/*
 * Copyright 2021 Haiku, Inc. All rights reserved.
 * Distributed under the terms of the MIT License.
 */
#include <int.h>
#include <interrupt_controller.h>
#include <kernel.h>
#include <vm/vm.h>

#include "arch_int_gicv2.h"
#include "gicv2_regs.h"

#define GIC_SPI_IRQ_START	32


GICv2InterruptController::GICv2InterruptController(uint32_t gicd_addr, uint32_t gicc_addr)
: InterruptController()
{
	area_id gicd_area = vm_map_physical_memory(B_SYSTEM_TEAM, "intc-gicv2-gicd",
		(void**)&fGicdRegs, B_ANY_KERNEL_ADDRESS, GICD_REG_SIZE,
		B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA,
		gicd_addr ? gicd_addr : GICD_REG_START, false);
	if (gicd_area < 0) {
		panic("not able to map the memory area for gicd\n");
	}

	area_id gicc_area = vm_map_physical_memory(B_SYSTEM_TEAM, "intc-gicv2-gicc",
		(void**)&fGiccRegs, B_ANY_KERNEL_ADDRESS, GICC_REG_SIZE,
		B_KERNEL_READ_AREA | B_KERNEL_WRITE_AREA,
		gicc_addr ? gicc_addr : GICC_REG_START, false);
	if (gicc_area < 0) {
		panic("not able to map the memory area for gicc\n");
	}

	// disable GICD
	fGicdRegs[GICD_REG_CTLR] = 0;

	// disable GICC
	fGiccRegs[GICC_REG_CTLR] = 0;

	// TODO: disable all interrupts
	fGicdRegs[GICD_REG_ICENABLER] = 0xffffffff;
	fGicdRegs[GICD_REG_ICENABLER+1] = 0xffffffff;

	// set PMR and BPR
	fGiccRegs[GICC_REG_PMR] = 0xff;
	fGiccRegs[GICC_REG_BPR] = 0x07;

	// enable GICC
	fGiccRegs[GICC_REG_CTLR] = 0x03;

	// enable GICD
	fGicdRegs[GICD_REG_CTLR] = 0x03;
}


void GICv2InterruptController::EnableInterrupt(int irq)
{
	irq += GIC_SPI_IRQ_START;

	uint32_t ena_reg = GICD_REG_ISENABLER + irq / 32;
	uint32_t ena_val = 1 << (irq % 32);
	fGicdRegs[ena_reg] = ena_val;

	uint32_t prio_reg = GICD_REG_IPRIORITYR + irq / 4;
	uint32_t prio_val = fGicdRegs[prio_reg];
	prio_val |= 0x80 << (irq % 4 * 8);
	fGicdRegs[prio_reg] = prio_val;
}


void GICv2InterruptController::DisableInterrupt(int irq)
{
	irq += GIC_SPI_IRQ_START;
	fGicdRegs[GICD_REG_ICENABLER + irq / 32] = 1 << (irq % 32);
}


void GICv2InterruptController::HandleInterrupt()
{
	uint32_t iar = fGiccRegs[GICC_REG_IAR];
	uint32_t irqnr = iar & 0x3FF;
	if ((irqnr == 1022) || (irqnr == 1023)) {
		dprintf("spurious interrupt\n");
	} else {
		int_io_interrupt_handler(irqnr-GIC_SPI_IRQ_START, true);
	}

	fGiccRegs[GICC_REG_EOIR] = iar;
}