[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / mmc / mmc_block.c

/*
 * Block driver for media (i.e., flash cards)
 *
 * Copyright 2002 Hewlett-Packard Company
 *
 * Use consistent with the GNU GPL is permitted,
 * provided that this copyright notice is
 * preserved in its entirety in all copies and derived works.
 *
 * HEWLETT-PACKARD COMPANY MAKES NO WARRANTIES, EXPRESSED OR IMPLIED,
 * AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR ITS
 * FITNESS FOR ANY PARTICULAR PURPOSE.
 *
 * Many thanks to Alessandro Rubini and Jonathan Corbet!
 *
 * Author:  Andrew Christian
 *          28 May 2002
 */
#include <linux/moduleparam.h>
#include <linux/module.h>
#include <linux/init.h>

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/hdreg.h>
#include <linux/kdev_t.h>
#include <linux/blkdev.h>
#include <linux/devfs_fs_kernel.h>

#include <linux/mmc/card.h>
#include <linux/mmc/protocol.h>

#include <asm/system.h>
#include <asm/uaccess.h>

#include "mmc_queue.h"

/*
 * max 8 partitions per card
 */
#define MMC_SHIFT	3

static int major;

/*
 * There is one mmc_blk_data per slot.
 */
struct mmc_blk_data {
	spinlock_t	lock;
	struct gendisk	*disk;
	struct mmc_queue queue;

	unsigned int	usage;
	unsigned int	block_bits;
	unsigned int	read_only;
};

static DECLARE_MUTEX(open_lock);

static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
	struct mmc_blk_data *md;

	down(&open_lock);
	md = disk->private_data;
	if (md && md->usage == 0)
		md = NULL;
	if (md)
		md->usage++;
	up(&open_lock);

	return md;
}

static void mmc_blk_put(struct mmc_blk_data *md)
{
	down(&open_lock);
	md->usage--;
	if (md->usage == 0) {
		put_disk(md->disk);
		mmc_cleanup_queue(&md->queue);
		kfree(md);
	}
	up(&open_lock);
}

static int mmc_blk_open(struct inode *inode, struct file *filp)
{
	struct mmc_blk_data *md;
	int ret = -ENXIO;

	md = mmc_blk_get(inode->i_bdev->bd_disk);
	if (md) {
		if (md->usage == 2)
			check_disk_change(inode->i_bdev);
		ret = 0;

		if ((filp->f_mode & FMODE_WRITE) && md->read_only)
			ret = -EROFS;
	}

	return ret;
}

static int mmc_blk_release(struct inode *inode, struct file *filp)
{
	struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;

	mmc_blk_put(md);
	return 0;
}

static int
mmc_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
	geo->heads = 4;
	geo->sectors = 16;
	return 0;
}

static struct block_device_operations mmc_bdops = {
	.open			= mmc_blk_open,
	.release		= mmc_blk_release,
	.getgeo			= mmc_blk_getgeo,
	.owner			= THIS_MODULE,
};

struct mmc_blk_request {
	struct mmc_request	mrq;
	struct mmc_command	cmd;
	struct mmc_command	stop;
	struct mmc_data		data;
};

static int mmc_blk_prep_rq(struct mmc_queue *mq, struct request *req)
{
	struct mmc_blk_data *md = mq->data;
	int stat = BLKPREP_OK;

	/*
	 * If we have no device, we haven't finished initialising.
	 */
	if (!md || !mq->card) {
		printk(KERN_ERR "%s: killing request - no device/host\n",
		       req->rq_disk->disk_name);
		stat = BLKPREP_KILL;
	}

	return stat;
}

static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
{
	struct mmc_blk_data *md = mq->data;
	struct mmc_card *card = md->queue.card;
	int ret;

	if (mmc_card_claim_host(card))
		goto cmd_err;

	do {
		struct mmc_blk_request brq;
		struct mmc_command cmd;

		memset(&brq, 0, sizeof(struct mmc_blk_request));
		brq.mrq.cmd = &brq.cmd;
		brq.mrq.data = &brq.data;

		brq.cmd.arg = req->sector << 9;
		brq.cmd.flags = MMC_RSP_R1;
		brq.data.timeout_ns = card->csd.tacc_ns * 10;
		brq.data.timeout_clks = card->csd.tacc_clks * 10;
		brq.data.blksz_bits = md->block_bits;
		brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
		brq.stop.opcode = MMC_STOP_TRANSMISSION;
		brq.stop.arg = 0;
		brq.stop.flags = MMC_RSP_R1B;

