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/slab.h>
  27 #include <linux/errno.h>
  28 #include <linux/hdreg.h>
  29 #include <linux/kdev_t.h>
  30 #include <linux/blkdev.h>
  31 #include <linux/mutex.h>
  32 #include <linux/scatterlist.h>
  33 #include <linux/string_helpers.h>
  34
  35 #include <linux/mmc/card.h>
  36 #include <linux/mmc/host.h>
  37 #include <linux/mmc/mmc.h>
  38 #include <linux/mmc/sd.h>
  39
  40 #include <asm/system.h>
  41 #include <asm/uaccess.h>
  42
  43 #include "queue.h"
  44
  45 MODULE_ALIAS("mmc:block");
  46
  47 /*
  48  * max 8 partitions per card
  49  */
  50 #define MMC_SHIFT       3
  51 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
  52
  53 static DECLARE_BITMAP(dev_use, MMC_NUM_MINORS);
  54
  55 /*
  56  * There is one mmc_blk_data per slot.
  57  */
  58 struct mmc_blk_data {
  59         spinlock_t      lock;
  60         struct gendisk  *disk;
  61         struct mmc_queue queue;
  62
  63         unsigned int    usage;
  64         unsigned int    read_only;
  65 };
  66
  67 static DEFINE_MUTEX(open_lock);
  68
  69 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  70 {
  71         struct mmc_blk_data *md;
  72
  73         mutex_lock(&open_lock);
  74         md = disk->private_data;
  75         if (md && md->usage == 0)
  76                 md = NULL;
  77         if (md)
  78                 md->usage++;
  79         mutex_unlock(&open_lock);
  80
  81         return md;
  82 }
  83
  84 static void mmc_blk_put(struct mmc_blk_data *md)
  85 {
  86         mutex_lock(&open_lock);
  87         md->usage--;
  88         if (md->usage == 0) {
  89                 int devmaj = MAJOR(disk_devt(md->disk));
  90                 int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
  91
  92                 if (!devmaj)
  93                         devidx = md->disk->first_minor >> MMC_SHIFT;
  94
  95                 blk_cleanup_queue(md->queue.queue);
  96
  97                 __clear_bit(devidx, dev_use);
  98
  99                 put_disk(md->disk);
 100                 kfree(md);
 101         }
 102         mutex_unlock(&open_lock);
 103 }
 104
 105 static int mmc_blk_open(struct block_device *bdev, fmode_t mode)
 106 {
 107         struct mmc_blk_data *md = mmc_blk_get(bdev->bd_disk);
 108         int ret = -ENXIO;
 109
 110         if (md) {
 111                 if (md->usage == 2)
 112                         check_disk_change(bdev);
 113                 ret = 0;
 114
 115                 if ((mode & FMODE_WRITE) && md->read_only) {
 116                         mmc_blk_put(md);
 117                         ret = -EROFS;
 118                 }
 119         }
 120
 121         return ret;
 122 }
 123
 124 static int mmc_blk_release(struct gendisk *disk, fmode_t mode)
 125 {
 126         struct mmc_blk_data *md = disk->private_data;
 127
 128         mmc_blk_put(md);
 129         return 0;
 130 }
 131
 132 static int
 133 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 134 {
 135         geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
 136         geo->heads = 4;
 137         geo->sectors = 16;
 138         return 0;
 139 }
 140
 141 static const struct block_device_operations mmc_bdops = {
 142         .open                   = mmc_blk_open,
 143         .release                = mmc_blk_release,
 144         .getgeo                 = mmc_blk_getgeo,
 145         .owner                  = THIS_MODULE,
 146 };
 147
 148 struct mmc_blk_request {
 149         struct mmc_request      mrq;
 150         struct mmc_command      cmd;
 151         struct mmc_command      stop;
 152         struct mmc_data         data;
 153 };
 154
 155 static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
 156 {
 157         int err;
 158         u32 result;
 159         __be32 *blocks;
 160
 161         struct mmc_request mrq;
 162         struct mmc_command cmd;
 163         struct mmc_data data;
 164         unsigned int timeout_us;
 165
 166         struct scatterlist sg;
 167
 168         memset(&cmd, 0, sizeof(struct mmc_command));
 169
 170         cmd.opcode = MMC_APP_CMD;
 171         cmd.arg = card->rca << 16;
 172         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 173
 174         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 175         if (err)
