alauda.c

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/*
 * Driver for Alauda-based card readers
 *
 * Current development and maintenance by:
 *   (c) 2005 Daniel Drake <[email protected]>
 *
 * The 'Alauda' is a chip manufacturered by RATOC for OEM use.
 *
 * Alauda implements a vendor-specific command set to access two media reader
 * ports (XD, SmartMedia). This driver converts SCSI commands to the commands
 * which are accepted by these devices.
 *
 * The driver was developed through reverse-engineering, with the help of the
 * sddr09 driver which has many similarities, and with some help from the
 * (very old) vendor-supplied GPL sma03 driver.
 *
 * For protocol info, see http://alauda.sourceforge.net
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/slab.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>

#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"

MODULE_DESCRIPTION("Driver for Alauda-based card readers");
MODULE_AUTHOR("Daniel Drake <[email protected]>");
MODULE_LICENSE("GPL");

/*
 * Status bytes
 */
#define ALAUDA_STATUS_ERROR     0x01
#define ALAUDA_STATUS_READY     0x40

/*
 * Control opcodes (for request field)
 */
#define ALAUDA_GET_XD_MEDIA_STATUS  0x08
#define ALAUDA_GET_SM_MEDIA_STATUS  0x98
#define ALAUDA_ACK_XD_MEDIA_CHANGE  0x0a
#define ALAUDA_ACK_SM_MEDIA_CHANGE  0x9a
#define ALAUDA_GET_XD_MEDIA_SIG     0x86
#define ALAUDA_GET_SM_MEDIA_SIG     0x96

/*
 * Bulk command identity (byte 0)
 */
#define ALAUDA_BULK_CMD         0x40

/*
 * Bulk opcodes (byte 1)
 */
#define ALAUDA_BULK_GET_REDU_DATA   0x85
#define ALAUDA_BULK_READ_BLOCK      0x94
#define ALAUDA_BULK_ERASE_BLOCK     0xa3
#define ALAUDA_BULK_WRITE_BLOCK     0xb4
#define ALAUDA_BULK_GET_STATUS2     0xb7
#define ALAUDA_BULK_RESET_MEDIA     0xe0

/*
 * Port to operate on (byte 8)
 */
#define ALAUDA_PORT_XD          0x00
#define ALAUDA_PORT_SM          0x01

/*
 * LBA and PBA are unsigned ints. Special values.
 */
#define UNDEF    0xffff
#define SPARE    0xfffe
#define UNUSABLE 0xfffd

struct alauda_media_info {
    unsigned long capacity;     /* total media size in bytes */
    unsigned int pagesize;      /* page size in bytes */
    unsigned int blocksize;     /* number of pages per block */
    unsigned int uzonesize;     /* number of usable blocks per zone */
    unsigned int zonesize;      /* number of blocks per zone */
    unsigned int blockmask;     /* mask to get page from address */

    unsigned char pageshift;
    unsigned char blockshift;
    unsigned char zoneshift;

    u16 **lba_to_pba;       /* logical to physical block map */
    u16 **pba_to_lba;       /* physical to logical block map */
};

struct alauda_info {
    struct alauda_media_info port[2];
    int wr_ep;          /* endpoint to write data out of */

    unsigned char sense_key;
    unsigned long sense_asc;    /* additional sense code */
    unsigned long sense_ascq;   /* additional sense code qualifier */
};

#define short_pack(lsb,msb) ( ((u16)(lsb)) | ( ((u16)(msb))<<8 ) )
#define LSB_of(s) ((s)&0xFF)
#define MSB_of(s) ((s)>>8)

#define MEDIA_PORT(us) us->srb->device->lun
#define MEDIA_INFO(us) ((struct alauda_info *)us->extra)->port[MEDIA_PORT(us)]

#define PBA_LO(pba) ((pba & 0xF) << 5)
#define PBA_HI(pba) (pba >> 3)
#define PBA_ZONE(pba) (pba >> 11)

static int init_alauda(struct us_data *us);


/*
 * The table of devices
 */
#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
            vendorName, productName, useProtocol, useTransport, \
            initFunction, flags) \
{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
  .driver_info = (flags) }

static struct usb_device_id alauda_usb_ids[] = {
#   include "unusual_alauda.h"
    { }     /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, alauda_usb_ids);

#undef UNUSUAL_DEV

/*
 * The flags table
 */
#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
            vendor_name, product_name, use_protocol, use_transport, \
            init_function, Flags) \
{ \
    .vendorName = vendor_name,  \
    .productName = product_name,    \
    .useProtocol = use_protocol,    \
    .useTransport = use_transport,  \
    .initFunction = init_function,  \
}

static struct us_unusual_dev alauda_unusual_dev_list[] = {
#   include "unusual_alauda.h"
    { }     /* Terminating entry */
};

