/* Copyright (C) 2021,2022 fef <owo@fef.moe>.  All rights reserved. */

#include <arch/irq.h>

#include <gay/config.h>
#include <gay/errno.h>
#include <gay/irq.h>
#include <gay/kprintf.h>

void (*irq_table[NUM_IRQ])(void);

#if CFG_DEBUG_IRQ
	/*
	 * If CFG_DEBUG_IRQ is set, the IRQ entry points pass the IRQ number
	 * as an argument to the IRQ handler (see arch/<arch>/sys/irq.S).
	 */
	static void do_unknown_irq(unsigned int number)
	{
		kprintf("Unknown IRQ %d encountered!\n", number);
	}
#	define UNKNOWN_IRQ_HANDLER ((void (*)(void))do_unknown_irq)
#else
	static void do_unknown_irq(void)
	{
		kprintf("Unknown IRQ encountered!\n");
	}
#	define UNKNOWN_IRQ_HANDLER (do_unknown_irq)
#endif

void irq_init(void)
{
	for (unsigned int i = 0; i < NUM_IRQ; i++)
		irq_table[i] = UNKNOWN_IRQ_HANDLER;
	arch_irq_init();
}

int irq_enable(unsigned int number)
{
	if (number >= NUM_IRQ)
		return -ERANGE;
	if (irq_table[number] == UNKNOWN_IRQ_HANDLER)
		return -ENOENT;

	arch_irq_enable(number);
	return 0;
}

void irq_disable(unsigned int number)
{
	if (number < NUM_IRQ)
		arch_irq_disable(number);
}

int irq_attach(unsigned int number, void (*handler)(void))
{
	if (number >= NUM_IRQ)
		return -ERANGE;
	if (irq_table[number] != UNKNOWN_IRQ_HANDLER)
		return -EEXIST;

	irq_table[number] = handler;
	return 0;
}

void irq_detach(unsigned int number)
{
	if (number < NUM_IRQ)
		irq_table[number] = UNKNOWN_IRQ_HANDLER;
}