xref: /openbmc/u-boot/arch/powerpc/lib/interrupts.c (revision b24a8ec1)
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_msr (void)
37 {
38 	unsigned long msr;
39 
40 	asm volatile ("mfmsr %0":"=r" (msr):);
41 
42 	return msr;
43 }
44 
45 static __inline__ void set_msr (unsigned long msr)
46 {
47 	asm volatile ("mtmsr %0"::"r" (msr));
48 }
49 
50 static __inline__ unsigned long get_dec (void)
51 {
52 	unsigned long val;
53 
54 	asm volatile ("mfdec %0":"=r" (val):);
55 
56 	return val;
57 }
58 
59 
60 static __inline__ void set_dec (unsigned long val)
61 {
62 	if (val)
63 		asm volatile ("mtdec %0"::"r" (val));
64 }
65 
66 
67 void enable_interrupts (void)
68 {
69 	set_msr (get_msr () | MSR_EE);
70 }
71 
72 /* returns flag if MSR_EE was set before */
73 int disable_interrupts (void)
74 {
75 	ulong msr = get_msr ();
76 
77 	set_msr (msr & ~MSR_EE);
78 	return ((msr & MSR_EE) != 0);
79 }
80 
81 int interrupt_init (void)
82 {
83 	int ret;
84 
85 	/* call cpu specific function from $(CPU)/interrupts.c */
86 	ret = interrupt_init_cpu (&decrementer_count);
87 
88 	if (ret)
89 		return ret;
90 
91 	set_dec (decrementer_count);
92 
93 	set_msr (get_msr () | MSR_EE);
94 
95 	return (0);
96 }
97 
98 static volatile ulong timestamp = 0;
99 
100 void timer_interrupt (struct pt_regs *regs)
101 {
102 	/* call cpu specific function from $(CPU)/interrupts.c */
103 	timer_interrupt_cpu (regs);
104 
105 	/* Restore Decrementer Count */
106 	set_dec (decrementer_count);
107 
108 	timestamp++;
109 
110 #if defined(CONFIG_WATCHDOG) || defined (CONFIG_HW_WATCHDOG)
111 	if ((timestamp % (CONFIG_SYS_WATCHDOG_FREQ)) == 0)
112 		WATCHDOG_RESET ();
113 #endif    /* CONFIG_WATCHDOG || CONFIG_HW_WATCHDOG */
114 
115 #ifdef CONFIG_LED_STATUS
116 	status_led_tick (timestamp);
117 #endif /* CONFIG_LED_STATUS */
118 
119 #ifdef CONFIG_SHOW_ACTIVITY
120 	board_show_activity (timestamp);
121 #endif /* CONFIG_SHOW_ACTIVITY */
122 }
123 
124 ulong get_timer (ulong base)
125 {
126 	return (timestamp - base);
127 }
128