#undef UNUSUAL_DEV


/*
 * Media handling
 */

struct alauda_card_info {
    unsigned char id;       /* id byte */
    unsigned char chipshift;    /* 1<<cs bytes total capacity */
    unsigned char pageshift;    /* 1<<ps bytes in a page */
    unsigned char blockshift;   /* 1<<bs pages per block */
    unsigned char zoneshift;    /* 1<<zs blocks per zone */
};

static struct alauda_card_info alauda_card_ids[] = {
    /* NAND flash */
    { 0x6e, 20, 8, 4, 8},   /* 1 MB */
    { 0xe8, 20, 8, 4, 8},   /* 1 MB */
    { 0xec, 20, 8, 4, 8},   /* 1 MB */
    { 0x64, 21, 8, 4, 9},   /* 2 MB */
    { 0xea, 21, 8, 4, 9},   /* 2 MB */
    { 0x6b, 22, 9, 4, 9},   /* 4 MB */
    { 0xe3, 22, 9, 4, 9},   /* 4 MB */
    { 0xe5, 22, 9, 4, 9},   /* 4 MB */
    { 0xe6, 23, 9, 4, 10},  /* 8 MB */
    { 0x73, 24, 9, 5, 10},  /* 16 MB */
    { 0x75, 25, 9, 5, 10},  /* 32 MB */
    { 0x76, 26, 9, 5, 10},  /* 64 MB */
    { 0x79, 27, 9, 5, 10},  /* 128 MB */
    { 0x71, 28, 9, 5, 10},  /* 256 MB */

    /* MASK ROM */
    { 0x5d, 21, 9, 4, 8},   /* 2 MB */
    { 0xd5, 22, 9, 4, 9},   /* 4 MB */
    { 0xd6, 23, 9, 4, 10},  /* 8 MB */
    { 0x57, 24, 9, 4, 11},  /* 16 MB */
    { 0x58, 25, 9, 4, 12},  /* 32 MB */
    { 0,}
};

static struct alauda_card_info *alauda_card_find_id(unsigned char id) {
    int i;

    for (i = 0; alauda_card_ids[i].id != 0; i++)
        if (alauda_card_ids[i].id == id)
            return &(alauda_card_ids[i]);
    return NULL;
}

/*
 * ECC computation.
 */

static unsigned char parity[256];
static unsigned char ecc2[256];

static void nand_init_ecc(void) {
    int i, j, a;

    parity[0] = 0;
    for (i = 1; i < 256; i++)
        parity[i] = (parity[i&(i-1)] ^ 1);

    for (i = 0; i < 256; i++) {
        a = 0;
        for (j = 0; j < 8; j++) {
            if (i & (1<<j)) {
                if ((j & 1) == 0)
                    a ^= 0x04;
                if ((j & 2) == 0)
                    a ^= 0x10;
                if ((j & 4) == 0)
                    a ^= 0x40;
            }
        }
        ecc2[i] = ~(a ^ (a<<1) ^ (parity[i] ? 0xa8 : 0));
    }
}

/* compute 3-byte ecc on 256 bytes */
static void nand_compute_ecc(unsigned char *data, unsigned char *ecc) {
    int i, j, a;
    unsigned char par, bit, bits[8];

    par = 0;
    for (j = 0; j < 8; j++)
        bits[j] = 0;

    /* collect 16 checksum bits */
    for (i = 0; i < 256; i++) {
        par ^= data[i];
        bit = parity[data[i]];
        for (j = 0; j < 8; j++)
            if ((i & (1<<j)) == 0)
                bits[j] ^= bit;
    }

    /* put 4+4+4 = 12 bits in the ecc */
    a = (bits[3] << 6) + (bits[2] << 4) + (bits[1] << 2) + bits[0];
    ecc[0] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

    a = (bits[7] << 6) + (bits[6] << 4) + (bits[5] << 2) + bits[4];
    ecc[1] = ~(a ^ (a<<1) ^ (parity[par] ? 0xaa : 0));

    ecc[2] = ecc2[par];
}

static int nand_compare_ecc(unsigned char *data, unsigned char *ecc) {
    return (data[0] == ecc[0] && data[1] == ecc[1] && data[2] == ecc[2]);
}

static void nand_store_ecc(unsigned char *data, unsigned char *ecc) {
    memcpy(data, ecc, 3);
}

/*
 * Alauda driver
 */

/*
 * Forget our PBA <---> LBA mappings for a particular port
 */
static void alauda_free_maps (struct alauda_media_info *media_info)
{
    unsigned int shift = media_info->zoneshift
        + media_info->blockshift + media_info->pageshift;
    unsigned int num_zones = media_info->capacity >> shift;
    unsigned int i;

    if (media_info->lba_to_pba != NULL)
        for (i = 0; i < num_zones; i++) {
            kfree(media_info->lba_to_pba[i]);
            media_info->lba_to_pba[i] = NULL;
        }

    if (media_info->pba_to_lba != NULL)
        for (i = 0; i < num_zones; i++) {
            kfree(media_info->pba_to_lba[i]);
            media_info->pba_to_lba[i] = NULL;
        }
}

/*
 * Returns 2 bytes of status data
 * The first byte describes media status, and second byte describes door status
 */
static int alauda_get_media_status(struct us_data *us, unsigned char *data)
{
    int rc;
    unsigned char command;

    if (MEDIA_PORT(us) == ALAUDA_PORT_XD)
        command = ALAUDA_GET_XD_MEDIA_STATUS;
    else
        command = ALAUDA_GET_SM_MEDIA_STATUS;

    rc = usb_stor_ctrl_transfer(us, us->recv_ctrl_pipe,
        command, 0xc0, 0, 1, data, 2);

