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 #include <asm/mipsregs.h>
  26
  27 /*
  28  * timer without interrupts
  29  */
  30
  31 int timer_init(void)
  32 {
  33         write_c0_compare(0);
  34         write_c0_count(0);
  35
  36         return 0;
  37 }
  38
  39 void reset_timer(void)
  40 {
  41         write_c0_count(0);
  42 }
  43
  44 ulong get_timer(ulong base)
  45 {
  46         return read_c0_count() - base;
  47 }
  48
  49 void set_timer(ulong t)
  50 {
  51         write_c0_count(t);
  52 }
  53
  54 void udelay (unsigned long usec)
  55 {
  56         ulong tmo;
  57         ulong start = get_timer(0);
  58
  59         tmo = usec * (CFG_HZ / 1000000);
  60         while ((ulong)((read_c0_count() - start)) < tmo)
  61                 /*NOP*/;
  62 }
  63
  64 /*
  65  * This function is derived from PowerPC code (read timebase as long long).
  66  * On MIPS it just returns the timer value.
  67  */
  68 unsigned long long get_ticks(void)
  69 {
  70         return read_c0_count();
  71 }
  72
  73 /*
  74  * This function is derived from PowerPC code (timebase clock frequency).
  75  * On MIPS it returns the number of timer ticks per second.
  76  */
  77 ulong get_tbclk(void)
  78 {
  79         return CFG_HZ;
  80 }