/*
 * Copyright (c) 2014 Wind River Systems, Inc.
 * Copyright (c) 2020 Synopsys.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @file
 * @brief ARCv2 Interrupt Unit device driver
 *
 * The ARCv2 interrupt unit has 16 allocated exceptions associated with
 * vectors 0 to 15 and 240 interrupts associated with vectors 16 to 255.
 * The interrupt unit is optional in the ARCv2-based processors. When
 * building a processor, you can configure the processor to include an
 * interrupt unit. The ARCv2 interrupt unit is highly programmable.
 */

#include <zephyr/kernel.h>
#include <zephyr/arch/cpu.h>
#include <zephyr/device.h>
#include <zephyr/init.h>

/*
 * @brief Initialize the interrupt unit device driver
 *
 * Initializes the interrupt unit device driver and the device
 * itself.
 *
 * Interrupts are still locked at this point, so there is no need to protect
 * the window between a write to IRQ_SELECT and subsequent writes to the
 * selected IRQ's registers.
 *
 * @return 0 for success
 */
static int arc_v2_irq_unit_init(const struct device *unused)
{
	ARG_UNUSED(unused);
	int irq; /* the interrupt index */

	/* Interrupts from 0 to 15 are exceptions and they are ignored
	 * by IRQ auxiliary registers. For that reason we skip those
	 * values in this loop.
	 */
	for (irq = 16; irq < CONFIG_NUM_IRQS; irq++) {

		z_arc_v2_aux_reg_write(_ARC_V2_IRQ_SELECT, irq);
#ifdef CONFIG_ARC_SECURE_FIRMWARE
		z_arc_v2_aux_reg_write(_ARC_V2_IRQ_PRIORITY,
			 (CONFIG_NUM_IRQ_PRIO_LEVELS-1) |
			 _ARC_V2_IRQ_PRIORITY_SECURE); /* lowest priority */
#else
		z_arc_v2_aux_reg_write(_ARC_V2_IRQ_PRIORITY,
			 (CONFIG_NUM_IRQ_PRIO_LEVELS-1)); /* lowest priority */
#endif
		z_arc_v2_aux_reg_write(_ARC_V2_IRQ_ENABLE, _ARC_V2_INT_DISABLE);
		z_arc_v2_aux_reg_write(_ARC_V2_IRQ_TRIGGER, _ARC_V2_INT_LEVEL);
	}

	return 0;
}

SYS_INIT(arc_v2_irq_unit_init, PRE_KERNEL_1, 0);