drivers/usb/storage/transport.h

   1 /* Driver for USB Mass Storage compliant devices
   2  * Transport Functions Header File
   3  *
   4  * $Id: transport.h,v 1.18 2002/04/21 02:57:59 mdharm Exp $
   5  *
   6  * Current development and maintenance by:
   7  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   8  *
   9  * This driver is based on the 'USB Mass Storage Class' document. This
  10  * describes in detail the protocol used to communicate with such
  11  * devices.  Clearly, the designers had SCSI and ATAPI commands in
  12  * mind when they created this document.  The commands are all very
  13  * similar to commands in the SCSI-II and ATAPI specifications.
  14  *
  15  * It is important to note that in a number of cases this class
  16  * exhibits class-specific exemptions from the USB specification.
  17  * Notably the usage of NAK, STALL and ACK differs from the norm, in
  18  * that they are used to communicate wait, failed and OK on commands.
  19  *
  20  * Also, for certain devices, the interrupt endpoint is used to convey
  21  * status of a command.
  22  *
  23  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  24  * information about this driver.
  25  *
  26  * This program is free software; you can redistribute it and/or modify it
  27  * under the terms of the GNU General Public License as published by the
  28  * Free Software Foundation; either version 2, or (at your option) any
  29  * later version.
  30  *
  31  * This program is distributed in the hope that it will be useful, but
  32  * WITHOUT ANY WARRANTY; without even the implied warranty of
  33  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  34  * General Public License for more details.
  35  *
  36  * You should have received a copy of the GNU General Public License along
  37  * with this program; if not, write to the Free Software Foundation, Inc.,
  38  * 675 Mass Ave, Cambridge, MA 02139, USA.
  39  */
  40
  41 #ifndef _TRANSPORT_H_
  42 #define _TRANSPORT_H_
  43
  44 #include <linux/blkdev.h>
  45
  46 /*
  47  * Bulk only data structures
  48  */
  49
  50 /* command block wrapper */
  51 struct bulk_cb_wrap {
  52         __le32  Signature;              /* contains 'USBC' */
  53         __u32   Tag;                    /* unique per command id */
  54         __le32  DataTransferLength;     /* size of data */
  55         __u8    Flags;                  /* direction in bit 0 */
  56         __u8    Lun;                    /* LUN normally 0 */
  57         __u8    Length;                 /* of of the CDB */
  58         __u8    CDB[16];                /* max command */
  59 };
  60
  61 #define US_BULK_CB_WRAP_LEN     31
  62 #define US_BULK_CB_SIGN         0x43425355      /*spells out USBC */
  63 #define US_BULK_FLAG_IN         1
  64 #define US_BULK_FLAG_OUT        0
  65
  66 /* command status wrapper */
  67 struct bulk_cs_wrap {
  68         __le32  Signature;              /* should = 'USBS' */
  69         __u32   Tag;                    /* same as original command */
  70         __le32  Residue;                /* amount not transferred */
  71         __u8    Status;                 /* see below */
  72         __u8    Filler[18];
  73 };
  74
  75 #define US_BULK_CS_WRAP_LEN     13
  76 #define US_BULK_CS_SIGN         0x53425355      /* spells out 'USBS' */
  77 #define US_BULK_STAT_OK         0
  78 #define US_BULK_STAT_FAIL       1
  79 #define US_BULK_STAT_PHASE      2
  80
  81 /* bulk-only class specific requests */
  82 #define US_BULK_RESET_REQUEST   0xff
  83 #define US_BULK_GET_MAX_LUN     0xfe
  84
  85 /*
  86  * usb_stor_bulk_transfer_xxx() return codes, in order of severity
  87  */
  88
  89 #define USB_STOR_XFER_GOOD      0       /* good transfer                 */
  90 #define USB_STOR_XFER_SHORT     1       /* transferred less than expected */
  91 #define USB_STOR_XFER_STALLED   2       /* endpoint stalled              */
  92 #define USB_STOR_XFER_LONG      3       /* device tried to send too much */
  93 #define USB_STOR_XFER_ERROR     4       /* transfer died in the middle   */
  94
  95 /*
  96  * Transport return codes
  97  */
  98
  99 #define USB_STOR_TRANSPORT_GOOD    0   /* Transport good, command good     */
 100 #define USB_STOR_TRANSPORT_FAILED  1   /* Transport good, command failed   */
 101 #define USB_STOR_TRANSPORT_NO_SENSE 2  /* Command failed, no auto-sense    */
 102 #define USB_STOR_TRANSPORT_ERROR   3   /* Transport bad (i.e. device dead) */
 103
 104 /*
 105  * We used to have USB_STOR_XFER_ABORTED and USB_STOR_TRANSPORT_ABORTED
 106  * return codes.  But now the transport and low-level transfer routines
 107  * treat an abort as just another error (-ENOENT for a cancelled URB).
 108  * It is up to the invoke_transport() function to test for aborts and
 109  * distinguish them from genuine communication errors.
 110  */
 111
 112 /*
 113  * CBI accept device specific command
 114  */
 115
 116 #define US_CBI_ADSC             0
 117
 118 extern int usb_stor_CBI_transport(struct scsi_cmnd *, struct us_data*);
 119
 120 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
 121 extern int usb_stor_CB_reset(struct us_data*);
 122
 123 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
 124 extern int usb_stor_Bulk_max_lun(struct us_data*);
 125 extern int usb_stor_Bulk_reset(struct us_data*);
 126
 127 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
 128 extern void usb_stor_stop_transport(struct us_data*);
 129
 130 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
 131                 u8 request, u8 requesttype, u16 value, u16 index,
 132                 void *data, u16 size, int timeout);
 133 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
 134
 135 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
 136                 u8 request, u8 requesttype, u16 value, u16 index,
 137                 void *data, u16 size);
 138 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
 139                 void *buf, unsigned int length, unsigned int *act_len);
 140 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
 141                 void *buf, unsigned int length, int use_sg, int *residual);
 142 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
 143                 struct scsi_cmnd* srb);
 144
 145 extern int usb_stor_port_reset(struct us_data *us);
 146 #endif