 176                 return (u32)-1;
 177         if (!mmc_host_is_spi(card->host) && !(cmd.resp[0] & R1_APP_CMD))
 178                 return (u32)-1;
 179
 180         memset(&cmd, 0, sizeof(struct mmc_command));
 181
 182         cmd.opcode = SD_APP_SEND_NUM_WR_BLKS;
 183         cmd.arg = 0;
 184         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 185
 186         memset(&data, 0, sizeof(struct mmc_data));
 187
 188         data.timeout_ns = card->csd.tacc_ns * 100;
 189         data.timeout_clks = card->csd.tacc_clks * 100;
 190
 191         timeout_us = data.timeout_ns / 1000;
 192         timeout_us += data.timeout_clks * 1000 /
 193                 (card->host->ios.clock / 1000);
 194
 195         if (timeout_us > 100000) {
 196                 data.timeout_ns = 100000000;
 197                 data.timeout_clks = 0;
 198         }
 199
 200         data.blksz = 4;
 201         data.blocks = 1;
 202         data.flags = MMC_DATA_READ;
 203         data.sg = &sg;
 204         data.sg_len = 1;
 205
 206         memset(&mrq, 0, sizeof(struct mmc_request));
 207
 208         mrq.cmd = &cmd;
 209         mrq.data = &data;
 210
 211         blocks = kmalloc(4, GFP_KERNEL);
 212         if (!blocks)
 213                 return (u32)-1;
 214
 215         sg_init_one(&sg, blocks, 4);
 216
 217         mmc_wait_for_req(card->host, &mrq);
 218
 219         result = ntohl(*blocks);
 220         kfree(blocks);
 221
 222         if (cmd.error || data.error)
 223                 result = (u32)-1;
 224
 225         return result;
 226 }
 227
 228 static u32 get_card_status(struct mmc_card *card, struct request *req)
 229 {
 230         struct mmc_command cmd;
 231         int err;
 232
 233         memset(&cmd, 0, sizeof(struct mmc_command));
 234         cmd.opcode = MMC_SEND_STATUS;
 235         if (!mmc_host_is_spi(card->host))
 236                 cmd.arg = card->rca << 16;
 237         cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
 238         err = mmc_wait_for_cmd(card->host, &cmd, 0);
 239         if (err)
 240                 printk(KERN_ERR "%s: error %d sending status comand",
 241                        req->rq_disk->disk_name, err);
 242         return cmd.resp[0];
 243 }
 244
 245 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 246 {
 247         struct mmc_blk_data *md = mq->data;
 248         struct mmc_card *card = md->queue.card;
 249         struct mmc_blk_request brq;
 250         int ret = 1, disable_multi = 0;
 251
 252         mmc_claim_host(card->host);
 253
 254         do {
 255                 struct mmc_command cmd;
 256                 u32 readcmd, writecmd, status = 0;
 257
 258                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 259                 brq.mrq.cmd = &brq.cmd;
 260                 brq.mrq.data = &brq.data;
 261
 262                 brq.cmd.arg = blk_rq_pos(req);
 263                 if (!mmc_card_blockaddr(card))
 264                         brq.cmd.arg <<= 9;
 265                 brq.cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
 266                 brq.data.blksz = 512;
 267                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 268                 brq.stop.arg = 0;
 269                 brq.stop.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
 270                 brq.data.blocks = blk_rq_sectors(req);
 271
 272                 /*
 273                  * The block layer doesn't support all sector count
 274                  * restrictions, so we need to be prepared for too big
 275                  * requests.
 276                  */
 277                 if (brq.data.blocks > card->host->max_blk_count)
 278                         brq.data.blocks = card->host->max_blk_count;
 279
 280                 /*
 281                  * After a read error, we redo the request one sector at a time
 282                  * in order to accurately determine which sectors can be read
 283                  * successfully.
 284                  */
 285                 if (disable_multi && brq.data.blocks > 1)
 286                         brq.data.blocks = 1;
 287
 288                 if (brq.data.blocks > 1) {
 289                         /* SPI multiblock writes terminate using a special
 290                          * token, not a STOP_TRANSMISSION request.
