linux/arch/csky/lib/delay.c
Guo Ren c5af58b769 csky: Library functions
This patch adds string optimize codes and some auxiliary codes.

Signed-off-by: Chen Linfei <linfei_chen@c-sky.com>
Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2018-10-26 00:54:24 +08:00

40 lines
812 B
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
void __delay(unsigned long loops)
{
asm volatile (
"mov r0, r0\n"
"1:declt %0\n"
"bf 1b"
: "=r"(loops)
: "0"(loops));
}
EXPORT_SYMBOL(__delay);
void __const_udelay(unsigned long xloops)
{
unsigned long long loops;
loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
__delay(loops >> 32);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
}
EXPORT_SYMBOL(__ndelay);