// SPDX-License-Identifier: GPL-2.0-only /* * Carsten Langgaard, carstenl@mips.com * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. * * Setting up the clock on the MIPS boards. */ #include <linux/init.h> #include <linux/kernel_stat.h> #include <linux/ptrace.h> #include <linux/sched.h> #include <linux/spinlock.h> #include <linux/mc146818rtc.h> #include <linux/irq.h> #include <linux/timex.h> #include <asm/mipsregs.h> #include <asm/time.h> #include <asm/mach-rc32434/rc32434.h> extern unsigned int idt_cpu_freq; /* * Figure out the r4k offset, the amount to increment the compare * register for each time tick. There is no RTC available. * * The RC32434 counts at half the CPU *core* speed. */ static unsigned long __init cal_r4koff(void) { mips_hpt_frequency = idt_cpu_freq * IDT_CLOCK_MULT / 2; return mips_hpt_frequency / HZ; } void __init plat_time_init(void) { unsigned int est_freq; unsigned long flags, r4k_offset; local_irq_save(flags); printk(KERN_INFO "calculating r4koff... "); r4k_offset = cal_r4koff(); printk("%08lx(%d)\n", r4k_offset, (int) r4k_offset); est_freq = 2 * r4k_offset * HZ; est_freq += 5000; /* round */ est_freq -= est_freq % 10000; printk(KERN_INFO "CPU frequency %d.%02d MHz\n", est_freq / 1000000, (est_freq % 1000000) * 100 / 1000000); local_irq_restore(flags); }