1 /* $NetBSD: mc146818.c,v 1.21 2024/03/06 02:31:44 thorpej 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /*
28 * mc146818 and compatible time of day chip subroutines
29 */
30
31 #include <sys/cdefs.h>
32 __KERNEL_RCSID(0, "$NetBSD: mc146818.c,v 1.21 2024/03/06 02:31:44 thorpej Exp $");
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/device.h>
37 #include <sys/errno.h>
38
39 #include <sys/bus.h>
40
41 #include <dev/clock_subr.h>
42
43 #include <dev/ic/mc146818reg.h>
44 #include <dev/ic/mc146818var.h>
45
46 void
mc146818_attach(struct mc146818_softc * sc)47 mc146818_attach(struct mc146818_softc *sc)
48 {
49 todr_chip_handle_t handle;
50
51 #ifdef DIAGNOSTIC
52 if (sc->sc_mcread == NULL ||
53 sc->sc_mcwrite == NULL)
54 panic("%s: invalid read/write functions", __func__);
55 #endif
56
57 aprint_normal(": mc146818 compatible time-of-day clock");
58
59 handle = &sc->sc_handle;
60 handle->cookie = sc;
61 KASSERT(handle->todr_gettime == NULL);
62 KASSERT(handle->todr_settime == NULL);
63 if (handle->todr_gettime_ymdhms == NULL) {
64 handle->todr_gettime_ymdhms = mc146818_gettime_ymdhms;
65 }
66 if (handle->todr_settime_ymdhms == NULL) {
67 handle->todr_settime_ymdhms = mc146818_settime_ymdhms;
68 }
69
70 todr_attach(handle);
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
mc146818_gettime_ymdhms(todr_chip_handle_t handle,struct clock_ymdhms * dt)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 timeout = 1000000; /* XXX how long should we wait? */
89 for (;;) {
90 if (((*sc->sc_mcread)(sc, MC_REGA) & MC_REGA_UIP) == 0)
91 break;
92 if (--timeout < 0) {
93 printf("%s: timeout\n", __func__);
94 return EBUSY;
95 }
96 }
97
98 #define FROMREG(x) ((sc->sc_flag & MC146818_BCD) ? bcdtobin(x) : (x))
99
100 dt->dt_sec = FROMREG((*sc->sc_mcread)(sc, MC_SEC));
101 dt->dt_min = FROMREG((*sc->sc_mcread)(sc, MC_MIN));
102 dt->dt_hour = FROMREG((*sc->sc_mcread)(sc, MC_HOUR));
103 dt->dt_wday = FROMREG((*sc->sc_mcread)(sc, MC_DOW));
104 dt->dt_day = FROMREG((*sc->sc_mcread)(sc, MC_DOM));
105 dt->dt_mon = FROMREG((*sc->sc_mcread)(sc, MC_MONTH));
106 year = FROMREG((*sc->sc_mcread)(sc, MC_YEAR));
107 if (sc->sc_getcent) {
108 cent = (*sc->sc_getcent)(sc);
109 year += cent * 100;
110 }
111
112 #undef FROMREG
113
114 year += sc->sc_year0;
115 if (year < POSIX_BASE_YEAR &&
116 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
117 year += 100;
118 dt->dt_year = year;
119
120 splx(s);
121
122 return 0;
123 }
124
125 /*
126 * todr_settime function:
127 * Set the time of day clock based on the value of the struct timeval arg.
128 * Return 0 on success, an error number othersize.
129 */
130 int
mc146818_settime_ymdhms(todr_chip_handle_t handle,struct clock_ymdhms * dt)131 mc146818_settime_ymdhms(todr_chip_handle_t handle, struct clock_ymdhms *dt)
132 {
133 struct mc146818_softc *sc;
134 int s, cent, year;
135
136 sc = handle->cookie;
137
138 s = splclock(); /* XXX really needed? */
139
140 /*
141 * Disable RTC updates during clock updates
142 */
143
144 (*sc->sc_mcwrite)(sc, MC_REGB,
145 (*sc->sc_mcread)(sc, MC_REGB) | MC_REGB_SET);
146
147 #define TOREG(x) ((sc->sc_flag & MC146818_BCD) ? bintobcd(x) : (x))
148
149 (*sc->sc_mcwrite)(sc, MC_SEC, TOREG(dt->dt_sec));
150 (*sc->sc_mcwrite)(sc, MC_MIN, TOREG(dt->dt_min));
151 (*sc->sc_mcwrite)(sc, MC_HOUR, TOREG(dt->dt_hour));
152 (*sc->sc_mcwrite)(sc, MC_DOW, TOREG(dt->dt_wday));
153 (*sc->sc_mcwrite)(sc, MC_DOM, TOREG(dt->dt_day));
154 (*sc->sc_mcwrite)(sc, MC_MONTH, TOREG(dt->dt_mon));
155
156 year = dt->dt_year - sc->sc_year0;
157 if (sc->sc_setcent) {
158 cent = year / 100;
159 (*sc->sc_setcent)(sc, cent);
160 year -= cent * 100;
161 }
162 if (year > 99 &&
163 (sc->sc_flag & MC146818_NO_CENT_ADJUST) == 0)
164 year -= 100;
165 (*sc->sc_mcwrite)(sc, MC_YEAR, TOREG(year));
166
167 #undef TOREG
168
169 /*
170 * Re-enable RTC updates
171 */
172
173 (*sc->sc_mcwrite)(sc, MC_REGB,
174 (*sc->sc_mcread)(sc, MC_REGB) & ~MC_REGB_SET);
175
176 splx(s);
177
178 return 0;
179 }
180