linux/arch/nds32/include/asm/delay.h

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