SAFE public projects git trees. - safe/jmp/linux-2.6/blob - drivers/mmc/card/block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  * Copyright 2005-2008 Pierre Ossman
   6  *
   7  * Use consistent with the GNU GPL is permitted,
   8  * provided that this copyright notice is
   9  * preserved in its entirety in all copies and derived works.
  10  *
  11  * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
  12  * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
  13  * FITNESS FOR ANY PARTICULAR PURPOSE.
  14  *
  15  * Many thanks to Alessandro Rubini and Jonathan Corbet!
  16  *
  17  * Author:  Andrew Christian
  18  *          28 May 2002
  19  */
  20 #include <linux/moduleparam.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23
  24 #include <linux/kernel.h>
  25 #include <linux/fs.h>
  26 #include <linux/errno.h>
  27 #include <linux/hdreg.h>
  28 #include <linux/kdev_t.h>
  29 #include <linux/blkdev.h>
  30 #include <linux/mutex.h>
  31 #include <linux/scatterlist.h>
  32 #include <linux/string_helpers.h>
  33
  34 #include <linux/mmc/card.h>
  35 #include <linux/mmc/host.h>
  36 #include <linux/mmc/mmc.h>
  37 #include <linux/mmc/sd.h>
  38
  39 #include <asm/system.h>
  40 #include <asm/uaccess.h>
  41
  42 #include "queue.h"
  43
  44 MODULE_ALIAS("mmc:block");
  45
  46 /*
  47  * max 8 partitions per card
  48  */
  49 #define MMC_SHIFT       3
  50 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
  51
  52 static DECLARE_BITMAP(dev_use, MMC_NUM_MINORS);
  53
  54 /*
  55  * There is one mmc_blk_data per slot.
  56  */
  57 struct mmc_blk_data {
  58         spinlock_t      lock;
  59         struct gendisk  *disk;
  60         struct mmc_queue queue;
  61
  62         unsigned int    usage;
  63         unsigned int    read_only;
  64 };
  65
  66 static DEFINE_MUTEX(open_lock);
  67
  68 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  69 {
  70         struct mmc_blk_data *md;
  71
  72         mutex_lock(&open_lock);
  73         md = disk->private_data;
  74         if (md && md->usage == 0)
  75                 md = NULL;
  76         if (md)
  77                 md->usage++;
  78         mutex_unlock(&open_lock);
  79
  80         return md;
  81 }
  82
  83 static void mmc_blk_put(struct mmc_blk_data *md)
  84 {
  85         mutex_lock(&open_lock);
  86         md->usage--;
  87         if (md->usage == 0) {
  88                 int devmaj = MAJOR(disk_devt(md->disk));
  89                 int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
  90
  91                 if (!devmaj)
  92                         devidx = md->disk->first_minor >> MMC_SHIFT;
  93
  94                 __clear_bit(devidx, dev_use);
  95
  96                 put_disk(md->disk);
  97                 kfree(md);
  98         }
  99         mutex_unlock(&open_lock);
 100 }
 101
 102 static int mmc_blk_open(struct block_device *bdev, fmode_t mode)
 103 {
 104         struct mmc_blk_data *md = mmc_blk_get(bdev->bd_disk);
 105         int ret = -ENXIO;
 106
 107         if (md) {
 108                 if (md->usage == 2)
 109                         check_disk_change(bdev);
 110                 ret = 0;
 111
 112                 if ((mode & FMODE_WRITE) && md->read_only) {
 113                         mmc_blk_put(md);
 114                         ret = -EROFS;
 115                 }
 116         }
 117
 118         return ret;
 119 }
 120
 121 static int mmc_blk_release(struct gendisk *disk, fmode_t mode)
 122 {
 123         struct mmc_blk_data *md = disk->private_data;
 124
 125         mmc_blk_put(md);
 126         return 0;
 127 }
 128
 129 static int
 130 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 131 {
 132         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 133         geo->heads = 4;
 134         geo->sectors = 16;
 135         return 0;
 136 }
 137
 138 static const struct block_device_operations mmc_bdops = {
 139         .open                   = mmc_blk_open,
 140         .release                = mmc_blk_release,
 141         .getgeo                 = mmc_blk_getgeo,
 142         .owner                  = THIS_MODULE,
 143 };
 144
 145 struct mmc_blk_request {
 146         struct mmc_request      mrq;
 147         struct mmc_command      cmd;
 148         struct mmc_command      stop;
 149         struct mmc_data         data;
 150 };
 151
 152 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 153 {
 154         int err;
 155         u32 result;
 156         __be32 *blocks;
 157
 158         struct mmc_request mrq;
 159         struct mmc_command cmd;
 160         struct mmc_data data;
 161         unsigned int timeout_us;
 162
