diff options
Diffstat (limited to 'include/linux/mc6821.h')
| -rw-r--r-- | include/linux/mc6821.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/mc6821.h b/include/linux/mc6821.h new file mode 100644 index 000000000000..28e301e295da --- /dev/null +++ b/include/linux/mc6821.h @@ -0,0 +1,51 @@ +#ifndef _MC6821_H_ +#define _MC6821_H_ + +/* + * This file describes the memery mapping of the MC6821 PIA. + * The unions describe overlayed registers. Which of them is used is + * determined by bit 2 of the corresponding control register. + * this files expects the PIA_REG_PADWIDTH to be defined the numeric + * value of the register spacing. + * + * Data came from MFC-31-Developer Kit (from Ralph Seidel, + * zodiac@darkness.gun.de) and Motorola Data Sheet (from + * Richard Hirst, srh@gpt.co.uk) + * + * 6.11.95 copyright Joerg Dorchain (dorchain@mpi-sb.mpg.de) + * + */ + +#ifndef PIA_REG_PADWIDTH +#define PIA_REG_PADWIDTH 255 +#endif + +struct pia { + union { + volatile u_char pra; + volatile u_char ddra; + } ua; + u_char pad1[PIA_REG_PADWIDTH]; + volatile u_char cra; + u_char pad2[PIA_REG_PADWIDTH]; + union { + volatile u_char prb; + volatile u_char ddrb; + } ub; + u_char pad3[PIA_REG_PADWIDTH]; + volatile u_char crb; + u_char pad4[PIA_REG_PADWIDTH]; +}; + +#define ppra ua.pra +#define pddra ua.ddra +#define pprb ub.prb +#define pddrb ub.ddrb + +#define PIA_C1_ENABLE_IRQ (1<<0) +#define PIA_C1_LOW_TO_HIGH (1<<1) +#define PIA_DDR (1<<2) +#define PIA_IRQ2 (1<<6) +#define PIA_IRQ1 (1<<7) + +#endif |