aboutsummaryrefslogtreecommitdiffstats
path: root/arch/m68k/amiga/cia.c
blob: 7d55682615e3604ffeef19fab1708d4a9bf57ef0 (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
/*
 *  linux/arch/m68k/amiga/cia.c - CIA support
 *
 *  Copyright (C) 1996 Roman Zippel
 *
 *  The concept of some functions bases on the original Amiga OS function
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>

#include <asm/irq.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>

struct ciabase {
	volatile struct CIA *cia;
	unsigned char icr_mask, icr_data;
	unsigned short int_mask;
	int handler_irq, cia_irq, server_irq;
	char *name;
	irq_handler_t irq_list[CIA_IRQS];
} ciaa_base = {
	.cia		= &ciaa,
	.int_mask	= IF_PORTS,
	.handler_irq	= IRQ_AMIGA_AUTO_2,
	.cia_irq	= IRQ_AMIGA_CIAA,
	.server_irq	= IRQ_AMIGA_PORTS,
	.name		= "CIAA handler"
}, ciab_base = {
	.cia		= &ciab,
	.int_mask	= IF_EXTER,
	.handler_irq	= IRQ_AMIGA_AUTO_6,
	.cia_irq	= IRQ_AMIGA_CIAB,
	.server_irq	= IRQ_AMIGA_EXTER,
	.name		= "CIAB handler"
};

/*
 *  Cause or clear CIA interrupts, return old interrupt status.
 */

unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
{
	unsigned char old;

	old = (base->icr_data |= base->cia->icr);
	if (mask & CIA_ICR_SETCLR)
		base->icr_data |= mask;
	else
		base->icr_data &= ~mask;
	if (base->icr_data & base->icr_mask)
		custom.intreq = IF_SETCLR | base->int_mask;
	return old & base->icr_mask;
}

/*
 *  Enable or disable CIA interrupts, return old interrupt mask,
 *  interrupts will only be enabled if a handler exists
 */

unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
{
	unsigned char old, tmp;
	int i;

	old = base->icr_mask;
	base->icr_data |= base->cia->icr;
	base->cia->icr = mask;
	if (mask & CIA_ICR_SETCLR)
		base->icr_mask |= mask;
	else
		base->icr_mask &= ~mask;
	base->icr_mask &= CIA_ICR_ALL;
	for (i = 0, tmp = 1; i < CIA_IRQS; i++, tmp <<= 1) {
		if ((tmp & base->icr_mask) && !base->irq_list[i].handler) {
			base->icr_mask &= ~tmp;
			base->cia->icr = tmp;
		}
	}
	if (base->icr_data & base->icr_mask)
		custom.intreq = IF_SETCLR | base->int_mask;
	return old;
}

int cia_request_irq(struct ciabase *base, unsigned int irq,
                    irqreturn_t (*handler)(int, void *, struct pt_regs *),
                    unsigned long flags, const char *devname, void *dev_id)
{
	unsigned char mask;

	base->irq_list[irq].handler = handler;
	base->irq_list[irq].flags   = flags;
	base->irq_list[irq].dev_id  = dev_id;
	base->irq_list[irq].devname = devname;

	/* enable the interrupt */
	mask = 1 << irq;
	cia_set_irq(base, mask);
	cia_able_irq(base, CIA_ICR_SETCLR | mask);
	return 0;
}

void cia_free_irq(struct ciabase *base, unsigned int irq, void *dev_id)
{
	if (base->irq_list[irq].dev_id != dev_id)
		printk("%s: removing probably wrong IRQ %i from %s\n",
		       __FUNCTION__, base->cia_irq + irq,
		       base->irq_list[irq].devname);

	base->irq_list[irq].handler = NULL;
	base->irq_list[irq].flags   = 0;

	cia_able_irq(base, 1 << irq);
}

static irqreturn_t cia_handler(int irq, void *dev_id, struct pt_regs *fp)
{
	struct ciabase *base = (struct ciabase *)dev_id;
	int mach_irq, i;
	unsigned char ints;

	mach_irq = base->cia_irq;
	irq = SYS_IRQS + mach_irq;
	ints = cia_set_irq(base, CIA_ICR_ALL);
	custom.intreq = base->int_mask;
	for (i = 0; i < CIA_IRQS; i++, irq++, mach_irq++) {
		if (ints & 1) {
			kstat_cpu(0).irqs[irq]++;
			base->irq_list[i].handler(mach_irq, base->irq_list[i].dev_id, fp);
		}
		ints >>= 1;
	}
	amiga_do_irq_list(base->server_irq, fp);
	return IRQ_HANDLED;
}

void __init cia_init_IRQ(struct ciabase *base)
{
	int i;

	/* init isr handlers */
	for (i = 0; i < CIA_IRQS; i++) {
		base->irq_list[i].handler = NULL;
		base->irq_list[i].flags   = 0;
	}

	/* clear any pending interrupt and turn off all interrupts */
	cia_set_irq(base, CIA_ICR_ALL);
	cia_able_irq(base, CIA_ICR_ALL);

	/* install CIA handler */
	request_irq(base->handler_irq, cia_handler, 0, base->name, base);

	custom.intena = IF_SETCLR | base->int_mask;
}

int cia_get_irq_list(struct ciabase *base, struct seq_file *p)
{
	int i, j;

	j = base->cia_irq;
	for (i = 0; i < CIA_IRQS; i++) {
		seq_printf(p, "cia  %2d: %10d ", j + i,
			       kstat_cpu(0).irqs[SYS_IRQS + j + i]);
		seq_puts(p, "  ");
		seq_printf(p, "%s\n", base->irq_list[i].devname);
	}
	return 0;
}