/* Driver for Lexar "Jumpshot" Compact Flash reader
 *
 * jumpshot driver v0.1:
 *
 * First release
 *
 * Current development and maintenance by:
 *   (c) 2000 Jimmie Mayfield (mayfield+usb@sackheads.org)
 *
 *   Many thanks to Robert Baruch for the SanDisk SmartMedia reader driver
 *   which I used as a template for this driver.
 *
 *   Some bugfixes and scatter-gather code by Gregory P. Smith 
 *   (greg-usb@electricrain.com)
 *
 *   Fix for media change by Joerg Schneider (js@joergschneider.com)
 *
 * Developed with the assistance of:
 *
 *   (C) 2002 Alan Stern <stern@rowland.org>
 *
 * 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.
 */
 
 /*
  * This driver attempts to support the Lexar Jumpshot USB CompactFlash 
  * reader.  Like many other USB CompactFlash readers, the Jumpshot contains
  * a USB-to-ATA chip. 
  *
  * This driver supports reading and writing.  If you're truly paranoid,
  * however, you can force the driver into a write-protected state by setting
  * the WP enable bits in jumpshot_handle_mode_sense.  See the comments
  * in that routine.
  */

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

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

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


MODULE_DESCRIPTION("Driver for Lexar \"Jumpshot\" Compact Flash reader");
MODULE_AUTHOR("Jimmie Mayfield <mayfield+usb@sackheads.org>");
MODULE_LICENSE("GPL");

/*
 * 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)|(USB_US_TYPE_STOR<<24) }

struct usb_device_id jumpshot_usb_ids[] = {
#       include "unusual_jumpshot.h"
        { }             /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, jumpshot_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 jumpshot_unusual_dev_list[] = {
#       include "unusual_jumpshot.h"
        { }             /* Terminating entry */
};

#undef UNUSUAL_DEV


struct jumpshot_info {
   unsigned long   sectors;     /* total sector count */
   unsigned long   ssize;       /* sector size in bytes */

   /* the following aren't used yet */
   unsigned char   sense_key;
   unsigned long   sense_asc;   /* additional sense code */
   unsigned long   sense_ascq;  /* additional sense code qualifier */
};

static inline int jumpshot_bulk_read(struct us_data *us,
                                     unsigned char *data, 
                                     unsigned int len)
{
        if (len == 0)
                return USB_STOR_XFER_GOOD;

        US_DEBUGP("jumpshot_bulk_read:  len = %d\n", len);
        return usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
                        data, len, NULL);
}


static inline int jumpshot_bulk_write(struct us_data *us,
                                      unsigned char *data, 
                                      unsigned int len)
{
        if (len == 0)
                return USB_STOR_XFER_GOOD;

        US_DEBUGP("jumpshot_bulk_write:  len = %d\n", len);
        return usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
                        data, len, NULL);
}


static int jumpshot_get_status(struct us_data  *us)
{
        int rc;

        if (!us)
                return USB_STOR_TRANSPORT_ERROR;

        // send the setup
        rc = usb_stor_ctrl_transfer(us, us->recv_ctrl_pipe,
                                   0, 0xA0, 0, 7, us->iobuf, 1);

        if (rc != USB_STOR_XFER_GOOD)
                return USB_STOR_TRANSPORT_ERROR;

        if (us->iobuf[0] != 0x50) {
                US_DEBUGP("jumpshot_get_status:  0x%2x\n",
                          us->iobuf[0]);
                return USB_STOR_TRANSPORT_ERROR;
        }

        return USB_STOR_TRANSPORT_GOOD;
}

static int jumpshot_read_data(struct us_data *us,
                              struct jumpshot_info *info,
                              u32 sector,
                              u32 sectors)
{
        unsigned char *command = us->iobuf;
        unsigned char *buffer;
        unsigned char  thistime;
        unsigned int totallen, alloclen;
        int len, result;
        unsigned int sg_offset = 0;
        struct scatterlist *sg = NULL;

        // we're working in LBA mode.  according to the ATA spec, 
        // we can support up to 28-bit addressing.  I don't know if Jumpshot
        // supports beyond 24-bit addressing.  It's kind of hard to test 
        // since it requires > 8GB CF card.

        if (sector > 0x0FFFFFFF)
                return USB_STOR_TRANSPORT_ERROR;

        totallen = sectors * info->ssize;

        // Since we don't read more than 64 KB 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.

