drivers/usb/storage/protocol.h

   1 /*
   2  * Driver for USB Mass Storage compliant devices
   3  * Protocol Functions Header File
   4  *
   5  * Current development and maintenance by:
   6  *   (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   7  *
   8  * This driver is based on the 'USB Mass Storage Class' document. This
   9  * describes in detail the protocol used to communicate with such
  10  * devices.  Clearly, the designers had SCSI and ATAPI commands in
  11  * mind when they created this document.  The commands are all very
  12  * similar to commands in the SCSI-II and ATAPI specifications.
  13  *
  14  * It is important to note that in a number of cases this class
  15  * exhibits class-specific exemptions from the USB specification.
  16  * Notably the usage of NAK, STALL and ACK differs from the norm, in
  17  * that they are used to communicate wait, failed and OK on commands.
  18  *
  19  * Also, for certain devices, the interrupt endpoint is used to convey
  20  * status of a command.
  21  *
  22  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  23  * information about this driver.
  24  *
  25  * This program is free software; you can redistribute it and/or modify it
  26  * under the terms of the GNU General Public License as published by the
  27  * Free Software Foundation; either version 2, or (at your option) any
  28  * later version.
  29  *
  30  * This program is distributed in the hope that it will be useful, but
  31  * WITHOUT ANY WARRANTY; without even the implied warranty of
  32  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  33  * General Public License for more details.
  34  *
  35  * You should have received a copy of the GNU General Public License along
  36  * with this program; if not, write to the Free Software Foundation, Inc.,
  37  * 675 Mass Ave, Cambridge, MA 02139, USA.
  38  */
  39
  40 #ifndef _PROTOCOL_H_
  41 #define _PROTOCOL_H_
  42
  43 /* Protocol handling routines */
  44 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
  45 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
  46 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
  47                 struct us_data*);
  48
  49 /* struct scsi_cmnd transfer buffer access utilities */
  50 enum xfer_buf_dir       {TO_XFER_BUF, FROM_XFER_BUF};
  51
  52 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
  53         unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
  54         unsigned int *offset, enum xfer_buf_dir dir);
  55
  56 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
  57         unsigned int buflen, struct scsi_cmnd *srb);
  58 #endif