xref: /freebsd/contrib/ntp/kernel/sys/i8253.h (revision c0b746e5)
1 /* Copyright (c) 1995 Vixie Enterprises
2  *
3  * Permission to use, copy, modify, and distribute this software for any
4  * purpose with or without fee is hereby granted, provided that the above
5  * copyright notice and this permission notice appear in all copies, and that
6  * the name of Vixie Enterprises not be used in advertising or publicity
7  * pertaining to distribution of the document or software without specific,
8  * written prior permission.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND VIXIE ENTERPRISES DISCLAIMS ALL
11  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
12  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL VIXIE ENTERPRISES
13  * BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
14  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
15  * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
16  * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
17  * SOFTWARE.
18  */
19 
20 #ifndef _I8253_DEFINED
21 #define _I8253_DEFINED
22 
23 typedef union {
24 	unsigned char	i;
25 	struct {
26 		unsigned int	bcd	: 1;
27 #define				i8253_binary	0
28 #define				i8253_bcd	1
29 		unsigned int	mode	: 3;
30 #define				i8253_termcnt	0
31 #define				i8253_oneshot	1
32 #define				i8253_rategen	2
33 #define				i8253_sqrwave	3
34 #define				i8253_softstb	4
35 #define				i8253_hardstb	5
36 		unsigned int	rl	: 2;
37 #define				i8253_latch	0
38 #define				i8253_lsb	1
39 #define				i8253_msb	2
40 #define				i8253_lmb	3
41 		unsigned int	cntr	: 2;
42 #define				i8253_cntr_0	0
43 #define				i8253_cntr_1	1
44 #define				i8253_cntr_2	2
45 	} s;
46 } i8253_ctrl;
47 
48 #endif /*_I8253_DEFINED*/
49