 163         struct scatterlist sg;
 164
 165         memset(&cmd, 0, sizeof(struct mmc_command));
 166
 167         cmd.opcode = MMC_APP_CMD;
 168         cmd.arg = card->rca << 16;
 169         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 170
 171         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 172         if (err)
 173                 return (u32)-1;
 174         if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
 175                 return (u32)-1;
 176
 177         memset(&cmd, 0, sizeof(struct mmc_command));
 178
 179         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 180         cmd.arg = 0;
 181         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 182
 183         memset(&data, 0, sizeof(struct mmc_data));
 184
 185         data.timeout_ns = card->csd.tacc_ns * 100;
 186         data.timeout_clks = card->csd.tacc_clks * 100;
 187
 188         timeout_us = data.timeout_ns / 1000;
 189         timeout_us += data.timeout_clks * 1000 /
 190                 (card->host->ios.clock / 1000);
 191
 192         if (timeout_us > 100000) {
 193                 data.timeout_ns = 100000000;
 194                 data.timeout_clks = 0;
 195         }
 196
 197         data.blksz = 4;
 198         data.blocks = 1;
 199         data.flags = MMC_DATA_READ;
 200         data.sg = &sg;
 201         data.sg_len = 1;
 202
 203         memset(&mrq, 0, sizeof(struct mmc_request));
 204
 205         mrq.cmd = &cmd;
 206         mrq.data = &data;
 207
 208         blocks = kmalloc(4, GFP_KERNEL);
 209         if (!blocks)
 210                 return (u32)-1;
 211
 212         sg_init_one(&sg, blocks, 4);
 213
 214         mmc_wait_for_req(card->host, &mrq);
 215
 216         result = ntohl(*blocks);
 217         kfree(blocks);
 218
 219         if (cmd.error || data.error)
 220                 result = (u32)-1;
 221
 222         return result;
 223 }
 224
 225 static u32 get_card_status(struct mmc_card *card, struct request *req)
 226 {
 227         struct mmc_command cmd;
 228         int err;
 229
 230         memset(&cmd, 0, sizeof(struct mmc_command));
 231         cmd.opcode = MMC_SEND_STATUS;
 232         if (!mmc_host_is_spi(card->host))
 233                 cmd.arg = card->rca << 16;
 234         cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
 235         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 236         if (err)
 237                 printk(KERN_ERR "%s: error %d sending status comand",
 238                        req->rq_disk->disk_name, err);
 239         return cmd.resp[0];
 240 }
 241
 242 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 243 {
 244         struct mmc_blk_data *md = mq->data;
 245         struct mmc_card *card = md->queue.card;
 246         struct mmc_blk_request brq;
 247         int ret = 1, disable_multi = 0;
 248
 249         mmc_claim_host(card->host);
 250
 251         do {
 252                 struct mmc_command cmd;
 253                 u32 readcmd, writecmd, status = 0;
 254
 255                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 256                 brq.mrq.cmd = &brq.cmd;
 257                 brq.mrq.data = &brq.data;
 258
 259                 brq.cmd.arg = blk_rq_pos(req);
 260                 if (!mmc_card_blockaddr(card))
 261                         brq.cmd.arg <<= 9;
 262                 brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 263                 brq.data.blksz = 512;
 264                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 265                 brq.stop.arg = 0;
 266                 brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 267                 brq.data.blocks = blk_rq_sectors(req);
 268
 269                 /*
 270                  * The block layer doesn't support all sector count
 271                  * restrictions, so we need to be prepared for too big
 272                  * requests.
 273                  */
 274                 if (brq.data.blocks > card->host->max_blk_count)
 275                         brq.data.blocks = card->host->max_blk_count;
 276
 277                 /*
 278                  * After a read error, we redo the request one sector at a time
 279                  * in order to accurately determine which sectors can be read
 280                  * successfully.
 281                  */
 282                 if (disable_multi && brq.data.blocks > 1)
 283                         brq.data.blocks = 1;
 284
 285                 if (brq.data.blocks > 1) {
 286                         /* SPI multiblock writes terminate using a special
 287                          * token, not a STOP_TRANSMISSION request.
