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
  32 int timer_inited;
  33 ulong timer_ticks;
  34
  35 int 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
  49 void 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
  59 void reset_timer(void)
  60 {
  61         reset_timer_masked();
  62 }
  63
  64 ulong 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
  75 ulong get_timer(ulong base)
  76 {
  77        return (get_timer_masked() - base);
  78 }
  79
  80 void set_timer(ulong t)
  81 {
  82         timer_ticks = t;
  83 }
  84
  85 void 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
  99 void 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 }