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

   1/* SPDX-License-Identifier: GPL-2.0 */
   2// Copyright (C) 2005-2017 Andes Technology Corporation
   3
   4#ifndef __NDS32_DELAY_H__
   5#define __NDS32_DELAY_H__
   6
   7#include <asm/param.h>
   8
   9/* There is no clocksource cycle counter in the CPU. */
  10static inline void __delay(unsigned long loops)
  11{
  12        __asm__ __volatile__(".align 2\n"
  13                             "1:\n"
  14                             "\taddi\t%0, %0, -1\n"
  15                             "\tbgtz\t%0, 1b\n"
  16                             :"=r"(loops)
  17                             :"0"(loops));
  18}
  19
  20static inline void __udelay(unsigned long usecs, unsigned long lpj)
  21{
  22        usecs *= (unsigned long)(((0x8000000000000000ULL / (500000 / HZ)) +
  23                                  0x80000000ULL) >> 32);
  24        usecs = (unsigned long)(((unsigned long long)usecs * lpj) >> 32);
  25        __delay(usecs);
  26}
  27
  28#define udelay(usecs) __udelay((usecs), loops_per_jiffy)
  29
  30/* make sure "usecs *= ..." in udelay do not overflow. */
  31#if HZ >= 1000
  32#define MAX_UDELAY_MS   1
  33#elif HZ <= 200
  34#define MAX_UDELAY_MS   5
  35#else
  36#define MAX_UDELAY_MS   (1000 / HZ)
  37#endif
  38
  39#endif
  40