drivers/usb/storage/protocol.h

   1 /* Driver for USB Mass Storage compliant devices
   2  * Protocol 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 _PROTOCOL_H_
  40 #define _PROTOCOL_H_
  41
  42 /* Protocol handling routines */
  43 extern void usb_stor_pad12_command(struct scsi_cmnd*, struct us_data*);
  44 extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
  45 extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
  46                 struct us_data*);
  47
  48 /* struct scsi_cmnd transfer buffer access utilities */
  49 enum xfer_buf_dir       {TO_XFER_BUF, FROM_XFER_BUF};
  50
  51 extern unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
  52         unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **,
  53         unsigned int *offset, enum xfer_buf_dir dir);
  54
  55 extern void usb_stor_set_xfer_buf(unsigned char *buffer,
  56         unsigned int buflen, struct scsi_cmnd *srb);
  57 #endif