        alloclen = min(totallen, 65536u);
        buffer = kmalloc(alloclen, GFP_NOIO);
        if (buffer == NULL)
                return USB_STOR_TRANSPORT_ERROR;

        do {
                // loop, never allocate or transfer more than 64k at once
                // (min(128k, 255*info->ssize) is the real limit)
                len = min(totallen, alloclen);
                thistime = (len / info->ssize) & 0xff;

                command[0] = 0;
                command[1] = thistime;
                command[2] = sector & 0xFF;
                command[3] = (sector >>  8) & 0xFF;
                command[4] = (sector >> 16) & 0xFF;

                command[5] = 0xE0 | ((sector >> 24) & 0x0F);
                command[6] = 0x20;

                // send the setup + command
                result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
                                               0, 0x20, 0, 1, command, 7);
                if (result != USB_STOR_XFER_GOOD)
                        goto leave;

                // read the result
                result = jumpshot_bulk_read(us, buffer, len);
                if (result != USB_STOR_XFER_GOOD)
                        goto leave;

                US_DEBUGP("jumpshot_read_data:  %d bytes\n", len);

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

                sector += thistime;
                totallen -= len;
        } while (totallen > 0);

        kfree(buffer);
        return USB_STOR_TRANSPORT_GOOD;

 leave:
        kfree(buffer);
        return USB_STOR_TRANSPORT_ERROR;
}


static int jumpshot_write_data(struct us_data *us,
                               struct jumpshot_info *info,
                               u32 sector,
                               u32 sectors)
{
        unsigned char *command = us->iobuf;
        unsigned char *buffer;
        unsigned char  thistime;
        unsigned int totallen, alloclen;
        int len, result, waitcount;
        unsigned int sg_offset = 0;
        struct scatterlist *sg = NULL;

        // we're working in LBA mode.  according to the ATA spec, 
        // we can support up to 28-bit addressing.  I don't know if Jumpshot
        // supports beyond 24-bit addressing.  It's kind of hard to test 
        // since it requires > 8GB CF card.
        //
        if (sector > 0x0FFFFFFF)
                return USB_STOR_TRANSPORT_ERROR;

        totallen = sectors * info->ssize;

        // Since we don't write more than 64 KB 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.

        alloclen = min(totallen, 65536u);
        buffer = kmalloc(alloclen, GFP_NOIO);
        if (buffer == NULL)
                return USB_STOR_TRANSPORT_ERROR;

        do {
                // loop, never allocate or transfer more than 64k at once
                // (min(128k, 255*info->ssize) is the real limit)

                len = min(totallen, alloclen);
                thistime = (len / info->ssize) & 0xff;

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

                command[0] = 0;
                command[1] = thistime;
                command[2] = sector & 0xFF;
                command[3] = (sector >>  8) & 0xFF;
                command[4] = (sector >> 16) & 0xFF;

                command[5] = 0xE0 | ((sector >> 24) & 0x0F);
                command[6] = 0x30;

                // send the setup + command
                result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
                        0, 0x20, 0, 1, command, 7);
                if (result != USB_STOR_XFER_GOOD)
                        goto leave;

                // send the data
                result = jumpshot_bulk_write(us, buffer, len);
                if (result != USB_STOR_XFER_GOOD)
                        goto leave;

                // read the result.  apparently the bulk write can complete
                // before the jumpshot drive is finished writing.  so we loop
                // here until we get a good return code
                waitcount = 0;
                do {
                        result = jumpshot_get_status(us);
                        if (result != USB_STOR_TRANSPORT_GOOD) {
                                // I have not experimented to find the smallest value.
                                //
                                msleep(50); 
                        }
                } while ((result != USB_STOR_TRANSPORT_GOOD) && (waitcount < 10));

                if (result != USB_STOR_TRANSPORT_GOOD)
                        US_DEBUGP("jumpshot_write_data:  Gah!  Waitcount = 10.  Bad write!?\n");

                sector += thistime;
                totallen -= len;
        } while (totallen > 0);

        kfree(buffer);
        return result;

 leave:
        kfree(buffer);
        return USB_STOR_TRANSPORT_ERROR;
}

static int jumpshot_id_device(struct us_data *us,
                              struct jumpshot_info *info)
{
        unsigned char *command = us->iobuf;
        unsigned char *reply;
        int      rc;

        if (!info)
                return USB_STOR_TRANSPORT_ERROR;

        command[0] = 0xE0;
        command[1] = 0xEC;
        reply = kmalloc(512, GFP_NOIO);
        if (!reply)
                return USB_STOR_TRANSPORT_ERROR;

        // send the setup
        rc = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
                                   0, 0x20, 0, 6, command, 2);

        if (rc != USB_STOR_XFER_GOOD) {
                US_DEBUGP("jumpshot_id_device:  Gah! "
                          "send_control for read_capacity failed\n");
                rc = USB_STOR_TRANSPORT_ERROR;
                goto leave;
        }

