1 /*
2 * linux/arch/m68k/amiga/cia.c - CIA support
3 *
4 * Copyright (C) 1996 Roman Zippel
5 *
6 * The concept of some functions bases on the original Amiga OS function
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file COPYING in the main directory of this archive
10 * for more details.
11 */
12
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/sched.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/init.h>
20
21 #include <asm/irq.h>
22 #include <asm/amigahw.h>
23 #include <asm/amigaints.h>
24
25 struct ciabase {
26 volatile struct CIA *cia;
27 u_char icr_mask, icr_data;
28 u_short int_mask;
29 int handler_irq, cia_irq, server_irq;
30 char *name;
31 } ciaa_base = {
32 &ciaa, 0, 0, IF_PORTS,
33 IRQ_AMIGA_AUTO_2, IRQ_AMIGA_CIAA,
34 IRQ_AMIGA_PORTS,
35 "CIAA handler"
36 }, ciab_base = {
37 &ciab, 0, 0, IF_EXTER,
38 IRQ_AMIGA_AUTO_6, IRQ_AMIGA_CIAB,
39 IRQ_AMIGA_EXTER,
40 "CIAB handler"
41 };
42
43 #define CIA_SET_BASE_ADJUST_IRQ(base, irq) \
44 do { \
45 if (irq >= IRQ_AMIGA_CIAB) { \
46 base = &ciab_base; \
47 irq -= IRQ_AMIGA_CIAB; \
48 } else { \
49 base = &ciaa_base; \
50 irq -= IRQ_AMIGA_CIAA; \
51 } \
52 } while (0)
53
54 /*
55 * Cause or clear CIA interrupts, return old interrupt status.
56 */
57
cia_set_irq_private(struct ciabase * base,unsigned char mask)58 static unsigned char cia_set_irq_private(struct ciabase *base,
59 unsigned char mask)
60 {
61 u_char old;
62
63 old = (base->icr_data |= base->cia->icr);
64 if (mask & CIA_ICR_SETCLR)
65 base->icr_data |= mask;
66 else
67 base->icr_data &= ~mask;
68 if (base->icr_data & base->icr_mask)
69 custom.intreq = IF_SETCLR | base->int_mask;
70 return old & base->icr_mask;
71 }
72
cia_set_irq(unsigned int irq,int set)73 unsigned char cia_set_irq(unsigned int irq, int set)
74 {
75 struct ciabase *base;
76 unsigned char mask;
77
78 if (irq >= IRQ_AMIGA_CIAB)
79 mask = (1 << (irq - IRQ_AMIGA_CIAB));
80 else
81 mask = (1 << (irq - IRQ_AMIGA_CIAA));
82 mask |= (set) ? CIA_ICR_SETCLR : 0;
83
84 CIA_SET_BASE_ADJUST_IRQ(base, irq);
85
86 return cia_set_irq_private(base, mask);
87 }
88
cia_get_irq_mask(unsigned int irq)89 unsigned char cia_get_irq_mask(unsigned int irq)
90 {
91 struct ciabase *base;
92
93 CIA_SET_BASE_ADJUST_IRQ(base, irq);
94
95 return base->cia->icr;
96 }
97
98 /*
99 * Enable or disable CIA interrupts, return old interrupt mask.
100 */
101
cia_able_irq_private(struct ciabase * base,unsigned char mask)102 static unsigned char cia_able_irq_private(struct ciabase *base,
103 unsigned char mask)
104 {
105 u_char old;
106
107 old = base->icr_mask;
108 base->icr_data |= base->cia->icr;
109 base->cia->icr = mask;
110 if (mask & CIA_ICR_SETCLR)
111 base->icr_mask |= mask;
112 else
113 base->icr_mask &= ~mask;
114 base->icr_mask &= CIA_ICR_ALL;
115
116 if (base->icr_data & base->icr_mask)
117 custom.intreq = IF_SETCLR | base->int_mask;
118 return old;
119 }
120
cia_able_irq(unsigned int irq,int enable)121 unsigned char cia_able_irq(unsigned int irq, int enable)
122 {
123 struct ciabase *base;
124 unsigned char mask;
125
126 if (irq >= IRQ_AMIGA_CIAB)
127 mask = (1 << (irq - IRQ_AMIGA_CIAB));
128 else
129 mask = (1 << (irq - IRQ_AMIGA_CIAA));
130 mask |= (enable) ? CIA_ICR_SETCLR : 0;
131
132 CIA_SET_BASE_ADJUST_IRQ(base, irq);
133
134 return cia_able_irq_private(base, mask);
135 }
136
cia_handler(int irq,void * dev_id,struct pt_regs * fp)137 static void cia_handler(int irq, void *dev_id, struct pt_regs *fp)
138 {
139 struct ciabase *base = (struct ciabase *)dev_id;
140 irq_desc_t *desc;
141 struct irqaction *action;
142 int i;
143 unsigned char ints;
144
145 irq = base->cia_irq;
146 desc = irq_desc + irq;
147 ints = cia_set_irq_private(base, CIA_ICR_ALL);
148 custom.intreq = base->int_mask;
149 for (i = 0; i < CIA_IRQS; i++, irq++) {
150 if (ints & 1) {
151 kstat.irqs[0][irq]++;
152 action = desc->action;
153 action->handler(irq, action->dev_id, fp);
154 }
155 ints >>= 1;
156 desc++;
157 }
158 amiga_do_irq_list(base->server_irq, fp);
159 }
160
cia_init_IRQ(struct ciabase * base)161 void __init cia_init_IRQ(struct ciabase *base)
162 {
163 extern struct irqaction amiga_sys_irqaction[AUTO_IRQS];
164 struct irqaction *action;
165
166 /* clear any pending interrupt and turn off all interrupts */
167 cia_set_irq_private(base, CIA_ICR_ALL);
168 cia_able_irq_private(base, CIA_ICR_ALL);
169
170 /* install CIA handler */
171 action = &amiga_sys_irqaction[base->handler_irq-IRQ_AMIGA_AUTO];
172 action->handler = cia_handler;
173 action->dev_id = base;
174 action->name = base->name;
175 setup_irq(base->handler_irq, &amiga_sys_irqaction[base->handler_irq-IRQ_AMIGA_AUTO]);
176
177 custom.intena = IF_SETCLR | base->int_mask;
178 }
179