drivers/usb/storage/transport.h

   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 */
  49 struct 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 */
  65 struct 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
 116 extern int usb_stor_CBI_transport(struct scsi_cmnd *, struct us_data*);
 117
 118 extern int usb_stor_CB_transport(struct scsi_cmnd *, struct us_data*);
 119 extern int usb_stor_CB_reset(struct us_data*);
 120
 121 extern int usb_stor_Bulk_transport(struct scsi_cmnd *, struct us_data*);
 122 extern int usb_stor_Bulk_max_lun(struct us_data*);
 123 extern int usb_stor_Bulk_reset(struct us_data*);
 124
 125 extern void usb_stor_invoke_transport(struct scsi_cmnd *, struct us_data*);
 126 extern void usb_stor_stop_transport(struct us_data*);
 127
 128 extern int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
 129                 u8 request, u8 requesttype, u16 value, u16 index,
 130                 void *data, u16 size, int timeout);
 131 extern int usb_stor_clear_halt(struct us_data *us, unsigned int pipe);
 132
 133 extern int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
 134                 u8 request, u8 requesttype, u16 value, u16 index,
 135                 void *data, u16 size);
 136 extern int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
 137                 void *buf, unsigned int length, unsigned int *act_len);
 138 extern int usb_stor_bulk_transfer_sg(struct us_data *us, unsigned int pipe,
 139                 void *buf, unsigned int length, int use_sg, int *residual);
 140 extern int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
 141                 struct scsi_cmnd* srb);
 142
 143 extern int usb_stor_port_reset(struct us_data *us);
 144 #endif