pic.h

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/*
 * PROJECT:     NEC PC-98 series onboard hardware
 * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
 * PURPOSE:     Intel 8259A PIC header file
 * COPYRIGHT:   Copyright 2020 Dmitry Borisov (di.sean@protonmail.com)
 */

#pragma once

#define PIC1_CONTROL_PORT      0x00
#define PIC1_DATA_PORT         0x02
#define PIC2_CONTROL_PORT      0x08
#define PIC2_DATA_PORT         0x0A

#define PIC_TIMER_IRQ      0
#define PIC_CASCADE_IRQ    7
#define PIC_RTC_IRQ        15

/*
 * Definitions for ICW/OCW Bits
 */
typedef enum _I8259_ICW1_OPERATING_MODE
{
    Cascade,
    Single
} I8259_ICW1_OPERATING_MODE;

typedef enum _I8259_ICW1_INTERRUPT_MODE
{
    EdgeTriggered,
    LevelTriggered
} I8259_ICW1_INTERRUPT_MODE;

typedef enum _I8259_ICW1_INTERVAL
{
    Interval8,
    Interval4
} I8259_ICW1_INTERVAL;

typedef enum _I8259_ICW4_SYSTEM_MODE
{
    Mcs8085Mode,
    New8086Mode
} I8259_ICW4_SYSTEM_MODE;

typedef enum _I8259_ICW4_EOI_MODE
{
    NormalEoi,
    AutomaticEoi
} I8259_ICW4_EOI_MODE;

typedef enum _I8259_ICW4_BUFFERED_MODE
{
    NonBuffered,
    NonBuffered2,
    BufferedSlave,
    BufferedMaster
} I8259_ICW4_BUFFERED_MODE;

typedef enum _I8259_READ_REQUEST
{
    InvalidRequest,
    InvalidRequest2,
    ReadIdr,
    ReadIsr
} I8259_READ_REQUEST;

typedef enum _I8259_EOI_MODE
{
    RotateAutoEoiClear,
    NonSpecificEoi,
    InvalidEoiMode,
    SpecificEoi,
    RotateAutoEoiSet,
    RotateNonSpecific,
    SetPriority,
    RotateSpecific
} I8259_EOI_MODE;

/*
 * Definitions for ICW Registers
 */
typedef union _I8259_ICW1
{
    struct
    {
        UCHAR NeedIcw4:1;
        UCHAR OperatingMode:1;
        UCHAR Interval:1;
        UCHAR InterruptMode:1;
        UCHAR Init:1;
        UCHAR InterruptVectorAddress:3;
    };
    UCHAR Bits;
} I8259_ICW1, *PI8259_ICW1;

typedef union _I8259_ICW2
{
    struct
    {
        UCHAR Sbz:3;
        UCHAR InterruptVector:5;
    };
    UCHAR Bits;
} I8259_ICW2, *PI8259_ICW2;

typedef union _I8259_ICW3
{
    union
    {
        struct
        {
            UCHAR SlaveIrq0:1;
            UCHAR SlaveIrq1:1;
            UCHAR SlaveIrq2:1;
            UCHAR SlaveIrq3:1;
            UCHAR SlaveIrq4:1;
            UCHAR SlaveIrq5:1;
            UCHAR SlaveIrq6:1;
            UCHAR SlaveIrq7:1;
        };
        struct
        {
            UCHAR SlaveId:3;
            UCHAR Reserved:5;
        };
    };
    UCHAR Bits;
} I8259_ICW3, *PI8259_ICW3;

typedef union _I8259_ICW4
{
    struct
    {
        UCHAR SystemMode:1;
        UCHAR EoiMode:1;
        UCHAR BufferedMode:2;
        UCHAR SpecialFullyNestedMode:1;
        UCHAR Reserved:3;
    };
    UCHAR Bits;
} I8259_ICW4, *PI8259_ICW4;

typedef union _I8259_OCW2
{
    struct
    {
        UCHAR IrqNumber:3;
        UCHAR Sbz:2;
        UCHAR EoiMode:3;
    };
    UCHAR Bits;
} I8259_OCW2, *PI8259_OCW2;

typedef union _I8259_OCW3
{
    struct
    {
        UCHAR ReadRequest:2;
        UCHAR PollCommand:1;
        UCHAR Sbo:1;
        UCHAR Sbz:1;
        UCHAR SpecialMaskMode:2;
        UCHAR Reserved:1;
    };
    UCHAR Bits;
} I8259_OCW3, *PI8259_OCW3;

typedef union _I8259_ISR
{
    struct
    {
        UCHAR Irq0:1;
        UCHAR Irq1:1;
        UCHAR Irq2:1;
        UCHAR Irq3:1;
        UCHAR Irq4:1;
        UCHAR Irq5:1;
        UCHAR Irq6:1;
        UCHAR Irq7:1;
    };
    UCHAR Bits;
} I8259_ISR, *PI8259_ISR;

typedef I8259_ISR I8259_IDR, *PI8259_IDR;

/*
 * NESA Edge/Level Triggered Register
 */
#define EISA_ELCR_MASTER       0x98D2
#define EISA_ELCR_SLAVE        0x98D4

typedef union _EISA_ELCR
{
    struct
    {
        struct
        {
            UCHAR Irq0Level:1;
            UCHAR Irq1Level:1;
            UCHAR Irq2Level:1;
            UCHAR Irq3Level:1;
            UCHAR Irq4Level:1;
            UCHAR Irq5Level:1;
            UCHAR Irq6Level:1;
            UCHAR Irq7Level:1;
        } Master;
        struct
        {
            UCHAR Irq8Level:1;
            UCHAR Irq9Level:1;
            UCHAR Irq10Level:1;
            UCHAR Irq11Level:1;
            UCHAR Irq12Level:1;
            UCHAR Irq13Level:1;
            UCHAR Irq14Level:1;
            UCHAR Irq15Level:1;
        } Slave;
    };
    USHORT Bits;
} EISA_ELCR, *PEISA_ELCR;

typedef union _PIC_MASK
{
    struct
    {
        UCHAR Master;
        UCHAR Slave;
    };
    USHORT Both;
} PIC_MASK, *PPIC_MASK;