
 775                 .name = "maple_unsupported_device",
 776                 .bus = &maple_bus_type,
 777         },
 778 };
 779 /*
 780  * maple_bus_type - core maple bus structure
 781  */
 782 struct bus_type maple_bus_type = {
 783         .name = "maple",
 784         .match = maple_match_bus_driver,
 785         .uevent = maple_bus_uevent,
 786 };
 787 EXPORT_SYMBOL_GPL(maple_bus_type);
 788
 789 static struct device maple_bus = {
 790         .init_name = "maple",
 791         .release = maple_bus_release,
 792 };
 793
 794 static int __init maple_bus_init(void)
 795 {
 796         int retval, i;
 797         struct maple_device *mdev[MAPLE_PORTS];
 798
 799         __raw_writel(0, MAPLE_ENABLE);
 800
 801         retval = device_register(&maple_bus);
 802         if (retval)
 803                 goto cleanup;
 804
 805         retval = bus_register(&maple_bus_type);
 806         if (retval)
 807                 goto cleanup_device;
 808
 809         retval = driver_register(&maple_unsupported_device.drv);
 810         if (retval)
 811                 goto cleanup_bus;
 812
 813         /* allocate memory for maple bus dma */
 814         retval = maple_get_dma_buffer();
 815         if (retval) {
 816                 dev_err(&maple_bus, "failed to allocate DMA buffers\n");
 817                 goto cleanup_basic;
 818         }
 819
 820         /* set up DMA interrupt handler */
 821         retval = maple_set_dma_interrupt_handler();
 822         if (retval) {
 823                 dev_err(&maple_bus, "bus failed to grab maple "
 824                         "DMA IRQ\n");
 825                 goto cleanup_dma;
 826         }
 827
 828         /* set up VBLANK interrupt handler */
 829         retval = maple_set_vblank_interrupt_handler();
 830         if (retval) {
 831                 dev_err(&maple_bus, "bus failed to grab VBLANK IRQ\n");
 832                 goto cleanup_irq;
 833         }
 834
 835         maple_queue_cache = KMEM_CACHE(maple_buffer, SLAB_HWCACHE_ALIGN);
 836
 837         if (!maple_queue_cache) {
 838                 retval = -ENOMEM;
 839                 goto cleanup_bothirqs;
 840         }
 841
 842         INIT_LIST_HEAD(&maple_waitq);
 843         INIT_LIST_HEAD(&maple_sentq);
 844
 845         /* setup maple ports */
 846         for (i = 0; i < MAPLE_PORTS; i++) {
 847                 checked[i] = false;
 848                 empty[i] = false;
 849                 mdev[i] = maple_alloc_dev(i, 0);
 850                 if (!mdev[i]) {
 851                         while (i-- > 0)
 852                                 maple_free_dev(mdev[i]);
 853                         retval = -ENOMEM;
 854                         goto cleanup_cache;
 855                 }
 856                 baseunits[i] = mdev[i];
 857                 atomic_set(&mdev[i]->busy, 1);
 858                 maple_add_packet(mdev[i], 0, MAPLE_COMMAND_DEVINFO, 0, NULL);
 859                 subdevice_map[i] = 0;
 860         }
 861
 862         maple_pnp_time = jiffies + HZ;
 863         /* prepare initial queue */
 864         maple_send();
 865         dev_info(&maple_bus, "bus core now registered\n");
 866
 867         return 0;
 868
 869 cleanup_cache:
 870         kmem_cache_destroy(maple_queue_cache);
 871
 872 cleanup_bothirqs:
 873         free_irq(HW_EVENT_VSYNC, 0);
 874
 875 cleanup_irq:
 876         free_irq(HW_EVENT_MAPLE_DMA, 0);
 877
 878 cleanup_dma:
 879         free_pages((unsigned long) maple_sendbuf, MAPLE_DMA_PAGES);
 880
 881 cleanup_basic:
 882         driver_unregister(&maple_unsupported_device.drv);
 883
 884 cleanup_bus:
 885         bus_unregister(&maple_bus_type);
 886
 887 cleanup_device:
 888         device_unregister(&maple_bus);
 889
 890 cleanup:
 891         printk(KERN_ERR "Maple bus registration failed\n");
 892         return retval;
 893 }
 894 /* Push init to later to ensure hardware gets detected */
 895 fs_initcall(maple_bus_init);