    US_DEBUGP("alauda_get_media_status: Media status %02X %02X\n",
        data[0], data[1]);

    return rc;
}

/*
 * Clears the "media was changed" bit so that we know when it changes again
 * in the future.
 */
static int alauda_ack_media(struct us_data *us)
{
    unsigned char command;

    if (MEDIA_PORT(us) == ALAUDA_PORT_XD)
        command = ALAUDA_ACK_XD_MEDIA_CHANGE;
    else
        command = ALAUDA_ACK_SM_MEDIA_CHANGE;

    return usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
        command, 0x40, 0, 1, NULL, 0);
}

/*
 * Retrieves a 4-byte media signature, which indicates manufacturer, capacity,
 * and some other details.
 */
static int alauda_get_media_signature(struct us_data *us, unsigned char *data)
{
    unsigned char command;

    if (MEDIA_PORT(us) == ALAUDA_PORT_XD)
        command = ALAUDA_GET_XD_MEDIA_SIG;
    else
        command = ALAUDA_GET_SM_MEDIA_SIG;

    return usb_stor_ctrl_transfer(us, us->recv_ctrl_pipe,
        command, 0xc0, 0, 0, data, 4);
}

/*
 * Resets the media status (but not the whole device?)
 */
static int alauda_reset_media(struct us_data *us)
{
    unsigned char *command = us->iobuf;

    memset(command, 0, 9);
    command[0] = ALAUDA_BULK_CMD;
    command[1] = ALAUDA_BULK_RESET_MEDIA;
    command[8] = MEDIA_PORT(us);

    return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
}

/*
 * Examines the media and deduces capacity, etc.
 */
static int alauda_init_media(struct us_data *us)
{
    unsigned char *data = us->iobuf;
    int ready = 0;
    struct alauda_card_info *media_info;
    unsigned int num_zones;

    while (ready == 0) {
        msleep(20);

        if (alauda_get_media_status(us, data) != USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (data[0] & 0x10)
            ready = 1;
    }

    US_DEBUGP("alauda_init_media: We are ready for action!\n");

    if (alauda_ack_media(us) != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    msleep(10);

    if (alauda_get_media_status(us, data) != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    if (data[0] != 0x14) {
        US_DEBUGP("alauda_init_media: Media not ready after ack\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    if (alauda_get_media_signature(us, data) != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("alauda_init_media: Media signature: %02X %02X %02X %02X\n",
        data[0], data[1], data[2], data[3]);
    media_info = alauda_card_find_id(data[1]);
    if (media_info == NULL) {
        printk(KERN_WARNING
            "alauda_init_media: Unrecognised media signature: "
            "%02X %02X %02X %02X\n",
            data[0], data[1], data[2], data[3]);
        return USB_STOR_TRANSPORT_ERROR;
    }

    MEDIA_INFO(us).capacity = 1 << media_info->chipshift;
    US_DEBUGP("Found media with capacity: %ldMB\n",
        MEDIA_INFO(us).capacity >> 20);

    MEDIA_INFO(us).pageshift = media_info->pageshift;
    MEDIA_INFO(us).blockshift = media_info->blockshift;
    MEDIA_INFO(us).zoneshift = media_info->zoneshift;

    MEDIA_INFO(us).pagesize = 1 << media_info->pageshift;
    MEDIA_INFO(us).blocksize = 1 << media_info->blockshift;
    MEDIA_INFO(us).zonesize = 1 << media_info->zoneshift;

    MEDIA_INFO(us).uzonesize = ((1 << media_info->zoneshift) / 128) * 125;
    MEDIA_INFO(us).blockmask = MEDIA_INFO(us).blocksize - 1;

    num_zones = MEDIA_INFO(us).capacity >> (MEDIA_INFO(us).zoneshift
        + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift);
    MEDIA_INFO(us).pba_to_lba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO);
    MEDIA_INFO(us).lba_to_pba = kcalloc(num_zones, sizeof(u16*), GFP_NOIO);

    if (alauda_reset_media(us) != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Examines the media status and does the right thing when the media has gone,
 * appeared, or changed.
 */
static int alauda_check_media(struct us_data *us)
{
    struct alauda_info *info = (struct alauda_info *) us->extra;
    unsigned char status[2];
    int rc;

    rc = alauda_get_media_status(us, status);

    /* Check for no media or door open */
    if ((status[0] & 0x80) || ((status[0] & 0x1F) == 0x10)
        || ((status[1] & 0x01) == 0)) {
        US_DEBUGP("alauda_check_media: No media, or door open\n");
        alauda_free_maps(&MEDIA_INFO(us));
        info->sense_key = 0x02;
        info->sense_asc = 0x3A;
        info->sense_ascq = 0x00;
        return USB_STOR_TRANSPORT_FAILED;
    }