		if (rq_data_dir(req) == READ) {
			brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
			brq.data.flags |= MMC_DATA_READ;
		} else {
			brq.cmd.opcode = MMC_WRITE_BLOCK;
			brq.data.flags |= MMC_DATA_WRITE;
			brq.data.blocks = 1;
		}
		brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;

		brq.data.sg = mq->sg;
		brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);

		mmc_wait_for_req(card->host, &brq.mrq);
		if (brq.cmd.error) {
			printk(KERN_ERR "%s: error %d sending read/write command\n",
			       req->rq_disk->disk_name, brq.cmd.error);
			goto cmd_err;
		}

		if (brq.data.error) {
			printk(KERN_ERR "%s: error %d transferring data\n",
			       req->rq_disk->disk_name, brq.data.error);
			goto cmd_err;
		}

		if (brq.stop.error) {
			printk(KERN_ERR "%s: error %d sending stop command\n",
			       req->rq_disk->disk_name, brq.stop.error);
			goto cmd_err;
		}

		do {
			int err;

			cmd.opcode = MMC_SEND_STATUS;
			cmd.arg = card->rca << 16;
			cmd.flags = MMC_RSP_R1;
			err = mmc_wait_for_cmd(card->host, &cmd, 5);
			if (err) {
				printk(KERN_ERR "%s: error %d requesting status\n",
				       req->rq_disk->disk_name, err);
				goto cmd_err;
			}
		} while (!(cmd.resp[0] & R1_READY_FOR_DATA));

#if 0
		if (cmd.resp[0] & ~0x00000900)
			printk(KERN_ERR "%s: status = %08x\n",
			       req->rq_disk->disk_name, cmd.resp[0]);
		if (mmc_decode_status(cmd.resp))
			goto cmd_err;
#endif

		/*
		 * A block was successfully transferred.
		 */
		spin_lock_irq(&md->lock);
		ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
		if (!ret) {
			/*
			 * The whole request completed successfully.
			 */
			add_disk_randomness(req->rq_disk);
			blkdev_dequeue_request(req);
			end_that_request_last(req, 1);
		}
		spin_unlock_irq(&md->lock);
	} while (ret);

	mmc_card_release_host(card);

	return 1;

 cmd_err:
	mmc_card_release_host(card);

	/*
	 * This is a little draconian, but until we get proper
	 * error handling sorted out here, its the best we can
	 * do - especially as some hosts have no idea how much
	 * data was transferred before the error occurred.
	 */
	spin_lock_irq(&md->lock);
	do {
		ret = end_that_request_chunk(req, 0,
				req->current_nr_sectors << 9);
	} while (ret);

	add_disk_randomness(req->rq_disk);
	blkdev_dequeue_request(req);
	end_that_request_last(req, 0);
	spin_unlock_irq(&md->lock);

	return 0;
}

#define MMC_NUM_MINORS	(256 >> MMC_SHIFT)

static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];

static inline int mmc_blk_readonly(struct mmc_card *card)
{
	return mmc_card_readonly(card) ||
	       !(card->csd.cmdclass & CCC_BLOCK_WRITE);
}

static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
{
	struct mmc_blk_data *md;
	int devidx, ret;

	devidx = find_first_zero_bit(dev_use, MMC_NUM_MINORS);
	if (devidx >= MMC_NUM_MINORS)
		return ERR_PTR(-ENOSPC);
	__set_bit(devidx, dev_use);

	md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
	if (!md) {
		ret = -ENOMEM;
		goto out;
	}

	memset(md, 0, sizeof(struct mmc_blk_data));

	/*
	 * Set the read-only status based on the supported commands
	 * and the write protect switch.
	 */
	md->read_only = mmc_blk_readonly(card);

