xref: /illumos-gate/usr/src/uts/common/sys/pit.h (revision 2d6eb4a5)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*	Copyright (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
23 /*	All Rights Reserved	*/
24 
25 /*
26  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #ifndef _SYS_PIT_H
31 #define	_SYS_PIT_H
32 
33 #ifdef __cplusplus
34 extern "C" {
35 #endif
36 
37 /* Definitions for 8254 Programmable Interrupt Timer ports on AT 386 */
38 #define	PITCTR0_PORT	0x40		/* counter 0 port */
39 #define	PITCTR1_PORT	0x41		/* counter 1 port */
40 #define	PITCTR2_PORT	0x42		/* counter 2 port */
41 #define	PITCTL_PORT	0x43		/* PIT control port */
42 #define	PITAUX_PORT	0x61		/* PIT auxiliary port */
43 #define	SANITY_CTR0	0x48		/* sanity timer counter */
44 #define	SANITY_CTL	0x4B		/* sanity control word */
45 #define	SANITY_CHECK	0x461		/* bit 7 set if sanity timer went off */
46 #define	FAILSAFE_NMI	0x80		/* to test if sanity timer went off */
47 #define	ENABLE_SANITY	0x04		/* Enables sanity clock NMI ints */
48 #define	RESET_SANITY	0x00		/* resets sanity NMI interrupt */
49 
50 /* PIT Status Byte */
51 
52 #define	PITSTAT_OUTPUT	7		/* OUTPUT status bit */
53 #define	PITSTAT_NULLCNT	6		/* NULL COUNT status bit */
54 
55 /* Definitions for 8254 commands */
56 
57 #define	PIT_READBACK	0xc0		/* read-back command */
58 #define	PIT_READBACKC0	0x02		/* enable read-back for counter 0 */
59 
60 /* Following are used for Timer 0 */
61 #define	PIT_C0		0x00		/* select counter 0 */
62 #define	PIT_LOADMODE	0x30		/* load least significant byte */
63 					/* followed by most significant byte */
64 #define	PIT_NDIVMODE	0x04		/* divide by N counter */
65 #define	PIT_SQUAREMODE	0x06		/* square-wave mode */
66 #define	PIT_ENDSIGMODE	0x00		/* assert OUT at end-of-count mode */
67 
68 /* Used for Timer 1. Used for delay calculations in countdown mode */
69 #define	PIT_C1		0x40		/* select counter 1 */
70 #define	PIT_READMODE	0x30		/* read or load least significant */
71 					/* byte followed by most significant */
72 #define	PIT_RATEMODE	0x06		/* square-wave mode for USART */
73 
74 #define	PIT_C2		0x80		/* select counter 2 */
75 
76 #define	SANITY_NUM	0xFFFF		/* Sanity timer fires every .2 secs */
77 /* bits used in auxiliary control port for timer 2 */
78 #define	PITAUX_GATE2	0x01		/* aux port, PIT gate 2 input */
79 #define	PITAUX_OUT2	0x02		/* aux port, PIT clock out 2 enable */
80 #define	PIT_HZ		1193182		/* 8254's cycles per second */
81 
82 #ifdef __cplusplus
83 }
84 #endif
85 
86 #endif	/* _SYS_PIT_H */
87