LXR uboot/lib_ppc/interrupts.c

   1/*
   2 * (C) Copyright 2000-2002
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4 *
   5 * (C) Copyright 2003
   6 * Gleb Natapov <gnatapov@mrv.com>
   7 *
   8 * See file CREDITS for list of people who contributed to this
   9 * project.
  10 *
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public License as
  13 * published by the Free Software Foundation; either version 2 of
  14 * the License, or (at your option) any later version.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 * You should have received a copy of the GNU General Public License
  22 * along with this program; if not, write to the Free Software
  23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  24 * MA 02111-1307 USA
  25 */
  26
  27#include <common.h>
  28#include <asm/processor.h>
  29#include <watchdog.h>
  30#ifdef CONFIG_STATUS_LED
  31#include <status_led.h>
  32#endif
  33
  34#ifdef CONFIG_SHOW_ACTIVITY
  35void board_show_activity (ulong) __attribute__((weak, alias("__board_show_activity")));
  36
  37void __board_show_activity (ulong dummy)
  38{
  39        return;
  40}
  41#endif /* CONFIG_SHOW_ACTIVITY */
  42
  43#ifndef CONFIG_SYS_WATCHDOG_FREQ
  44#define CONFIG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
  45#endif
  46
  47extern int interrupt_init_cpu (unsigned *);
  48extern void timer_interrupt_cpu (struct pt_regs *);
  49
  50static unsigned decrementer_count; /* count value for 1e6/HZ microseconds */
  51
  52static __inline__ unsigned long get_msr (void)
  53{
  54        unsigned long msr;
  55
  56        asm volatile ("mfmsr %0":"=r" (msr):);
  57
  58        return msr;
  59}
  60
  61static __inline__ void set_msr (unsigned long msr)
  62{
  63        asm volatile ("mtmsr %0"::"r" (msr));
  64}
  65
  66static __inline__ unsigned long get_dec (void)
  67{
  68        unsigned long val;
  69
  70        asm volatile ("mfdec %0":"=r" (val):);
  71
  72        return val;
  73}
  74
  75
  76static __inline__ void set_dec (unsigned long val)
  77{
  78        if (val)
  79                asm volatile ("mtdec %0"::"r" (val));
  80}
  81
  82
  83void enable_interrupts (void)
  84{
  85        set_msr (get_msr () | MSR_EE);
  86}
  87
  88/* returns flag if MSR_EE was set before */
  89int disable_interrupts (void)
  90{
  91        ulong msr = get_msr ();
  92
  93        set_msr (msr & ~MSR_EE);
  94        return ((msr & MSR_EE) != 0);
  95}
  96
  97int interrupt_init (void)
  98{
  99        int ret;
 100
 101        /* call cpu specific function from $(CPU)/interrupts.c */
 102        ret = interrupt_init_cpu (&decrementer_count);
 103
 104        if (ret)
 105                return ret;
 106
 107        set_dec (decrementer_count);
 108
 109        set_msr (get_msr () | MSR_EE);
 110
 111        return (0);
 112}
 113
 114static volatile ulong timestamp = 0;
 115
 116void timer_interrupt (struct pt_regs *regs)
 117{
 118        /* call cpu specific function from $(CPU)/interrupts.c */
 119        timer_interrupt_cpu (regs);
 120
 121        /* Restore Decrementer Count */
 122        set_dec (decrementer_count);
 123
 124        timestamp++;
 125
 126#if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
 127        if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
 128                WATCHDOG_RESET ();
 129#endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 130
 131#ifdef CONFIG_STATUS_LED
 132        status_led_tick (timestamp);
 133#endif /* CONFIG_STATUS_LED */
 134
 135#ifdef CONFIG_SHOW_ACTIVITY
 136        board_show_activity (timestamp);
 137#endif /* CONFIG_SHOW_ACTIVITY */
 138}
 139
 140void reset_timer (void)
 141{
 142        timestamp = 0;
 143}
 144
 145ulong get_timer (ulong base)
 146{
 147        return (timestamp - base);
 148}
 149
 150void set_timer (ulong t)
 151{
 152        timestamp = t;
 153}
 154