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 brq.data.timeout_ns = card->csd.tacc_ns * 10;
183 brq.data.timeout_clks = card->csd.tacc_clks * 10;
186 * Scale up the timeout by the r2w factor
188 if (rq_data_dir(req) == WRITE) {
189 brq.data.timeout_ns <<= card->csd.r2w_factor;
190 brq.data.timeout_clks <<= card->csd.r2w_factor;
194 * SD cards use a 100 multiplier and has a upper limit
196 if (mmc_card_sd(card)) {
197 unsigned int limit_us, timeout_us;
199 brq.data.timeout_ns *= 10;
200 brq.data.timeout_clks *= 10;
202 if (rq_data_dir(req) == READ)
207 timeout_us = brq.data.timeout_ns / 1000;
208 timeout_us += brq.data.timeout_clks * 1000 /
209 (card->host->ios.clock / 1000);
211 if (timeout_us > limit_us) {
212 brq.data.timeout_ns = limit_us * 1000;
213 brq.data.timeout_clks = 0;
217 if (rq_data_dir(req) == READ) {
218 brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
219 brq.data.flags |= MMC_DATA_READ;
221 brq.cmd.opcode = MMC_WRITE_BLOCK;
222 brq.data.flags |= MMC_DATA_WRITE;
226 if (brq.data.blocks > 1) {
227 brq.data.flags |= MMC_DATA_MULTI;
228 brq.mrq.stop = &brq.stop;
233 brq.data.sg = mq->sg;
234 brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
236 mmc_wait_for_req(card->host, &brq.mrq);
238 printk(KERN_ERR "%s: error %d sending read/write command\n",
239 req->rq_disk->disk_name, brq.cmd.error);
243 if (brq.data.error) {
244 printk(KERN_ERR "%s: error %d transferring data\n",
245 req->rq_disk->disk_name, brq.data.error);
249 if (brq.stop.error) {
250 printk(KERN_ERR "%s: error %d sending stop command\n",
251 req->rq_disk->disk_name, brq.stop.error);
258 cmd.opcode = MMC_SEND_STATUS;
259 cmd.arg = card->rca << 16;
260 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
261 err = mmc_wait_for_cmd(card->host, &cmd, 5);
263 printk(KERN_ERR "%s: error %d requesting status\n",
264 req->rq_disk->disk_name, err);
267 } while (!(cmd.resp[0] & R1_READY_FOR_DATA));
270 if (cmd.resp[0] & ~0x00000900)
271 printk(KERN_ERR "%s: status = %08x\n",
272 req->rq_disk->disk_name, cmd.resp[0]);
273 if (mmc_decode_status(cmd.resp))
278 * A block was successfully transferred.
280 spin_lock_irq(&md->lock);
281 ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
284 * The whole request completed successfully.
286 add_disk_randomness(req->rq_disk);
287 blkdev_dequeue_request(req);
288 end_that_request_last(req, 1);
290 spin_unlock_irq(&md->lock);
293 mmc_card_release_host(card);
298 mmc_card_release_host(card);
301 * This is a little draconian, but until we get proper
302 * error handling sorted out here, its the best we can
303 * do - especially as some hosts have no idea how much
304 * data was transferred before the error occurred.
306 spin_lock_irq(&md->lock);
308 ret = end_that_request_chunk(req, 0,
309 req->current_nr_sectors << 9);
312 add_disk_randomness(req->rq_disk);
313 blkdev_dequeue_request(req);
314 end_that_request_last(req, 0);
315 spin_unlock_irq(&md->lock);
320 #define MMC_NUM_MINORS (256 >> MMC_SHIFT)
322 static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
324 static inline int mmc_blk_readonly(struct mmc_card *card)
326 return mmc_card_readonly(card) ||
327 !(card->csd.cmdclass & CCC_BLOCK_WRITE);
330 static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
332 struct mmc_blk_data *md;
335 devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
336 if (devidx >= MMC_NUM_MINORS)
337 return ERR_PTR(-ENOSPC);
338 __set_bit(devidx, dev_use);
340 md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
346 memset(md, 0, sizeof(struct mmc_blk_data));
349 * Set the read-only status based on the supported commands
350 * and the write protect switch.
352 md->read_only = mmc_blk_readonly(card);
355 * Figure out a workable block size. MMC cards have:
356 * - two block sizes, one for read and one for write.
357 * - may support partial reads and/or writes
358 * (allows block sizes smaller than specified)
360 md->block_bits = card->csd.read_blkbits;
361 if (card->csd.write_blkbits != card->csd.read_blkbits) {
362 if (card->csd.write_blkbits < card->csd.read_blkbits &&
363 card->csd.read_partial) {
365 * write block size is smaller than read block
366 * size, but we support partial reads, so choose
367 * the smaller write block size.