	/*
	 * Figure out a workable block size.  MMC cards have:
	 *  - two block sizes, one for read and one for write.
	 *  - may support partial reads and/or writes
	 *    (allows block sizes smaller than specified)
	 */
	md->block_bits = card->csd.read_blkbits;
	if (card->csd.write_blkbits != card->csd.read_blkbits) {
		if (card->csd.write_blkbits < card->csd.read_blkbits &&
		    card->csd.read_partial) {
			/*
			 * write block size is smaller than read block
			 * size, but we support partial reads, so choose
			 * the smaller write block size.
			 */
			md->block_bits = card->csd.write_blkbits;
		} else if (card->csd.write_blkbits > card->csd.read_blkbits &&
			   card->csd.write_partial) {
			/*
			 * read block size is smaller than write block
			 * size, but we support partial writes.  Use read
			 * block size.
			 */
		} else {
			/*
			 * We don't support this configuration for writes.
			 */
			printk(KERN_ERR "%s: unable to select block size for "
				"writing (rb%u wb%u rp%u wp%u)\n",
				md->disk->disk_name,
				1 << card->csd.read_blkbits,
				1 << card->csd.write_blkbits,
				card->csd.read_partial,
				card->csd.write_partial);
			md->read_only = 1;
		}
	}

	/*
	 * Refuse to allow block sizes smaller than 512 bytes.
	 */
	if (md->block_bits < 9) {
		printk(KERN_ERR "%s: unable to support block size %u\n",
			mmc_card_id(card), 1 << md->block_bits);
		ret = -EINVAL;
		goto err_kfree;
	}

	md->disk = alloc_disk(1 << MMC_SHIFT);
	if (md->disk == NULL) {
		ret = -ENOMEM;
		goto err_kfree;
	}

	spin_lock_init(&md->lock);
	md->usage = 1;

	ret = mmc_init_queue(&md->queue, card, &md->lock);
	if (ret)
		goto err_putdisk;

	md->queue.prep_fn = mmc_blk_prep_rq;
	md->queue.issue_fn = mmc_blk_issue_rq;
	md->queue.data = md;

	md->disk->major	= major;
	md->disk->first_minor = devidx << MMC_SHIFT;
	md->disk->fops = &mmc_bdops;
	md->disk->private_data = md;
	md->disk->queue = md->queue.queue;
	md->disk->driverfs_dev = &card->dev;

	/*
	 * As discussed on lkml, GENHD_FL_REMOVABLE should:
	 *
	 * - be set for removable media with permanent block devices
	 * - be unset for removable block devices with permanent media
	 *
	 * Since MMC block devices clearly fall under the second
	 * case, we do not set GENHD_FL_REMOVABLE.  Userspace
	 * should use the block device creation/destruction hotplug
	 * messages to tell when the card is present.
	 */

	sprintf(md->disk->disk_name, "mmcblk%d", devidx);
	sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);

	blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);

	/*
	 * The CSD capacity field is in units of read_blkbits.
	 * set_capacity takes units of 512 bytes.
	 */
	set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
	return md;

 err_putdisk:
	put_disk(md->disk);
 err_kfree:
	kfree(md);
 out:
	return ERR_PTR(ret);
}

static int
mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
{
	struct mmc_command cmd;
	int err;

	mmc_card_claim_host(card);
	cmd.opcode = MMC_SET_BLOCKLEN;
	cmd.arg = 1 << md->block_bits;
	cmd.flags = MMC_RSP_R1;
	err = mmc_wait_for_cmd(card->host, &cmd, 5);
	mmc_card_release_host(card);

	if (err) {
		printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
			md->disk->disk_name, cmd.arg, err);
		return -EINVAL;
	}

	return 0;
}

static int mmc_blk_probe(struct mmc_card *card)
{
	struct mmc_blk_data *md;
	int err;

	/*
	 * Check that the card supports the command class(es) we need.
	 */
	if (!(card->csd.cmdclass & CCC_BLOCK_READ))
		return -ENODEV;

	md = mmc_blk_alloc(card);
	if (IS_ERR(md))
		return PTR_ERR(md);

	err = mmc_blk_set_blksize(md, card);
	if (err)
		goto out;

	printk(KERN_INFO "%s: %s %s %luKiB %s\n",
		md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
		get_capacity(md->disk) >> 1, md->read_only ? "(ro)" : "");

	mmc_set_drvdata(card, md);
	add_disk(md->disk);
	return 0;

 out:
	mmc_blk_put(md);

	return err;
}

static void mmc_blk_remove(struct mmc_card *card)
{
	struct mmc_blk_data *md = mmc_get_drvdata(card);

	if (md) {
		int devidx;

		del_gendisk(md->disk);

