linux/arch/mips/cobalt/time.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Cobalt time initialization.
   4 *
   5 *  Copyright (C) 2007  Yoichi Yuasa <yuasa@linux-mips.org>
   6 */
   7#include <linux/i8253.h>
   8#include <linux/init.h>
   9
  10#include <asm/gt64120.h>
  11#include <asm/time.h>
  12
  13#define GT641XX_BASE_CLOCK      50000000        /* 50MHz */
  14
  15void __init plat_time_init(void)
  16{
  17        u32 start, end;
  18        int i = HZ / 10;
  19
  20        setup_pit_timer();
  21
  22        gt641xx_set_base_clock(GT641XX_BASE_CLOCK);
  23
  24        /*
  25         * MIPS counter frequency is measured during a 100msec interval
  26         * using GT64111 timer0.
  27         */
  28        while (!gt641xx_timer0_state())
  29                ;
  30
  31        start = read_c0_count();
  32
  33        while (i--)
  34                while (!gt641xx_timer0_state())
  35                        ;
  36
  37        end = read_c0_count();
  38
  39        mips_hpt_frequency = (end - start) * 10;
  40        printk(KERN_INFO "MIPS counter frequency %dHz\n", mips_hpt_frequency);
  41}
  42