aboutsummaryrefslogtreecommitdiffstats
path: root/cpu/nios2/interrupts.c
blob: d0855502cf40b5a508acada361b4c5a5a452bb1b (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
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/*
 * (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>
 *
 * 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 <nios2.h>
#include <nios2-io.h>
#include <asm/io.h>
#include <asm/ptrace.h>
#include <common.h>
#include <command.h>
#include <watchdog.h>
#ifdef CONFIG_STATUS_LED
#include <status_led.h>
#endif

#if defined(CFG_NIOS_TMRBASE) && !defined(CFG_NIOS_TMRIRQ)
#error CFG_NIOS_TMRIRQ not defined (see documentation)
#endif

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

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

static struct irq_action vecs[32];

/*************************************************************************/
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 tmr_isr (void *arg)
{
	nios_timer_t *tmr = (nios_timer_t *)arg;
	/* Interrupt is cleared by writing anything to the
	 * status register.
	 */
	writel (&tmr->status, 0);
	timestamp += CFG_NIOS_TMRMS;
#ifdef CONFIG_STATUS_LED
	status_led_tick(timestamp);
#endif
}

static void tmr_init (void)
{
	nios_timer_t *tmr =(nios_timer_t *)CFG_NIOS_TMRBASE;

	writel (&tmr->status, 0);
	writel (&tmr->control, 0);
	writel (&tmr->control, NIOS_TIMER_STOP);

#if defined(CFG_NIOS_TMRCNT)
	writel (&tmr->periodl, CFG_NIOS_TMRCNT & 0xffff);
	writel (&tmr->periodh, (CFG_NIOS_TMRCNT >> 16) & 0xffff);
#endif
	writel (&tmr->control, NIOS_TIMER_ITO | NIOS_TIMER_CONT |
			  NIOS_TIMER_START );
	irq_install_handler (CFG_NIOS_TMRIRQ, tmr_isr, (void *)tmr);
}

#endif /* CFG_NIOS_TMRBASE */

/*************************************************************************/
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;
	}

#if defined(CFG_NIOS_TMRBASE)
	tmr_init ();
#endif

	enable_interrupts ();
	return (0);
}


/*************************************************************************/
#if (CONFIG_COMMANDS & CFG_CMD_IRQ) || defined(CONFIG_CMD_IRQ)
int do_irqinfo (cmd_tbl_t *cmdtp, int flag, int argc, char *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  /* CONFIG_COMMANDS & CFG_CMD_IRQ */