 288                          */
 289                         if (!mmc_host_is_spi(card->host)
 290                                         || rq_data_dir(req) == READ)
 291                                 brq.mrq.stop = &brq.stop;
 292                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 293                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 294                 } else {
 295                         brq.mrq.stop = NULL;
 296                         readcmd = MMC_READ_SINGLE_BLOCK;
 297                         writecmd = MMC_WRITE_BLOCK;
 298                 }
 299
 300                 if (rq_data_dir(req) == READ) {
 301                         brq.cmd.opcode = readcmd;
 302                         brq.data.flags |= MMC_DATA_READ;
 303                 } else {
 304                         brq.cmd.opcode = writecmd;
 305                         brq.data.flags |= MMC_DATA_WRITE;
 306                 }
 307
 308                 mmc_set_data_timeout(&brq.data, card);
 309
 310                 brq.data.sg = mq->sg;
 311                 brq.data.sg_len = mmc_queue_map_sg(mq);
 312
 313                 /*
 314                  * Adjust the sg list so it is the same size as the
 315                  * request.
 316                  */
 317                 if (brq.data.blocks != blk_rq_sectors(req)) {
 318                         int i, data_size = brq.data.blocks << 9;
 319                         struct scatterlist *sg;
 320
 321                         for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
 322                                 data_size -= sg->length;
 323                                 if (data_size <= 0) {
 324                                         sg->length += data_size;
 325                                         i++;
 326                                         break;
 327                                 }
 328                         }
 329                         brq.data.sg_len = i;
 330                 }
 331
 332                 mmc_queue_bounce_pre(mq);
 333
 334                 mmc_wait_for_req(card->host, &brq.mrq);
 335
 336                 mmc_queue_bounce_post(mq);
 337
 338                 /*
 339                  * Check for errors here, but don't jump to cmd_err
 340                  * until later as we need to wait for the card to leave
 341                  * programming mode even when things go wrong.
 342                  */
 343                 if (brq.cmd.error || brq.data.error || brq.stop.error) {
 344                         if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
 345                                 /* Redo read one sector at a time */
 346                                 printk(KERN_WARNING "%s: retrying using single "
 347                                        "block read\n", req->rq_disk->disk_name);
 348                                 disable_multi = 1;
 349                                 continue;
 350                         }
 351                         status = get_card_status(card, req);
 352                 }
 353
 354                 if (brq.cmd.error) {
 355                         printk(KERN_ERR "%s: error %d sending read/write "
 356                                "command, response %#x, card status %#x\n",
 357                                req->rq_disk->disk_name, brq.cmd.error,
 358                                brq.cmd.resp[0], status);
 359                 }
 360
 361                 if (brq.data.error) {
 362                         if (brq.data.error == -ETIMEDOUT && brq.mrq.stop)
 363                                 /* 'Stop' response contains card status */
 364                                 status = brq.mrq.stop->resp[0];
 365                         printk(KERN_ERR "%s: error %d transferring data,"
 366                                " sector %u, nr %u, card status %#x\n",
 367                                req->rq_disk->disk_name, brq.data.error,
 368                                (unsigned)blk_rq_pos(req),
 369                                (unsigned)blk_rq_sectors(req), status);
 370                 }
 371
 372                 if (brq.stop.error) {
 373                         printk(KERN_ERR "%s: error %d sending stop command, "
 374                                "response %#x, card status %#x\n",
 375                                req->rq_disk->disk_name, brq.stop.error,
 376                                brq.stop.resp[0], status);
 377                 }
 378
 379                 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
 380                         do {
 381                                 int err;
 382
 383                                 cmd.opcode = MMC_SEND_STATUS;
 384                                 cmd.arg = card->rca << 16;
 385                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 386                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 387                                 if (err) {
 388                                         printk(KERN_ERR "%s: error %d requesting status\n",
 389                                                req->rq_disk->disk_name, err);
 390                                         goto cmd_err;
 391                                 }
 392                                 /*
 393                                  * Some cards mishandle the status bits,
 394                                  * so make sure to check both the busy
 395                                  * indication and the card state.