 291                          */
 292                         if (!mmc_host_is_spi(card->host)
 293                                         || rq_data_dir(req) == READ)
 294                                 brq.mrq.stop = &brq.stop;
 295                         readcmd = MMC_READ_MULTIPLE_BLOCK;
 296                         writecmd = MMC_WRITE_MULTIPLE_BLOCK;
 297                 } else {
 298                         brq.mrq.stop = NULL;
 299                         readcmd = MMC_READ_SINGLE_BLOCK;
 300                         writecmd = MMC_WRITE_BLOCK;
 301                 }
 302
 303                 if (rq_data_dir(req) == READ) {
 304                         brq.cmd.opcode = readcmd;
 305                         brq.data.flags |= MMC_DATA_READ;
 306                 } else {
 307                         brq.cmd.opcode = writecmd;
 308                         brq.data.flags |= MMC_DATA_WRITE;
 309                 }
 310
 311                 mmc_set_data_timeout(&brq.data, card);
 312
 313                 brq.data.sg = mq->sg;
 314                 brq.data.sg_len = mmc_queue_map_sg(mq);
 315
 316                 /*
 317                  * Adjust the sg list so it is the same size as the
 318                  * request.
 319                  */
 320                 if (brq.data.blocks != blk_rq_sectors(req)) {
 321                         int i, data_size = brq.data.blocks << 9;
 322                         struct scatterlist *sg;
 323
 324                         for_each_sg(brq.data.sg, sg, brq.data.sg_len, i) {
 325                                 data_size -= sg->length;
 326                                 if (data_size <= 0) {
 327                                         sg->length += data_size;
 328                                         i++;
 329                                         break;
 330                                 }
 331                         }
 332                         brq.data.sg_len = i;
 333                 }
 334
 335                 mmc_queue_bounce_pre(mq);
 336
 337                 mmc_wait_for_req(card->host, &brq.mrq);
 338
 339                 mmc_queue_bounce_post(mq);
 340
 341                 /*
 342                  * Check for errors here, but don't jump to cmd_err
 343                  * until later as we need to wait for the card to leave
 344                  * programming mode even when things go wrong.
 345                  */
 346                 if (brq.cmd.error || brq.data.error || brq.stop.error) {
 347                         if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
 348                                 /* Redo read one sector at a time */
 349                                 printk(KERN_WARNING "%s: retrying using single "
 350                                        "block read\n", req->rq_disk->disk_name);
 351                                 disable_multi = 1;
 352                                 continue;
 353                         }
 354                         status = get_card_status(card, req);
 355                 }
 356
 357                 if (brq.cmd.error) {
 358                         printk(KERN_ERR "%s: error %d sending read/write "
 359                                "command, response %#x, card status %#x\n",
 360                                req->rq_disk->disk_name, brq.cmd.error,
 361                                brq.cmd.resp[0], status);
 362                 }
 363
 364                 if (brq.data.error) {
 365                         if (brq.data.error == -ETIMEDOUT && brq.mrq.stop)
 366                                 /* 'Stop' response contains card status */
 367                                 status = brq.mrq.stop->resp[0];
 368                         printk(KERN_ERR "%s: error %d transferring data,"
 369                                " sector %u, nr %u, card status %#x\n",
 370                                req->rq_disk->disk_name, brq.data.error,
 371                                (unsigned)blk_rq_pos(req),
 372                                (unsigned)blk_rq_sectors(req), status);
 373                 }
 374
 375                 if (brq.stop.error) {
 376                         printk(KERN_ERR "%s: error %d sending stop command, "
 377                                "response %#x, card status %#x\n",
 378                                req->rq_disk->disk_name, brq.stop.error,
 379                                brq.stop.resp[0], status);
 380                 }
 381
 382                 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
 383                         do {
 384                                 int err;
 385
 386                                 cmd.opcode = MMC_SEND_STATUS;
 387                                 cmd.arg = card->rca << 16;
 388                                 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
 389                                 err = mmc_wait_for_cmd(card->host, &cmd, 5);
 390                                 if (err) {
 391                                         printk(KERN_ERR "%s: error %d requesting status\n",
 392                                                req->rq_disk->disk_name, err);
 393                                         goto cmd_err;
 394                                 }
 395                                 /*
 396                                  * Some cards mishandle the status bits,
 397                                  * so make sure to check both the busy
 398                                  * indication and the card state.
 399                                  */
 400                         } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
 401                                 (R1_CURRENT_STATE(cmd.resp[0]) == 7));
 402
 403 #if 0
 404                         if (cmd.resp[0] & ~0x00000900)
 405                                 printk(KERN_ERR "%s: status = %08x\n",
 406                                        req->rq_disk->disk_name, cmd.resp[0]);
 407                         if (mmc_decode_status(cmd.resp))
 408                                 goto cmd_err;
 409 #endif
 410                 }
 411
 412                 if (brq.cmd.error || brq.stop.error || brq.data.error) {
 413                         if (rq_data_dir(req) == READ) {
 414                                 /*
 415                                  * After an error, we redo I/O one sector at a
 416                                  * time, so we only reach here after trying to
 417                                  * read a single sector.
