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