xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 7ac40f5f59dea6e9ab4869e974bdd4026274e921)
1 /*
2  * Copyright (c) 2000 Sascha Schumann. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY SASCHA SCHUMANN ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
15  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
16  * EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
18  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
19  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
20  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
21  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
22  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  *
24  * $FreeBSD$
25  *
26  */
27 
28 #include "opt_pcfclock.h"
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/sockio.h>
34 #include <sys/mbuf.h>
35 #include <sys/kernel.h>
36 #include <sys/conf.h>
37 #include <sys/fcntl.h>
38 #include <sys/uio.h>
39 
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 
43 #include <dev/ppbus/ppbconf.h>
44 #include <dev/ppbus/ppb_msq.h>
45 #include <dev/ppbus/ppbio.h>
46 
47 #include "ppbus_if.h"
48 
49 #define PCFCLOCK_NAME "pcfclock"
50 
51 struct pcfclock_data {
52 	int	count;
53 };
54 
55 #define DEVTOSOFTC(dev) \
56 	((struct pcfclock_data *)device_get_softc(dev))
57 #define UNITOSOFTC(unit) \
58 	((struct pcfclock_data *)devclass_get_softc(pcfclock_devclass, (unit)))
59 #define UNITODEVICE(unit) \
60 	(devclass_get_device(pcfclock_devclass, (unit)))
61 
62 static devclass_t pcfclock_devclass;
63 
64 static	d_open_t		pcfclock_open;
65 static	d_close_t		pcfclock_close;
66 static	d_read_t		pcfclock_read;
67 
68 #define CDEV_MAJOR 140
69 static struct cdevsw pcfclock_cdevsw = {
70 	.d_open =	pcfclock_open,
71 	.d_close =	pcfclock_close,
72 	.d_read =	pcfclock_read,
73 	.d_name =	PCFCLOCK_NAME,
74 	.d_maj =	CDEV_MAJOR,
75 };
76 
77 #ifndef PCFCLOCK_MAX_RETRIES
78 #define PCFCLOCK_MAX_RETRIES 10
79 #endif
80 
81 #define AFC_HI 0
82 #define AFC_LO AUTOFEED
83 
84 /* AUTO FEED is used as clock */
85 #define AUTOFEED_CLOCK(val) \
86 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
87 
88 /* SLCT is used as clock */
89 #define CLOCK_OK \
90 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
91 
92 /* PE is used as data */
93 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
94 
95 /* the first byte sent as reply must be 00001001b */
96 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
97 
98 #define NR(buf, off) (buf[off+1]*10+buf[off])
99 
100 /* check for correct input values */
101 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
102 	NR(buf, 14) <= 99 && \
103 	NR(buf, 12) <= 12 && \
104 	NR(buf, 10) <= 31 && \
105 	NR(buf,  6) <= 23 && \
106 	NR(buf,  4) <= 59 && \
107 	NR(buf,  2) <= 59)
108 
109 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
110 
111 #define PCFCLOCK_CMD_TIME 0		/* send current time */
112 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
113 
114 static void
115 pcfclock_identify(driver_t *driver, device_t parent)
116 {
117 
118 	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
119 }
120 
121 static int
122 pcfclock_probe(device_t dev)
123 {
124 	struct pcfclock_data *sc;
125 
126 	device_set_desc(dev, "PCF-1.0");
127 
128 	sc = DEVTOSOFTC(dev);
129 	bzero(sc, sizeof(struct pcfclock_data));
130 
131 	return (0);
132 }
133 
134 static int
135 pcfclock_attach(device_t dev)
136 {
137 	int unit;
138 
139 	unit = device_get_unit(dev);
140 
141 	make_dev(&pcfclock_cdevsw, unit,
142 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
143 
144 	return (0);
145 }
146 
147 static int
148 pcfclock_open(dev_t dev, int flag, int fms, struct thread *td)
149 {
150 	u_int unit = minor(dev);
151 	struct pcfclock_data *sc = UNITOSOFTC(unit);
152 	device_t pcfclockdev = UNITODEVICE(unit);
153 	device_t ppbus = device_get_parent(pcfclockdev);
154 	int res;
155 
156 	if (!sc)
157 		return (ENXIO);
158 
159 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
160 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
161 		return (res);
162 
163 	sc->count++;
