LXR uboot/lib_mips/time.c

   1/*
   2 * (C) Copyright 2003
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23
  24#include <common.h>
  25
  26
  27static inline void mips_compare_set(u32 v)
  28{
  29        asm volatile ("mtc0 %0, $11" : : "r" (v));
  30}
  31
  32static inline void mips_count_set(u32 v)
  33{
  34        asm volatile ("mtc0 %0, $9" : : "r" (v));
  35}
  36
  37
  38static inline u32 mips_count_get(void)
  39{
  40        u32 count;
  41
  42        asm volatile ("mfc0 %0, $9" : "=r" (count) :);
  43        return count;
  44}
  45
  46/*
  47 * timer without interrupts
  48 */
  49
  50int timer_init(void)
  51{
  52        mips_compare_set(0);
  53        mips_count_set(0);
  54
  55        return 0;
  56}
  57
  58void reset_timer(void)
  59{
  60        mips_count_set(0);
  61}
  62
  63ulong get_timer(ulong base)
  64{
  65        return mips_count_get() - base;
  66}
  67
  68void set_timer(ulong t)
  69{
  70        mips_count_set(t);
  71}
  72
  73void udelay (unsigned long usec)
  74{
  75        ulong tmo;
  76        ulong start = get_timer(0);
  77
  78        tmo = usec * (CFG_HZ / 1000000);
  79        while ((ulong)((mips_count_get() - start)) < tmo)
  80                /*NOP*/;
  81}
  82
  83/*
  84 * This function is derived from PowerPC code (read timebase as long long).
  85 * On MIPS it just returns the timer value.
  86 */
  87unsigned long long get_ticks(void)
  88{
  89        return mips_count_get();
  90}
  91
  92/*
  93 * This function is derived from PowerPC code (timebase clock frequency).
  94 * On MIPS it returns the number of timer ticks per second.
  95 */
  96ulong get_tbclk(void)
  97{
  98        return CFG_HZ;
  99}
 100