linux/drivers/usb/storage/transport.h
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   1/* Driver for USB Mass Storage compliant devices
   2 * Transport Functions Header File
   3 *
   4 * Current development and maintenance by:
   5 *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   6 *
   7 * This driver is based on the 'USB Mass Storage Class' document. This
   8 * describes in detail the protocol used to communicate with such
   9 * devices.  Clearly, the designers had SCSI and ATAPI commands in
  10 * mind when they created this document.  The commands are all very
  11 * similar to commands in the SCSI-II and ATAPI specifications.
  12 *
  13 * It is important to note that in a number of cases this class
  14 * exhibits class-specific exemptions from the USB specification.
  15 * Notably the usage of NAK, STALL and ACK differs from the norm, in
  16 * that they are used to communicate wait, failed and OK on commands.
  17 *
  18 * Also, for certain devices, the interrupt endpoint is used to convey
  19 * status of a command.
  20 *
  21 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  22 * information about this driver.
  23 *
  24 * This program is free software; you can redistribute it and/or modify it
  25 * under the terms of the GNU General Public License as published by the
  26 * Free Software Foundation; either version 2, or (at your option) any
  27 * later version.
  28 *
  29 * This program is distributed in the hope that it will be useful, but
  30 * WITHOUT ANY WARRANTY; without even the implied warranty of
  31 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  32 * General Public License for more details.
  33 *
  34 * You should have received a copy of the GNU General Public License along
  35 * with this program; if not, write to the Free Software Foundation, Inc.,
  36 * 675 Mass Ave, Cambridge, MA 02139, USA.
  37 */
  38
  39#ifndef _TRANSPORT_H_
  40#define _TRANSPORT_H_
  41
  42#include <linux/blkdev.h>
  43
  44/*
  45 * Bulk only data structures
  46 */
  47
  48/* command block wrapper */
  49struct bulk_cb_wrap {
  50        __le32  Signature;              /* contains 'USBC' */
  51        __u32   Tag;                    /* unique per command id */
  52        __le32  DataTransferLength;     /* size of data */
  53        __u8    Flags;                  /* direction in bit 0 */
  54        __u8    Lun;                    /* LUN normally 0 */
  55        __u8    Length;                 /* of of the CDB */
  56        __u8    CDB[16];                /* max command */
  57};
  58
  59#define US_BULK_CB_WRAP_LEN     31
  60#define US_BULK_CB_SIGN         0x43425355      /*spells out USBC */
  61#define US_BULK_FLAG_IN         1
  62#define US_BULK_FLAG_OUT        0
  63
  64/* command status wrapper */
  65struct bulk_cs_wrap {
  66        __le32  Signature;              /* should = 'USBS' */
  67        __u32   Tag;                    /* same as original command */
  68        __le32  Residue;                /* amount not transferred */
  69        __u8    Status;                 /* see below */
  70        __u8    Filler[18];
  71};
  72
  73#define US_BULK_CS_WRAP_LEN     13
  74#define US_BULK_CS_SIGN         0x53425355      /* spells out 'USBS' */
  75#define US_BULK_STAT_OK         0
  76#define US_BULK_STAT_FAIL       1
  77#define US_BULK_STAT_PHASE      2
  78
  79/* bulk-only class specific requests */
  80#define US_BULK_RESET_REQUEST   0xff
  81#define US_BULK_GET_MAX_LUN     0xfe
  82
  83/*
  84 * usb_stor_bulk_transfer_xxx() return codes, in order of severity
  85 */
  86
  87#define USB_STOR_XFER_GOOD      0       /* good transfer                 */
  88#define USB_STOR_XFER_SHORT     1       /* transferred less than expected */
  89#define USB_STOR_XFER_STALLED   2       /* endpoint stalled              */
  90#define USB_STOR_XFER_LONG      3       /* device tried to send too much */
  91#define USB_STOR_XFER_ERROR     4       /* transfer died in the middle   */
  92
  93/*
  94 * Transport return codes
  95 */
  96
  97#define USB_STOR_TRANSPORT_GOOD    0   /* Transport good, command good     */
  98#define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
  99#define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
 100#define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
 101
 102/*
 103 * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
 104 * return codes.  But now the transport and low-level transfer routines
 105 * treat an abort as just another error (-ENOENT for a cancelled URB).
 106 * It is up to the invoke_transport() function to test for aborts and
 107 * distinguish them from genuine communication errors.
 108 */
 109
 110/*
 111 * CBI accept device specific command
 112 */
 113
 114#define US_CBI_ADSC             0
 115
 116extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
 117extern int usb_stor_CB_reset(struct us_data*);
 118
 119extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
 120extern int usb_stor_Bulk_max_lun(struct us_data*);
 121extern int usb_stor_Bulk_reset(struct us_data*);
 122
 123extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
 124extern void usb_stor_stop_transport(struct us_data*);
 125
 126extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
 127                u8 request, u8 requesttype, u16 value, u16 index,
 128                void *data, u16 size, int timeout);
 129extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
 130
 131extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
 132                u8 request, u8 requesttype, u16 value, u16 index,
 133                void *data, u16 size);
 134extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
 135                void *buf, unsigned int length, unsigned int *act_len);
 136extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
 137                void *buf, unsigned int length, int use_sg, int *residual);
 138extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
 139                struct scsi_cmnd* srb);
 140
 141extern int usb_stor_port_reset(struct us_data *us);
 142#endif
 143