mirror of https://gitee.com/openkylin/linux.git
40 lines
938 B
C
40 lines
938 B
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
// Copyright (C) 2005-2017 Andes Technology Corporation
|
|
|
|
#ifndef __NDS32_DELAY_H__
|
|
#define __NDS32_DELAY_H__
|
|
|
|
#include <asm/param.h>
|
|
|
|
/* There is no clocksource cycle counter in the CPU. */
|
|
static inline void __delay(unsigned long loops)
|
|
{
|
|
__asm__ __volatile__(".align 2\n"
|
|
"1:\n"
|
|
"\taddi\t%0, %0, -1\n"
|
|
"\tbgtz\t%0, 1b\n"
|
|
:"=r"(loops)
|
|
:"0"(loops));
|
|
}
|
|
|
|
static inline void __udelay(unsigned long usecs, unsigned long lpj)
|
|
{
|
|
usecs *= (unsigned long)(((0x8000000000000000ULL / (500000 / HZ)) +
|
|
0x80000000ULL) >> 32);
|
|
usecs = (unsigned long)(((unsigned long long)usecs * lpj) >> 32);
|
|
__delay(usecs);
|
|
}
|
|
|
|
#define udelay(usecs) __udelay((usecs), loops_per_jiffy)
|
|
|
|
/* make sure "usecs *= ..." in udelay do not overflow. */
|
|
#if HZ >= 1000
|
|
#define MAX_UDELAY_MS 1
|
|
#elif HZ <= 200
|
|
#define MAX_UDELAY_MS 5
|
|
#else
|
|
#define MAX_UDELAY_MS (1000 / HZ)
|
|
#endif
|
|
|
|
#endif
|