		/*
		 * I think this is needed.
		 */
		md->disk->queue = NULL;

		devidx = md->disk->first_minor >> MMC_SHIFT;
		__clear_bit(devidx, dev_use);

		mmc_blk_put(md);
	}
	mmc_set_drvdata(card, NULL);
}

#ifdef CONFIG_PM
static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
{
	struct mmc_blk_data *md = mmc_get_drvdata(card);

	if (md) {
		mmc_queue_suspend(&md->queue);
	}
	return 0;
}

static int mmc_blk_resume(struct mmc_card *card)
{
	struct mmc_blk_data *md = mmc_get_drvdata(card);

	if (md) {
		mmc_blk_set_blksize(md, card);
		mmc_queue_resume(&md->queue);
	}
	return 0;
}
#else
#define	mmc_blk_suspend	NULL
#define mmc_blk_resume	NULL
#endif

static struct mmc_driver mmc_driver = {
	.drv		= {
		.name	= "mmcblk",
	},
	.probe		= mmc_blk_probe,
	.remove		= mmc_blk_remove,
	.suspend	= mmc_blk_suspend,
	.resume		= mmc_blk_resume,
};

static int __init mmc_blk_init(void)
{
	int res = -ENOMEM;

	res = register_blkdev(major, "mmc");
	if (res < 0) {
		printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
		       major, res);
		goto out;
	}
	if (major == 0)
		major = res;

	devfs_mk_dir("mmc");
	return mmc_register_driver(&mmc_driver);

 out:
	return res;
}

static void __exit mmc_blk_exit(void)
{
	mmc_unregister_driver(&mmc_driver);
	devfs_remove("mmc");
	unregister_blkdev(major, "mmc");
}

module_init(mmc_blk_init);
module_exit(mmc_blk_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");

