drivers/mmc/mmc_block.c

   1 /*
   2  * Block driver for media (i.e., flash cards)
   3  *
   4  * Copyright 2002 Hewlett-Packard Company
   5  *
   6  * Use consistent with the GNU GPL is permitted,
   7  * provided that this copyright notice is
   8  * preserved in its entirety in all copies and derived works.
   9  *
  10  * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
  11  * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
  12  * FITNESS FOR ANY PARTICULAR PURPOSE.
  13  *
  14  * Many thanks to Alessandro Rubini and Jonathan Corbet!
  15  *
  16  * Author:  Andrew Christian
  17  *          28 May 2002
  18  */
  19 #include <linux/moduleparam.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22
  23 #include <linux/sched.h>
  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/devfs_fs_kernel.h>
  31
  32 #include <linux/mmc/card.h>
  33 #include <linux/mmc/protocol.h>
  34
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37
  38 #include "mmc_queue.h"
  39
  40 /*
  41  * max 8 partitions per card
  42  */
  43 #define MMC_SHIFT       3
  44
  45 static int major;
  46
  47 /*
  48  * There is one mmc_blk_data per slot.
  49  */
  50 struct mmc_blk_data {
  51         spinlock_t      lock;
  52         struct gendisk  *disk;
  53         struct mmc_queue queue;
  54
  55         unsigned int    usage;
  56         unsigned int    block_bits;
  57 };
  58
  59 static DECLARE_MUTEX(open_lock);
  60
  61 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
  62 {
  63         struct mmc_blk_data *md;
  64
  65         down(&open_lock);
  66         md = disk->private_data;
  67         if (md && md->usage == 0)
  68                 md = NULL;
  69         if (md)
  70                 md->usage++;
  71         up(&open_lock);
  72
  73         return md;
  74 }
  75
  76 static void mmc_blk_put(struct mmc_blk_data *md)
  77 {
  78         down(&open_lock);
  79         md->usage--;
  80         if (md->usage == 0) {
  81                 put_disk(md->disk);
  82                 mmc_cleanup_queue(&md->queue);
  83                 kfree(md);
  84         }
  85         up(&open_lock);
  86 }
  87
  88 static int mmc_blk_open(struct inode *inode, struct file *filp)
  89 {
  90         struct mmc_blk_data *md;
  91         int ret = -ENXIO;
  92
  93         md = mmc_blk_get(inode->i_bdev->bd_disk);
  94         if (md) {
  95                 if (md->usage == 2)
  96                         check_disk_change(inode->i_bdev);
  97                 ret = 0;
  98         }
  99
 100         return ret;
 101 }
 102
 103 static int mmc_blk_release(struct inode *inode, struct file *filp)
 104 {
 105         struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
 106
 107         mmc_blk_put(md);
 108         return 0;
 109 }
 110
 111 static int
 112 mmc_blk_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
 113 {
 114         struct block_device *bdev = inode->i_bdev;
 115
 116         if (cmd == HDIO_GETGEO) {
 117                 struct hd_geometry geo;
 118
 119                 memset(&geo, 0, sizeof(struct hd_geometry));
 120
 121                 geo.cylinders   = get_capacity(bdev->bd_disk) / (4 * 16);
 122                 geo.heads       = 4;
 123                 geo.sectors     = 16;
 124                 geo.start       = get_start_sect(bdev);
 125
 126                 return copy_to_user((void __user *)arg, &geo, sizeof(geo))
 127                         ? -EFAULT : 0;
 128         }
 129
 130         return -ENOTTY;
 131 }
 132
 133 static struct block_device_operations mmc_bdops = {
 134         .open                   = mmc_blk_open,
 135         .release                = mmc_blk_release,
 136         .ioctl                  = mmc_blk_ioctl,
 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 int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
 148 {
 149         struct mmc_blk_data *md = mq->data;
 150         int stat = BLKPREP_OK;
 151
 152         /*
 153          * If we have no device, we haven't finished initialising.