 418                                  */
 419                                 spin_lock_irq(&md->lock);
 420                                 ret = __blk_end_request(req, -EIO, brq.data.blksz);
 421                                 spin_unlock_irq(&md->lock);
 422                                 continue;
 423                         }
 424                         goto cmd_err;
 425                 }
 426
 427                 /*
 428                  * A block was successfully transferred.
 429                  */
 430                 spin_lock_irq(&md->lock);
 431                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 432                 spin_unlock_irq(&md->lock);
 433         } while (ret);
 434
 435         mmc_release_host(card->host);
 436
 437         return 1;
 438
 439  cmd_err:
 440         /*
 441          * If this is an SD card and we're writing, we can first
 442          * mark the known good sectors as ok.
 443          *
 444          * If the card is not SD, we can still ok written sectors
 445          * as reported by the controller (which might be less than
 446          * the real number of written sectors, but never more).
 447          */
 448         if (mmc_card_sd(card)) {
 449                 u32 blocks;
 450
 451                 blocks = mmc_sd_num_wr_blocks(card);
 452                 if (blocks != (u32)-1) {
 453                         spin_lock_irq(&md->lock);
 454                         ret = __blk_end_request(req, 0, blocks << 9);
 455                         spin_unlock_irq(&md->lock);
 456                 }
 457         } else {
 458                 spin_lock_irq(&md->lock);
 459                 ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 460                 spin_unlock_irq(&md->lock);
 461         }
 462
 463         mmc_release_host(card->host);
 464
 465         spin_lock_irq(&md->lock);
 466         while (ret)
 467                 ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 468         spin_unlock_irq(&md->lock);
 469
 470         return 0;
 471 }
 472
 473
 474 static inline int mmc_blk_readonly(struct mmc_card *card)
 475 {
 476         return mmc_card_readonly(card) ||
 477                !(card->csd.cmdclass & CCC_BLOCK_WRITE);
 478 }
 479
 480 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 481 {
 482         struct mmc_blk_data *md;
 483         int devidx, ret;
 484
 485         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 486         if (devidx >= MMC_NUM_MINORS)
 487                 return ERR_PTR(-ENOSPC);
 488         __set_bit(devidx, dev_use);
 489
 490         md = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 491         if (!md) {
 492                 ret = -ENOMEM;
 493                 goto out;
 494         }
 495
 496
 497         /*
 498          * Set the read-only status based on the supported commands
 499          * and the write protect switch.
 500          */
 501         md->read_only = mmc_blk_readonly(card);
 502
 503         md->disk = alloc_disk(1 << MMC_SHIFT);
 504         if (md->disk == NULL) {
 505                 ret = -ENOMEM;
 506                 goto err_kfree;
 507         }
 508
 509         spin_lock_init(&md->lock);
 510         md->usage = 1;
 511
 512         ret = mmc_init_queue(&md->queue, card, &md->lock);
 513         if (ret)
 514                 goto err_putdisk;
 515
 516         md->queue.issue_fn = mmc_blk_issue_rq;
 517         md->queue.data = md;
 518
 519         md->disk->major = MMC_BLOCK_MAJOR;
 520         md->disk->first_minor = devidx << MMC_SHIFT;
 521         md->disk->fops = &mmc_bdops;
 522         md->disk->private_data = md;
 523         md->disk->queue = md->queue.queue;
 524         md->disk->driverfs_dev = &card->dev;
 525
 526         /*
 527          * As discussed on lkml, GENHD_FL_REMOVABLE should:
 528          *
 529          * - be set for removable media with permanent block devices
 530          * - be unset for removable block devices with permanent media
 531          *
 532          * Since MMC block devices clearly fall under the second
 533          * case, we do not set GENHD_FL_REMOVABLE.  Userspace
 534          * should use the block device creation/destruction hotplug
 535          * messages to tell when the card is present.
 536          */
 537
 538         sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 539
 540         blk_queue_logical_block_size(md->queue.queue, 512);
 541
 542         if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
 543                 /*
 544                  * The EXT_CSD sector count is in number or 512 byte
 545                  * sectors.
 546                  */
 547                 set_capacity(md->disk, card->ext_csd.sectors);
 548         } else {
 549                 /*
 550                  * The CSD capacity field is in units of read_blkbits.
 551                  * set_capacity takes units of 512 bytes.
