LXR linux/arch/mips/sgi-ip30/ip30-timer.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * ip30-timer.c: Clocksource/clockevent support for the
   4 *               HEART chip in SGI Octane (IP30) systems.
   5 *
   6 * Copyright (C) 2004-2007 Stanislaw Skowronek <skylark@unaligned.org>
   7 * Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
   8 * Copyright (C) 2011 Joshua Kinard <kumba@gentoo.org>
   9 */
  10
  11#include <linux/clocksource.h>
  12#include <linux/cpumask.h>
  13#include <linux/init.h>
  14#include <linux/kernel.h>
  15#include <linux/percpu.h>
  16#include <linux/sched_clock.h>
  17
  18#include <asm/time.h>
  19#include <asm/cevt-r4k.h>
  20#include <asm/sgi/heart.h>
  21
  22static u64 ip30_heart_counter_read(struct clocksource *cs)
  23{
  24        return heart_read(&heart_regs->count);
  25}
  26
  27struct clocksource ip30_heart_clocksource = {
  28        .name   = "HEART",
  29        .rating = 400,
  30        .read   = ip30_heart_counter_read,
  31        .mask   = CLOCKSOURCE_MASK(52),
  32        .flags  = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
  33};
  34
  35static u64 notrace ip30_heart_read_sched_clock(void)
  36{
  37        return heart_read(&heart_regs->count);
  38}
  39
  40static void __init ip30_heart_clocksource_init(void)
  41{
  42        struct clocksource *cs = &ip30_heart_clocksource;
  43
  44        clocksource_register_hz(cs, HEART_CYCLES_PER_SEC);
  45
  46        sched_clock_register(ip30_heart_read_sched_clock, 52,
  47                             HEART_CYCLES_PER_SEC);
  48}
  49
  50void __init plat_time_init(void)
  51{
  52        int irq = get_c0_compare_int();
  53
  54        cp0_timer_irq_installed = 1;
  55        c0_compare_irqaction.percpu_dev_id = &mips_clockevent_device;
  56        c0_compare_irqaction.flags &= ~IRQF_SHARED;
  57        irq_set_handler(irq, handle_percpu_devid_irq);
  58        irq_set_percpu_devid(irq);
  59        setup_percpu_irq(irq, &c0_compare_irqaction);
  60        enable_percpu_irq(irq, IRQ_TYPE_NONE);
  61
  62        ip30_heart_clocksource_init();
  63}
  64