xref: /openbmc/u-boot/arch/nios2/cpu/interrupts.c (revision cbd2fba1)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2000-2002
4  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5  *
6  * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
7  * Scott McNutt <smcnutt@psyent.com>
8  */
9 
10 #include <common.h>
11 #include <command.h>
12 #include <asm/nios2.h>
13 #include <asm/types.h>
14 #include <asm/io.h>
15 #include <asm/ptrace.h>
16 
17 /*************************************************************************/
18 struct	irq_action {
19 	interrupt_handler_t *handler;
20 	void *arg;
21 	int count;
22 };
23 
24 static struct irq_action vecs[32];
25 
26 int disable_interrupts (void)
27 {
28 	int val = rdctl (CTL_STATUS);
29 	wrctl (CTL_STATUS, val & ~STATUS_IE);
30 	return (val & STATUS_IE);
31 }
32 
33 void enable_interrupts( void )
34 {
35 	int val = rdctl (CTL_STATUS);
36 	wrctl (CTL_STATUS, val | STATUS_IE);
37 }
38 
39 void external_interrupt (struct pt_regs *regs)
40 {
41 	unsigned irqs;
42 	struct irq_action *act;
43 
44 	/* Evaluate only irqs that are both enabled AND pending */
45 	irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING);
46 	act = vecs;
47 
48 	/* Assume (as does the Nios2 HAL) that bit 0 is highest
49 	 * priority. NOTE: There is ALWAYS a handler assigned
50 	 * (the default if no other).
51 	 */
52 	while (irqs) {
53 		if (irqs & 1) {
54 			act->handler (act->arg);
55 			act->count++;
56 		}
57 		irqs >>=1;
58 		act++;
59 	}
60 }
61 
62 static void def_hdlr (void *arg)
63 {
64 	unsigned irqs = rdctl (CTL_IENABLE);
65 
66 	/* Disable the individual interrupt -- with gratuitous
67 	 * warning.
68 	 */
69 	irqs &= ~(1 << (int)arg);
70 	wrctl (CTL_IENABLE, irqs);
71 	printf ("WARNING: Disabling unhandled interrupt: %d\n",
72 			(int)arg);
73 }
74 
75 /*************************************************************************/
76 void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg)
77 {
78 
79 	int flag;
80 	struct irq_action *act;
81 	unsigned ena = rdctl (CTL_IENABLE);
82 
83 	if ((irq < 0) || (irq > 31))
84 		return;
85 	act = &vecs[irq];
86 
87 	flag = disable_interrupts ();
88 	if (hdlr) {
89 		act->handler = hdlr;
90 		act->arg = arg;
91 		ena |= (1 << irq);		/* enable */
92 	} else {
93 		act->handler = def_hdlr;
94 		act->arg = (void *)irq;
95 		ena &= ~(1 << irq);		/* disable */
96 	}
97 	wrctl (CTL_IENABLE, ena);
98 	if (flag) enable_interrupts ();
99 }
100 
101 
102 int interrupt_init (void)
103 {
104 	int i;
105 
106 	/* Assign the default handler to all */
107 	for (i = 0; i < 32; i++) {
108 		vecs[i].handler = def_hdlr;
109 		vecs[i].arg = (void *)i;
110 		vecs[i].count = 0;
111 	}
112 
113 	enable_interrupts ();
114 	return (0);
115 }
116 
117 
118 /*************************************************************************/
119 #if defined(CONFIG_CMD_IRQ)
120 int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
121 {
122 	int i;
123 	struct irq_action *act = vecs;
124 
125 	printf ("\nInterrupt-Information:\n\n");
126 	printf ("Nr  Routine   Arg       Count\n");
127 	printf ("-----------------------------\n");
128 
129 	for (i=0; i<32; i++) {
130 		if (act->handler != def_hdlr) {
131 			printf ("%02d  %08lx  %08lx  %d\n",
132 				i,
133 				(ulong)act->handler,
134 				(ulong)act->arg,
135 				act->count);
136 		}
137 		act++;
138 	}
139 	printf ("\n");
140 
141 	return (0);
142 }
143 #endif
144