xref: /openbmc/u-boot/arch/powerpc/lib/interrupts.c (revision c6af2e7d)
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 ulong get_timer (ulong base)
141 {
142 	return (timestamp - base);
143 }
144