xref: /freebsd/sys/x86/isa/atrtc.c (revision d8b878873e7aa8df1972cc6a642804b17eb61087)
1 /*-
2  * Copyright (c) 2008 Poul-Henning Kamp
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_isa.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/clock.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/kernel.h>
41 #include <sys/module.h>
42 
43 #include <isa/rtc.h>
44 #ifdef DEV_ISA
45 #include <isa/isareg.h>
46 #include <isa/isavar.h>
47 #endif
48 
49 #define	RTC_LOCK	mtx_lock_spin(&clock_lock)
50 #define	RTC_UNLOCK	mtx_unlock_spin(&clock_lock)
51 
52 int	atrtcclock_disable = 0;
53 
54 static	int	rtc_reg = -1;
55 static	u_char	rtc_statusa = RTCSA_DIVIDER | RTCSA_NOPROF;
56 static	u_char	rtc_statusb = RTCSB_24HR;
57 
58 /*
59  * RTC support routines
60  */
61 
62 int
63 rtcin(int reg)
64 {
65 	u_char val;
66 
67 	RTC_LOCK;
68 	if (rtc_reg != reg) {
69 		inb(0x84);
70 		outb(IO_RTC, reg);
71 		rtc_reg = reg;
72 		inb(0x84);
73 	}
74 	val = inb(IO_RTC + 1);
75 	RTC_UNLOCK;
76 	return (val);
77 }
78 
79 void
80 writertc(int reg, u_char val)
81 {
82 
83 	RTC_LOCK;
84 	if (rtc_reg != reg) {
85 		inb(0x84);
86 		outb(IO_RTC, reg);
87 		rtc_reg = reg;
88 		inb(0x84);
89 	}
90 	outb(IO_RTC + 1, val);
91 	inb(0x84);
92 	RTC_UNLOCK;
93 }
94 
95 static __inline int
96 readrtc(int port)
97 {
98 	return(bcd2bin(rtcin(port)));
99 }
100 
101 void
102 atrtc_start(void)
103 {
104 
105 	writertc(RTC_STATUSA, rtc_statusa);
106 	writertc(RTC_STATUSB, RTCSB_24HR);
107 }
108 
109 void
110 atrtc_rate(unsigned rate)
111 {
112 
113 	rtc_statusa = RTCSA_DIVIDER | rate;
114 	writertc(RTC_STATUSA, rtc_statusa);
115 }
116 
117 void
118 atrtc_enable_intr(void)
119 {
120 
121 	rtc_statusb |= RTCSB_PINTR;
122 	writertc(RTC_STATUSB, rtc_statusb);
123 	rtcin(RTC_INTR);
124 }
125 
126 void
127 atrtc_restore(void)
128 {
129 
130 	/* Restore all of the RTC's "status" (actually, control) registers. */
131 	rtcin(RTC_STATUSA);	/* dummy to get rtc_reg set */
132 	writertc(RTC_STATUSB, RTCSB_24HR);
133 	writertc(RTC_STATUSA, rtc_statusa);
134 	writertc(RTC_STATUSB, rtc_statusb);
135 	rtcin(RTC_INTR);
136 }
137 
138 int
139 atrtc_setup_clock(void)
140 {
141 	int diag;
142 
143 	if (atrtcclock_disable)
144 		return (0);
145 
146 	diag = rtcin(RTC_DIAG);
147 	if (diag != 0) {
148 		printf("RTC BIOS diagnostic error %b\n",
149 		    diag, RTCDG_BITS);
150 		return (0);
151 	}
152 
153 	stathz = RTC_NOPROFRATE;
154 	profhz = RTC_PROFRATE;
155 
156 	return (1);
157 }
158 
159 /**********************************************************************
160  * RTC driver for subr_rtc
161  */
162 
163 #include "clock_if.h"
164 
165 #include <sys/rman.h>
166 
167 struct atrtc_softc {
168 	int port_rid, intr_rid;
169 	struct resource *port_res;
170 	struct resource *intr_res;
171 };
172 
173 /*
174  * Attach to the ISA PnP descriptors for the timer and realtime clock.
175  */
176 static struct isa_pnp_id atrtc_ids[] = {
177 	{ 0x000bd041 /* PNP0B00 */, "AT realtime clock" },
178 	{ 0 }
179 };
180 
181 static int
182 atrtc_probe(device_t dev)
183 {
184 	int result;
185 
186 	device_set_desc(dev, "AT Real Time Clock");
187 	result = ISA_PNP_PROBE(device_get_parent(dev), dev, atrtc_ids);
188 	/* ENXIO if wrong PnP-ID, ENOENT ifno PnP-ID, zero if good PnP-iD */
189 	if (result != ENOENT)
190 		return(result);
191 	/* All PC's have an RTC, and we're hosed without it, so... */
192 	return (BUS_PROBE_LOW_PRIORITY);
193 }
194 
195 static int
196 atrtc_attach(device_t dev)
197 {
198 	struct atrtc_softc *sc;
199 	int i;
200 
201 	/*
202 	 * Not that we need them or anything, but grab our resources
203 	 * so they show up, correctly attributed, in the big picture.
