linux-zen-server/arch/mips/sgi-ip30/ip30-timer.c

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2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* ip30-timer.c: Clocksource/clockevent support for the
* HEART chip in SGI Octane (IP30) systems.
*
* Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
* Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
* Copyright (C) 2011 Joshua Kinard <kumba@gentoo.org>
*/
#include <linux/clocksource.h>
#include <linux/cpumask.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/percpu.h>
#include <linux/sched_clock.h>
#include <asm/time.h>
#include <asm/cevt-r4k.h>
#include <asm/sgi/heart.h>
static u64 ip30_heart_counter_read(struct clocksource *cs)
{
return heart_read(&heart_regs->count);
}
struct clocksource ip30_heart_clocksource = {
.name = "HEART",
.rating = 400,
.read = ip30_heart_counter_read,
.mask = CLOCKSOURCE_MASK(52),
.flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
};
static u64 notrace ip30_heart_read_sched_clock(void)
{
return heart_read(&heart_regs->count);
}
static void __init ip30_heart_clocksource_init(void)
{
struct clocksource *cs = &ip30_heart_clocksource;
clocksource_register_hz(cs, HEART_CYCLES_PER_SEC);
sched_clock_register(ip30_heart_read_sched_clock, 52,
HEART_CYCLES_PER_SEC);
}
void __init plat_time_init(void)
{
int irq = get_c0_compare_int();
cp0_timer_irq_installed = 1;
c0_compare_irqaction.percpu_dev_id = &mips_clockevent_device;
c0_compare_irqaction.flags &= ~IRQF_SHARED;
irq_set_handler(irq, handle_percpu_devid_irq);
irq_set_percpu_devid(irq);
setup_percpu_irq(irq, &c0_compare_irqaction);
enable_percpu_irq(irq, IRQ_TYPE_NONE);
ip30_heart_clocksource_init();
}