1 /* $NetBSD: rtc.c,v 1.3 2025/01/07 22:37:13 jakllsch Exp $ */
2
3 /*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * William Jolitz and Don Ahn.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)clock.c 7.2 (Berkeley) 5/12/91
35 */
36 /*-
37 * Copyright (c) 1993, 1994 Charles M. Hannum.
38 *
39 * This code is derived from software contributed to Berkeley by
40 * William Jolitz and Don Ahn.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. All advertising materials mentioning features or use of this software
51 * must display the following acknowledgement:
52 * This product includes software developed by the University of
53 * California, Berkeley and its contributors.
54 * 4. Neither the name of the University nor the names of its contributors
55 * may be used to endorse or promote products derived from this software
56 * without specific prior written permission.
57 *
58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
68 * SUCH DAMAGE.
69 *
70 * @(#)clock.c 7.2 (Berkeley) 5/12/91
71 */
72 /*
73 * Mach Operating System
74 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
75 * All Rights Reserved.
76 *
77 * Permission to use, copy, modify and distribute this software and its
78 * documentation is hereby granted, provided that both the copyright
79 * notice and this permission notice appear in all copies of the
80 * software, derivative works or modified versions, and any portions
81 * thereof, and that both notices appear in supporting documentation.
82 *
83 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
84 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
85 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
86 *
87 * Carnegie Mellon requests users of this software to return to
88 *
89 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
90 * School of Computer Science
91 * Carnegie Mellon University
92 * Pittsburgh PA 15213-3890
93 *
94 * any improvements or extensions that they make and grant Carnegie Mellon
95 * the rights to redistribute these changes.
96 */
97 /*
98 Copyright 1988, 1989 by Intel Corporation, Santa Clara, California.
99
100 All Rights Reserved
101
102 Permission to use, copy, modify, and distribute this software and
103 its documentation for any purpose and without fee is hereby
104 granted, provided that the above copyright notice appears in all
105 copies and that both the copyright notice and this permission notice
106 appear in supporting documentation, and that the name of Intel
107 not be used in advertising or publicity pertaining to distribution
108 of the software without specific, written prior permission.
109
110 INTEL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
111 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS,
112 IN NO EVENT SHALL INTEL BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
113 CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
114 LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
115 NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
116 WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
117 */
118
119 /*
120 * Primitive RTC chip routines.
121 */
122
123 #include <sys/cdefs.h>
124 __KERNEL_RCSID(0, "$NetBSD: rtc.c,v 1.3 2025/01/07 22:37:13 jakllsch Exp $");
125
126 #include <sys/param.h>
