release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/lib/delay.c

   1 /*
   2  *      Precise Delay Loops for SuperH
   3  *
   4  *      Copyright (C) 1999 Niibe Yutaka & Kaz Kojima
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/delay.h>
   9
  10 void __delay(unsigned long loops)
  11 {
  12         __asm__ __volatile__(
  13                 "tst    %0, %0\n\t"
  14                 "1:\t"
  15                 "bf/s   1b\n\t"
  16                 " dt    %0"
  17                 : "=r" (loops)
  18                 : "0" (loops)
  19                 : "t");
  20 }
  21
  22 inline void __const_udelay(unsigned long xloops)
  23 {
  24         xloops *= 4;
  25         __asm__("dmulu.l        %0, %2\n\t"
  26                 "sts    mach, %0"
  27                 : "=r" (xloops)
  28                 : "0" (xloops),
  29                   "r" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4))
  30                 : "macl", "mach");
  31         __delay(++xloops);
  32 }
  33
  34 void __udelay(unsigned long usecs)
  35 {
  36         __const_udelay(usecs * 0x000010c6);  /* 2**32 / 1000000 */
  37 }
  38
  39 void __ndelay(unsigned long nsecs)
  40 {
  41         __const_udelay(nsecs * 0x00000005);
  42 }