164 
165 	return (0);
166 }
167 
168 static int
169 pcfclock_close(dev_t dev, int flags, int fmt, struct thread *td)
170 {
171 	u_int unit = minor(dev);
172 	struct pcfclock_data *sc = UNITOSOFTC(unit);
173 	device_t pcfclockdev = UNITODEVICE(unit);
174 	device_t ppbus = device_get_parent(pcfclockdev);
175 
176 	sc->count--;
177 	if (sc->count == 0)
178 		ppb_release_bus(ppbus, pcfclockdev);
179 
180 	return (0);
181 }
182 
183 static void
184 pcfclock_write_cmd(dev_t dev, unsigned char command)
185 {
186 	u_int unit = minor(dev);
187 	device_t ppidev = UNITODEVICE(unit);
188         device_t ppbus = device_get_parent(ppidev);
189 	unsigned char ctr = 14;
190 	char i;
191 
192 	for (i = 0; i <= 7; i++) {
193 		ppb_wdtr(ppbus, i);
194 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
195 		DELAY(3000);
196 	}
197 	ppb_wdtr(ppbus, command);
198 	AUTOFEED_CLOCK(AFC_LO);
199 	DELAY(3000);
200 	AUTOFEED_CLOCK(AFC_HI);
201 }
202 
203 static void
204 pcfclock_display_data(dev_t dev, char buf[18])
205 {
206 	u_int unit = minor(dev);
207 #ifdef PCFCLOCK_VERBOSE
208 	int year;
209 
210 	year = NR(buf, 14);
211 	if (year < 70)
212 		year += 100;
213 
214 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
215 			"battery status: %s\n",
216 			unit,
217 			NR(buf, 10), NR(buf, 12), 1900 + year,
218 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
219 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
220 #else
221 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
222 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
223 				unit);
224 #endif
225 }
226 
227 static int
228 pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
229 {
230 	u_int unit = minor(dev);
231 	device_t ppidev = UNITODEVICE(unit);
232         device_t ppbus = device_get_parent(ppidev);
233 	int i;
234 	char waitfor;
235 	int offset;
236 
237 	/* one byte per four bits */
238 	bzero(buf, ((bits + 3) >> 2) + 1);
239 
240 	waitfor = 100;
241 	for (i = 0; i <= bits; i++) {
242 		/* wait for clock, maximum (waitfor*100) usec */
243 		while(!CLOCK_OK && --waitfor > 0)
244 			DELAY(100);
245 
246 		/* timed out? */
247 		if (!waitfor)
248 			return (EIO);
249 
250 		waitfor = 100; /* reload */
251 
252 		/* give it some time */
253 		DELAY(500);
254 
255 		/* calculate offset into buffer */
256 		offset = i >> 2;
257 		buf[offset] <<= 1;
258 
259 		if (BIT_SET)
260 			buf[offset] |= 1;
261 	}
262 
263 	return (0);
264 }
265 
266 static int
267 pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
268 {
269 	u_int unit = minor(dev);
270 	device_t ppidev = UNITODEVICE(unit);
271         device_t ppbus = device_get_parent(ppidev);
272 	int error = 0;
273 
274 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
275 
276 	while (--maxretries > 0) {
277 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
278 		if (pcfclock_read_data(dev, buf, 68))
279 			continue;
280 
281 		if (!PCFCLOCK_CORRECT_SYNC(buf))
282 			continue;
283 
284 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
285 			continue;
286 
287 		break;
288 	}
289 
290 	if (!maxretries)
291 		error = EIO;
292 
293 	return (error);
294 }
295 
296 static int
297 pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
298 {
299 	u_int unit = minor(dev);
300 	char buf[18];
301 	int error = 0;
302 
303 	if (uio->uio_resid < 18)
304 		return (ERANGE);
305 
306 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
307 
308 	if (error) {
309 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
310 	} else {
311 		pcfclock_display_data(dev, buf);
312 
313 		uiomove(buf, 18, uio);
314 	}
315 
316 	return (error);
317 }
318 
319 static device_method_t pcfclock_methods[] = {
320 	/* device interface */
321 	DEVMETHOD(device_identify,	pcfclock_identify),
322 	DEVMETHOD(device_probe,		pcfclock_probe),
323 	DEVMETHOD(device_attach,	pcfclock_attach),
324 
325 	{ 0, 0 }
326 };
327 
328 static driver_t pcfclock_driver = {
329 	PCFCLOCK_NAME,
330 	pcfclock_methods,
331 	sizeof(struct pcfclock_data),
332 };
333 
334 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
335