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