127 #include <sys/systm.h>
128 #include <sys/time.h>
129 #include <sys/timetc.h>
130 #include <sys/kernel.h>
131
132 #include <dev/isa/isareg.h>
133 #include <dev/isa/isavar.h>
134 #include <i386/isa/nvram.h>
135
136 #include <machine/pio.h>
137
138 #include <dev/ic/mc146818reg.h>
139 #include <x86/rtc.h>
140
141 #ifndef __x86_64__
142 #include "mca.h"
143 #endif
144 #if NMCA > 0
145 #include <machine/mca_machdep.h> /* for MCA_system */
146 #endif
147
148 #include "acpica.h"
149 #if NACPICA > 0
150 #include <dev/acpi/acpivar.h>
151 #endif
152
153 static void rtcinit(void);
154 static int rtcget(mc_todregs *);
155 static void rtcput(mc_todregs *);
156 static int cmoscheck(void);
157 static int clock_expandyear(int);
158
159 /* XXX use sc? */
160 u_int
mc146818_read(void * sc,u_int reg)161 mc146818_read(void *sc, u_int reg)
162 {
163
164 outb(IO_RTC, reg);
165 return (inb(IO_RTC+1));
166 }
167
168 void
mc146818_write(void * sc,u_int reg,u_int datum)169 mc146818_write(void *sc, u_int reg, u_int datum)
170 {
171
172 outb(IO_RTC, reg);
173 outb(IO_RTC+1, datum);
174 }
175
176 static void
rtcinit(void)177 rtcinit(void)
178 {
179 static int first_rtcopen_ever = 1;
180
181 if (!first_rtcopen_ever)
182 return;
183 first_rtcopen_ever = 0;
184
185 mc146818_write(NULL, MC_REGA, /* XXX softc */
186 MC_BASE_32_KHz | MC_RATE_1024_Hz);
187 mc146818_write(NULL, MC_REGB, MC_REGB_24HR); /* XXX softc */
188 }
189
190 static int
rtcget(mc_todregs * regs)191 rtcget(mc_todregs *regs)
192 {
193
194 rtcinit();
195 if ((mc146818_read(NULL, MC_REGD) & MC_REGD_VRT) == 0) /* XXX softc */
196 return (-1);
197 MC146818_GETTOD(NULL, regs); /* XXX softc */
198 return (0);
199 }
200
201 static void
rtcput(mc_todregs * regs)202 rtcput(mc_todregs *regs)
203 {
204
205 rtcinit();
206 MC146818_PUTTOD(NULL, regs); /* XXX softc */
207 }
208
209 /*
210 * check whether the CMOS layout is "standard"-like (ie, not PS/2-like),
211 * to be called at splclock()
212 */
213 static int
cmoscheck(void)214 cmoscheck(void)
215 {
216 int i;
217 unsigned short cksum = 0;
218
219 for (i = 0x10; i <= 0x2d; i++)
220 cksum += mc146818_read(NULL, i); /* XXX softc */
221
222 return (cksum == (mc146818_read(NULL, 0x2e) << 8)
223 + mc146818_read(NULL, 0x2f));
224 }
225
226 #if NMCA > 0
227 /*
228 * Check whether the CMOS layout is PS/2 like, to be called at splclock().
229 */
230 static int cmoscheckps2(void);
231 static int
cmoscheckps2(void)232 cmoscheckps2(void)
233 {
234 #if 0
235 /* Disabled until I find out the CRC checksum algorithm IBM uses */
236 int i;
237 unsigned short cksum = 0;
238
239 for (i = 0x10; i <= 0x31; i++)
240 cksum += mc146818_read(NULL, i); /* XXX softc */
241
242 return (cksum == (mc146818_read(NULL, 0x32) << 8)
243 + mc146818_read(NULL, 0x33));
244 #else
245 /* Check 'incorrect checksum' bit of IBM PS/2 Diagnostic Status Byte */
246 return ((mc146818_read(NULL, NVRAM_DIAG) & (1<<6)) == 0);
247 #endif
248 }
249 #endif /* NMCA > 0 */
250
251 /*
252 * patchable to control century byte handling:
253 * 1: always update
254 * -1: never touch
255 * 0: try to figure out itself
256 */
257 int rtc_update_century = 0;
258
259 /*
260 * Expand a two-digit year as read from the clock chip
261 * into full width.
262 * Being here, deal with the CMOS century byte.