 154          */
 155         if (!md || !mq->card) {
 156                 printk(KERN_ERR "%s: killing request - no device/host\n",
 157                        req->rq_disk->disk_name);
 158                 stat = BLKPREP_KILL;
 159         }
 160
 161         return stat;
 162 }
 163
 164 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 165 {
 166         struct mmc_blk_data *md = mq->data;
 167         struct mmc_card *card = md->queue.card;
 168         int ret;
 169
 170         if (mmc_card_claim_host(card))
 171                 goto cmd_err;
 172
 173         do {
 174                 struct mmc_blk_request brq;
 175                 struct mmc_command cmd;
 176
 177                 memset(&brq, 0, sizeof(struct mmc_blk_request));
 178                 brq.mrq.cmd = &brq.cmd;
 179                 brq.mrq.data = &brq.data;
 180
 181                 brq.cmd.arg = req->sector << 9;
 182                 brq.cmd.flags = MMC_RSP_R1;
 183                 brq.data.req = req;
 184                 brq.data.timeout_ns = card->csd.tacc_ns * 10;
 185                 brq.data.timeout_clks = card->csd.tacc_clks * 10;
 186                 brq.data.blksz_bits = md->block_bits;
 187                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
 188                 brq.stop.opcode = MMC_STOP_TRANSMISSION;
 189                 brq.stop.arg = 0;
 190                 brq.stop.flags = MMC_RSP_R1B;
 191
 192                 if (rq_data_dir(req) == READ) {
 193                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
 194                         brq.data.flags |= MMC_DATA_READ;
 195                 } else {
 196                         brq.cmd.opcode = MMC_WRITE_BLOCK;
 197                         brq.cmd.flags = MMC_RSP_R1B;
 198                         brq.data.flags |= MMC_DATA_WRITE;
 199                         brq.data.blocks = 1;
 200                 }
 201                 brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
 202
 203                 mmc_wait_for_req(card->host, &brq.mrq);
 204                 if (brq.cmd.error) {
 205                         printk(KERN_ERR "%s: error %d sending read/write command\n",
 206                                req->rq_disk->disk_name, brq.cmd.error);
 207                         goto cmd_err;
 208                 }
 209
 210                 if (brq.data.error) {
 211                         printk(KERN_ERR "%s: error %d transferring data\n",
 212                                req->rq_disk->disk_name, brq.data.error);
 213                         goto cmd_err;
 214                 }
 215
 216                 if (brq.stop.error) {
 217                         printk(KERN_ERR "%s: error %d sending stop command\n",
 218                                req->rq_disk->disk_name, brq.stop.error);
 219                         goto cmd_err;
 220                 }
 221
 222                 do {
 223                         int err;
 224
 225                         cmd.opcode = MMC_SEND_STATUS;
 226                         cmd.arg = card->rca << 16;
 227                         cmd.flags = MMC_RSP_R1;
 228                         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 229                         if (err) {
 230                                 printk(KERN_ERR "%s: error %d requesting status\n",
 231                                        req->rq_disk->disk_name, err);
 232                                 goto cmd_err;
 233                         }
 234                 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
 235
 236 #if 0
 237                 if (cmd.resp[0] & ~0x00000900)
 238                         printk(KERN_ERR "%s: status = %08x\n",
 239                                req->rq_disk->disk_name, cmd.resp[0]);
 240                 if (mmc_decode_status(cmd.resp))
 241                         goto cmd_err;
 242 #endif
 243
 244                 /*
 245                  * A block was successfully transferred.
 246                  */
 247                 spin_lock_irq(&md->lock);
 248                 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
 249                 if (!ret) {
 250                         /*
 251                          * The whole request completed successfully.
 252                          */
 253                         add_disk_randomness(req->rq_disk);
 254                         blkdev_dequeue_request(req);
 255                         end_that_request_last(req);
 256                 }
 257                 spin_unlock_irq(&md->lock);
 258         } while (ret);
 259
 260         mmc_card_release_host(card);
 261
 262         return 1;
 263
 264  cmd_err:
 265         mmc_card_release_host(card);
 266
 267         /*
 268          * This is a little draconian, but until we get proper
 269          * error handling sorted out here, its the best we can
 270          * do - especially as some hosts have no idea how much
 271          * data was transferred before the error occurred.
 272          */
 273         spin_lock_irq(&md->lock);
 274         do {
 275                 ret = end_that_request_chunk(req, 0,
 276                                 req->current_nr_sectors << 9);
 277         } while (ret);
 278
 279         add_disk_randomness(req->rq_disk);
 280         blkdev_dequeue_request(req);
 281         end_that_request_last(req);
 282         spin_unlock_irq(&md->lock);
 283
 284         return 0;
 285 }
 286
 287 #define MMC_NUM_MINORS  (256 >> MMC_SHIFT)
 288
 289 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
 290
 291 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
 292 {
 293         struct mmc_blk_data *md;
 294         int devidx, ret;
 295
 296         devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
 297         if (devidx >= MMC_NUM_MINORS)
 298                 return ERR_PTR(-ENOSPC);
 299         __set_bit(devidx, dev_use);
 300
 301         md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
 302         if (md) {
