mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
54 lines
1.3 KiB
54 lines
1.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Carsten Langgaard, [email protected] |
|
* 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); |
|
}
|
|
|