xref: /netbsd-src/sys/dev/ic/mc146818.c (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: mc146818.c,v 1.13 2007/10/19 11:59:56 ad Exp $	*/
2 
3 /*
4  * Copyright (c) 2003 Izumi Tsutsui.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * mc146818 and compatible time of day chip subroutines
31  */
32 
33 #include <sys/cdefs.h>
34 __KERNEL_RCSID(0, "$NetBSD: mc146818.c,v 1.13 2007/10/19 11:59:56 ad Exp $");
35 
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/device.h>
39 #include <sys/errno.h>
40 
41 #include <sys/bus.h>
42 
43 #include <dev/clock_subr.h>
44 
45 #include <dev/ic/mc146818reg.h>
46 #include <dev/ic/mc146818var.h>
47 
48 int mc146818_gettime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
49 int mc146818_settime_ymdhms(todr_chip_handle_t, struct clock_ymdhms *);
50 
51 void
52 mc146818_attach(struct mc146818_softc *sc)
53 {
54 	todr_chip_handle_t handle;
55 
56 #ifdef DIAGNOSTIC
57 	if (sc->sc_mcread == NULL ||
58 	    sc->sc_mcwrite == NULL)
59 		panic("mc146818_attach: invalid read/write functions");
60 #endif
61 
62 	printf(": mc146818 compatible time-of-day clock");
63 
64 	handle = &sc->sc_handle;
65 	handle->cookie = sc;
66 	handle->todr_gettime = NULL;
67 	handle->todr_settime = NULL;
68 	handle->todr_gettime_ymdhms = mc146818_gettime_ymdhms;
69 	handle->todr_settime_ymdhms = mc146818_settime_ymdhms;
70 	handle->todr_setwen  = NULL;
71 }
72 
73 /*
74  * todr_gettime function:
75  *  Get time of day and convert it to a struct timeval.
76  *  Return 0 on success, an error number othersize.
77  */
78 int
79 mc146818_gettime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
80 {
81 	struct mc146818_softc *sc;
82 	int s, timeout, cent, year;
83 
84 	sc = handle->cookie;
85 
86 	s = splclock();		/* XXX really needed? */
87 
88 	todr_wenable(handle, 1);
89 
90 	timeout = 1000000;	/* XXX how long should we wait? */
91 	for (;;) {
92 		if ((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP)
93 			break;
94 		if (--timeout < 0) {
95 			printf("mc146818_gettime: timeout\n");
96 			return EBUSY;
97 		}
98 	}
99 
100 #define	FROMREG(x)	((sc->sc_flag & MC146818_BCD) ? FROMBCD(x) : (x))
101 
102 	dt->dt_sec  = FROMREG((*sc->sc_mcread)(sc, MC_SEC));
103 	dt->dt_min  = FROMREG((*sc->sc_mcread)(sc, MC_MIN));
104 	dt->dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR));
105 	dt->dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW));
106 	dt->dt_day  = FROMREG((*sc->sc_mcread)(sc, MC_DOM));
107 	dt->dt_mon  = FROMREG((*sc->sc_mcread)(sc, MC_MONTH));
108 	year       = FROMREG((*sc->sc_mcread)(sc, MC_YEAR));
109 	if (sc->sc_getcent) {
110 		cent = (*sc->sc_getcent)(sc);
111 		year += cent * 100;
112 	}
113 
114 #undef FROMREG
115 
116 	year += sc->sc_year0;
117 	if (year < POSIX_BASE_YEAR &&
118 	    (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
119 		year += 100;
120 	dt->dt_year = year;
121 
122 	todr_wenable(handle, 0);
123 
124 	splx(s);
125 
126 	return 0;
127 }
128 
129 /*
130  * todr_settime function:
131  *  Set the time of day clock based on the value of the struct timeval arg.
132  *  Return 0 on success, an error number othersize.
133  */
134 int
135 mc146818_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
136 {
137 	struct mc146818_softc *sc;
138 	int s, timeout, cent, year;
139 
140 	sc = handle->cookie;
141 
142 	s = splclock();		/* XXX really needed? */
143 
144 	todr_wenable(handle, 1);
145 
146 	timeout = 1000000;	/* XXX how long should we wait? */
147 	for (;;) {
148 		if ((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP)
149 			break;
150 		if (--timeout < 0) {
151 			printf("mc146818_settime: timeout\n");
152 			return EBUSY;
153 		}
154 	}
155 
156 #define	TOREG(x)	((sc->sc_flag & MC146818_BCD) ? TOBCD(x) : (x))
157 
158 	(*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt->dt_sec));
159 	(*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt->dt_min));
160 	(*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt->dt_hour));
161 	(*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt->dt_wday));
162 	(*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt->dt_day));
163 	(*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt->dt_mon));
164 
165 	year = dt->dt_year - sc->sc_year0;
166 	if (sc->sc_setcent) {
167 		cent = year / 100;
168 		(*sc->sc_setcent)(sc, cent);
169 		year -= cent * 100;
170 	}
171 	if (year > 99 &&
172 	    (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
173 		year -= 100;
174 	(*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year));
175 
176 #undef TOREG
177 
178 	todr_wenable(handle, 0);
179 
180 	splx(s);
181 
182 	return 0;
183 }
184