/*
 * Copyright (c) 2026, Chloe M.
 * Provided under the BSD-3 clause.
 *
 * Description: IRQ chip management
 * Author:      Chloe M.
 */

#include <drivers/acpi/tables.h>
#include <drivers/acpi/acpi.h>
#include <machine/irqchip.h>
#include <machine/pio.h>
#include <ke/knot.h>
#include <ex/trace.h>

/* PIC data ports */
#define PIC_MASTER_DATA 0x21
#define PIC_SLAVE_DATA  0xA1

#define DTRACE(Fmt, ...) \
    TRACE("[ IRQCHIP ]: " Fmt, ##__VA_ARGS__)

/* Set if dual i8259 is present */
#define MADT_PCAT_COMPAT BIT(0)

VOID
MdIrqChipInit(VOID)
{
    ACPI_MADT *Madt;

    Madt = AcpiQuery("APIC");
    if (Madt == NULL) {
        KeKnot(
            KNOT_UNBOUND_RSRC,
            "could not locate ACPI MADT\n"
        );
    }

    /*
     * If we have a dual-i8259 configuration present on the
     * machine, we'll want to disable it so it doesn't mess
     * up Local APIC operation and such.
     */
    if (ISSET(Madt->Flags, MADT_PCAT_COMPAT)) {
        DTRACE("detected dual i8259; disabling...\n");
        MdOutb(PIC_MASTER_DATA, 0xFF);
        MdOutb(PIC_SLAVE_DATA, 0xFF);
    }
}