module_param(major, int, 0444);
MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");
Commit	Line	Data
1da177e4 LT	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;
a6f6c96b	57	unsigned int read_only;
1da177e4 LT	58	};
	59
	60	static DECLARE_MUTEX(open_lock);
	61
	62	static struct mmc_blk_data mmc_blk_get(struct gendisk disk)
	63	{
	64	struct mmc_blk_data *md;
	65
	66	down(&open_lock);
	67	md = disk->private_data;
	68	if (md && md->usage == 0)
	69	md = NULL;
	70	if (md)
	71	md->usage++;
	72	up(&open_lock);
	73
	74	return md;
	75	}
	76
	77	static void mmc_blk_put(struct mmc_blk_data *md)
	78	{
	79	down(&open_lock);
	80	md->usage--;
	81	if (md->usage == 0) {
	82	put_disk(md->disk);
	83	mmc_cleanup_queue(&md->queue);
	84	kfree(md);
	85	}
	86	up(&open_lock);
	87	}
	88
	89	static int mmc_blk_open(struct inode inode, struct file filp)
	90	{
	91	struct mmc_blk_data *md;
	92	int ret = -ENXIO;
	93
	94	md = mmc_blk_get(inode->i_bdev->bd_disk);
	95	if (md) {
	96	if (md->usage == 2)
	97	check_disk_change(inode->i_bdev);
	98	ret = 0;
a00fc090	99
a6f6c96b	100	if ((filp->f_mode & FMODE_WRITE) && md->read_only)
a00fc090	101	ret = -EROFS;
1da177e4 LT	102	}
	103
	104	return ret;
	105	}
	106
	107	static int mmc_blk_release(struct inode inode, struct file filp)
	108	{
	109	struct mmc_blk_data *md = inode->i_bdev->bd_disk->private_data;
	110
	111	mmc_blk_put(md);
	112	return 0;
	113	}
	114
	115	static int
a885c8c4	116	mmc_blk_getgeo(struct block_device bdev, struct hd_geometry geo)
1da177e4	117	{
a885c8c4 CH	118	geo->cylinders = get_capacity(bdev->bd_disk) / (4 * 16);
	119	geo->heads = 4;
	120	geo->sectors = 16;
	121	return 0;
1da177e4 LT	122	}
	123
	124	static struct block_device_operations mmc_bdops = {
	125	.open = mmc_blk_open,
	126	.release = mmc_blk_release,
a885c8c4	127	.getgeo = mmc_blk_getgeo,
1da177e4 LT	128	.owner = THIS_MODULE,
	129	};
	130
	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;
	136	};
	137
	138	static int mmc_blk_prep_rq(struct mmc_queue mq, struct request req)
	139	{
	140	struct mmc_blk_data *md = mq->data;
	141	int stat = BLKPREP_OK;
	142
	143	/*
	144	* If we have no device, we haven't finished initialising.
	145	*/
	146	if (!md \|\| !mq->card) {
	147	printk(KERN_ERR "%s: killing request - no device/host\n",
	148	req->rq_disk->disk_name);
	149	stat = BLKPREP_KILL;
	150	}
	151
	152	return stat;
	153	}
	154
	155	static int mmc_blk_issue_rq(struct mmc_queue mq, struct request req)
	156	{
	157	struct mmc_blk_data *md = mq->data;
	158	struct mmc_card *card = md->queue.card;
	159	int ret;
	160
	161	if (mmc_card_claim_host(card))
	162	goto cmd_err;
	163
	164	do {
	165	struct mmc_blk_request brq;
	166	struct mmc_command cmd;
	167
	168	memset(&brq, 0, sizeof(struct mmc_blk_request));
	169	brq.mrq.cmd = &brq.cmd;
	170	brq.mrq.data = &brq.data;
	171
	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;
	179	brq.stop.arg = 0;
	180	brq.stop.flags = MMC_RSP_R1B;
	181
	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;
	185	} else {
	186	brq.cmd.opcode = MMC_WRITE_BLOCK;
1da177e4 LT	187	brq.data.flags \|= MMC_DATA_WRITE;
	188	brq.data.blocks = 1;
	189	}
	190	brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL;
	191
	192	brq.data.sg = mq->sg;
	193	brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg);
	194
	195	mmc_wait_for_req(card->host, &brq.mrq);
	196	if (brq.cmd.error) {
	197	printk(KERN_ERR "%s: error %d sending read/write command\n",
	198	req->rq_disk->disk_name, brq.cmd.error);
	199	goto cmd_err;
	200	}
	201
	202	if (brq.data.error) {
	203	printk(KERN_ERR "%s: error %d transferring data\n",
	204	req->rq_disk->disk_name, brq.data.error);
	205	goto cmd_err;
	206	}
	207
	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);
	211	goto cmd_err;
	212	}
	213
	214	do {
	215	int err;
	216
	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);
	221	if (err) {
	222	printk(KERN_ERR "%s: error %d requesting status\n",
	223	req->rq_disk->disk_name, err);
	224	goto cmd_err;
	225	}
	226	} while (!(cmd.resp[0] & R1_READY_FOR_DATA));
