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/mutex.h>
32 #include <linux/mmc/card.h>
33 #include <linux/mmc/host.h>
34 #include <linux/mmc/protocol.h>
36 #include <asm/system.h>
37 #include <asm/uaccess.h>
39 #include "mmc_queue.h"
42 * max 8 partitions per card
49 * There is one mmc_blk_data per slot.
54 struct mmc_queue queue;
57 unsigned int block_bits;
58 unsigned int read_only;
61 static DEFINE_MUTEX(open_lock);
63 static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
65 struct mmc_blk_data *md;
67 mutex_lock(&open_lock);
68 md = disk->private_data;
69 if (md && md->usage == 0)
73 mutex_unlock(&open_lock);
78 static void mmc_blk_put(struct mmc_blk_data *md)
80 mutex_lock(&open_lock);
84 mmc_cleanup_queue(&md->queue);
87 mutex_unlock(&open_lock);
90 static int mmc_blk_open(struct inode *inode, struct file *filp)
92 struct mmc_blk_data *md;
95 md = mmc_blk_get(inode->i_bdev->bd_disk);
98 check_disk_change(inode->i_bdev);
101 if ((filp->f_mode & FMODE_WRITE) && md->read_only)
108 static int mmc_blk_release(struct inode *inode, struct file *filp)
110 struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
117 mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
119 geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
125 static struct block_device_operations mmc_bdops = {
126 .open = mmc_blk_open,
127 .release = mmc_blk_release,
128 .getgeo = mmc_blk_getgeo,
129 .owner = THIS_MODULE,
132 struct mmc_blk_request {
133 struct mmc_request mrq;
134 struct mmc_command cmd;
135 struct mmc_command stop;
136 struct mmc_data data;
139 static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
141 struct mmc_blk_data *md = mq->data;
142 int stat = BLKPREP_OK;
145 * If we have no device, we haven't finished initialising.
147 if (!md || !mq->card) {
148 printk(KERN_ERR "%s: killing request - no device/host\n",
149 req->rq_disk->disk_name);
156 static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
158 struct mmc_blk_data *md = mq->data;
159 struct mmc_card *card = md->queue.card;
162 if (mmc_card_claim_host(card))
166 struct mmc_blk_request brq;
167 struct mmc_command cmd;
169 memset(&brq, 0, sizeof(struct mmc_blk_request));
170 brq.mrq.cmd = &brq.cmd;
171 brq.mrq.data = &brq.data;
173 brq.cmd.arg = req->sector << 9;
174 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
175 brq.data.blksz_bits = md->block_bits;
176 brq.data.blksz = 1 << 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 | MMC_CMD_AC;
182 mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ);
184 if (rq_data_dir(req) == READ) {
185 brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
186 brq.data.flags |= MMC_DATA_READ;
188 brq.cmd.opcode = MMC_WRITE_BLOCK;
189 brq.data.flags |= MMC_DATA_WRITE;
193 if (brq.data.blocks > 1) {
194 brq.data.flags |= MMC_DATA_MULTI;
195 brq.mrq.stop = &brq.stop;
200 brq.data.sg = mq->sg;
201 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
203 mmc_wait_for_req(card->host, &brq.mrq);
205 printk(KERN_ERR "%s: error %d sending read/write command\n",
206 req->rq_disk->disk_name, brq.cmd.error);
210 if (brq.data.error) {
211 printk(KERN_ERR "%s: error %d transferring data\n",
212 req->rq_disk->disk_name, brq.data.error);
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);
225 cmd.opcode = MMC_SEND_STATUS;
226 cmd.arg = card->rca << 16;
227 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
228 err = mmc_wait_for_cmd(card->host, &cmd, 5);
230 printk(KERN_ERR "%s: error %d requesting status\n",
231 req->rq_disk->disk_name, err);
234 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
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))
245 * A block was successfully transferred.
247 spin_lock_irq(&md->lock);
248 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
251 * The whole request completed successfully.
253 add_disk_randomness(req->rq_disk);
254 blkdev_dequeue_request(req);
255 end_that_request_last(req, 1);
257 spin_unlock_irq(&md->lock);
260 mmc_card_release_host(card);
265 mmc_card_release_host(card);
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.
273 spin_lock_irq(&md->lock);
275 ret = end_that_request_chunk(req, 0,
276 req->current_nr_sectors << 9);
279 add_disk_randomness(req->rq_disk);
280 blkdev_dequeue_request(req);
281 end_that_request_last(req, 0);
282 spin_unlock_irq(&md->lock);
287 #define MMC_NUM_MINORS (256 >> MMC_SHIFT)
289 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
291 static inline int mmc_blk_readonly(struct mmc_card *card)
293 return mmc_card_readonly(card) ||
294 !(card->csd.cmdclass & CCC_BLOCK_WRITE);
297 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
299 struct mmc_blk_data *md;
302 devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
303 if (devidx >= MMC_NUM_MINORS)
304 return ERR_PTR(-ENOSPC);
305 __set_bit(devidx, dev_use);
307 md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
313 memset(md, 0, sizeof(struct mmc_blk_data));
316 * Set the read-only status based on the supported commands
317 * and the write protect switch.
