sysdeps/unix/sysv/linux/scsi/sg.h

   1 /* Copyright (C) 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20    History:
  21     Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user
  22      process control of SCSI devices.
  23     Development Sponsored by Killy Corp. NY NY
  24 */
  25
  26 #ifndef _SCSI_SG_H
  27 #define _SCSI_SG_H      1
  28
  29 /* An SG device is accessed by writing "packets" to it, the replies
  30    are then read using the read call.  The same header is used for
  31    replies; ignore the reply_len field.  */
  32
  33 struct sg_header
  34  {
  35    int pack_len;                        /* length of incoming packet
  36                                            (including header).  */
  37    int reply_len;                       /* max length of expected reply.  */
  38    int pack_id;                         /* id number of packet.  */
  39    int result;                          /* 0==ok, otherwise error number.  */
  40    unsigned int twelve_byte:1;          /* force 12 byte command length for
  41                                            group 6 & 7 commands.  */
  42    unsigned int other_flags:31;         /* for future use.  */
  43    unsigned char sense_buffer[16];      /* used only by reads. */
  44    /* command follows then data for command.  */
  45  };
  46
  47 /* ioctl's */
  48 #define SG_SET_TIMEOUT 0x2201  /* set timeout *(int *)arg==timeout */
  49 #define SG_GET_TIMEOUT 0x2202  /* get timeout return timeout */
  50
  51 #define SG_DEFAULT_TIMEOUT (60*HZ) /* 1 minute timeout */
  52 #define SG_DEFAULT_RETRIES 1
  53
  54 #define SG_MAX_QUEUE 4 /* maximum outstanding request, arbitrary, may be
  55                           changed if sufficient DMA buffer room available.  */
  56
  57 #define SG_BIG_BUFF 32768
  58
  59 #endif  /* scsi/sg.h */