diff options
Diffstat (limited to 'drivers/mmc/card/block.c')
-rw-r--r-- | drivers/mmc/card/block.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c new file mode 100644 index 0000000..d24ab23 --- /dev/null +++ b/drivers/mmc/card/block.c @@ -0,0 +1,665 @@ +/* + * Block driver for media (i.e., flash cards) + * + * Copyright 2002 Hewlett-Packard Company + * Copyright 2005-2007 Pierre Ossman + * + * 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/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/mutex.h> +#include <linux/scatterlist.h> + +#include <linux/mmc/card.h> +#include <linux/mmc/host.h> +#include <linux/mmc/mmc.h> +#include <linux/mmc/sd.h> + +#include <asm/system.h> +#include <asm/uaccess.h> + +#include "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); + 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 u32 mmc_sd_num_wr_blocks(struct mmc_card *card) +{ + int err; + u32 blocks; + + struct mmc_request mrq; + struct mmc_command cmd; + struct mmc_data data; + unsigned int timeout_us; + + struct scatterlist sg; + + memset(&cmd, 0, sizeof(struct mmc_command)); + + cmd.opcode = MMC_APP_CMD; + cmd.arg = card->rca << 16; + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + + err = mmc_wait_for_cmd(card->host, &cmd, 0); + if ((err != MMC_ERR_NONE) || !(cmd.resp[0] & R1_APP_CMD)) + return (u32)-1; + + memset(&cmd, 0, sizeof(struct mmc_command)); + + cmd.opcode = SD_APP_SEND_NUM_WR_BLKS; + cmd.arg = 0; + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC; + + memset(&data, 0, sizeof(struct mmc_data)); + + data.timeout_ns = card->csd.tacc_ns * 100; + data.timeout_clks = card->csd.tacc_clks * 100; + + timeout_us = data.timeout_ns / 1000; + timeout_us += data.timeout_clks * 1000 / + (card->host->ios.clock / 1000); + + if (timeout_us > 100000) { + data.timeout_ns = 100000000; + data.timeout_clks = 0; + } + + data.blksz = 4; + data.blocks = 1; + data.flags = MMC_DATA_READ; + data.sg = &sg; + data.sg_len = 1; + + memset(&mrq, 0, sizeof(struct mmc_request)); + + mrq.cmd = &cmd; + mrq.data = &data; + + sg_init_one(&sg, &blocks, 4); + + mmc_wait_for_req(card->host, &mrq); + + if (cmd.error != MMC_ERR_NONE || data.error != MMC_ERR_NONE) + return (u32)-1; + + blocks = ntohl(blocks); + + return blocks; +} + +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; + struct mmc_blk_request brq; + int ret = 1, sg_pos, data_size; + + mmc_claim_host(card->host); + + do { + struct mmc_command cmd; + u32 readcmd, writecmd; + + memset(&brq, 0, sizeof(struct mmc_blk_request)); + brq.mrq.cmd = &brq.cmd; + brq.mrq.data = &brq.data; + + brq.cmd.arg = req->sector; + if (!mmc_card_blockaddr(card)) + brq.cmd.arg <<= 9; + brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC; + brq.data.blksz = 1 << md->block_bits; + brq.stop.opcode = MMC_STOP_TRANSMISSION; + brq.stop.arg = 0; + brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC; + brq.data.blocks = req->nr_sectors >> (md->block_bits - 9); + if (brq.data.blocks > card->host->max_blk_count) + brq.data.blocks = card->host->max_blk_count; + + mmc_set_data_timeout(&brq.data, card, rq_data_dir(req) != READ); + + /* + * If the host doesn't support multiple block writes, force + * block writes to single block. SD cards are excepted from + * this rule as they support querying the number of + * successfully written sectors. + */ + if (rq_data_dir(req) != READ && + !