319 md->read_only = mmc_blk_readonly(card);
322 * Figure out a workable block size. MMC cards have:
323 * - two block sizes, one for read and one for write.
324 * - may support partial reads and/or writes
325 * (allows block sizes smaller than specified)
327 md->block_bits = card->csd.read_blkbits;
328 if (card->csd.write_blkbits != card->csd.read_blkbits) {
329 if (card->csd.write_blkbits < card->csd.read_blkbits &&
330 card->csd.read_partial) {
332 * write block size is smaller than read block
333 * size, but we support partial reads, so choose
334 * the smaller write block size.
336 md->block_bits = card->csd.write_blkbits;
337 } else if (card->csd.write_blkbits > card->csd.read_blkbits &&
338 card->csd.write_partial) {
340 * read block size is smaller than write block
341 * size, but we support partial writes. Use read
346 * We don't support this configuration for writes.
348 printk(KERN_ERR "%s: unable to select block size for "
349 "writing (rb%u wb%u rp%u wp%u)\n",
351 1 << card->csd.read_blkbits,
352 1 << card->csd.write_blkbits,
353 card->csd.read_partial,
354 card->csd.write_partial);
360 * Refuse to allow block sizes smaller than 512 bytes.
362 if (md->block_bits < 9) {
363 printk(KERN_ERR "%s: unable to support block size %u\n",
364 mmc_card_id(card), 1 << md->block_bits);
369 md->disk = alloc_disk(1 << MMC_SHIFT);
370 if (md->disk == NULL) {
375 spin_lock_init(&md->lock);
378 ret = mmc_init_queue(&md->queue, card, &md->lock);
382 md->queue.prep_fn = mmc_blk_prep_rq;
383 md->queue.issue_fn = mmc_blk_issue_rq;
386 md->disk->major = major;
387 md->disk->first_minor = devidx << MMC_SHIFT;
388 md->disk->fops = &mmc_bdops;
389 md->disk->private_data = md;
390 md->disk->queue = md->queue.queue;
391 md->disk->driverfs_dev = &card->dev;
394 * As discussed on lkml, GENHD_FL_REMOVABLE should:
396 * - be set for removable media with permanent block devices
397 * - be unset for removable block devices with permanent media
399 * Since MMC block devices clearly fall under the second
400 * case, we do not set GENHD_FL_REMOVABLE. Userspace
401 * should use the block device creation/destruction hotplug
402 * messages to tell when the card is present.
405 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
407 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
410 * The CSD capacity field is in units of read_blkbits.
411 * set_capacity takes units of 512 bytes.
413 set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
425 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
427 struct mmc_command cmd;
430 mmc_card_claim_host(card);
431 cmd.opcode = MMC_SET_BLOCKLEN;
432 cmd.arg = 1 << md->block_bits;
433 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
434 err = mmc_wait_for_cmd(card->host, &cmd, 5);
435 mmc_card_release_host(card);
438 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
439 md->disk->disk_name, cmd.arg, err);
446 static int mmc_blk_probe(struct mmc_card *card)
448 struct mmc_blk_data *md;
452 * Check that the card supports the command class(es) we need.
454 if (!(card->csd.cmdclass & CCC_BLOCK_READ))
457 md = mmc_blk_alloc(card);
461 err = mmc_blk_set_blksize(md, card);
465 printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
466 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
467 (unsigned long long)(get_capacity(md->disk) >> 1),
468 md->read_only ? "(ro)" : "");
470 mmc_set_drvdata(card, md);
480 static void mmc_blk_remove(struct mmc_card *card)
482 struct mmc_blk_data *md = mmc_get_drvdata(card);
487 del_gendisk(md->disk);
490 * I think this is needed.
492 md->disk->queue = NULL;
494 devidx = md->disk->first_minor >> MMC_SHIFT;
495 __clear_bit(devidx, dev_use);
499 mmc_set_drvdata(card, NULL);
503 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
505 struct mmc_blk_data *md = mmc_get_drvdata(card);
508 mmc_queue_suspend(&md->queue);
513 static int mmc_blk_resume(struct mmc_card *card)
515 struct mmc_blk_data *md = mmc_get_drvdata(card);
518 mmc_blk_set_blksize(md, card);
519 mmc_queue_resume(&md->queue);
524 #define mmc_blk_suspend NULL
525 #define mmc_blk_resume NULL
528 static struct mmc_driver mmc_driver = {
532 .probe = mmc_blk_probe,
533 .remove = mmc_blk_remove,
534 .suspend = mmc_blk_suspend,
535 .resume = mmc_blk_resume,
538 static int __init mmc_blk_init(void)
542 res = register_blkdev(major, "mmc");
544 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
551 return mmc_register_driver(&mmc_driver);
557 static void __exit mmc_blk_exit(void)
559 mmc_unregister_driver(&mmc_driver);
560 unregister_blkdev(major, "mmc");
563 module_init(mmc_blk_init);
564 module_exit(mmc_blk_exit);
566 MODULE_LICENSE("GPL");
567 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
569 module_param(major, int, 0444);
570 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");