summaryrefslogtreecommitdiff
path: root/arch/nios2/cpu/interrupts.c
blob: 9d85eb03a6e813f6def8463dc5597f87387e9e55 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
/*
 * (C) Copyright 2000-2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2004, Psyent Corporation <www.psyent.com>
 * Scott McNutt <smcnutt@psyent.com>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <asm/nios2.h>
#include <asm/types.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <common.h>
#include <command.h>

/*************************************************************************/
struct	irq_action {
	interrupt_handler_t *handler;
	void *arg;
	int count;
};

static struct irq_action vecs[32];

int disable_interrupts (void)
{
	int val = rdctl (CTL_STATUS);
	wrctl (CTL_STATUS, val & ~STATUS_IE);
	return (val & STATUS_IE);
}

void enable_interrupts( void )
{
	int val = rdctl (CTL_STATUS);
	wrctl (CTL_STATUS, val | STATUS_IE);
}

void external_interrupt (struct pt_regs *regs)
{
	unsigned irqs;
	struct irq_action *act;

	/* Evaluate only irqs that are both enabled AND pending */
	irqs = rdctl (CTL_IENABLE) & rdctl (CTL_IPENDING);
	act = vecs;

	/* Assume (as does the Nios2 HAL) that bit 0 is highest
	 * priority. NOTE: There is ALWAYS a handler assigned
	 * (the default if no other).
	 */
	while (irqs) {
		if (irqs & 1) {
			act->handler (act->arg);
			act->count++;
		}
		irqs >>=1;
		act++;
	}
}

static void def_hdlr (void *arg)
{
	unsigned irqs = rdctl (CTL_IENABLE);

	/* Disable the individual interrupt -- with gratuitous
	 * warning.
	 */
	irqs &= ~(1 << (int)arg);
	wrctl (CTL_IENABLE, irqs);
	printf ("WARNING: Disabling unhandled interrupt: %d\n",
			(int)arg);
}

/*************************************************************************/
void irq_install_handler (int irq, interrupt_handler_t *hdlr, void *arg)
{

	int flag;
	struct irq_action *act;
	unsigned ena = rdctl (CTL_IENABLE);

	if ((irq < 0) || (irq > 31))
		return;
	act = &vecs[irq];

	flag = disable_interrupts ();
	if (hdlr) {
		act->handler = hdlr;
		act->arg = arg;
		ena |= (1 << irq);		/* enable */
	} else {
		act->handler = def_hdlr;
		act->arg = (void *)irq;
		ena &= ~(1 << irq);		/* disable */
	}
	wrctl (CTL_IENABLE, ena);
	if (flag) enable_interrupts ();
}


int interrupt_init (void)
{
	int i;

	/* Assign the default handler to all */
	for (i = 0; i < 32; i++) {
		vecs[i].handler = def_hdlr;
		vecs[i].arg = (void *)i;
		vecs[i].count = 0;
	}

	enable_interrupts ();
	return (0);
}


/*************************************************************************/
#if defined(CONFIG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	int i;
	struct irq_action *act = vecs;

	printf ("\nInterrupt-Information:\n\n");
	printf ("Nr  Routine   Arg       Count\n");
	printf ("-----------------------------\n");

	for (i=0; i<32; i++) {
		if (act->handler != def_hdlr) {
			printf ("%02d  %08lx  %08lx  %d\n",
				i,
				(ulong)act->handler,
				(ulong)act->arg,
				act->count);
		}
		act++;
	}
	printf ("\n");

	return (0);
}
#endif