arch/powerpc/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  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include <common.h>
  12 #include <asm/processor.h>
  13 #include <watchdog.h>
  14 #ifdef CONFIG_LED_STATUS
  15 #include <status_led.h>
  16 #endif
  17
  18 #ifdef CONFIG_SHOW_ACTIVITY
  19 void board_show_activity (ulong) __attribute__((weak, alias("__board_show_activity")));
  20
  21 void __board_show_activity (ulong dummy)
  22 {
  23         return;
  24 }
  25 #endif /* CONFIG_SHOW_ACTIVITY */
  26
  27 #ifndef CONFIG_SYS_WATCHDOG_FREQ
  28 #define CONFIG_SYS_WATCHDOG_FREQ (CONFIG_SYS_HZ / 2)
  29 #endif
  30
  31 extern int interrupt_init_cpu (unsigned *);
  32 extern void timer_interrupt_cpu (struct pt_regs *);
  33
  34 static unsigned decrementer_count; /* count value for 1e6/HZ microseconds */
  35
  36 static __inline__ unsigned long get_dec (void)
  37 {
  38         unsigned long val;
  39
  40         asm volatile ("mfdec %0":"=r" (val):);
  41
  42         return val;
  43 }
  44
  45
  46 static __inline__ void set_dec (unsigned long val)
  47 {
  48         if (val)
  49                 asm volatile ("mtdec %0"::"r" (val));
  50 }
  51
  52
  53 void enable_interrupts (void)
  54 {
  55         set_msr (get_msr () | MSR_EE);
  56 }
  57
  58 /* returns flag if MSR_EE was set before */
  59 int disable_interrupts (void)
  60 {
  61         ulong msr = get_msr ();
  62
  63         set_msr (msr & ~MSR_EE);
  64         return ((msr & MSR_EE) != 0);
  65 }
  66
  67 int interrupt_init (void)
  68 {
  69         int ret;
  70
  71         /* call cpu specific function from $(CPU)/interrupts.c */
  72         ret = interrupt_init_cpu (&decrementer_count);
  73
  74         if (ret)
  75                 return ret;
  76
  77         set_dec (decrementer_count);
  78
  79         set_msr (get_msr () | MSR_EE);
  80
  81         return (0);
  82 }
  83
  84 static volatile ulong timestamp = 0;
  85
  86 void timer_interrupt (struct pt_regs *regs)
  87 {
  88         /* call cpu specific function from $(CPU)/interrupts.c */
  89         timer_interrupt_cpu (regs);
  90
  91         /* Restore Decrementer Count */
  92         set_dec (decrementer_count);
  93
  94         timestamp++;
  95
  96 #if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
  97         if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
  98                 WATCHDOG_RESET ();
  99 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
 100
 101 #ifdef CONFIG_LED_STATUS
 102         status_led_tick (timestamp);
 103 #endif /* CONFIG_LED_STATUS */
 104
 105 #ifdef CONFIG_SHOW_ACTIVITY
 106         board_show_activity (timestamp);
 107 #endif /* CONFIG_SHOW_ACTIVITY */
 108 }
 109
 110 ulong get_timer (ulong base)
 111 {
 112         return (timestamp - base);
 113 }