| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | #ifndef _MC6821_H_ |
| 2 | #define _MC6821_H_ |
| 3 | |
| 4 | /* |
| 5 | * This file describes the memery mapping of the MC6821 PIA. |
| 6 | * The unions describe overlayed registers. Which of them is used is |
| 7 | * determined by bit 2 of the corresponding control register. |
| 8 | * this files expects the PIA_REG_PADWIDTH to be defined the numeric |
| 9 | * value of the register spacing. |
| 10 | * |
| 11 | * Data came from MFC-31-Developer Kit (from Ralph Seidel, |
| 12 | * zodiac@darkness.gun.de) and Motorola Data Sheet (from |
| 13 | * Richard Hirst, srh@gpt.co.uk) |
| 14 | * |
| 15 | * 6.11.95 copyright Joerg Dorchain (dorchain@mpi-sb.mpg.de) |
| 16 | * |
| 17 | */ |
| 18 | |
| 19 | #ifndef PIA_REG_PADWIDTH |
| 20 | #define PIA_REG_PADWIDTH 255 |
| 21 | #endif |
| 22 | |
| 23 | struct pia { |
| 24 | union { |
| 25 | volatile u_char pra; |
| 26 | volatile u_char ddra; |
| 27 | } ua; |
| 28 | u_char pad1[PIA_REG_PADWIDTH]; |
| 29 | volatile u_char cra; |
| 30 | u_char pad2[PIA_REG_PADWIDTH]; |
| 31 | union { |
| 32 | volatile u_char prb; |
| 33 | volatile u_char ddrb; |
| 34 | } ub; |
| 35 | u_char pad3[PIA_REG_PADWIDTH]; |
| 36 | volatile u_char crb; |
| 37 | u_char pad4[PIA_REG_PADWIDTH]; |
| 38 | }; |
| 39 | |
| 40 | #define ppra ua.pra |
| 41 | #define pddra ua.ddra |
| 42 | #define pprb ub.prb |
| 43 | #define pddrb ub.ddrb |
| 44 | |
| 45 | #define PIA_C1_ENABLE_IRQ (1<<0) |
| 46 | #define PIA_C1_LOW_TO_HIGH (1<<1) |
| 47 | #define PIA_DDR (1<<2) |
| 48 | #define PIA_IRQ2 (1<<6) |
| 49 | #define PIA_IRQ1 (1<<7) |
| 50 | |
| 51 | #endif |