204 	 */
205 
206 	sc = device_get_softc(dev);
207 	if (!(sc->port_res = bus_alloc_resource(dev, SYS_RES_IOPORT,
208 	    &sc->port_rid, IO_RTC, IO_RTC + 1, 2, RF_ACTIVE)))
209 		device_printf(dev,"Warning: Couldn't map I/O.\n");
210 	if (!(sc->intr_res = bus_alloc_resource(dev, SYS_RES_IRQ,
211 	    &sc->intr_rid, 8, 8, 1, RF_ACTIVE)))
212 		device_printf(dev,"Warning: Couldn't map Interrupt.\n");
213 	clock_register(dev, 1000000);
214 	if (resource_int_value("atrtc", 0, "clock", &i) == 0 && i == 0)
215 		atrtcclock_disable = 1;
216 	return(0);
217 }
218 
219 static int
220 atrtc_resume(device_t dev)
221 {
222 
223 	atrtc_restore();
224 	return(0);
225 }
226 
227 static int
228 atrtc_settime(device_t dev __unused, struct timespec *ts)
229 {
230 	struct clocktime ct;
231 
232 	clock_ts_to_ct(ts, &ct);
233 
234 	/* Disable RTC updates and interrupts. */
235 	writertc(RTC_STATUSB, RTCSB_HALT | RTCSB_24HR);
236 
237 	writertc(RTC_SEC, bin2bcd(ct.sec)); 		/* Write back Seconds */
238 	writertc(RTC_MIN, bin2bcd(ct.min)); 		/* Write back Minutes */
239 	writertc(RTC_HRS, bin2bcd(ct.hour));		/* Write back Hours   */
240 
241 	writertc(RTC_WDAY, ct.dow + 1);			/* Write back Weekday */
242 	writertc(RTC_DAY, bin2bcd(ct.day));		/* Write back Day */
243 	writertc(RTC_MONTH, bin2bcd(ct.mon));           /* Write back Month   */
244 	writertc(RTC_YEAR, bin2bcd(ct.year % 100));	/* Write back Year    */
245 #ifdef USE_RTC_CENTURY
246 	writertc(RTC_CENTURY, bin2bcd(ct.year / 100));	/* ... and Century    */
247 #endif
248 
249 	/* Reenable RTC updates and interrupts. */
250 	writertc(RTC_STATUSB, rtc_statusb);
251 	rtcin(RTC_INTR);
252 	return (0);
253 }
254 
255 static int
256 atrtc_gettime(device_t dev, struct timespec *ts)
257 {
258 	struct clocktime ct;
259 	int s;
260 
261 	/* Look if we have a RTC present and the time is valid */
262 	if (!(rtcin(RTC_STATUSD) & RTCSD_PWR)) {
263 		device_printf(dev, "WARNING: Battery failure indication\n");
264 		return (EINVAL);
265 	}
266 
267 	/* wait for time update to complete */
268 	/* If RTCSA_TUP is zero, we have at least 244us before next update */
269 	s = splhigh();
270 	while (rtcin(RTC_STATUSA) & RTCSA_TUP) {
271 		splx(s);
272 		s = splhigh();
273 	}
274 	ct.nsec = 0;
275 	ct.sec = readrtc(RTC_SEC);
276 	ct.min = readrtc(RTC_MIN);
277 	ct.hour = readrtc(RTC_HRS);
278 	ct.day = readrtc(RTC_DAY);
279 	ct.dow = readrtc(RTC_WDAY) - 1;
280 	ct.mon = readrtc(RTC_MONTH);
281 	ct.year = readrtc(RTC_YEAR);
282 #ifdef USE_RTC_CENTURY
283 	ct.year += readrtc(RTC_CENTURY) * 100;
284 #else
285 	ct.year += 2000;
286 #endif
287 	/* Set dow = -1 because some clocks don't set it correctly. */
288 	ct.dow = -1;
289 	return (clock_ct_to_ts(&ct, ts));
290 }
291 
292 static device_method_t atrtc_methods[] = {
293 	/* Device interface */
294 	DEVMETHOD(device_probe,		atrtc_probe),
295 	DEVMETHOD(device_attach,	atrtc_attach),
296 	DEVMETHOD(device_detach,	bus_generic_detach),
297 	DEVMETHOD(device_shutdown,	bus_generic_shutdown),
298 	DEVMETHOD(device_suspend,	bus_generic_suspend),
299 		/* XXX stop statclock? */
300 	DEVMETHOD(device_resume,	atrtc_resume),
301 
302 	/* clock interface */
303 	DEVMETHOD(clock_gettime,	atrtc_gettime),
304 	DEVMETHOD(clock_settime,	atrtc_settime),
305 
306 	{ 0, 0 }
307 };
308 
309 static driver_t atrtc_driver = {
310 	"atrtc",
311 	atrtc_methods,
312 	sizeof(struct atrtc_softc),
313 };
314 
315 static devclass_t atrtc_devclass;
316 
317 DRIVER_MODULE(atrtc, isa, atrtc_driver, atrtc_devclass, 0, 0);
318 DRIVER_MODULE(atrtc, acpi, atrtc_driver, atrtc_devclass, 0, 0);
319 
320 #include "opt_ddb.h"
321 #ifdef DDB
322 #include <ddb/ddb.h>
323 
324 DB_SHOW_COMMAND(rtc, rtc)
325 {
326 	printf("%02x/%02x/%02x %02x:%02x:%02x, A = %02x, B = %02x, C = %02x\n",
327 		rtcin(RTC_YEAR), rtcin(RTC_MONTH), rtcin(RTC_DAY),
328 		rtcin(RTC_HRS), rtcin(RTC_MIN), rtcin(RTC_SEC),
329 		rtcin(RTC_STATUSA), rtcin(RTC_STATUSB), rtcin(RTC_INTR));
330 }
331 #endif /* DDB */
332