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 #ifndef CONFIG_JzRISC
  27
  28 static inline void mips_compare_set(u32 v)
  29 {
  30         asm volatile ("mtc0 %0, $11" : : "r" (v));
  31 }
  32
  33 static inline void mips_count_set(u32 v)
  34 {
  35         asm volatile ("mtc0 %0, $9" : : "r" (v));
  36 }
  37
  38
  39 static inline u32 mips_count_get(void)
  40 {
  41         u32 count;
  42
  43         asm volatile ("mfc0 %0, $9" : "=r" (count) :);
  44         return count;
  45 }
  46
  47 /*
  48  * timer without interrupts
  49  */
  50
  51 int timer_init(void)
  52 {
  53         mips_compare_set(0);
  54         mips_count_set(0);
  55
  56         return 0;
  57 }
  58
  59 void reset_timer(void)
  60 {
  61         mips_count_set(0);
  62 }
  63
  64 ulong get_timer(ulong base)
  65 {
  66         return mips_count_get() - base;
  67 }
  68
  69 void set_timer(ulong t)
  70 {
  71         mips_count_set(t);
  72 }
  73
  74 void udelay (unsigned long usec)
  75 {
  76         ulong tmo;
  77         ulong start = get_timer(0);
  78
  79         tmo = usec * (CFG_HZ / 1000000);
  80         while ((ulong)((mips_count_get() - start)) < tmo)
  81                 /*NOP*/;
  82 }
  83
  84 /*
  85  * This function is derived from PowerPC code (read timebase as long long).
  86  * On MIPS it just returns the timer value.
  87  */
  88 unsigned long long get_ticks(void)
  89 {
  90         return mips_count_get();
  91 }
  92
  93 /*
  94  * This function is derived from PowerPC code (timebase clock frequency).
  95  * On MIPS it returns the number of timer ticks per second.
  96  */
  97 ulong get_tbclk(void)
  98 {
  99         return CFG_HZ;
 100 }
 101
 102 #endif /* !CONFIG_JzRISC */