summaryrefslogtreecommitdiff
path: root/cpu/nios/interrupts.c
blob: 48fc81e584882b6c2ccbb4a1efedf71f9a204765 (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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
/*
 * (C) Copyright 2000-2002
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * (C) Copyright 2003, Psyent Corporation <www.psyent.com>
 * Scott McNutt <smcnutt@psyent.com>
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */


#include <nios.h>
#include <nios-io.h>
#include <asm/ptrace.h>
#include <common.h>
#include <command.h>
#include <watchdog.h>
#ifdef CONFIG_STATUS_LED
#include <status_led.h>
#endif

/****************************************************************************/

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

static struct irq_action irq_vecs[64];

/*************************************************************************/
volatile ulong timestamp = 0;

void reset_timer (void)
{
	timestamp = 0;
}

ulong get_timer (ulong base)
{
	WATCHDOG_RESET ();
	return (timestamp - base);
}

void set_timer (ulong t)
{
	timestamp = t;
}


/* The board must handle this interrupt if a timer is not
 * provided.
 */
#if defined(CFG_NIOS_TMRBASE)
void timer_interrupt (struct pt_regs *regs)
{
	/* Interrupt is cleared by writing anything to the
	 * status register.
	 */
	nios_timer_t *tmr = (nios_timer_t *)CFG_NIOS_TMRBASE;
	tmr->status = 0;
	timestamp += CFG_NIOS_TMRMS;
#ifdef CONFIG_STATUS_LED
	status_led_tick(timestamp);
#endif
}
#endif

/*************************************************************************/
int disable_interrupts (void)
{
	int val = 0;

	/* Writing anything to CLR_IE disables interrupts */
	val = rdctl (CTL_STATUS);
	wrctl (CTL_CLR_IE, 0);
	return (val & STATUS_IE);
}

void enable_interrupts( void )
{
	/* Writing anything SET_IE enables interrupts */
	wrctl (CTL_SET_IE, 0);
}

void external_interrupt (struct pt_regs *regs)
{
	unsigned vec;

	vec = (regs->status & STATUS_IPRI) >> 9;	/* ipri */

	irq_vecs[vec].count++;
	if (irq_vecs[vec].handler != NULL) {
		(*irq_vecs[vec].handler)(irq_vecs[vec].arg);
	} else {
		/* A sad side-effect of masking a bogus interrupt is
		 * that lower priority interrupts will also be disabled.
		 * This is probably not what we want ... so hang insted.
		 */
		printf ("Unhandled interrupt: 0x%x\n", vec);
		disable_interrupts ();
		hang ();
	}
}

/*************************************************************************/
int interrupt_init (void)
{
	int vec;

#if defined(CFG_NIOS_TMRBASE)
	nios_timer_t *tmr = (nios_timer_t *)CFG_NIOS_TMRBASE;

	tmr->control &= ~NIOS_TIMER_ITO;
	tmr->control |= NIOS_TIMER_STOP;
#if defined(CFG_NIOS_TMRCNT)
	tmr->periodl = CFG_NIOS_TMRCNT & 0xffff;
	tmr->periodh = (CFG_NIOS_TMRCNT >> 16) & 0xffff;
#endif
#endif

	for (vec=0; vec<64; vec++ ) {
		irq_vecs[vec].handler = NULL;
		irq_vecs[vec].arg = NULL;
		irq_vecs[vec].count = 0;
	}

	/* Need timus interruptus -- start the lopri timer */
#if defined(CFG_NIOS_TMRBASE)
	tmr->control |= ( NIOS_TIMER_ITO |
			  NIOS_TIMER_CONT |
			  NIOS_TIMER_START );
	ipri (CFG_NIOS_TMRIRQ + 1);
#endif
	enable_interrupts ();
	return (0);
}

void irq_install_handler (int vec, interrupt_handler_t *handler, void *arg)
{
	struct irq_action *irqa = irq_vecs;
	int   i = vec;
	int flag;

	if (irqa[i].handler != NULL) {
		printf ("Interrupt vector %d: handler 0x%x "
			"replacing 0x%x\n",
			vec, (uint)handler, (uint)irqa[i].handler);
	}

	flag = disable_interrupts ();
	irqa[i].handler = handler;
	irqa[i].arg = arg;
	if (flag )
		enable_interrupts ();
}

/*************************************************************************/
#if (CONFIG_COMMANDS & CFG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int vec;

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

	for (vec=0; vec<64; vec++) {
		if (irq_vecs[vec].handler != NULL) {
			printf ("%02d  %08lx  %08lx  %d\n",
				vec,
				(ulong)irq_vecs[vec].handler<<1,
				(ulong)irq_vecs[vec].arg,
				irq_vecs[vec].count);
		}
	}

	return (0);
}
#endif  /* CONFIG_COMMANDS & CFG_CMD_IRQ */