2 * Block driver for media (i.e., flash cards)
4 * Copyright 2002 Hewlett-Packard Company
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.
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.
14 * Many thanks to Alessandro Rubini and Jonathan Corbet!
16 * Author: Andrew Christian
19 #include <linux/moduleparam.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
23 #include <linux/sched.h>
24 #include <linux/kernel.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>
32 #include <linux/mmc/card.h>
33 #include <linux/mmc/protocol.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
38 #include "mmc_queue.h"
41 * max 8 partitions per card
48 * There is one mmc_blk_data per slot.
53 struct mmc_queue queue;
56 unsigned int block_bits;
57 unsigned int read_only;
60 static DECLARE_MUTEX(open_lock);
62 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
64 struct mmc_blk_data *md;
67 md = disk->private_data;
68 if (md && md->usage == 0)
77 static void mmc_blk_put(struct mmc_blk_data *md)
83 mmc_cleanup_queue(&md->queue);
89 static int mmc_blk_open(struct inode *inode, struct file *filp)
91 struct mmc_blk_data *md;
94 md = mmc_blk_get(inode->i_bdev->bd_disk);
97 check_disk_change(inode->i_bdev);
100 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
107 static int mmc_blk_release(struct inode *inode, struct file *filp)
109 struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
116 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
118 geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
124 static struct block_device_operations mmc_bdops = {
125 .open = mmc_blk_open,
126 .release = mmc_blk_release,
127 .getgeo = mmc_blk_getgeo,
128 .owner = THIS_MODULE,
131 struct mmc_blk_request {
132 struct mmc_request mrq;
133 struct mmc_command cmd;
134 struct mmc_command stop;
135 struct mmc_data data;
138 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
140 struct mmc_blk_data *md = mq->data;
141 int stat = BLKPREP_OK;
144 * If we have no device, we haven't finished initialising.
146 if (!md || !mq->card) {
147 printk(KERN_ERR "%s: killing request - no device/host\n",
148 req->rq_disk->disk_name);
155 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
157 struct mmc_blk_data *md = mq->data;
158 struct mmc_card *card = md->queue.card;
161 if (mmc_card_claim_host(card))
165 struct mmc_blk_request brq;
166 struct mmc_command cmd;
168 memset(&brq, 0, sizeof(struct mmc_blk_request));
169 brq.mrq.cmd = &brq.cmd;
170 brq.mrq.data = &brq.data;
172 brq.cmd.arg = req->sector << 9;
173 brq.cmd.flags = MMC_RSP_R1;
174 brq.data.timeout_ns = card->csd.tacc_ns * 10;
175 brq.data.timeout_clks = card->csd.tacc_clks * 10;
176 brq.data.blksz_bits = md->block_bits;
177 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
178 brq.stop.opcode = MMC_STOP_TRANSMISSION;
180 brq.stop.flags = MMC_RSP_R1B;
182 if (rq_data_dir(req) == READ) {
183 brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
184 brq.data.flags |= MMC_DATA_READ;
186 brq.cmd.opcode = MMC_WRITE_BLOCK;
187 brq.data.flags |= MMC_DATA_WRITE;
190 brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
192 brq.data.sg = mq->sg;
193 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
195 mmc_wait_for_req(card->host, &brq.mrq);
197 printk(KERN_ERR "%s: error %d sending read/write command\n",
198 req->rq_disk->disk_name, brq.cmd.error);
202 if (brq.data.error) {
203 printk(KERN_ERR "%s: error %d transferring data\n",
204 req->rq_disk->disk_name, brq.data.error);
208 if (brq.stop.error) {
209 printk(KERN_ERR "%s: error %d sending stop command\n",
210 req->rq_disk->disk_name, brq.stop.error);
217 cmd.opcode = MMC_SEND_STATUS;
218 cmd.arg = card->rca << 16;
219 cmd.flags = MMC_RSP_R1;
220 err = mmc_wait_for_cmd(card->host, &cmd, 5);
222 printk(KERN_ERR "%s: error %d requesting status\n",
223 req->rq_disk->disk_name, err);
226 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
229 if (cmd.resp[0] & ~0x00000900)
230 printk(KERN_ERR "%s: status = %08x\n",
231 req->rq_disk->disk_name, cmd.resp[0]);
232 if (mmc_decode_status(cmd.resp))
237 * A block was successfully transferred.
239 spin_lock_irq(&md->lock);
240 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
243 * The whole request completed successfully.
245 add_disk_randomness(req->rq_disk);
246 blkdev_dequeue_request(req);
247 end_that_request_last(req, 1);
249 spin_unlock_irq(&md->lock);
252 mmc_card_release_host(card);
257 mmc_card_release_host(card);
260 * This is a little draconian, but until we get proper
261 * error handling sorted out here, its the best we can
262 * do - especially as some hosts have no idea how much
263 * data was transferred before the error occurred.
265 spin_lock_irq(&md->lock);
267 ret = end_that_request_chunk(req, 0,
268 req->current_nr_sectors << 9);
271 add_disk_randomness(req->rq_disk);
272 blkdev_dequeue_request(req);
273 end_that_request_last(req, 0);
274 spin_unlock_irq(&md->lock);
279 #define MMC_NUM_MINORS (256 >> MMC_SHIFT)
281 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
283 static inline int mmc_blk_readonly(struct mmc_card *card)
285 return mmc_card_readonly(card) ||
286 !(card->csd.cmdclass & CCC_BLOCK_WRITE);
289 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
291 struct mmc_blk_data *md;
294 devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
295 if (devidx >= MMC_NUM_MINORS)
296 return ERR_PTR(-ENOSPC);
297 __set_bit(devidx, dev_use);
299 md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
305 memset(md, 0, sizeof(struct mmc_blk_data));
308 * Set the read-only status based on the supported commands
309 * and the write protect switch.