369 md->block_bits = card->csd.write_blkbits;
370 } else if (card->csd.write_blkbits > card->csd.read_blkbits &&
371 card->csd.write_partial) {
373 * read block size is smaller than write block
374 * size, but we support partial writes. Use read
379 * We don't support this configuration for writes.
381 printk(KERN_ERR "%s: unable to select block size for "
382 "writing (rb%u wb%u rp%u wp%u)\n",
384 1 << card->csd.read_blkbits,
385 1 << card->csd.write_blkbits,
386 card->csd.read_partial,
387 card->csd.write_partial);
393 * Refuse to allow block sizes smaller than 512 bytes.
395 if (md->block_bits < 9) {
396 printk(KERN_ERR "%s: unable to support block size %u\n",
397 mmc_card_id(card), 1 << md->block_bits);
402 md->disk = alloc_disk(1 << MMC_SHIFT);
403 if (md->disk == NULL) {
408 spin_lock_init(&md->lock);
411 ret = mmc_init_queue(&md->queue, card, &md->lock);
415 md->queue.prep_fn = mmc_blk_prep_rq;
416 md->queue.issue_fn = mmc_blk_issue_rq;
419 md->disk->major = major;
420 md->disk->first_minor = devidx << MMC_SHIFT;
421 md->disk->fops = &mmc_bdops;
422 md->disk->private_data = md;
423 md->disk->queue = md->queue.queue;
424 md->disk->driverfs_dev = &card->dev;
427 * As discussed on lkml, GENHD_FL_REMOVABLE should:
429 * - be set for removable media with permanent block devices
430 * - be unset for removable block devices with permanent media
432 * Since MMC block devices clearly fall under the second
433 * case, we do not set GENHD_FL_REMOVABLE. Userspace
434 * should use the block device creation/destruction hotplug
435 * messages to tell when the card is present.
438 sprintf(md->disk->disk_name, "mmcblk%d", devidx);
440 blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
443 * The CSD capacity field is in units of read_blkbits.
444 * set_capacity takes units of 512 bytes.
446 set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
458 mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
460 struct mmc_command cmd;
463 mmc_card_claim_host(card);
464 cmd.opcode = MMC_SET_BLOCKLEN;
465 cmd.arg = 1 << md->block_bits;
466 cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
467 err = mmc_wait_for_cmd(card->host, &cmd, 5);
468 mmc_card_release_host(card);
471 printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
472 md->disk->disk_name, cmd.arg, err);
479 static int mmc_blk_probe(struct mmc_card *card)
481 struct mmc_blk_data *md;
485 * Check that the card supports the command class(es) we need.
487 if (!(card->csd.cmdclass & CCC_BLOCK_READ))
490 md = mmc_blk_alloc(card);
494 err = mmc_blk_set_blksize(md, card);
498 printk(KERN_INFO "%s: %s %s %lluKiB %s\n",
499 md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
500 (unsigned long long)(get_capacity(md->disk) >> 1),
501 md->read_only ? "(ro)" : "");
503 mmc_set_drvdata(card, md);
513 static void mmc_blk_remove(struct mmc_card *card)
515 struct mmc_blk_data *md = mmc_get_drvdata(card);
520 del_gendisk(md->disk);
523 * I think this is needed.
525 md->disk->queue = NULL;
527 devidx = md->disk->first_minor >> MMC_SHIFT;
528 __clear_bit(devidx, dev_use);
532 mmc_set_drvdata(card, NULL);
536 static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
538 struct mmc_blk_data *md = mmc_get_drvdata(card);
541 mmc_queue_suspend(&md->queue);
546 static int mmc_blk_resume(struct mmc_card *card)
548 struct mmc_blk_data *md = mmc_get_drvdata(card);
551 mmc_blk_set_blksize(md, card);
552 mmc_queue_resume(&md->queue);
557 #define mmc_blk_suspend NULL
558 #define mmc_blk_resume NULL
561 static struct mmc_driver mmc_driver = {
565 .probe = mmc_blk_probe,
566 .remove = mmc_blk_remove,
567 .suspend = mmc_blk_suspend,
568 .resume = mmc_blk_resume,
571 static int __init mmc_blk_init(void)
575 res = register_blkdev(major, "mmc");
577 printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
584 return mmc_register_driver(&mmc_driver);
590 static void __exit mmc_blk_exit(void)
592 mmc_unregister_driver(&mmc_driver);
593 unregister_blkdev(major, "mmc");
596 module_init(mmc_blk_init);
597 module_exit(mmc_blk_exit);
599 MODULE_LICENSE("GPL");
600 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
602 module_param(major, int, 0444);
603 MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");