263 */
264 static int centb = NVRAM_CENTURY;
265 static int
clock_expandyear(int clockyear)266 clock_expandyear(int clockyear)
267 {
268 int s, clockcentury, cmoscentury;
269
270 clockcentury = (clockyear < 70) ? 20 : 19;
271 clockyear += 100 * clockcentury;
272
273 if (rtc_update_century < 0)
274 return (clockyear);
275
276 s = splclock();
277 #if NACPICA > 0
278 if (acpi_active && AcpiGbl_FADT.Century >= MC_NVRAM_START &&
279 AcpiGbl_FADT.Century < (MC_NVRAM_START + MC_NVRAM_SIZE))
280 cmoscentury = mc146818_read(NULL,
281 (centb = AcpiGbl_FADT.Century));
282 else
283 #endif
284 if (cmoscheck())
285 cmoscentury = mc146818_read(NULL, NVRAM_CENTURY);
286 #if NMCA > 0
287 else if (MCA_system && cmoscheckps2())
288 cmoscentury = mc146818_read(NULL, (centb = 0x37));
289 #endif
290 else
291 cmoscentury = 0;
292 splx(s);
293 if (!cmoscentury) {
294 #ifdef DIAGNOSTIC
295 printf("clock: unknown CMOS layout\n");
296 #endif
297 return (clockyear);
298 }
299 cmoscentury = bcdtobin(cmoscentury);
300
301 if (cmoscentury != clockcentury) {
302 /* XXX note: saying "century is 20" might confuse the naive. */
303 printf("WARNING: NVRAM century is %d but RTC year is %d\n",
304 cmoscentury, clockyear);
305
306 /* Kludge to roll over century. */
307 if ((rtc_update_century > 0) ||
308 ((cmoscentury == 19) && (clockcentury == 20) &&
309 (clockyear == 2000))) {
310 printf("WARNING: Setting NVRAM century to %d\n",
311 clockcentury);
312 s = splclock();
313 mc146818_write(NULL, centb, bintobcd(clockcentury));
314 splx(s);
315 }
316 } else if (cmoscentury == 19 && rtc_update_century == 0)
317 rtc_update_century = 1; /* will update later in resettodr() */
318
319 return (clockyear);
320 }
321
322 int
rtc_get_ymdhms(todr_chip_handle_t tch,struct clock_ymdhms * dt)323 rtc_get_ymdhms(todr_chip_handle_t tch, struct clock_ymdhms *dt)
324 {
325 int s;
326 mc_todregs rtclk;
327
328 s = splclock();
329 if (rtcget(&rtclk)) {
330 splx(s);
331 return -1;
332 }
333 splx(s);
334
335 dt->dt_sec = bcdtobin(rtclk[MC_SEC]);
336 dt->dt_min = bcdtobin(rtclk[MC_MIN]);
337 dt->dt_hour = bcdtobin(rtclk[MC_HOUR]);
338 dt->dt_day = bcdtobin(rtclk[MC_DOM]);
339 dt->dt_mon = bcdtobin(rtclk[MC_MONTH]);
340 dt->dt_year = clock_expandyear(bcdtobin(rtclk[MC_YEAR]));
341
342 return 0;
343 }
344
345 int
rtc_set_ymdhms(todr_chip_handle_t tch,struct clock_ymdhms * dt)346 rtc_set_ymdhms(todr_chip_handle_t tch, struct clock_ymdhms *dt)
347 {
348 mc_todregs rtclk;
349 int century;
350 int s;
351
352 s = splclock();
353 if (rtcget(&rtclk))
354 memset(&rtclk, 0, sizeof(rtclk));
355 splx(s);
356
357 rtclk[MC_SEC] = bintobcd(dt->dt_sec);
358 rtclk[MC_MIN] = bintobcd(dt->dt_min);
359 rtclk[MC_HOUR] = bintobcd(dt->dt_hour);
360 rtclk[MC_DOW] = dt->dt_wday + 1;
361 rtclk[MC_YEAR] = bintobcd(dt->dt_year % 100);
362 rtclk[MC_MONTH] = bintobcd(dt->dt_mon);
363 rtclk[MC_DOM] = bintobcd(dt->dt_day);
364
365 #ifdef DEBUG_CLOCK
366 printf("setclock: %x/%x/%x %x:%x:%x\n", rtclk[MC_YEAR], rtclk[MC_MONTH],
367 rtclk[MC_DOM], rtclk[MC_HOUR], rtclk[MC_MIN], rtclk[MC_SEC]);
368 #endif
369 s = splclock();
370 rtcput(&rtclk);
371 if (rtc_update_century > 0) {
372 century = bintobcd(dt->dt_year / 100);
373 mc146818_write(NULL, centb, century); /* XXX softc */
374 }
375 splx(s);
376 return 0;
377
378 }
379
380 void
rtc_register(void)381 rtc_register(void)
382 {
383 static struct todr_chip_handle tch;
384 tch.todr_gettime_ymdhms = rtc_get_ymdhms;
385 tch.todr_settime_ymdhms = rtc_set_ymdhms;
386 tch.todr_setwen = NULL;
387
388 todr_attach(&tch);
389 }
390
391