    /* Check for media change */
    if (status[0] & 0x08) {
        US_DEBUGP("alauda_check_media: Media change detected\n");
        alauda_free_maps(&MEDIA_INFO(us));
        alauda_init_media(us);

        info->sense_key = UNIT_ATTENTION;
        info->sense_asc = 0x28;
        info->sense_ascq = 0x00;
        return USB_STOR_TRANSPORT_FAILED;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Checks the status from the 2nd status register
 * Returns 3 bytes of status data, only the first is known
 */
static int alauda_check_status2(struct us_data *us)
{
    int rc;
    unsigned char command[] = {
        ALAUDA_BULK_CMD, ALAUDA_BULK_GET_STATUS2,
        0, 0, 0, 0, 3, 0, MEDIA_PORT(us)
    };
    unsigned char data[3];

    rc = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    rc = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
        data, 3, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    US_DEBUGP("alauda_check_status2: %02X %02X %02X\n", data[0], data[1], data[2]);
    if (data[0] & ALAUDA_STATUS_ERROR)
        return USB_STOR_XFER_ERROR;

    return USB_STOR_XFER_GOOD;
}

/*
 * Gets the redundancy data for the first page of a PBA
 * Returns 16 bytes.
 */
static int alauda_get_redu_data(struct us_data *us, u16 pba, unsigned char *data)
{
    int rc;
    unsigned char command[] = {
        ALAUDA_BULK_CMD, ALAUDA_BULK_GET_REDU_DATA,
        PBA_HI(pba), PBA_ZONE(pba), 0, PBA_LO(pba), 0, 0, MEDIA_PORT(us)
    };

    rc = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
        data, 16, NULL);
}

/*
 * Finds the first unused PBA in a zone
 * Returns the absolute PBA of an unused PBA, or 0 if none found.
 */
static u16 alauda_find_unused_pba(struct alauda_media_info *info,
    unsigned int zone)
{
    u16 *pba_to_lba = info->pba_to_lba[zone];
    unsigned int i;

    for (i = 0; i < info->zonesize; i++)
        if (pba_to_lba[i] == UNDEF)
            return (zone << info->zoneshift) + i;

    return 0;
}

/*
 * Reads the redundancy data for all PBA's in a zone
 * Produces lba <--> pba mappings
 */
static int alauda_read_map(struct us_data *us, unsigned int zone)
{
    unsigned char *data = us->iobuf;
    int result;
    int i, j;
    unsigned int zonesize = MEDIA_INFO(us).zonesize;
    unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
    unsigned int lba_offset, lba_real, blocknum;
    unsigned int zone_base_lba = zone * uzonesize;
    unsigned int zone_base_pba = zone * zonesize;
    u16 *lba_to_pba = kcalloc(zonesize, sizeof(u16), GFP_NOIO);
    u16 *pba_to_lba = kcalloc(zonesize, sizeof(u16), GFP_NOIO);
    if (lba_to_pba == NULL || pba_to_lba == NULL) {
        result = USB_STOR_TRANSPORT_ERROR;
        goto error;
    }

    US_DEBUGP("alauda_read_map: Mapping blocks for zone %d\n", zone);

    /* 1024 PBA's per zone */
    for (i = 0; i < zonesize; i++)
        lba_to_pba[i] = pba_to_lba[i] = UNDEF;

    for (i = 0; i < zonesize; i++) {
        blocknum = zone_base_pba + i;

        result = alauda_get_redu_data(us, blocknum, data);
        if (result != USB_STOR_XFER_GOOD) {
            result = USB_STOR_TRANSPORT_ERROR;
            goto error;
        }

        /* special PBAs have control field 0^16 */
        for (j = 0; j < 16; j++)
            if (data[j] != 0)
                goto nonz;
        pba_to_lba[i] = UNUSABLE;
        US_DEBUGP("alauda_read_map: PBA %d has no logical mapping\n", blocknum);
        continue;

    nonz:
        /* unwritten PBAs have control field FF^16 */
        for (j = 0; j < 16; j++)
            if (data[j] != 0xff)
                goto nonff;
        continue;

    nonff:
        /* normal PBAs start with six FFs */
        if (j < 6) {
            US_DEBUGP("alauda_read_map: PBA %d has no logical mapping: "
                   "reserved area = %02X%02X%02X%02X "
                   "data status %02X block status %02X\n",
                   blocknum, data[0], data[1], data[2], data[3],
                   data[4], data[5]);
            pba_to_lba[i] = UNUSABLE;
            continue;
        }

        if ((data[6] >> 4) != 0x01) {
            US_DEBUGP("alauda_read_map: PBA %d has invalid address "
                   "field %02X%02X/%02X%02X\n",
                   blocknum, data[6], data[7], data[11], data[12]);
            pba_to_lba[i] = UNUSABLE;
            continue;
        }

        /* check even parity */
        if (parity[data[6] ^ data[7]]) {
            printk(KERN_WARNING
                   "alauda_read_map: Bad parity in LBA for block %d"
                   " (%02X %02X)\n", i, data[6], data[7]);
            pba_to_lba[i] = UNUSABLE;
            continue;
        }

        lba_offset = short_pack(data[7], data[6]);
        lba_offset = (lba_offset & 0x07FF) >> 1;
        lba_real = lba_offset + zone_base_lba;