	227
	228	#if 0
	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))
	233	goto cmd_err;
	234	#endif
	235
	236	/*
	237	* A block was successfully transferred.
	238	*/
	239	spin_lock_irq(&md->lock);
	240	ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
	241	if (!ret) {
	242	/*
	243	* The whole request completed successfully.
	244	*/
	245	add_disk_randomness(req->rq_disk);
	246	blkdev_dequeue_request(req);
8ffdc655	247	end_that_request_last(req, 1);
1da177e4 LT	248	}
	249	spin_unlock_irq(&md->lock);
	250	} while (ret);
	251
	252	mmc_card_release_host(card);
	253
	254	return 1;
	255
	256	cmd_err:
	257	mmc_card_release_host(card);
	258
	259	/*
	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.
	264	*/
	265	spin_lock_irq(&md->lock);
	266	do {
	267	ret = end_that_request_chunk(req, 0,
	268	req->current_nr_sectors << 9);
	269	} while (ret);
	270
	271	add_disk_randomness(req->rq_disk);
	272	blkdev_dequeue_request(req);
8ffdc655	273	end_that_request_last(req, 0);
1da177e4 LT	274	spin_unlock_irq(&md->lock);
	275
	276	return 0;
	277	}
	278
	279	#define MMC_NUM_MINORS (256 >> MMC_SHIFT)
	280
	281	static unsigned long dev_use[MMC_NUM_MINORS/(8*sizeof(unsigned long))];
	282
a6f6c96b RK	283	static inline int mmc_blk_readonly(struct mmc_card *card)
	284	{
	285	return mmc_card_readonly(card) \|\|
	286	!(card->csd.cmdclass & CCC_BLOCK_WRITE);
	287	}
	288
1da177e4 LT	289	static struct mmc_blk_data mmc_blk_alloc(struct mmc_card card)
	290	{
	291	struct mmc_blk_data *md;
	292	int devidx, ret;
	293
	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);
	298
	299	md = kmalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);
a6f6c96b RK	300	if (!md) {
	301	ret = -ENOMEM;
	302	goto out;
	303	}
1da177e4	304
a6f6c96b	305	memset(md, 0, sizeof(struct mmc_blk_data));
1da177e4	306
a6f6c96b RK	307	/*
	308	* Set the read-only status based on the supported commands
	309	* and the write protect switch.
	310	*/
	311	md->read_only = mmc_blk_readonly(card);
1da177e4	312
a6f6c96b RK	313	/*
	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)
	318	*/
	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) {
	323	/*
	324	* write block size is smaller than read block
	325	* size, but we support partial reads, so choose
	326	* the smaller write block size.
	327	*/
	328	md->block_bits = card->csd.write_blkbits;
	329	} else if (card->csd.write_blkbits > card->csd.read_blkbits &&
	330	card->csd.write_partial) {
	331	/*
	332	* read block size is smaller than write block
	333	* size, but we support partial writes. Use read
	334	* block size.
	335	*/
	336	} else {
	337	/*
	338	* We don't support this configuration for writes.
	339	*/
	340	printk(KERN_ERR "%s: unable to select block size for "
	341	"writing (rb%u wb%u rp%u wp%u)\n",
	342	md->disk->disk_name,
	343	1 << card->csd.read_blkbits,
	344	1 << card->csd.write_blkbits,
	345	card->csd.read_partial,
	346	card->csd.write_partial);
	347	md->read_only = 1;
1da177e4	348	}
a6f6c96b	349	}
1da177e4	350
a6f6c96b RK	351	/*
	352	* Refuse to allow block sizes smaller than 512 bytes.
	353	*/
	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);
	357	ret = -EINVAL;
	358	goto err_kfree;
	359	}
1da177e4	360
a6f6c96b RK	361	md->disk = alloc_disk(1 << MMC_SHIFT);
	362	if (md->disk == NULL) {
	363	ret = -ENOMEM;
	364	goto err_kfree;
	365	}
1da177e4	366
a6f6c96b RK	367	spin_lock_init(&md->lock);
a6f6c96b RK	368	md->usage = 1;
1da177e4	369
a6f6c96b RK	370	ret = mmc_init_queue(&md->queue, card, &md->lock);
	371	if (ret)
	372	goto err_putdisk;
1da177e4	373
a6f6c96b RK	374	md->queue.prep_fn = mmc_blk_prep_rq;
	375	md->queue.issue_fn = mmc_blk_issue_rq;
	376	md->queue.data = md;
d2b18394	377
a6f6c96b RK	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;
	384
	385	/*
	386	* As discussed on lkml, GENHD_FL_REMOVABLE should:
	387	*
	388	* - be set for removable media with permanent block devices
	389	* - be unset for removable block devices with permanent media
	390	*
	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.
	395	*/
