/*
* 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/mutex.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 DEFINE_MUTEX(open_lock);
static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
{
struct mmc_blk_data *md;
mutex_lock(&open_lock);
md = disk->private_data;
if (md && md->usage == 0)
md = NULL;
if (md)
md->usage++;
mutex_unlock(&open_lock);
return md;
}
static void mmc_blk_put(struct mmc_blk_data *md)
{
mutex_lock(&open_lock);
md->usage--;
if (md->usage == 0) {
put_disk(md->disk);
mmc_cleanup_queue(&md->queue);
kfree(md);
}
mutex_unlock(&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;
}
if (brq.data.blocks > 1) {
brq.data.flags |= MMC_DATA_MULTI;
brq.mrq.stop = &brq.stop;
} else {
brq.mrq.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 %lluKiB %s\n",
md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
(unsigned long long)(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");