        /*
         * Every 1024 physical blocks ("zone"), the LBA numbers
         * go back to zero, but are within a higher block of LBA's.
         * Also, there is a maximum of 1000 LBA's per zone.
         * In other words, in PBA 1024-2047 you will find LBA 0-999
         * which are really LBA 1000-1999. This allows for 24 bad
         * or special physical blocks per zone.
         */

        if (lba_offset >= uzonesize) {
            printk(KERN_WARNING
                   "alauda_read_map: Bad low LBA %d for block %d\n",
                   lba_real, blocknum);
            continue;
        }

        if (lba_to_pba[lba_offset] != UNDEF) {
            printk(KERN_WARNING
                   "alauda_read_map: "
                   "LBA %d seen for PBA %d and %d\n",
                   lba_real, lba_to_pba[lba_offset], blocknum);
            continue;
        }

        pba_to_lba[i] = lba_real;
        lba_to_pba[lba_offset] = blocknum;
        continue;
    }

    MEDIA_INFO(us).lba_to_pba[zone] = lba_to_pba;
    MEDIA_INFO(us).pba_to_lba[zone] = pba_to_lba;
    result = 0;
    goto out;

error:
    kfree(lba_to_pba);
    kfree(pba_to_lba);
out:
    return result;
}

/*
 * Checks to see whether we have already mapped a certain zone
 * If we haven't, the map is generated
 */
static void alauda_ensure_map_for_zone(struct us_data *us, unsigned int zone)
{
    if (MEDIA_INFO(us).lba_to_pba[zone] == NULL
        || MEDIA_INFO(us).pba_to_lba[zone] == NULL)
        alauda_read_map(us, zone);
}

/*
 * Erases an entire block
 */
static int alauda_erase_block(struct us_data *us, u16 pba)
{
    int rc;
    unsigned char command[] = {
        ALAUDA_BULK_CMD, ALAUDA_BULK_ERASE_BLOCK, PBA_HI(pba),
        PBA_ZONE(pba), 0, PBA_LO(pba), 0x02, 0, MEDIA_PORT(us)
    };
    unsigned char buf[2];

    US_DEBUGP("alauda_erase_block: Erasing PBA %d\n", pba);

    rc = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    rc = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
        buf, 2, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    US_DEBUGP("alauda_erase_block: Erase result: %02X %02X\n",
        buf[0], buf[1]);
    return rc;
}

/*
 * Reads data from a certain offset page inside a PBA, including interleaved
 * redundancy data. Returns (pagesize+64)*pages bytes in data.
 */
static int alauda_read_block_raw(struct us_data *us, u16 pba,
        unsigned int page, unsigned int pages, unsigned char *data)
{
    int rc;
    unsigned char command[] = {
        ALAUDA_BULK_CMD, ALAUDA_BULK_READ_BLOCK, PBA_HI(pba),
        PBA_ZONE(pba), 0, PBA_LO(pba) + page, pages, 0, MEDIA_PORT(us)
    };

    US_DEBUGP("alauda_read_block: pba %d page %d count %d\n",
        pba, page, pages);

    rc = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
        data, (MEDIA_INFO(us).pagesize + 64) * pages, NULL);
}

/*
 * Reads data from a certain offset page inside a PBA, excluding redundancy
 * data. Returns pagesize*pages bytes in data. Note that data must be big enough
 * to hold (pagesize+64)*pages bytes of data, but you can ignore those 'extra'
 * trailing bytes outside this function.
 */
static int alauda_read_block(struct us_data *us, u16 pba,
        unsigned int page, unsigned int pages, unsigned char *data)
{
    int i, rc;
    unsigned int pagesize = MEDIA_INFO(us).pagesize;

    rc = alauda_read_block_raw(us, pba, page, pages, data);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    /* Cut out the redundancy data */
    for (i = 0; i < pages; i++) {
        int dest_offset = i * pagesize;
        int src_offset = i * (pagesize + 64);
        memmove(data + dest_offset, data + src_offset, pagesize);
    }

    return rc;
}

/*
 * Writes an entire block of data and checks status after write.
 * Redundancy data must be already included in data. Data should be
 * (pagesize+64)*blocksize bytes in length.
 */
static int alauda_write_block(struct us_data *us, u16 pba, unsigned char *data)
{
    int rc;
    struct alauda_info *info = (struct alauda_info *) us->extra;
    unsigned char command[] = {
        ALAUDA_BULK_CMD, ALAUDA_BULK_WRITE_BLOCK, PBA_HI(pba),
        PBA_ZONE(pba), 0, PBA_LO(pba), 32, 0, MEDIA_PORT(us)
    };

