xref: /freebsd/sys/dev/ic/i8259.h (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2003 Peter Wemm
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /*
32  * Register defintions for the i8259A programmable interrupt controller.
33  */
34 
35 #ifndef _DEV_IC_I8259_H_
36 #define	_DEV_IC_I8259_H_
37 
38 /* Initialization control word 1. Written to even address. */
39 #define	ICW1_IC4	0x01		/* ICW4 present */
40 #define	ICW1_SNGL	0x02		/* 1 = single, 0 = cascaded */
41 #define	ICW1_ADI	0x04		/* 1 = 4, 0 = 8 byte vectors */
42 #define	ICW1_LTIM	0x08		/* 1 = level trigger, 0 = edge */
43 #define	ICW1_RESET	0x10		/* must be 1 */
44 /* 0x20 - 0x80 - in 8080/8085 mode only */
45 
46 /* Initialization control word 2. Written to the odd address. */
47 /* No definitions, it is the base vector of the IDT for 8086 mode */
48 
49 /* Initialization control word 3. Written to the odd address. */
50 /* For a master PIC, bitfield indicating a slave 8259 on given input */
51 /* For slave, lower 3 bits are the slave's ID binary id on master */
52 
53 /* Initialization control word 4. Written to the odd address. */
54 #define	ICW4_8086	0x01		/* 1 = 8086, 0 = 8080 */
55 #define	ICW4_AEOI	0x02		/* 1 = Auto EOI */
56 #define	ICW4_MS		0x04		/* 1 = buffered master, 0 = slave */
57 #define	ICW4_BUF	0x08		/* 1 = enable buffer mode */
58 #define	ICW4_SFNM	0x10		/* 1 = special fully nested mode */
59 
60 /* Operation control words.  Written after initialization. */
61 
62 /* Operation control word type 1 */
63 /*
64  * No definitions.  Written to the odd address.  Bitmask for interrupts.
65  * 1 = disabled.
66  */
67 
68 /* Operation control word type 2.  Bit 3 (0x08) must be zero. Even address. */
69 #define	OCW2_L0		0x01		/* Level */
70 #define	OCW2_L1		0x02
71 #define	OCW2_L2		0x04
72 /* 0x08 must be 0 to select OCW2 vs OCW3 */
73 /* 0x10 must be 0 to select OCW2 vs ICW1 */
74 #define	OCW2_EOI	0x20		/* 1 = EOI */
75 #define	OCW2_SL		0x40		/* EOI mode */
76 #define	OCW2_R		0x80		/* EOI mode */
77 
78 /* Operation control word type 3.  Bit 3 (0x08) must be set. Even address. */
79 #define	OCW3_RIS	0x01		/* 1 = read IS, 0 = read IR */
80 #define	OCW3_RR		0x02		/* register read */
81 #define	OCW3_P		0x04		/* poll mode command */
82 /* 0x08 must be 1 to select OCW3 vs OCW2 */
83 #define	OCW3_SEL	0x08		/* must be 1 */
84 /* 0x10 must be 0 to select OCW3 vs ICW1 */
85 #define	OCW3_SMM	0x20		/* special mode mask */
86 #define	OCW3_ESMM	0x40		/* enable SMM */
87 
88 #endif /* !_DEV_IC_I8259_H_ */
89