/* * (C) Copyright 2002 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se. * * SPDX-License-Identifier: GPL-2.0+ */ /* i8254.h Intel 8254 PIT registers */ #ifndef _ASMI386_I8254_H_ #define _ASMI386_I8954_H_ 1 #define PIT_T0 0x00 /* PIT channel 0 count/status */ #define PIT_T1 0x01 /* PIT channel 1 count/status */ #define PIT_T2 0x02 /* PIT channel 2 count/status */ #define PIT_COMMAND 0x03 /* PIT mode control, latch and read back */ /* PIT Command Register Bit Definitions */ #define PIT_CMD_CTR0 0x00 /* Select PIT counter 0 */ #define PIT_CMD_CTR1 0x40 /* Select PIT counter 1 */ #define PIT_CMD_CTR2 0x80 /* Select PIT counter 2 */ #define PIT_CMD_LATCH 0x00 /* Counter Latch Command */ #define PIT_CMD_LOW 0x10 /* Access counter bits 7-0 */ #define PIT_CMD_HIGH 0x20 /* Access counter bits 15-8 */ #define PIT_CMD_BOTH 0x30 /* Access counter bits 15-0 in two accesses */ #define PIT_CMD_MODE0 0x00 /* Select mode 0 */ #define PIT_CMD_MODE1 0x02 /* Select mode 1 */ #define PIT_CMD_MODE2 0x04 /* Select mode 2 */ #define PIT_CMD_MODE3 0x06 /* Select mode 3 */ #define PIT_CMD_MODE4 0x08 /* Select mode 4 */ #define PIT_CMD_MODE5 0x0A /* Select mode 5 */ #endif