(card->host->caps & MMC_CAP_MULTIWRITE) && + !mmc_card_sd(card)) + brq.data.blocks = 1; + + if (brq.data.blocks > 1) { + brq.data.flags |= MMC_DATA_MULTI; + brq.mrq.stop = &brq.stop; + readcmd = MMC_READ_MULTIPLE_BLOCK; + writecmd = MMC_WRITE_MULTIPLE_BLOCK; + } else { + brq.mrq.stop = NULL; + readcmd = MMC_READ_SINGLE_BLOCK; + writecmd = MMC_WRITE_BLOCK; + } + + if (rq_data_dir(req) == READ) { + brq.cmd.opcode = readcmd; + brq.data.flags |= MMC_DATA_READ; + } else { + brq.cmd.opcode = writecmd; + brq.data.flags |= MMC_DATA_WRITE; + } + + brq.data.sg = mq->sg; + brq.data.sg_len = blk_rq_map_sg(req->q, req, brq.data.sg); + + if (brq.data.blocks != + (req->nr_sectors >> (md->block_bits - 9))) { + data_size = brq.data.blocks * brq.data.blksz; + for (sg_pos = 0; sg_pos < brq.data.sg_len; sg_pos++) { + data_size -= mq->sg[sg_pos].length; + if (data_size <= 0) { + mq->sg[sg_pos].length += data_size; + sg_pos++; + break; + } + } + brq.data.sg_len = sg_pos; + } + + 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; + } + + if (rq_data_dir(req) != READ) { + do { + int err; + + cmd.opcode = MMC_SEND_STATUS; + cmd.arg = card->rca << 16; + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + 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_release_host(card->host); + + return 1; + + cmd_err: + /* + * If this is an SD card and we're writing, we can first + * mark the known good sectors as ok. + * + * If the card is not SD, we can still ok written sectors + * if the controller can do proper error reporting. + * + * For reads we just fail the entire chunk as that should + * be safe in all cases. + */ + if (rq_data_dir(req) != READ && mmc_card_sd(card)) { + u32 blocks; + unsigned int bytes; + + blocks = mmc_sd_num_wr_blocks(card); + if (blocks != (u32)-1) { + if (card->csd.write_partial) + bytes = blocks << md->block_bits; + else + bytes = blocks << 9; + spin_lock_irq(&md->lock); + ret = end_that_request_chunk(req, 1, bytes); + spin_unlock_irq(&md->lock); + } + } else if (rq_data_dir(req) != READ && + (card->host->caps & MMC_CAP_MULTIWRITE)) { + spin_lock_irq(&md->lock); + ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered); + spin_unlock_irq(&md->lock); + } + + mmc_release_host(card->host); + + spin_lock_irq(&md->lock); + while (ret) { + ret = end_that_request_chunk(req, 0, + req->current_nr_sectors << 9); + } + + 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); + + /* + * Both SD and MMC specifications state (although a bit + * unclearly in the MMC case) that a block size of 512 + * bytes must always be supported by the card. + */ + md->block_bits = 9; + + 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); + + blk_queue_hardsect_size(md->queue.queue, 1 << md->block_bits); + + if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) { + /* + * The EXT_CSD sector count is in number or 512 byte + * sectors. + */ + set_capacity(md->disk, card->ext_csd.sectors); + } else { + /* + * 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; + + /* Block-addressed cards ignore MMC_SET_BLOCKLEN. */ + if (mmc_card_blockaddr(card)) + return 0; + + mmc_claim_host(card->host); + cmd.opcode = MMC_SET_BLOCKLEN; + cmd.arg = 1 << md->block_bits; + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC; + err = mmc_wait_for_cmd(card->host, &cmd, 5); + mmc_release_host(card->host); + + 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; + + /* Stop new requests from getting into the queue */ + del_gendisk(md->disk); + + /* Then flush out any already in there */ + mmc_cleanup_queue(&md->queue); + + 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; + + return mmc_register_driver(&mmc_driver); + + out: + return res; +} + +static void __exit mmc_blk_exit(void) +{ + mmc_unregister_driver(&mmc_driver); + 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"); |