 552                  */
 553                 set_capacity(md->disk,
 554                         card->csd.capacity << (card->csd.read_blkbits - 9));
 555         }
 556         return md;
 557
 558  err_putdisk:
 559         put_disk(md->disk);
 560  err_kfree:
 561         kfree(md);
 562  out:
 563         return ERR_PTR(ret);
 564 }
 565
 566 static int
 567 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 568 {
 569         struct mmc_command cmd;
 570         int err;
 571
 572         /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */
 573         if (mmc_card_blockaddr(card))
 574                 return 0;
 575
 576         mmc_claim_host(card->host);
 577         cmd.opcode = MMC_SET_BLOCKLEN;
 578         cmd.arg = 512;
 579         cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
 580         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 581         mmc_release_host(card->host);
 582
 583         if (err) {
 584                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 585                         md->disk->disk_name, cmd.arg, err);
 586                 return -EINVAL;
 587         }
 588
 589         return 0;
 590 }
 591
 592 static int mmc_blk_probe(struct mmc_card *card)
 593 {
 594         struct mmc_blk_data *md;
 595         int err;
 596
 597         char cap_str[10];
 598
 599         /*
 600          * Check that the card supports the command class(es) we need.
 601          */
 602         if (!(card->csd.cmdclass & CCC_BLOCK_READ))
 603                 return -ENODEV;
 604
 605         md = mmc_blk_alloc(card);
 606         if (IS_ERR(md))
 607                 return PTR_ERR(md);
 608
 609         err = mmc_blk_set_blksize(md, card);
 610         if (err)
 611                 goto out;
 612
 613         string_get_size((u64)get_capacity(md->disk) << 9, STRING_UNITS_2,
 614                         cap_str, sizeof(cap_str));
 615         printk(KERN_INFO "%s: %s %s %s %s\n",
 616                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 617                 cap_str, md->read_only ? "(ro)" : "");
 618
 619         mmc_set_drvdata(card, md);
 620         add_disk(md->disk);
 621         return 0;
 622
 623  out:
 624         mmc_cleanup_queue(&md->queue);
 625         mmc_blk_put(md);
 626
 627         return err;
 628 }
 629
 630 static void mmc_blk_remove(struct mmc_card *card)
 631 {
 632         struct mmc_blk_data *md = mmc_get_drvdata(card);
 633
 634         if (md) {
 635                 /* Stop new requests from getting into the queue */
 636                 del_gendisk(md->disk);
 637
 638                 /* Then flush out any already in there */
 639                 mmc_cleanup_queue(&md->queue);
 640
 641                 mmc_blk_put(md);
 642         }
 643         mmc_set_drvdata(card, NULL);
 644 }
 645
 646 #ifdef CONFIG_PM
 647 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
 648 {
 649         struct mmc_blk_data *md = mmc_get_drvdata(card);
 650
 651         if (md) {
 652                 mmc_queue_suspend(&md->queue);
 653         }
 654         return 0;
 655 }
 656
 657 static int mmc_blk_resume(struct mmc_card *card)
 658 {
 659         struct mmc_blk_data *md = mmc_get_drvdata(card);
 660
 661         if (md) {
 662                 mmc_blk_set_blksize(md, card);
 663                 mmc_queue_resume(&md->queue);
 664         }
 665         return 0;
 666 }
 667 #else
 668 #define mmc_blk_suspend NULL
 669 #define mmc_blk_resume  NULL
 670 #endif
 671
 672 static struct mmc_driver mmc_driver = {
 673         .drv            = {
 674                 .name   = "mmcblk",
 675         },
 676         .probe          = mmc_blk_probe,
 677         .remove         = mmc_blk_remove,
 678         .suspend        = mmc_blk_suspend,
 679         .resume         = mmc_blk_resume,
 680 };
 681
 682 static int __init mmc_blk_init(void)
 683 {
 684         int res;
 685
 686         res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 687         if (res)
 688                 goto out;
 689
 690         res = mmc_register_driver(&mmc_driver);
 691         if (res)
 692                 goto out2;
 693
 694         return 0;
 695  out2:
 696         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 697  out:
 698         return res;
 699 }
 700
 701 static void __exit mmc_blk_exit(void)
 702 {
 703         mmc_unregister_driver(&mmc_driver);
 704         unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");
 705 }
 706
 707 module_init(mmc_blk_init);
 708 module_exit(mmc_blk_exit);
 709
 710 MODULE_LICENSE("GPL");
 711 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 712