/* SPDX-License-Identifier: GPL-2.0 */ #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