xref: /openbmc/linux/arch/m68k/68000/ints.c (revision e65e175b)
1 /*
2  * ints.c - Generic interrupt controller support
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file COPYING in the main directory of this archive
6  * for more details.
7  *
8  * Copyright 1996 Roman Zippel
9  * Copyright 1999 D. Jeff Dionne <jeff@rt-control.com>
10  */
11 
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <asm/traps.h>
18 #include <asm/io.h>
19 #include <asm/machdep.h>
20 
21 #if defined(CONFIG_M68EZ328)
22 #include <asm/MC68EZ328.h>
23 #elif defined(CONFIG_M68VZ328)
24 #include <asm/MC68VZ328.h>
25 #else
26 #include <asm/MC68328.h>
27 #endif
28 
29 /* assembler routines */
30 asmlinkage void system_call(void);
31 asmlinkage void buserr(void);
32 asmlinkage void trap(void);
33 asmlinkage void trap3(void);
34 asmlinkage void trap4(void);
35 asmlinkage void trap5(void);
36 asmlinkage void trap6(void);
37 asmlinkage void trap7(void);
38 asmlinkage void trap8(void);
39 asmlinkage void trap9(void);
40 asmlinkage void trap10(void);
41 asmlinkage void trap11(void);
42 asmlinkage void trap12(void);
43 asmlinkage void trap13(void);
44 asmlinkage void trap14(void);
45 asmlinkage void trap15(void);
46 asmlinkage void trap33(void);
47 asmlinkage void trap34(void);
48 asmlinkage void trap35(void);
49 asmlinkage void trap36(void);
50 asmlinkage void trap37(void);
51 asmlinkage void trap38(void);
52 asmlinkage void trap39(void);
53 asmlinkage void trap40(void);
54 asmlinkage void trap41(void);
55 asmlinkage void trap42(void);
56 asmlinkage void trap43(void);
57 asmlinkage void trap44(void);
58 asmlinkage void trap45(void);
59 asmlinkage void trap46(void);
60 asmlinkage void trap47(void);
61 asmlinkage irqreturn_t bad_interrupt(int, void *);
62 asmlinkage irqreturn_t inthandler(void);
63 asmlinkage irqreturn_t inthandler1(void);
64 asmlinkage irqreturn_t inthandler2(void);
65 asmlinkage irqreturn_t inthandler3(void);
66 asmlinkage irqreturn_t inthandler4(void);
67 asmlinkage irqreturn_t inthandler5(void);
68 asmlinkage irqreturn_t inthandler6(void);
69 asmlinkage irqreturn_t inthandler7(void);
70 
71 /* The 68k family did not have a good way to determine the source
72  * of interrupts until later in the family.  The EC000 core does
73  * not provide the vector number on the stack, we vector everything
74  * into one vector and look in the blasted mask register...
75  * This code is designed to be fast, almost constant time, not clean!
76  */
77 void process_int(int vec, struct pt_regs *fp)
78 {
79 	int irq;
80 	int mask;
81 
82 	unsigned long pend = ISR;
83 
84 	while (pend) {
85 		if (pend & 0x0000ffff) {
86 			if (pend & 0x000000ff) {
87 				if (pend & 0x0000000f) {
88 					mask = 0x00000001;
89 					irq = 0;
90 				} else {
91 					mask = 0x00000010;
92 					irq = 4;
93 				}
94 			} else {
95 				if (pend & 0x00000f00) {
96 					mask = 0x00000100;
97 					irq = 8;
98 				} else {
99 					mask = 0x00001000;
100 					irq = 12;
101 				}
102 			}
103 		} else {
104 			if (pend & 0x00ff0000) {
105 				if (pend & 0x000f0000) {
106 					mask = 0x00010000;
107 					irq = 16;
108 				} else {
109 					mask = 0x00100000;
110 					irq = 20;
111 				}
112 			} else {
113 				if (pend & 0x0f000000) {
114 					mask = 0x01000000;
115 					irq = 24;
116 				} else {
117 					mask = 0x10000000;
118 					irq = 28;
119 				}
120 			}
121 		}
122 
123 		while (! (mask & pend)) {
124 			mask <<=1;
125 			irq++;
126 		}
127 
128 		do_IRQ(irq, fp);
129 		pend &= ~mask;
130 	}
131 }
132 
133 static void intc_irq_unmask(struct irq_data *d)
134 {
135 	IMR &= ~(1 << d->irq);
136 }
137 
138 static void intc_irq_mask(struct irq_data *d)
139 {
140 	IMR |= (1 << d->irq);
141 }
142 
143 static struct irq_chip intc_irq_chip = {
144 	.name		= "M68K-INTC",
145 	.irq_mask	= intc_irq_mask,
146 	.irq_unmask	= intc_irq_unmask,
147 };
148 
149 /*
150  * This function should be called during kernel startup to initialize
151  * the machine vector table.
152  */
153 void __init trap_init(void)
154 {
155 	int i;
156 
157 	/* set up the vectors */
158 	for (i = 72; i < 256; ++i)
159 		_ramvec[i] = (e_vector) bad_interrupt;
160 
161 	_ramvec[32] = system_call;
162 
163 	_ramvec[65] = (e_vector) inthandler1;
164 	_ramvec[66] = (e_vector) inthandler2;
165 	_ramvec[67] = (e_vector) inthandler3;
166 	_ramvec[68] = (e_vector) inthandler4;
167 	_ramvec[69] = (e_vector) inthandler5;
168 	_ramvec[70] = (e_vector) inthandler6;
169 	_ramvec[71] = (e_vector) inthandler7;
170 }
171 
172 void __init init_IRQ(void)
173 {
174 	int i;
175 
176 	IVR = 0x40; /* Set DragonBall IVR (interrupt base) to 64 */
177 
178 	/* turn off all interrupts */
179 	IMR = ~0;
180 
181 	for (i = 0; (i < NR_IRQS); i++) {
182 		irq_set_chip(i, &intc_irq_chip);
183 		irq_set_handler(i, handle_level_irq);
184 	}
185 }
186 
187