LXR uboot/arch/arm/cpu/arm920t/ks8695/timer.c

   1/*
   2 * (C) Copyright 2004-2005, Greg Ungerer <greg.ungerer@opengear.com>
   3 *
   4 * See file CREDITS for list of people who contributed to this
   5 * project.
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License as
   9 * published by the Free Software Foundation; either version 2 of
  10 * the License, or (at your option) any later version.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License
  18 * along with this program; if not, write to the Free Software
  19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20 * MA 02111-1307 USA
  21 */
  22
  23#include <common.h>
  24#include <asm/arch/platform.h>
  25
  26/*
  27 * Initial timer set constants. Nothing complicated, just set for a 1ms
  28 * tick.
  29 */
  30#define TIMER_INTERVAL  (TICKS_PER_uSEC * mSEC_1)
  31#define TIMER_COUNT     (TIMER_INTERVAL / 2)
  32#define TIMER_PULSE     TIMER_COUNT
  33
  34/*
  35 * Handy KS8695 register access functions.
  36 */
  37#define ks8695_read(a)    *((volatile ulong *) (KS8695_IO_BASE + (a)))
  38#define ks8695_write(a,v) *((volatile ulong *) (KS8695_IO_BASE + (a))) = (v)
  39
  40ulong timer_ticks;
  41
  42int timer_init (void)
  43{
  44        /* Set the hadware timer for 1ms */
  45        ks8695_write(KS8695_TIMER1, TIMER_COUNT);
  46        ks8695_write(KS8695_TIMER1_PCOUNT, TIMER_PULSE);
  47        ks8695_write(KS8695_TIMER_CTRL, 0x2);
  48        timer_ticks = 0;
  49
  50        return 0;
  51}
  52
  53ulong get_timer_masked(void)
  54{
  55        /* Check for timer wrap */
  56        if (ks8695_read(KS8695_INT_STATUS) & KS8695_INTMASK_TIMERINT1) {
  57                /* Clear interrupt condition */
  58                ks8695_write(KS8695_INT_STATUS, KS8695_INTMASK_TIMERINT1);
  59                timer_ticks++;
  60        }
  61        return timer_ticks;
  62}
  63
  64ulong get_timer(ulong base)
  65{
  66       return (get_timer_masked() - base);
  67}
  68
  69void __udelay(ulong usec)
  70{
  71        ulong start = get_timer_masked();
  72        ulong end;
  73
  74        /* Only 1ms resolution :-( */
  75        end = usec / 1000;
  76        while (get_timer(start) < end)
  77                ;
  78}
  79
  80void reset_cpu (ulong ignored)
  81{
  82        ulong tc;
  83
  84        /* Set timer0 to watchdog, and let it timeout */
  85        tc = ks8695_read(KS8695_TIMER_CTRL) & 0x2;
  86        ks8695_write(KS8695_TIMER_CTRL, tc);
  87        ks8695_write(KS8695_TIMER0, ((10 << 8) | 0xff));
  88        ks8695_write(KS8695_TIMER_CTRL, (tc | 0x1));
  89
  90        /* Should only wait here till watchdog resets */
  91        for (;;)
  92                ;
  93}
  94