arch/ppc/lib/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
  35 void board_show_activity (ulong) __attribute__((weak, alias("__board_show_activity")));
  36
  37 void __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
  47 extern int interrupt_init_cpu (unsigned *);
  48 extern void timer_interrupt_cpu (struct pt_regs *);
  49
  50 static unsigned decrementer_count; /* count value for 1e6/HZ microseconds */
  51
  52 static __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
  61 static __inline__ void set_msr (unsigned long msr)
  62 {
  63         asm volatile ("mtmsr %0"::"r" (msr));
  64 }
  65
  66 static __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
  76 static __inline__ void set_dec (unsigned long val)
  77 {
  78         if (val)
  79                 asm volatile ("mtdec %0"::"r" (val));
  80 }
  81
  82
  83 void enable_interrupts (void)
  84 {
  85         set_msr (get_msr () | MSR_EE);
  86 }
  87
  88 /* returns flag if MSR_EE was set before */
  89 int disable_interrupts (void)
  90 {
  91         ulong msr = get_msr ();
  92
  93         set_msr (msr & ~MSR_EE);
  94         return ((msr & MSR_EE) != 0);
  95 }
  96
  97 int 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
 114 static volatile ulong timestamp = 0;
 115
 116 void 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
 140 void reset_timer (void)
 141 {
 142         timestamp = 0;
 143 }
 144
 145 ulong get_timer (ulong base)
 146 {
 147         return (timestamp - base);
 148 }
 149
 150 void set_timer (ulong t)
 151 {
 152         timestamp = t;
 153 }