| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /************************************************************************* |
| 2 | * |
| 3 | * tape390.h |
| 4 | * enables user programs to display messages on the tape device |
| 5 | * |
| 6 | * S390 and zSeries version |
| 7 | * Copyright (C) 2001 IBM Corporation |
| 8 | * Author(s): Despina Papadopoulou <despina_p@de.ibm.com> |
| 9 | * |
| 10 | *************************************************************************/ |
| 11 | |
| 12 | #ifndef _TAPE390_H |
| 13 | #define _TAPE390_H |
| 14 | |
| 15 | #define TAPE390_DISPLAY _IOW('d', 1, struct display_struct) |
| 16 | |
| 17 | /* |
| 18 | * The TAPE390_DISPLAY ioctl calls the Load Display command |
| 19 | * which transfers 17 bytes of data from the channel to the subsystem: |
| 20 | * - 1 format control byte, and |
| 21 | * - two 8-byte messages |
| 22 | * |
| 23 | * Format control byte: |
| 24 | * 0-2: New Message Overlay |
| 25 | * 3: Alternate Messages |
| 26 | * 4: Blink Message |
| 27 | * 5: Display Low/High Message |
| 28 | * 6: Reserved |
| 29 | * 7: Automatic Load Request |
| 30 | * |
| 31 | */ |
| 32 | |
| 33 | typedef struct display_struct { |
| 34 | char cntrl; |
| 35 | char message1[8]; |
| 36 | char message2[8]; |
| 37 | } display_struct; |
| 38 | |
| 39 | #endif |