 396                                  */
 397                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
 398                                 (R1_CURRENT_STATE(cmd.resp[0]) == 7));
 399
 400 #if 0
 401                         if (cmd.resp[0] & ~0x00000900)
 402                                 printk(KERN_ERR "%s: status = %08x\n",
 403                                        req->rq_disk->disk_name, cmd.resp[0]);
 404                         if (mmc_decode_status(cmd.resp))
 405                                 goto cmd_err;
 406 #endif
 407                 }
 408
 409                 if (brq.cmd.error || brq.stop.error || brq.data.error) {
 410                         if (rq_data_dir(req) == READ) {
 411                                 /*
 412                                  * After an error, we redo I/O one sector at a
 413                                  * time, so we only reach here after trying to
 414                                  * read a single sector.
 415                                  */
 416                                 spin_lock_irq(&md->lock);
 417                                 ret = __blk_end_request(req, -EIO, brq.data.blksz);
 418                                 spin_unlock_irq(&md->lock);
 419                                 continue;
 420                         }
 421                         goto cmd_err;
 422                 }
 423
 424                 /*
 425                  * A block was successfully transferred.
 426                  */
 427                 spin_lock_irq(&md->lock);
 428                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 429                 spin_unlock_irq(&md->lock);
 430         } while (ret);
 431
 432         mmc_release_host(card->host);
 433
 434         return 1;
 435
 436  cmd_err:
 437         /*
 438          * If this is an SD card and we're writing, we can first
 439          * mark the known good sectors as ok.
 440          *
 441          * If the card is not SD, we can still ok written sectors
 442          * as reported by the controller (which might be less than
 443          * the real number of written sectors, but never more).
 444          */
 445         if (mmc_card_sd(card)) {
 446                 u32 blocks;
 447
 448                 blocks = mmc_sd_num_wr_blocks(card);
 449                 if (blocks != (u32)-1) {
 450                         spin_lock_irq(&md->lock);
 451                         ret = __blk_end_request(req, 0, blocks << 9);
 452                         spin_unlock_irq(&md->lock);
 453                 }
 454         } else {
 455                 spin_lock_irq(&md->lock);
 456                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 457                 spin_unlock_irq(&md->lock);
 458         }
 459
 460         mmc_release_host(card->host);
 461
 462         spin_lock_irq(&md->lock);
 463         while (ret)
 464                 ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 465         spin_unlock_irq(&md->lock);
 466
 467         return 0;
 468 }
 469
 470
 471 static inline int mmc_blk_readonly(struct mmc_card *card)
 472 {
 473         return mmc_card_readonly(card) ||
 474                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 475 }
 476
 477 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 478 {
 479         struct mmc_blk_data *md;
 480         int devidx, ret;
 481
 482         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 483         if (devidx >= MMC_NUM_MINORS)
 484                 return ERR_PTR(-ENOSPC);
 485         __set_bit(devidx, dev_use);
 486
 487         md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 488         if (!md) {
 489                 ret = -ENOMEM;
 490                 goto out;
 491         }
 492
 493
 494         /*
 495          * Set the read-only status based on the supported commands
 496          * and the write protect switch.
 497          */
 498         md->read_only = mmc_blk_readonly(card);
 499
 500         md->disk = alloc_disk(1 << MMC_SHIFT);
 501         if (md->disk == NULL) {
 502                 ret = -ENOMEM;
 503                 goto err_kfree;
 504         }
 505
 506         spin_lock_init(&md->lock);
 507         md->usage = 1;
 508
 509         ret = mmc_init_queue(&md->queue, card, &md->lock);
 510         if (ret)
 511                 goto err_putdisk;
 512
 513         md->queue.issue_fn = mmc_blk_issue_rq;
 514         md->queue.data = md;
 515
 516         md->disk->major = MMC_BLOCK_MAJOR;
 517         md->disk->first_minor = devidx << MMC_SHIFT;
 518         md->disk->fops = &mmc_bdops;
 519         md->disk->private_data = md;
 520         md->disk->queue = md->queue.queue;
 521         md->disk->driverfs_dev = &card->dev;
 522
 523         /*
 524          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 525          *
 526          * - be set for removable media with permanent block devices
 527          * - be unset for removable block devices with permanent media
 528          *
 529          * Since MMC block devices clearly fall under the second
 530          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 531          * should use the block device creation/destruction hotplug
 532          * messages to tell when the card is present.
 533          */
 534
 535         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 536
 537         blk_queue_logical_block_size(md->queue.queue, 512);
 538
 539         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 540                 /*
 541                  * The EXT_CSD sector count is in number or 512 byte
 542                  * sectors.
 543                  */
 544                 set_capacity(md->disk, card->ext_csd.sectors);
 545         } else {
 546                 /*
 547                  * The CSD capacity field is in units of read_blkbits.
