xref: /openbmc/u-boot/arch/nios2/cpu/interrupts.c (revision 1d2c0506)
1 /*
2  * (C) Copyright 2000-2002
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
6  * Scott McNutt <smcnutt@psyent.com>
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <command.h>
13 #include <asm/nios2.h>
14 #include <asm/types.h>
15 #include <asm/io.h>
16 #include <asm/ptrace.h>
17 
18 /*************************************************************************/
19 struct	irq_action {
20 	interrupt_handler_t *handler;
21 	void *arg;
22 	int count;
23 };
24 
25 static struct irq_action vecs[32];
26 
27 int disable_interrupts (void)
28 {
29 	int val = rdctl (CTL_STATUS);
30 	wrctl (CTL_STATUS, val & ~STATUS_IE);
31 	return (val & STATUS_IE);
32 }
33 
34 void enable_interrupts( void )
35 {
36 	int val = rdctl (CTL_STATUS);
37 	wrctl (CTL_STATUS, val | STATUS_IE);
38 }
39 
40 void external_interrupt (struct pt_regs *regs)
41 {
42 	unsigned irqs;
43 	struct irq_action *act;
44 
45 	/* Evaluate only irqs that are both enabled AND pending */
46 	irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING);
47 	act = vecs;
48 
49 	/* Assume (as does the Nios2 HAL) that bit 0 is highest
50 	 * priority. NOTE: There is ALWAYS a handler assigned
51 	 * (the default if no other).
52 	 */
53 	while (irqs) {
54 		if (irqs & 1) {
55 			act->handler (act->arg);
56 			act->count++;
57 		}
58 		irqs >>=1;
59 		act++;
60 	}
61 }
62 
63 static void def_hdlr (void *arg)
64 {
65 	unsigned irqs = rdctl (CTL_IENABLE);
66 
67 	/* Disable the individual interrupt -- with gratuitous
68 	 * warning.
69 	 */
70 	irqs &= ~(1 << (int)arg);
71 	wrctl (CTL_IENABLE, irqs);
72 	printf ("WARNING: Disabling unhandled interrupt: %d\n",
73 			(int)arg);
74 }
75 
76 /*************************************************************************/
77 void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg)
78 {
79 
80 	int flag;
81 	struct irq_action *act;
82 	unsigned ena = rdctl (CTL_IENABLE);
83 
84 	if ((irq < 0) || (irq > 31))
85 		return;
86 	act = &vecs[irq];
87 
88 	flag = disable_interrupts ();
89 	if (hdlr) {
90 		act->handler = hdlr;
91 		act->arg = arg;
92 		ena |= (1 << irq);		/* enable */
93 	} else {
94 		act->handler = def_hdlr;
95 		act->arg = (void *)irq;
96 		ena &= ~(1 << irq);		/* disable */
97 	}
98 	wrctl (CTL_IENABLE, ena);
99 	if (flag) enable_interrupts ();
100 }
101 
102 
103 int interrupt_init (void)
104 {
105 	int i;
106 
107 	/* Assign the default handler to all */
108 	for (i = 0; i < 32; i++) {
109 		vecs[i].handler = def_hdlr;
110 		vecs[i].arg = (void *)i;
111 		vecs[i].count = 0;
112 	}
113 
114 	enable_interrupts ();
115 	return (0);
116 }
117 
118 
119 /*************************************************************************/
120 #if defined(CONFIG_CMD_IRQ)
121 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
122 {
123 	int i;
124 	struct irq_action *act = vecs;
125 
126 	printf ("\nInterrupt-Information:\n\n");
127 	printf ("Nr  Routine   Arg       Count\n");
128 	printf ("-----------------------------\n");
129 
130 	for (i=0; i<32; i++) {
131 		if (act->handler != def_hdlr) {
132 			printf ("%02d  %08lx  %08lx  %d\n",
133 				i,
134 				(ulong)act->handler,
135 				(ulong)act->arg,
136 				act->count);
137 		}
138 		act++;
139 	}
140 	printf ("\n");
141 
142 	return (0);
143 }
144 #endif
145