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 <command.h>
11#include <irq_func.h>
12#include <asm/nios2.h>
13#include <asm/types.h>
14#include <asm/io.h>
15#include <asm/ptrace.h>
16
17/*************************************************************************/
18struct	irq_action {
19	interrupt_handler_t *handler;
20	void *arg;
21	int count;
22};
23
24static struct irq_action vecs[32];
25
26int disable_interrupts(void)
27{
28	int val = rdctl (CTL_STATUS);
29	wrctl (CTL_STATUS, val & ~STATUS_IE);
30	return (val & STATUS_IE);
31}
32
33void enable_interrupts( void )
34{
35	int val = rdctl (CTL_STATUS);
36	wrctl (CTL_STATUS, val | STATUS_IE);
37}
38
39void 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
62static 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/*************************************************************************/
76void 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
102int 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)
120int do_irqinfo(struct cmd_tbl *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