    US_DEBUGP("alauda_write_block: pba %d\n", pba);

    rc = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
        command, 9, NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    rc = usb_stor_bulk_transfer_buf(us, info->wr_ep, data,
        (MEDIA_INFO(us).pagesize + 64) * MEDIA_INFO(us).blocksize,
        NULL);
    if (rc != USB_STOR_XFER_GOOD)
        return rc;

    return alauda_check_status2(us);
}

/*
 * Write some data to a specific LBA.
 */
static int alauda_write_lba(struct us_data *us, u16 lba,
         unsigned int page, unsigned int pages,
         unsigned char *ptr, unsigned char *blockbuffer)
{
    u16 pba, lbap, new_pba;
    unsigned char *bptr, *cptr, *xptr;
    unsigned char ecc[3];
    int i, result;
    unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
    unsigned int zonesize = MEDIA_INFO(us).zonesize;
    unsigned int pagesize = MEDIA_INFO(us).pagesize;
    unsigned int blocksize = MEDIA_INFO(us).blocksize;
    unsigned int lba_offset = lba % uzonesize;
    unsigned int new_pba_offset;
    unsigned int zone = lba / uzonesize;

    alauda_ensure_map_for_zone(us, zone);

    pba = MEDIA_INFO(us).lba_to_pba[zone][lba_offset];
    if (pba == 1) {
        /* Maybe it is impossible to write to PBA 1.
           Fake success, but don't do anything. */
        printk(KERN_WARNING
               "alauda_write_lba: avoid writing to pba 1\n");
        return USB_STOR_TRANSPORT_GOOD;
    }

    new_pba = alauda_find_unused_pba(&MEDIA_INFO(us), zone);
    if (!new_pba) {
        printk(KERN_WARNING
               "alauda_write_lba: Out of unused blocks\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* read old contents */
    if (pba != UNDEF) {
        result = alauda_read_block_raw(us, pba, 0,
            blocksize, blockbuffer);
        if (result != USB_STOR_XFER_GOOD)
            return result;
    } else {
        memset(blockbuffer, 0, blocksize * (pagesize + 64));
    }

    lbap = (lba_offset << 1) | 0x1000;
    if (parity[MSB_of(lbap) ^ LSB_of(lbap)])
        lbap ^= 1;

    /* check old contents and fill lba */
    for (i = 0; i < blocksize; i++) {
        bptr = blockbuffer + (i * (pagesize + 64));
        cptr = bptr + pagesize;
        nand_compute_ecc(bptr, ecc);
        if (!nand_compare_ecc(cptr+13, ecc)) {
            US_DEBUGP("Warning: bad ecc in page %d- of pba %d\n",
                  i, pba);
            nand_store_ecc(cptr+13, ecc);
        }
        nand_compute_ecc(bptr + (pagesize / 2), ecc);
        if (!nand_compare_ecc(cptr+8, ecc)) {
            US_DEBUGP("Warning: bad ecc in page %d+ of pba %d\n",
                  i, pba);
            nand_store_ecc(cptr+8, ecc);
        }
        cptr[6] = cptr[11] = MSB_of(lbap);
        cptr[7] = cptr[12] = LSB_of(lbap);
    }

    /* copy in new stuff and compute ECC */
    xptr = ptr;
    for (i = page; i < page+pages; i++) {
        bptr = blockbuffer + (i * (pagesize + 64));
        cptr = bptr + pagesize;
        memcpy(bptr, xptr, pagesize);
        xptr += pagesize;
        nand_compute_ecc(bptr, ecc);
        nand_store_ecc(cptr+13, ecc);
        nand_compute_ecc(bptr + (pagesize / 2), ecc);
        nand_store_ecc(cptr+8, ecc);
    }

    result = alauda_write_block(us, new_pba, blockbuffer);
    if (result != USB_STOR_XFER_GOOD)
        return result;

    new_pba_offset = new_pba - (zone * zonesize);
    MEDIA_INFO(us).pba_to_lba[zone][new_pba_offset] = lba;
    MEDIA_INFO(us).lba_to_pba[zone][lba_offset] = new_pba;
    US_DEBUGP("alauda_write_lba: Remapped LBA %d to PBA %d\n",
        lba, new_pba);

    if (pba != UNDEF) {
        unsigned int pba_offset = pba - (zone * zonesize);
        result = alauda_erase_block(us, pba);
        if (result != USB_STOR_XFER_GOOD)
            return result;
        MEDIA_INFO(us).pba_to_lba[zone][pba_offset] = UNDEF;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Read data from a specific sector address
 */
static int alauda_read_data(struct us_data *us, unsigned long address,
        unsigned int sectors)
{
    unsigned char *buffer;
    u16 lba, max_lba;
    unsigned int page, len, offset;
    unsigned int blockshift = MEDIA_INFO(us).blockshift;
    unsigned int pageshift = MEDIA_INFO(us).pageshift;
    unsigned int blocksize = MEDIA_INFO(us).blocksize;
    unsigned int pagesize = MEDIA_INFO(us).pagesize;
    unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
    struct scatterlist *sg;
    int result;

    /*
     * Since we only read in one block at a time, we have to create
     * a bounce buffer and move the data a piece at a time between the
     * bounce buffer and the actual transfer buffer.
     * We make this buffer big enough to hold temporary redundancy data,
     * which we use when reading the data blocks.
     */

    len = min(sectors, blocksize) * (pagesize + 64);
    buffer = kmalloc(len, GFP_NOIO);
    if (buffer == NULL) {
        printk(KERN_WARNING "alauda_read_data: Out of memory\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* Figure out the initial LBA and page */
    lba = address >> blockshift;
    page = (address & MEDIA_INFO(us).blockmask);
    max_lba = MEDIA_INFO(us).capacity >> (blockshift + pageshift);

    result = USB_STOR_TRANSPORT_GOOD;
    offset = 0;
    sg = NULL;

    while (sectors > 0) {
        unsigned int zone = lba / uzonesize; /* integer division */
        unsigned int lba_offset = lba - (zone * uzonesize);
        unsigned int pages;
        u16 pba;
        alauda_ensure_map_for_zone(us, zone);

