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