linux_kernel/arch/mips/pic32/pic32mzda/time.c

/*
 * Joshua Henderson <joshua.henderson@microchip.com>
 * Copyright (C) 2015 Microchip Technology Inc.  All rights reserved.
 *
 *  This program is free software; you can distribute it and/or modify it
 *  under the terms of the GNU General Public License (Version 2) as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 *  for more details.
 */
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/irqdomain.h>

#include <asm/time.h>

#include "pic32mzda.h"

static const struct of_device_id pic32_infra_match[] = {
	{ .compatible = "microchip,pic32mzda-infra", },
	{ },
};

#define DEFAULT_CORE_TIMER_INTERRUPT 0

static unsigned int pic32_xlate_core_timer_irq(void)
{
	static struct device_node *node;
	unsigned int irq;

	node = of_find_matching_node(NULL, pic32_infra_match);

	if (WARN_ON(!node))
		goto default_map;

	irq = irq_of_parse_and_map(node, 0);
	if (!irq)
		goto default_map;

	return irq;

default_map:

	return irq_create_mapping(NULL, DEFAULT_CORE_TIMER_INTERRUPT);
}

unsigned int get_c0_compare_int(void)
{
	return pic32_xlate_core_timer_irq();
}

void __init plat_time_init(void)
{
	struct clk *clk;

	of_clk_init(NULL);
	clk = clk_get_sys("cpu_clk", NULL);
	if (IS_ERR(clk))
		panic("unable to get CPU clock, err=%ld", PTR_ERR(clk));

	clk_prepare_enable(clk);
	pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
	mips_hpt_frequency = clk_get_rate(clk) / 2;

	clocksource_probe();
}