1 /*	$NetBSD: clock_machdep.c,v 1.1 2002/02/22 19:43:58 uch Exp $	*/
2 
3 /*-
4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
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  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *        This product includes software developed by the NetBSD
18  *        Foundation, Inc. and its contributors.
19  * 4. Neither the name of The NetBSD Foundation nor the names of its
20  *    contributors may be used to endorse or promote products derived
21  *    from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 
39 #include <dev/clock_subr.h>
40 #include <sh3/clock.h>
41 
42 #ifdef DEBUG
43 #define STATIC
44 #else
45 #define STATIC static
46 #endif
47 
48 #define DREAMCAST_RTC		0xa0710000
49 
50 STATIC void dreamcast_rtc_init(void *);
51 STATIC void dreamcast_rtc_get(void *, time_t, struct clock_ymdhms *);
52 STATIC void dreamcast_rtc_set(void *, struct clock_ymdhms *);
53 
54 STATIC u_int32_t dreamcast_read_rtc(void);
55 
56 STATIC struct rtc_ops dreamcast_rtc_ops = {
57 	.init	= dreamcast_rtc_init,
58 	.get	= dreamcast_rtc_get,
59 	.set	= dreamcast_rtc_set
60 };
61 
62 void
63 machine_clock_init()
64 {
65 
66 	sh_clock_init(SH_CLOCK_NORTC, &dreamcast_rtc_ops);
67 }
68 
69 void
70 dreamcast_rtc_init(void *cookie)
71 {
72 	/* Nothing to do */
73 }
74 
75 void
76 dreamcast_rtc_get(void *cookie, time_t base, struct clock_ymdhms *dt)
77 {
78 
79 	clock_secs_to_ymdhms(dreamcast_read_rtc(), dt);
80 }
81 
82 void
83 dreamcast_rtc_set(void *cookie, struct clock_ymdhms *dt)
84 {
85 
86 	/* Not suppoted */
87 }
88 
89 u_int32_t
90 dreamcast_read_rtc()
91 {
92 	__volatile__ u_int32_t *rtc = (__volatile__ u_int32_t *)DREAMCAST_RTC;
93 	u_int32_t new, old;
94 	int i;
95 
96 	for (old = 0;;) {
97 		for (i = 0; i < 3; i++) {
98 			new = ((rtc[0] & 0xffff) << 16) | (rtc[1] & 0xffff);
99 			if (new != old)
100 				break;
101 		}
102 		if (i < 3)
103 			old = new;
104 		else
105 			break;
106 	}
107 
108 	/* offset 20 years */
109 	return (new - 631152000);
110 }
111