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/errno.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/init.h>
19 #include <linux/seq_file.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22
23 #include <asm/irq.h>
24 #include <asm/amigahw.h>
25 #include <asm/amigaints.h>
26
27 struct ciabase {
28 volatile struct CIA *cia;
29 unsigned char icr_mask, icr_data;
30 unsigned short int_mask;
31 int handler_irq, cia_irq, server_irq;
32 char *name;
33 } ciaa_base = {
34 .cia = &ciaa,
35 .int_mask = IF_PORTS,
36 .handler_irq = IRQ_AMIGA_PORTS,
37 .cia_irq = IRQ_AMIGA_CIAA,
38 .name = "CIAA"
39 }, ciab_base = {
40 .cia = &ciab,
41 .int_mask = IF_EXTER,
42 .handler_irq = IRQ_AMIGA_EXTER,
43 .cia_irq = IRQ_AMIGA_CIAB,
44 .name = "CIAB"
45 };
46
47 /*
48 * Cause or clear CIA interrupts, return old interrupt status.
49 */
50
cia_set_irq(struct ciabase * base,unsigned char mask)51 unsigned char cia_set_irq(struct ciabase *base, unsigned char mask)
52 {
53 unsigned char old;
54
55 old = (base->icr_data |= base->cia->icr);
56 if (mask & CIA_ICR_SETCLR)
57 base->icr_data |= mask;
58 else
59 base->icr_data &= ~mask;
60 if (base->icr_data & base->icr_mask)
61 amiga_custom.intreq = IF_SETCLR | base->int_mask;
62 return old & base->icr_mask;
63 }
64
65 /*
66 * Enable or disable CIA interrupts, return old interrupt mask,
67 */
68
cia_able_irq(struct ciabase * base,unsigned char mask)69 unsigned char cia_able_irq(struct ciabase *base, unsigned char mask)
70 {
71 unsigned char old;
72
73 old = base->icr_mask;
74 base->icr_data |= base->cia->icr;
75 base->cia->icr = mask;
76 if (mask & CIA_ICR_SETCLR)
77 base->icr_mask |= mask;
78 else
79 base->icr_mask &= ~mask;
80 base->icr_mask &= CIA_ICR_ALL;
81 if (base->icr_data & base->icr_mask)
82 amiga_custom.intreq = IF_SETCLR | base->int_mask;
83 return old;
84 }
85
cia_handler(int irq,void * dev_id)86 static irqreturn_t cia_handler(int irq, void *dev_id)
87 {
88 struct ciabase *base = dev_id;
89 int mach_irq;
90 unsigned char ints;
91
92 mach_irq = base->cia_irq;
93 ints = cia_set_irq(base, CIA_ICR_ALL);
94 amiga_custom.intreq = base->int_mask;
95 for (; ints; mach_irq++, ints >>= 1) {
96 if (ints & 1)
97 generic_handle_irq(mach_irq);
98 }
99 return IRQ_HANDLED;
100 }
101
cia_irq_enable(struct irq_data * data)102 static void cia_irq_enable(struct irq_data *data)
103 {
104 unsigned int irq = data->irq;
105 unsigned char mask;
106
107 if (irq >= IRQ_AMIGA_CIAB) {
108 mask = 1 << (irq - IRQ_AMIGA_CIAB);
109 cia_set_irq(&ciab_base, mask);
110 cia_able_irq(&ciab_base, CIA_ICR_SETCLR | mask);
111 } else {
112 mask = 1 << (irq - IRQ_AMIGA_CIAA);
113 cia_set_irq(&ciaa_base, mask);
114 cia_able_irq(&ciaa_base, CIA_ICR_SETCLR | mask);
115 }
116 }
117
cia_irq_disable(struct irq_data * data)118 static void cia_irq_disable(struct irq_data *data)
119 {
120 unsigned int irq = data->irq;
121
122 if (irq >= IRQ_AMIGA_CIAB)
123 cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
124 else
125 cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
126 }
127
128 static struct irq_chip cia_irq_chip = {
129 .name = "cia",
130 .irq_enable = cia_irq_enable,
131 .irq_disable = cia_irq_disable,
132 };
133
134 /*
135 * Override auto irq 2 & 6 and use them as general chain
136 * for external interrupts, we link the CIA interrupt sources
137 * into this chain.
138 */
139
auto_irq_enable(struct irq_data * data)140 static void auto_irq_enable(struct irq_data *data)
141 {
142 switch (data->irq) {
143 case IRQ_AUTO_2:
144 amiga_custom.intena = IF_SETCLR | IF_PORTS;
145 break;
146 case IRQ_AUTO_6:
147 amiga_custom.intena = IF_SETCLR | IF_EXTER;
148 break;
149 }
150 }
151
auto_irq_disable(struct irq_data * data)152 static void auto_irq_disable(struct irq_data *data)
153 {
154 switch (data->irq) {
155 case IRQ_AUTO_2:
156 amiga_custom.intena = IF_PORTS;
157 break;
158 case IRQ_AUTO_6:
159 amiga_custom.intena = IF_EXTER;
160 break;
161 }
162 }
163
164 static struct irq_chip auto_irq_chip = {
165 .name = "auto",
166 .irq_enable = auto_irq_enable,
167 .irq_disable = auto_irq_disable,
168 };
169
cia_init_IRQ(struct ciabase * base)170 void __init cia_init_IRQ(struct ciabase *base)
171 {
172 m68k_setup_irq_controller(&cia_irq_chip, handle_simple_irq,
173 base->cia_irq, CIA_IRQS);
174
175 /* clear any pending interrupt and turn off all interrupts */
176 cia_set_irq(base, CIA_ICR_ALL);
177 cia_able_irq(base, CIA_ICR_ALL);
178
179 /* override auto int and install CIA handler */
180 m68k_setup_irq_controller(&auto_irq_chip, handle_simple_irq,
181 base->handler_irq, 1);
182 m68k_irq_startup_irq(base->handler_irq);
183 if (request_irq(base->handler_irq, cia_handler, IRQF_SHARED,
184 base->name, base))
185 pr_err("Couldn't register %s interrupt\n", base->name);
186 }
187