311 md->read_only = mmc_blk_readonly(card);
314 * Figure out a workable block size. MMC cards have:
315 * - two block sizes, one for read and one for write.
316 * - may support partial reads and/or writes
317 * (allows block sizes smaller than specified)
319 md->block_bits = card->csd.read_blkbits;
320 if (card->csd.write_blkbits != card->csd.read_blkbits) {
321 if (card->csd.write_blkbits < card->csd.read_blkbits &&
322 card->csd.read_partial) {
324 * write block size is smaller than read block
325 * size, but we support partial reads, so choose
326 * the smaller write block size.
328 md->block_bits = card->csd.write_blkbits;
329 } else if (card->csd.write_blkbits > card->csd.read_blkbits &&
330 card->csd.write_partial) {
332 * read block size is smaller than write block
333 * size, but we support partial writes. Use read
338 * We don't support this configuration for writes.
340 printk(KERN_ERR "%s: unable to select block size for "
341 "writing (rb%u wb%u rp%u wp%u)\n",
343 1 << card->csd.read_blkbits,
344 1 << card->csd.write_blkbits,
345 card->csd.read_partial,
346 card->csd.write_partial);
352 * Refuse to allow block sizes smaller than 512 bytes.
354 if (md->block_bits < 9) {
355 printk(KERN_ERR "%s: unable to support block size %u\n",
356 mmc_card_id(card), 1 << md->block_bits);
361 md->disk = alloc_disk(1 << MMC_SHIFT);
362 if (md->disk == NULL) {
367 spin_lock_init(&md->lock);
370 ret = mmc_init_queue(&md->queue, card, &md->lock);
374 md->queue.prep_fn = mmc_blk_prep_rq;
375 md->queue.issue_fn = mmc_blk_issue_rq;
378 md->disk->major = major;
379 md->disk->first_minor = devidx << MMC_SHIFT;
380 md->disk->fops = &mmc_bdops;
381 md->disk->private_data = md;
382 md->disk->queue = md->queue.queue;
383 md->disk->driverfs_dev = &card->dev;
386 * As discussed on lkml, GENHD_FL_REMOVABLE should:
388 * - be set for removable media with permanent block devices
389 * - be unset for removable block devices with permanent media
391 * Since MMC block devices clearly fall under the second
392 * case, we do not set GENHD_FL_REMOVABLE. Userspace
393 * should use the block device creation/destruction hotplug
394 * messages to tell when the card is present.
397 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
398 sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
400 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
403 * The CSD capacity field is in units of read_blkbits.
404 * set_capacity takes units of 512 bytes.
406 set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
418 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
420 struct mmc_command cmd;
423 mmc_card_claim_host(card);
424 cmd.opcode = MMC_SET_BLOCKLEN;
425 cmd.arg = 1 << md->block_bits;
426 cmd.flags = MMC_RSP_R1;
427 err = mmc_wait_for_cmd(card->host, &cmd, 5);
428 mmc_card_release_host(card);
431 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
432 md->disk->disk_name, cmd.arg, err);
439 static int mmc_blk_probe(struct mmc_card *card)
441 struct mmc_blk_data *md;
445 * Check that the card supports the command class(es) we need.
447 if (!(card->csd.cmdclass & CCC_BLOCK_READ))
450 md = mmc_blk_alloc(card);
454 err = mmc_blk_set_blksize(md, card);
458 printk(KERN_INFO "%s: %s %s %luKiB %s\n",
459 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
460 get_capacity(md->disk) >> 1, md->read_only ? "(ro)" : "");
462 mmc_set_drvdata(card, md);
472 static void mmc_blk_remove(struct mmc_card *card)
474 struct mmc_blk_data *md = mmc_get_drvdata(card);
479 del_gendisk(md->disk);
482 * I think this is needed.
484 md->disk->queue = NULL;
486 devidx = md->disk->first_minor >> MMC_SHIFT;
487 __clear_bit(devidx, dev_use);
491 mmc_set_drvdata(card, NULL);
495 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
497 struct mmc_blk_data *md = mmc_get_drvdata(card);
500 mmc_queue_suspend(&md->queue);
505 static int mmc_blk_resume(struct mmc_card *card)
507 struct mmc_blk_data *md = mmc_get_drvdata(card);
510 mmc_blk_set_blksize(md, card);
511 mmc_queue_resume(&md->queue);
516 #define mmc_blk_suspend NULL
517 #define mmc_blk_resume NULL
520 static struct mmc_driver mmc_driver = {
524 .probe = mmc_blk_probe,
525 .remove = mmc_blk_remove,
526 .suspend = mmc_blk_suspend,
527 .resume = mmc_blk_resume,
530 static int __init mmc_blk_init(void)
534 res = register_blkdev(major, "mmc");
536 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
544 return mmc_register_driver(&mmc_driver);
550 static void __exit mmc_blk_exit(void)
552 mmc_unregister_driver(&mmc_driver);
554 unregister_blkdev(major, "mmc");
557 module_init(mmc_blk_init);
558 module_exit(mmc_blk_exit);
560 MODULE_LICENSE("GPL");
561 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
563 module_param(major, int, 0444);
564 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");