 303                 memset(md, 0, sizeof(struct mmc_blk_data));
 304
 305                 md->disk = alloc_disk(1 << MMC_SHIFT);
 306                 if (md->disk == NULL) {
 307                         kfree(md);
 308                         md = ERR_PTR(-ENOMEM);
 309                         goto out;
 310                 }
 311
 312                 spin_lock_init(&md->lock);
 313                 md->usage = 1;
 314
 315                 ret = mmc_init_queue(&md->queue, card, &md->lock);
 316                 if (ret) {
 317                         put_disk(md->disk);
 318                         kfree(md);
 319                         md = ERR_PTR(ret);
 320                         goto out;
 321                 }
 322                 md->queue.prep_fn = mmc_blk_prep_rq;
 323                 md->queue.issue_fn = mmc_blk_issue_rq;
 324                 md->queue.data = md;
 325
 326                 md->disk->major = major;
 327                 md->disk->first_minor = devidx << MMC_SHIFT;
 328                 md->disk->fops = &mmc_bdops;
 329                 md->disk->private_data = md;
 330                 md->disk->queue = md->queue.queue;
 331                 md->disk->driverfs_dev = &card->dev;
 332
 333                 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
 334                 sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
 335
 336                 md->block_bits = card->csd.read_blkbits;
 337
 338                 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
 339                 set_capacity(md->disk, card->csd.capacity);
 340         }
 341  out:
 342         return md;
 343 }
 344
 345 static int
 346 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
 347 {
 348         struct mmc_command cmd;
 349         int err;
 350
 351         mmc_card_claim_host(card);
 352         cmd.opcode = MMC_SET_BLOCKLEN;
 353         cmd.arg = 1 << card->csd.read_blkbits;
 354         cmd.flags = MMC_RSP_R1;
 355         err = mmc_wait_for_cmd(card->host, &cmd, 5);
 356         mmc_card_release_host(card);
 357
 358         if (err) {
 359                 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
 360                         md->disk->disk_name, cmd.arg, err);
 361                 return -EINVAL;
 362         }
 363
 364         return 0;
 365 }
 366
 367 static int mmc_blk_probe(struct mmc_card *card)
 368 {
 369         struct mmc_blk_data *md;
 370         int err;
 371
 372         if (card->csd.cmdclass & ~0x1ff)
 373                 return -ENODEV;
 374
 375         if (card->csd.read_blkbits < 9) {
 376                 printk(KERN_WARNING "%s: read blocksize too small (%u)\n",
 377                         mmc_card_id(card), 1 << card->csd.read_blkbits);
 378                 return -ENODEV;
 379         }
 380
 381         md = mmc_blk_alloc(card);
 382         if (IS_ERR(md))
 383                 return PTR_ERR(md);
 384
 385         err = mmc_blk_set_blksize(md, card);
 386         if (err)
 387                 goto out;
 388
 389         printk(KERN_INFO "%s: %s %s %dKiB\n",
 390                 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
 391                 (card->csd.capacity << card->csd.read_blkbits) / 1024);
 392
 393         mmc_set_drvdata(card, md);
 394         add_disk(md->disk);
 395         return 0;
 396
 397  out:
 398         mmc_blk_put(md);
 399
 400         return err;
 401 }
 402
 403 static void mmc_blk_remove(struct mmc_card *card)
 404 {
 405         struct mmc_blk_data *md = mmc_get_drvdata(card);
 406
 407         if (md) {
 408                 int devidx;
 409
 410                 del_gendisk(md->disk);
 411
 412                 /*
 413                  * I think this is needed.
 414                  */
 415                 md->disk->queue = NULL;
 416
 417                 devidx = md->disk->first_minor >> MMC_SHIFT;
 418                 __clear_bit(devidx, dev_use);
 419
 420                 mmc_blk_put(md);
 421         }
 422         mmc_set_drvdata(card, NULL);
 423 }
 424
 425 #ifdef CONFIG_PM
 426 static int mmc_blk_suspend(struct mmc_card *card, u32 state)
 427 {
 428         struct mmc_blk_data *md = mmc_get_drvdata(card);
 429
 430         if (md) {
 431                 mmc_queue_suspend(&md->queue);
 432         }
 433         return 0;
 434 }
 435
 436 static int mmc_blk_resume(struct mmc_card *card)
 437 {
 438         struct mmc_blk_data *md = mmc_get_drvdata(card);
 439
 440         if (md) {
 441                 mmc_blk_set_blksize(md, card);
 442                 mmc_queue_resume(&md->queue);
 443         }
 444         return 0;
 445 }
 446 #else
 447 #define mmc_blk_suspend NULL
 448 #define mmc_blk_resume  NULL
 449 #endif
 450
 451 static struct mmc_driver mmc_driver = {
 452         .drv            = {
 453                 .name   = "mmcblk",
 454         },
 455         .probe          = mmc_blk_probe,
 456         .remove         = mmc_blk_remove,
 457         .suspend        = mmc_blk_suspend,
 458         .resume         = mmc_blk_resume,
 459 };
 460
 461 static int __init mmc_blk_init(void)
 462 {
 463         int res = -ENOMEM;
 464
 465         res = register_blkdev(major, "mmc");
 466         if (res < 0) {
 467                 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
 468                        major, res);
 469                 goto out;
 470         }
 471         if (major == 0)
 472                 major = res;
 473
 474         devfs_mk_dir("mmc");
 475         return mmc_register_driver(&mmc_driver);
 476
 477  out:
 478         return res;
 479 }
 480
 481 static void __exit mmc_blk_exit(void)
 482 {
 483         mmc_unregister_driver(&mmc_driver);
 484         devfs_remove("mmc");
 485         unregister_blkdev(major, "mmc");
 486 }
 487
 488 module_init(mmc_blk_init);
 489 module_exit(mmc_blk_exit);
 490
 491 MODULE_LICENSE("GPL");
 492 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
 493
 494 module_param(major, int, 0444);
 495 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");