root/include/scsi/sg.h

/* */

INCLUDED FROM

   1 /*
   2    History:
   3     Started: Aug 9 by Lawrence Foard (entropy@world.std.com), to allow user 
   4      process control of SCSI devices.
   5     Development Sponsored by Killy Corp. NY NY
   6 */
   7 
   8 #ifndef _SCSI_GENERIC_H
   9 #define _SCSI_GENERIC_H
  10 
  11 /* 
  12  An SG device is accessed by writing "packets" to it, the replies
  13  are then read using the read call. The same header is used for 
  14  reply, just ignore reply_len field.
  15 */
  16 
  17 struct sg_header
  18  {
  19   int pack_len;    /* length of incoming packet <4096 (including header) */
  20   int reply_len;   /* maximum length <4096 of expected reply */
  21   int pack_id;     /* id number of packet */
  22   int result;      /* 0==ok, otherwise refer to errno codes */
  23   unsigned int twelve_byte:1; /* Force 12 byte command length for group 6 & 7 commands  */
  24   unsigned int other_flags:31;                  /* for future use */
  25   unsigned char sense_buffer[16]; /* used only by reads */
  26   /* command follows then data for command */
  27  };
  28 
  29 /* ioctl's */
  30 #define SG_SET_TIMEOUT 0x2201  /* set timeout *(int *)arg==timeout */
  31 #define SG_GET_TIMEOUT 0x2202  /* get timeout return timeout */
  32 
  33 #define SG_DEFAULT_TIMEOUT (60*HZ) /* 1 minute timeout */
  34 #define SG_DEFAULT_RETRIES 1
  35 
  36 #define SG_MAX_QUEUE 4 /* maximum outstanding request, arbitrary, may be
  37                           changed if sufficient DMA buffer room available */
  38 
  39 #define SG_BIG_BUFF 32768
  40 
  41 #endif

/* */