linuxdebug/arch/arm/mach-shmobile/timer.c

42 lines
853 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* SH-Mobile Timer
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2002 - 2009 Paul Mundt
*/
#include <linux/platform_device.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/of_address.h>
#include "common.h"
void __init shmobile_init_delay(void)
{
struct device_node *np;
u32 max_freq = 0;
for_each_of_cpu_node(np) {
u32 freq;
if (!of_property_read_u32(np, "clock-frequency", &freq))
max_freq = max(max_freq, freq);
}
if (!max_freq)
return;
/*
* Calculate a worst-case loops-per-jiffy value
* based on maximum cpu core hz setting and the
* __delay() implementation in arch/arm/lib/delay.S.
*
* This will result in a longer delay than expected
* when the cpu core runs on lower frequencies.
*/
if (!preset_lpj)
preset_lpj = max_freq / HZ;
}