        // read the reply
        rc = jumpshot_bulk_read(us, reply, 512);
        if (rc != USB_STOR_XFER_GOOD) {
                rc = USB_STOR_TRANSPORT_ERROR;
                goto leave;
        }

        info->sectors = ((u32)(reply[117]) << 24) |
                        ((u32)(reply[116]) << 16) |
                        ((u32)(reply[115]) <<  8) |
                        ((u32)(reply[114])      );

        rc = USB_STOR_TRANSPORT_GOOD;

 leave:
        kfree(reply);
        return rc;
}

static int jumpshot_handle_mode_sense(struct us_data *us,
                                      struct scsi_cmnd * srb, 
                                      int sense_6)
{
        static unsigned char rw_err_page[12] = {
                0x1, 0xA, 0x21, 1, 0, 0, 0, 0, 1, 0, 0, 0
        };
        static unsigned char cache_page[12] = {
                0x8, 0xA, 0x1, 0, 0, 0, 0, 0, 0, 0, 0, 0
        };
        static unsigned char rbac_page[12] = {
                0x1B, 0xA, 0, 0x81, 0, 0, 0, 0, 0, 0, 0, 0
        };
        static unsigned char timer_page[8] = {
                0x1C, 0x6, 0, 0, 0, 0
        };
        unsigned char pc, page_code;
        unsigned int i = 0;
        struct jumpshot_info *info = (struct jumpshot_info *) (us->extra);
        unsigned char *ptr = us->iobuf;

        pc = srb->cmnd[2] >> 6;
        page_code = srb->cmnd[2] & 0x3F;

        switch (pc) {
           case 0x0:
                US_DEBUGP("jumpshot_handle_mode_sense:  Current values\n");
                break;
           case 0x1:
                US_DEBUGP("jumpshot_handle_mode_sense:  Changeable values\n");
                break;
           case 0x2:
                US_DEBUGP("jumpshot_handle_mode_sense:  Default values\n");
                break;
           case 0x3:
                US_DEBUGP("jumpshot_handle_mode_sense:  Saves values\n");
                break;
        }

        memset(ptr, 0, 8);
        if (sense_6) {
                ptr[2] = 0x00;          // WP enable: 0x80
                i = 4;
        } else {
                ptr[3] = 0x00;          // WP enable: 0x80
                i = 8;
        }

        switch (page_code) {
           case 0x0:
                // vendor-specific mode
                info->sense_key = 0x05;
                info->sense_asc = 0x24;
                info->sense_ascq = 0x00;
                return USB_STOR_TRANSPORT_FAILED;

           case 0x1:
                memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
                i += sizeof(rw_err_page);
                break;

           case 0x8:
                memcpy(ptr + i, cache_page, sizeof(cache_page));
                i += sizeof(cache_page);
                break;

           case 0x1B:
                memcpy(ptr + i, rbac_page, sizeof(rbac_page));
                i += sizeof(rbac_page);
                break;

           case 0x1C:
                memcpy(ptr + i, timer_page, sizeof(timer_page));
                i += sizeof(timer_page);
                break;

           case 0x3F:
                memcpy(ptr + i, timer_page, sizeof(timer_page));
                i += sizeof(timer_page);
                memcpy(ptr + i, rbac_page, sizeof(rbac_page));
                i += sizeof(rbac_page);
                memcpy(ptr + i, cache_page, sizeof(cache_page));
                i += sizeof(cache_page);
                memcpy(ptr + i, rw_err_page, sizeof(rw_err_page));
                i += sizeof(rw_err_page);
                break;
        }

        if (sense_6)
                ptr[0] = i - 1;
        else
                ((__be16 *) ptr)[0] = cpu_to_be16(i - 2);
        usb_stor_set_xfer_buf(ptr, i, srb);

        return USB_STOR_TRANSPORT_GOOD;
}


static void jumpshot_info_destructor(void *extra)
{
        // this routine is a placeholder...
        // currently, we don't allocate any extra blocks so we're okay
}



// Transport for the Lexar 'Jumpshot'
//
static int jumpshot_transport(struct scsi_cmnd *srb, struct us_data *us)
{
        struct jumpshot_info *info;
        int rc;
        unsigned long block, blocks;
        unsigned char *ptr = us->iobuf;
        static unsigned char inquiry_response[8] = {
                0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
        };

        if (!us->extra) {
                us->extra = kzalloc(sizeof(struct jumpshot_info), GFP_NOIO);
                if (!us->extra) {
                        US_DEBUGP("jumpshot_transport:  Gah! Can't allocate storage for jumpshot info struct!\n");
                        return USB_STOR_TRANSPORT_ERROR;
                }
                us->extra_destructor = jumpshot_info_destructor;
        }

        info = (struct jumpshot_info *) (us->extra);

        if (srb->cmnd[0] == INQUIRY) {
                US_DEBUGP("jumpshot_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] == READ_CAPACITY) {
                info->ssize = 0x200;  // hard coded 512 byte sectors as per ATA spec

