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
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
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
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 unsigned long flags;
92
93 /* Interrupts get disabled while the timer irq flag is cleared and
94 * the timer interrupt serviced.
95 */
96 mach_irq = base->cia_irq;
97 local_irq_save(flags);
98 ints = cia_set_irq(base, CIA_ICR_ALL);
99 amiga_custom.intreq = base->int_mask;
100 if (ints & 1)
101 generic_handle_irq(mach_irq);
102 local_irq_restore(flags);
103 mach_irq++, ints >>= 1;
104 for (; ints; mach_irq++, ints >>= 1) {
105 if (ints & 1)
106 generic_handle_irq(mach_irq);
107 }
108 return IRQ_HANDLED;
109 }
110
111 static void cia_irq_enable(struct irq_data *data)
112 {
113 unsigned int irq = data->irq;
114 unsigned char mask;
115
116 if (irq >= IRQ_AMIGA_CIAB) {
117 mask = 1 << (irq - IRQ_AMIGA_CIAB);
118 cia_set_irq(&ciab_base, mask);
119 cia_able_irq(&ciab_base, CIA_ICR_SETCLR | mask);
120 } else {
121 mask = 1 << (irq - IRQ_AMIGA_CIAA);
122 cia_set_irq(&ciaa_base, mask);
123 cia_able_irq(&ciaa_base, CIA_ICR_SETCLR | mask);
124 }
125 }
126
127 static void cia_irq_disable(struct irq_data *data)
128 {
129 unsigned int irq = data->irq;
130
131 if (irq >= IRQ_AMIGA_CIAB)
132 cia_able_irq(&ciab_base, 1 << (irq - IRQ_AMIGA_CIAB));
133 else
134 cia_able_irq(&ciaa_base, 1 << (irq - IRQ_AMIGA_CIAA));
135 }
136
137 static struct irq_chip cia_irq_chip = {
138 .name = "cia",
139 .irq_enable = cia_irq_enable,
140 .irq_disable = cia_irq_disable,
141 };
142
143 /*
144 * Override auto irq 2 & 6 and use them as general chain
145 * for external interrupts, we link the CIA interrupt sources
146 * into this chain.
147 */
148
149 static void auto_irq_enable(struct irq_data *data)
150 {
151 switch (data->irq) {
152 case IRQ_AUTO_2:
153 amiga_custom.intena = IF_SETCLR | IF_PORTS;
154 break;
155 case IRQ_AUTO_6:
156 amiga_custom.intena = IF_SETCLR | IF_EXTER;
157 break;
158 }
159 }
160
161 static void auto_irq_disable(struct irq_data *data)
162 {
163 switch (data->irq) {
164 case IRQ_AUTO_2:
165 amiga_custom.intena = IF_PORTS;
166 break;
167 case IRQ_AUTO_6:
168 amiga_custom.intena = IF_EXTER;
169 break;
170 }
171 }
172
173 static struct irq_chip auto_irq_chip = {
174 .name = "auto",
175 .irq_enable = auto_irq_enable,
176 .irq_disable = auto_irq_disable,
177 };
178
179 void __init cia_init_IRQ(struct ciabase *base)
180 {
181 m68k_setup_irq_controller(&cia_irq_chip, handle_simple_irq,
182 base->cia_irq, CIA_IRQS);
183
184 /* clear any pending interrupt and turn off all interrupts */
185 cia_set_irq(base, CIA_ICR_ALL);
186 cia_able_irq(base, CIA_ICR_ALL);
187
188 /* override auto int and install CIA handler */
189 m68k_setup_irq_controller(&auto_irq_chip, handle_simple_irq,
190 base->handler_irq, 1);
191 m68k_irq_startup_irq(base->handler_irq);
192 if (request_irq(base->handler_irq, cia_handler, IRQF_SHARED,
193 base->name, base))
194 pr_err("Couldn't register %s interrupt\n", base->name);
195 }
196
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