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  * SPDX-License-Identifier:     GPL-2.0+
  14  */
  15
  16 #include <common.h>
  17 #if defined (CONFIG_IMX)
  18
  19 #include <asm/arch/imx-regs.h>
  20
  21 int timer_init (void)
  22 {
  23         int i;
  24         /* setup GP Timer 1 */
  25         TCTL1 = TCTL_SWR;
  26         for ( i=0; i<100; i++) TCTL1 = 0; /* We have no udelay by now */
  27         TPRER1 = get_PERCLK1() / 1000000; /* 1 MHz */
  28         TCTL1 |= TCTL_FRR | (1<<1); /* Freerun Mode, PERCLK1 input */
  29
  30         /* Reset the timer */
  31         TCTL1 &= ~TCTL_TEN;
  32         TCTL1 |= TCTL_TEN; /* Enable timer */
  33
  34         return (0);
  35 }
  36
  37 /*
  38  * timer without interrupts
  39  */
  40 ulong get_timer (ulong base)
  41 {
  42         return get_timer_masked() - base;
  43 }
  44
  45 ulong get_timer_masked (void)
  46 {
  47         return TCN1;
  48 }
  49
  50 void udelay_masked (unsigned long usec)
  51 {
  52         ulong endtime = get_timer_masked() + usec;
  53         signed long diff;
  54
  55         do {
  56                 ulong now = get_timer_masked ();
  57                 diff = endtime - now;
  58         } while (diff >= 0);
  59 }
  60
  61 void __udelay (unsigned long usec)
  62 {
  63         udelay_masked(usec);
  64 }
  65
  66 /*
  67  * This function is derived from PowerPC code (read timebase as long long).
  68  * On ARM it just returns the timer value.
  69  */
  70 unsigned long long get_ticks(void)
  71 {
  72         return get_timer(0);
  73 }
  74
  75 /*
  76  * This function is derived from PowerPC code (timebase clock frequency).
  77  * On ARM it returns the number of timer ticks per second.
  78  */
  79 ulong get_tbclk (void)
  80 {
  81         return CONFIG_SYS_HZ;
  82 }
  83
  84 /*
  85  * Reset the cpu by setting up the watchdog timer and let him time out
  86  */
  87 void reset_cpu (ulong ignored)
  88 {
  89         /* Disable watchdog and set Time-Out field to 0 */
  90         WCR = 0x00000000;
  91
  92         /* Write Service Sequence */
  93         WSR = 0x00005555;
  94         WSR = 0x0000AAAA;
  95
  96         /* Enable watchdog */
  97         WCR = 0x00000001;
  98
  99         while (1);
 100         /*NOTREACHED*/
 101 }
 102
 103 #endif /* defined (CONFIG_IMX) */