arch/arm/cpu/arm920t/imx/timer.c

   1 /*
   2  * (C) Copyright 2002
   3  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   4  * Marius Groeger <mgroeger@sysgo.de>
   5  *
   6  * (C) Copyright 2002
   7  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   8  * Alex Zuepke <azu@sysgo.de>
   9  *
  10  * (C) Copyright 2002
  11  * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
  12  *
  13  * See file CREDITS for list of people who contributed to this
  14  * project.
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation; either version 2 of
  19  * the License, or (at your option) any later version.
  20  *
  21  * This program is distributed in the hope that it will be useful,
  22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  * GNU General Public License for more details.
  25  *
  26  * You should have received a copy of the GNU General Public License
  27  * along with this program; if not, write to the Free Software
  28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  29  * MA 02111-1307 USA
  30  */
  31
  32 #include <common.h>
  33 #if defined (CONFIG_IMX)
  34
  35 #include <asm/arch/imx-regs.h>
  36
  37 int timer_init (void)
  38 {
  39         int i;
  40         /* setup GP Timer 1 */
  41         TCTL1 = TCTL_SWR;
  42         for ( i=0; i<100; i++) TCTL1 = 0; /* We have no udelay by now */
  43         TPRER1 = get_PERCLK1() / 1000000; /* 1 MHz */
  44         TCTL1 |= TCTL_FRR | (1<<1); /* Freerun Mode, PERCLK1 input */
  45
  46         reset_timer_masked();
  47
  48         return (0);
  49 }
  50
  51 /*
  52  * timer without interrupts
  53  */
  54 ulong get_timer (ulong base)
  55 {
  56         return get_timer_masked() - base;
  57 }
  58
  59 void reset_timer_masked (void)
  60 {
  61         TCTL1 &= ~TCTL_TEN;
  62         TCTL1 |= TCTL_TEN; /* Enable timer */
  63 }
  64
  65 ulong get_timer_masked (void)
  66 {
  67         return TCN1;
  68 }
  69
  70 void udelay_masked (unsigned long usec)
  71 {
  72         ulong endtime = get_timer_masked() + usec;
  73         signed long diff;
  74
  75         do {
  76                 ulong now = get_timer_masked ();
  77                 diff = endtime - now;
  78         } while (diff >= 0);
  79 }
  80
  81 void __udelay (unsigned long usec)
  82 {
  83         udelay_masked(usec);
  84 }
  85
  86 /*
  87  * This function is derived from PowerPC code (read timebase as long long).
  88  * On ARM it just returns the timer value.
  89  */
  90 unsigned long long get_ticks(void)
  91 {
  92         return get_timer(0);
  93 }
  94
  95 /*
  96  * This function is derived from PowerPC code (timebase clock frequency).
  97  * On ARM it returns the number of timer ticks per second.
  98  */
  99 ulong get_tbclk (void)
 100 {
 101         ulong tbclk;
 102
 103         tbclk = CONFIG_SYS_HZ;
 104
 105         return tbclk;
 106 }
 107
 108 /*
 109  * Reset the cpu by setting up the watchdog timer and let him time out
 110  */
 111 void reset_cpu (ulong ignored)
 112 {
 113         /* Disable watchdog and set Time-Out field to 0 */
 114         WCR = 0x00000000;
 115
 116         /* Write Service Sequence */
 117         WSR = 0x00005555;
 118         WSR = 0x0000AAAA;
 119
 120         /* Enable watchdog */
 121         WCR = 0x00000001;
 122
 123         while (1);
 124         /*NOTREACHED*/
 125 }
 126
 127 #endif /* defined (CONFIG_IMX) */