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/*

 * 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

#define MMC_NUM_MINORS  (256 >> MMC_SHIFT)

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

/*

 * 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) {

                int devidx = md->disk->first_minor >> MMC_SHIFT;

                __clear_bit(devidx, dev_use);

                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 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_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;

        err = mmc_wait_for_cmd(card->host, &cmd, 0);

        if (err)

                return (u32)-1;

        if (!mmc_host_is_spi(card->host) && !(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_SPI_R1 | 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 || data.error)

                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_SPI_R1 | 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_SPI_R1B | 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;

                /*

                 * 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) {

                        /* SPI multiblock writes terminate using a special

                         * token, not a STOP_TRANSMISSION request.

                         */

                        if (!mmc_host_is_spi(card->host)

                                        || rq_data_dir(req) == READ)

                                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;

                }

                mmc_set_data_timeout(&brq.data, card);

                brq.data.sg = mq->sg;

                brq.data.sg_len = mmc_queue_map_sg(mq);

                mmc_queue_bounce_pre(mq);

                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);

                mmc_queue_bounce_post(mq);

                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 (!mmc_host_is_spi(card->host) && 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;

                                }

                                /*

                                 * Some cards mishandle the status bits,

                                 * so make sure to check both the busy

                                 * indication and the card state.

                                 */

                        } while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||

                                (R1_CURRENT_STATE(cmd.resp[0]) == 7));

#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;

}

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 = kzalloc(sizeof(struct mmc_blk_data), GFP_KERNEL);

        if (!md) {

                ret = -ENOMEM;

                goto out;

        }

        /*

         * 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.issue_fn = mmc_blk_issue_rq;

        md->queue.data = md;

        md->disk->major = MMC_BLOCK_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_SPI_R1 | 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) {

                /* Stop new requests from getting into the queue */

                del_gendisk(md->disk);

                /* Then flush out any already in there */

                mmc_cleanup_queue(&md->queue);

                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(MMC_BLOCK_MAJOR, "mmc");

        if (res)

                goto out;

        return mmc_register_driver(&mmc_driver);

 out:

        return res;

}

static void __exit mmc_blk_exit(void)

{

        mmc_unregister_driver(&mmc_driver);

        unregister_blkdev(MMC_BLOCK_MAJOR, "mmc");

}

module_init(mmc_blk_init);

module_exit(mmc_blk_exit);

MODULE_LICENSE("GPL");

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