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

                rc = jumpshot_id_device(us, info);
                if (rc != USB_STOR_TRANSPORT_GOOD)
                        return rc;

                US_DEBUGP("jumpshot_transport:  READ_CAPACITY:  %ld sectors, %ld bytes per sector\n",
                          info->sectors, info->ssize);

                // build the reply
                //
                ((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
                ((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
                usb_stor_set_xfer_buf(ptr, 8, srb);

                return USB_STOR_TRANSPORT_GOOD;
        }

        if (srb->cmnd[0] == MODE_SELECT_10) {
                US_DEBUGP("jumpshot_transport:  Gah! MODE_SELECT_10.\n");
                return USB_STOR_TRANSPORT_ERROR;
        }

        if (srb->cmnd[0] == READ_10) {
                block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                        ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

                blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

                US_DEBUGP("jumpshot_transport:  READ_10: read block 0x%04lx  count %ld\n", block, blocks);
                return jumpshot_read_data(us, info, block, blocks);
        }

        if (srb->cmnd[0] == READ_12) {
                // I don't think we'll ever see a READ_12 but support it anyway...
                //
                block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                        ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

                blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
                         ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

                US_DEBUGP("jumpshot_transport:  READ_12: read block 0x%04lx  count %ld\n", block, blocks);
                return jumpshot_read_data(us, info, block, blocks);
        }

        if (srb->cmnd[0] == WRITE_10) {
                block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                        ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

                blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

                US_DEBUGP("jumpshot_transport:  WRITE_10: write block 0x%04lx  count %ld\n", block, blocks);
                return jumpshot_write_data(us, info, block, blocks);
        }

        if (srb->cmnd[0] == WRITE_12) {
                // I don't think we'll ever see a WRITE_12 but support it anyway...
                //
                block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                        ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

                blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
                         ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

                US_DEBUGP("jumpshot_transport:  WRITE_12: write block 0x%04lx  count %ld\n", block, blocks);
                return jumpshot_write_data(us, info, block, blocks);
        }


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

        if (srb->cmnd[0] == REQUEST_SENSE) {
                US_DEBUGP("jumpshot_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] == MODE_SENSE) {
                US_DEBUGP("jumpshot_transport:  MODE_SENSE_6 detected\n");
                return jumpshot_handle_mode_sense(us, srb, 1);
        }

        if (srb->cmnd[0] == MODE_SENSE_10) {
                US_DEBUGP("jumpshot_transport:  MODE_SENSE_10 detected\n");
                return jumpshot_handle_mode_sense(us, srb, 0);
        }

        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;
        }

        if (srb->cmnd[0] == START_STOP) {
                /* this is used by sd.c'check_scsidisk_media_change to detect
                   media change */
                US_DEBUGP("jumpshot_transport:  START_STOP.\n");
                /* the first jumpshot_id_device after a media change returns
                   an error (determined experimentally) */
                rc = jumpshot_id_device(us, info);
                if (rc == USB_STOR_TRANSPORT_GOOD) {
                        info->sense_key = NO_SENSE;
                        srb->result = SUCCESS;
                } else {
                        info->sense_key = UNIT_ATTENTION;
                        srb->result = SAM_STAT_CHECK_CONDITION;
                }
                return rc;
        }

        US_DEBUGP("jumpshot_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 jumpshot_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 - jumpshot_usb_ids) + jumpshot_unusual_dev_list);
        if (result)
                return result;

        us->transport_name  = "Lexar Jumpshot Control/Bulk";
        us->transport = jumpshot_transport;
        us->transport_reset = usb_stor_Bulk_reset;
        us->max_lun = 1;

        result = usb_stor_probe2(us);
        return result;
}

static struct usb_driver jumpshot_driver = {
        .name =         "ums-jumpshot",
        .probe =        jumpshot_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 =     jumpshot_usb_ids,
        .soft_unbind =  1,
};

static int __init jumpshot_init(void)
{
        return usb_register(&jumpshot_driver);
}

static void __exit jumpshot_exit(void)
{
        usb_deregister(&jumpshot_driver);
}

module_init(jumpshot_init);
module_exit(jumpshot_exit);