LXR uboot/cpu/arm920t/ks8695/interrupts.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 * Handy KS8695 register access functions.
  28 */
  29#define ks8695_read(a)    *((volatile ulong *) (KS8695_IO_BASE + (a)))
  30#define ks8695_write(a,v) *((volatile ulong *) (KS8695_IO_BASE + (a))) = (v)
  31
  32int timer_inited;
  33ulong timer_ticks;
  34
  35int interrupt_init (void)
  36{
  37        /* nothing happens here - we don't setup any IRQs */
  38        return (0);
  39}
  40
  41/*
  42 * Initial timer set constants. Nothing complicated, just set for a 1ms
  43 * tick.
  44 */
  45#define TIMER_INTERVAL  (TICKS_PER_uSEC * mSEC_1)
  46#define TIMER_COUNT     (TIMER_INTERVAL / 2)
  47#define TIMER_PULSE     TIMER_COUNT
  48
  49void reset_timer_masked(void)
  50{
  51        /* Set the hadware timer for 1ms */
  52        ks8695_write(KS8695_TIMER1, TIMER_COUNT);
  53        ks8695_write(KS8695_TIMER1_PCOUNT, TIMER_PULSE);
  54        ks8695_write(KS8695_TIMER_CTRL, 0x2);
  55        timer_ticks = 0;
  56        timer_inited++;
  57}
  58
  59void reset_timer(void)
  60{
  61        reset_timer_masked();
  62}
  63
  64ulong get_timer_masked(void)
  65{
  66        /* Check for timer wrap */
  67        if (ks8695_read(KS8695_INT_STATUS) & KS8695_INTMASK_TIMERINT1) {
  68                /* Clear interrupt condition */
  69                ks8695_write(KS8695_INT_STATUS, KS8695_INTMASK_TIMERINT1);
  70                timer_ticks++;
  71        }
  72        return timer_ticks;
  73}
  74
  75ulong get_timer(ulong base)
  76{
  77       return (get_timer_masked() - base);
  78}
  79
  80void set_timer(ulong t)
  81{
  82        timer_ticks = t;
  83}
  84
  85void udelay(ulong usec)
  86{
  87        ulong start = get_timer_masked();
  88        ulong end;
  89
  90        if (!timer_inited)
  91                reset_timer();
  92
  93        /* Only 1ms resolution :-( */
  94        end = usec / 1000;
  95        while (get_timer(start) < end)
  96                ;
  97}
  98
  99void reset_cpu (ulong ignored)
 100{
 101        ulong tc;
 102
 103        /* Set timer0 to watchdog, and let it timeout */
 104        tc = ks8695_read(KS8695_TIMER_CTRL) & 0x2;
 105        ks8695_write(KS8695_TIMER_CTRL, tc);
 106        ks8695_write(KS8695_TIMER0, ((10 << 8) | 0xff));
 107        ks8695_write(KS8695_TIMER_CTRL, (tc | 0x1));
 108
 109        /* Should only wait here till watchdog resets */
 110        for (;;)
 111                ;
 112}
 113