	396
	397	sprintf(md->disk->disk_name, "mmcblk%d", devidx);
	398	sprintf(md->disk->devfs_name, "mmc/blk%d", devidx);
	399
	400	blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits);
	401
	402	/*
	403	* The CSD capacity field is in units of read_blkbits.
	404	* set_capacity takes units of 512 bytes.
	405	*/
	406	set_capacity(md->disk, card->csd.capacity << (card->csd.read_blkbits - 9));
1da177e4	407	return md;
a6f6c96b RK	408
	409	err_putdisk:
	410	put_disk(md->disk);
	411	err_kfree:
	412	kfree(md);
	413	out:
	414	return ERR_PTR(ret);
1da177e4 LT	415	}
	416
	417	static int
	418	mmc_blk_set_blksize(struct mmc_blk_data md, struct mmc_card card)
	419	{
	420	struct mmc_command cmd;
	421	int err;
	422
	423	mmc_card_claim_host(card);
	424	cmd.opcode = MMC_SET_BLOCKLEN;
d2b18394	425	cmd.arg = 1 << md->block_bits;
1da177e4 LT	426	cmd.flags = MMC_RSP_R1;
	427	err = mmc_wait_for_cmd(card->host, &cmd, 5);
	428	mmc_card_release_host(card);
	429
	430	if (err) {
	431	printk(KERN_ERR "%s: unable to set block size to %d: %d\n",
	432	md->disk->disk_name, cmd.arg, err);
	433	return -EINVAL;
	434	}
	435
	436	return 0;
	437	}
	438
	439	static int mmc_blk_probe(struct mmc_card *card)
	440	{
	441	struct mmc_blk_data *md;
	442	int err;
	443
912490db PO	444	/*
	445	* Check that the card supports the command class(es) we need.
	446	*/
	447	if (!(card->csd.cmdclass & CCC_BLOCK_READ))
1da177e4 LT	448	return -ENODEV;
1da177e4 LT	449
1da177e4 LT	450	md = mmc_blk_alloc(card);
	451	if (IS_ERR(md))
	452	return PTR_ERR(md);
	453
	454	err = mmc_blk_set_blksize(md, card);
	455	if (err)
	456	goto out;
	457
d2b18394	458	printk(KERN_INFO "%s: %s %s %luKiB %s\n",
1da177e4	459	md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
a6f6c96b	460	get_capacity(md->disk) >> 1, md->read_only ? "(ro)" : "");
1da177e4 LT	461
	462	mmc_set_drvdata(card, md);
	463	add_disk(md->disk);
	464	return 0;
	465
	466	out:
	467	mmc_blk_put(md);
	468
	469	return err;
	470	}
	471
	472	static void mmc_blk_remove(struct mmc_card *card)
	473	{
	474	struct mmc_blk_data *md = mmc_get_drvdata(card);
	475
	476	if (md) {
	477	int devidx;
	478
	479	del_gendisk(md->disk);
	480
	481	/*
	482	* I think this is needed.
	483	*/
	484	md->disk->queue = NULL;
	485
	486	devidx = md->disk->first_minor >> MMC_SHIFT;
	487	__clear_bit(devidx, dev_use);
	488
	489	mmc_blk_put(md);
	490	}
	491	mmc_set_drvdata(card, NULL);
	492	}
	493
	494	#ifdef CONFIG_PM
	495	static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
	496	{
	497	struct mmc_blk_data *md = mmc_get_drvdata(card);
	498
	499	if (md) {
	500	mmc_queue_suspend(&md->queue);
	501	}
	502	return 0;
	503	}
	504
	505	static int mmc_blk_resume(struct mmc_card *card)
	506	{
	507	struct mmc_blk_data *md = mmc_get_drvdata(card);
	508
	509	if (md) {
	510	mmc_blk_set_blksize(md, card);
	511	mmc_queue_resume(&md->queue);
	512	}
	513	return 0;
	514	}
	515	#else
	516	#define mmc_blk_suspend NULL
	517	#define mmc_blk_resume NULL
	518	#endif
	519
	520	static struct mmc_driver mmc_driver = {
	521	.drv = {
	522	.name = "mmcblk",
	523	},
	524	.probe = mmc_blk_probe,
525	.remove = mmc_blk_remove,
526	.suspend = mmc_blk_suspend,
527	.resume = mmc_blk_resume,
528	};
529
530	static int __init mmc_blk_init(void)
531	{
532	int res = -ENOMEM;
533
534	res = register_blkdev(major, "mmc");
535	if (res < 0) {
536	printk(KERN_WARNING "Unable to get major %d for MMC media: %d\n",
537	major, res);
538	goto out;
539	}
540	if (major == 0)
541	major = res;
542
543	devfs_mk_dir("mmc");
544	return mmc_register_driver(&mmc_driver);
545
546	out:
547	return res;
548	}
549
550	static void __exit mmc_blk_exit(void)
551	{
552	mmc_unregister_driver(&mmc_driver);
553	devfs_remove("mmc");
554	unregister_blkdev(major, "mmc");
555	}
556
557	module_init(mmc_blk_init);
558	module_exit(mmc_blk_exit);
559
560	MODULE_LICENSE("GPL");
561	MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
562
563	module_param(major, int, 0444);
564	MODULE_PARM_DESC(major, "specify the major device number for MMC block driver");