 548                  * set_capacity takes units of 512 bytes.
 549                  */
 550                 set_capacity(md->disk,
 551                         card->csd.capacity << (card->csd.read_blkbits - 9));
 552         }
 553         return md;
 554
 555  err_putdisk:
 556         put_disk(md->disk);
 557  err_kfree:
 558         kfree(md);
 559  out:
 560         return ERR_PTR(ret);
 561 }
 562
 563 static int
 564 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 565 {
 566         struct mmc_command cmd;
 567         int err;
 568
 569         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 570         if (mmc_card_blockaddr(card))
 571                 return 0;
 572
 573         mmc_claim_host(card->host);
 574         cmd.opcode = MMC_SET_BLOCKLEN;
 575         cmd.arg = 512;
 576         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 577         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 578         mmc_release_host(card->host);
 579
 580         if (err) {
 581                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 582                         md->disk->disk_name, cmd.arg, err);
 583                 return -EINVAL;
 584         }
 585
 586         return 0;
 587 }
 588
 589 static int mmc_blk_probe(struct mmc_card *card)
 590 {
 591         struct mmc_blk_data *md;
 592         int err;
 593
 594         char cap_str[10];
 595
 596         /*
 597          * Check that the card supports the command class(es) we need.
 598          */
 599         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 600                 return -ENODEV;
 601
 602         md = mmc_blk_alloc(card);
 603         if (IS_ERR(md))
 604                 return PTR_ERR(md);
 605
 606         err = mmc_blk_set_blksize(md, card);
 607         if (err)
 608                 goto out;
 609
 610         string_get_size((u64)get_capacity(md->disk) << 9, STRING_UNITS_2,
 611                         cap_str, sizeof(cap_str));
 612         printk(KERN_INFO "%s: %s %s %s %s\n",
 613                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 614                 cap_str, md->read_only ? "(ro)" : "");
 615
 616         mmc_set_drvdata(card, md);
 617         add_disk(md->disk);
 618         return 0;
 619
 620  out:
 621         mmc_cleanup_queue(&md->queue);
 622         mmc_blk_put(md);
 623
 624         return err;
 625 }
 626
 627 static void mmc_blk_remove(struct mmc_card *card)
 628 {
 629         struct mmc_blk_data *md = mmc_get_drvdata(card);
 630
 631         if (md) {
 632                 /* Stop new requests from getting into the queue */
 633                 del_gendisk(md->disk);
 634
 635                 /* Then flush out any already in there */
 636                 mmc_cleanup_queue(&md->queue);
 637
 638                 mmc_blk_put(md);
 639         }
 640         mmc_set_drvdata(card, NULL);
 641 }
 642
 643 #ifdef CONFIG_PM
 644 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 645 {
 646         struct mmc_blk_data *md = mmc_get_drvdata(card);
 647
 648         if (md) {
 649                 mmc_queue_suspend(&md->queue);
 650         }
 651         return 0;
 652 }
 653
 654 static int mmc_blk_resume(struct mmc_card *card)
 655 {
 656         struct mmc_blk_data *md = mmc_get_drvdata(card);
 657
 658         if (md) {
 659                 mmc_blk_set_blksize(md, card);
 660                 mmc_queue_resume(&md->queue);
 661         }
 662         return 0;
 663 }
 664 #else
 665 #define mmc_blk_suspend NULL
 666 #define mmc_blk_resume  NULL
 667 #endif
 668
 669 static struct mmc_driver mmc_driver = {
 670         .drv            = {
 671                 .name   = "mmcblk",
 672         },
 673         .probe          = mmc_blk_probe,
 674         .remove         = mmc_blk_remove,
 675         .suspend        = mmc_blk_suspend,
 676         .resume         = mmc_blk_resume,
 677 };
 678
 679 static int __init mmc_blk_init(void)
 680 {
 681         int res;
 682
 683         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 684         if (res)
 685                 goto out;
 686
 687         res = mmc_register_driver(&mmc_driver);
 688         if (res)
 689                 goto out2;
 690
 691         return 0;
 692  out2:
 693         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 694  out:
 695         return res;
 696 }
 697
 698 static void __exit mmc_blk_exit(void)
 699 {
 700         mmc_unregister_driver(&mmc_driver);
 701         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 702 }
 703
 704 module_init(mmc_blk_init);
 705 module_exit(mmc_blk_exit);
 706
 707 MODULE_LICENSE("GPL");
 708 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 709