        /* Not overflowing capacity? */
        if (lba >= max_lba) {
            US_DEBUGP("Error: Requested lba %u exceeds "
                  "maximum %u\n", lba, max_lba);
            result = USB_STOR_TRANSPORT_ERROR;
            break;
        }

        /* Find number of pages we can read in this block */
        pages = min(sectors, blocksize - page);
        len = pages << pageshift;

        /* Find where this lba lives on disk */
        pba = MEDIA_INFO(us).lba_to_pba[zone][lba_offset];

        if (pba == UNDEF) { /* this lba was never written */
            US_DEBUGP("Read %d zero pages (LBA %d) page %d\n",
                  pages, lba, page);

            /* This is not really an error. It just means
               that the block has never been written.
               Instead of returning USB_STOR_TRANSPORT_ERROR
               it is better to return all zero data. */

            memset(buffer, 0, len);
        } else {
            US_DEBUGP("Read %d pages, from PBA %d"
                  " (LBA %d) page %d\n",
                  pages, pba, lba, page);

            result = alauda_read_block(us, pba, page, pages, buffer);
            if (result != USB_STOR_TRANSPORT_GOOD)
                break;
        }

        /* Store the data in the transfer buffer */
        usb_stor_access_xfer_buf(buffer, len, us->srb,
                &sg, &offset, TO_XFER_BUF);

        page = 0;
        lba++;
        sectors -= pages;
    }

    kfree(buffer);
    return result;
}

/*
 * Write data to a specific sector address
 */
static int alauda_write_data(struct us_data *us, unsigned long address,
        unsigned int sectors)
{
    unsigned char *buffer, *blockbuffer;
    unsigned int page, len, offset;
    unsigned int blockshift = MEDIA_INFO(us).blockshift;
    unsigned int pageshift = MEDIA_INFO(us).pageshift;
    unsigned int blocksize = MEDIA_INFO(us).blocksize;
    unsigned int pagesize = MEDIA_INFO(us).pagesize;
    struct scatterlist *sg;
    u16 lba, max_lba;
    int result;

    /*
     * Since we don't write the user data directly to the device,
     * we have to create a bounce buffer and move the data a piece
     * at a time between the bounce buffer and the actual transfer buffer.
     */

    len = min(sectors, blocksize) * pagesize;
    buffer = kmalloc(len, GFP_NOIO);
    if (buffer == NULL) {
        printk(KERN_WARNING "alauda_write_data: Out of memory\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /*
     * We also need a temporary block buffer, where we read in the old data,
     * overwrite parts with the new data, and manipulate the redundancy data
     */
    blockbuffer = kmalloc((pagesize + 64) * blocksize, GFP_NOIO);
    if (blockbuffer == NULL) {
        printk(KERN_WARNING "alauda_write_data: Out of memory\n");
        kfree(buffer);
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* Figure out the initial LBA and page */
    lba = address >> blockshift;
    page = (address & MEDIA_INFO(us).blockmask);
    max_lba = MEDIA_INFO(us).capacity >> (pageshift + blockshift);

    result = USB_STOR_TRANSPORT_GOOD;
    offset = 0;
    sg = NULL;

    while (sectors > 0) {
        /* Write as many sectors as possible in this block */
        unsigned int pages = min(sectors, blocksize - page);
        len = pages << pageshift;

        /* Not overflowing capacity? */
        if (lba >= max_lba) {
            US_DEBUGP("alauda_write_data: Requested lba %u exceeds "
                  "maximum %u\n", lba, max_lba);
            result = USB_STOR_TRANSPORT_ERROR;
            break;
        }

        /* Get the data from the transfer buffer */
        usb_stor_access_xfer_buf(buffer, len, us->srb,
                &sg, &offset, FROM_XFER_BUF);

        result = alauda_write_lba(us, lba, page, pages, buffer,
            blockbuffer);
        if (result != USB_STOR_TRANSPORT_GOOD)
            break;

        page = 0;
        lba++;
        sectors -= pages;
    }

    kfree(buffer);
    kfree(blockbuffer);
    return result;
}

/*
 * Our interface with the rest of the world
 */

static void alauda_info_destructor(void *extra)
{
    struct alauda_info *info = (struct alauda_info *) extra;
    int port;

    if (!info)
        return;

    for (port = 0; port < 2; port++) {
        struct alauda_media_info *media_info = &info->port[port];

        alauda_free_maps(media_info);
        kfree(media_info->lba_to_pba);
        kfree(media_info->pba_to_lba);
    }
}

/*
 * Initialize alauda_info struct and find the data-write endpoint
 */
static int init_alauda(struct us_data *us)
{
    struct alauda_info *info;
    struct usb_host_interface *altsetting = us->pusb_intf->cur_altsetting;
    nand_init_ecc();

    us->extra = kzalloc(sizeof(struct alauda_info), GFP_NOIO);
    if (!us->extra) {
        US_DEBUGP("init_alauda: Gah! Can't allocate storage for"
            "alauda info struct!\n");
        return USB_STOR_TRANSPORT_ERROR;
    }
    info = (struct alauda_info *) us->extra;
    us->extra_destructor = alauda_info_destructor;

    info->wr_ep = usb_sndbulkpipe(us->pusb_dev,
        altsetting->endpoint[0].desc.bEndpointAddress
        & USB_ENDPOINT_NUMBER_MASK);

    return USB_STOR_TRANSPORT_GOOD;
}

static int alauda_transport(struct scsi_cmnd *srb, struct us_data *us)
{
    int rc;
    struct alauda_info *info = (struct alauda_info *) us->extra;
    unsigned char *ptr = us->iobuf;
    static unsigned char inquiry_response[36] = {
        0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
    };

    if (srb->cmnd[0] == INQUIRY) {
        US_DEBUGP("alauda_transport: INQUIRY. "
            "Returning bogus response.\n");
        memcpy(ptr, inquiry_response, sizeof(inquiry_response));
        fill_inquiry_response(us, ptr, 36);
        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == TEST_UNIT_READY) {
        US_DEBUGP("alauda_transport: TEST_UNIT_READY.\n");
        return alauda_check_media(us);
    }

    if (srb->cmnd[0] == READ_CAPACITY) {
        unsigned int num_zones;
        unsigned long capacity;

        rc = alauda_check_media(us);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        num_zones = MEDIA_INFO(us).capacity >> (MEDIA_INFO(us).zoneshift
            + MEDIA_INFO(us).blockshift + MEDIA_INFO(us).pageshift);

        capacity = num_zones * MEDIA_INFO(us).uzonesize
            * MEDIA_INFO(us).blocksize;

        /* Report capacity and page size */
        ((__be32 *) ptr)[0] = cpu_to_be32(capacity - 1);
        ((__be32 *) ptr)[1] = cpu_to_be32(512);

        usb_stor_set_xfer_buf(ptr, 8, srb);
        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == READ_10) {
        unsigned int page, pages;

        rc = alauda_check_media(us);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        page = short_pack(srb->cmnd[3], srb->cmnd[2]);
        page <<= 16;
        page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
        pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

        US_DEBUGP("alauda_transport: READ_10: page %d pagect %d\n",
              page, pages);

        return alauda_read_data(us, page, pages);
    }

    if (srb->cmnd[0] == WRITE_10) {
        unsigned int page, pages;

        rc = alauda_check_media(us);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        page = short_pack(srb->cmnd[3], srb->cmnd[2]);
        page <<= 16;
        page |= short_pack(srb->cmnd[5], srb->cmnd[4]);
        pages = short_pack(srb->cmnd[8], srb->cmnd[7]);

        US_DEBUGP("alauda_transport: WRITE_10: page %d pagect %d\n",
              page, pages);

        return alauda_write_data(us, page, pages);
    }

    if (srb->cmnd[0] == REQUEST_SENSE) {
        US_DEBUGP("alauda_transport: REQUEST_SENSE.\n");

        memset(ptr, 0, 18);
        ptr[0] = 0xF0;
        ptr[2] = info->sense_key;
        ptr[7] = 11;
        ptr[12] = info->sense_asc;
        ptr[13] = info->sense_ascq;
        usb_stor_set_xfer_buf(ptr, 18, srb);

        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
        /* sure.  whatever.  not like we can stop the user from popping
           the media out of the device (no locking doors, etc) */
        return USB_STOR_TRANSPORT_GOOD;
    }

    US_DEBUGP("alauda_transport: Gah! Unknown command: %d (0x%x)\n",
        srb->cmnd[0], srb->cmnd[0]);
    info->sense_key = 0x05;
    info->sense_asc = 0x20;
    info->sense_ascq = 0x00;
    return USB_STOR_TRANSPORT_FAILED;
}

static int alauda_probe(struct usb_interface *intf,
             const struct usb_device_id *id)
{
    struct us_data *us;
    int result;

    result = usb_stor_probe1(&us, intf, id,
            (id - alauda_usb_ids) + alauda_unusual_dev_list);
    if (result)
        return result;

    us->transport_name  = "Alauda Control/Bulk";
    us->transport = alauda_transport;
    us->transport_reset = usb_stor_Bulk_reset;
    us->max_lun = 1;

    result = usb_stor_probe2(us);
    return result;
}

static struct usb_driver alauda_driver = {
    .name =     "ums-alauda",
    .probe =    alauda_probe,
    .disconnect =   usb_stor_disconnect,
    .suspend =  usb_stor_suspend,
    .resume =   usb_stor_resume,
    .reset_resume = usb_stor_reset_resume,
    .pre_reset =    usb_stor_pre_reset,
    .post_reset =   usb_stor_post_reset,
    .id_table = alauda_usb_ids,
    .soft_unbind =  1,
    .no_dynamic_id = 1,
};

module_usb_driver(alauda_driver);