xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_pcfclock.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/sockio.h>
36 #include <sys/mbuf.h>
37 #include <sys/kernel.h>
38 #include <sys/module.h>
39 #include <sys/conf.h>
40 #include <sys/fcntl.h>
41 #include <sys/uio.h>
42 
43 #include <machine/bus.h>
44 #include <machine/resource.h>
45 
46 #include <dev/ppbus/ppbconf.h>
47 #include <dev/ppbus/ppb_msq.h>
48 #include <dev/ppbus/ppbio.h>
49 
50 #include "ppbus_if.h"
51 
52 #define PCFCLOCK_NAME "pcfclock"
53 
54 struct pcfclock_data {
55 	int	count;
56 };
57 
58 #define DEVTOSOFTC(dev) \
59 	((struct pcfclock_data *)device_get_softc(dev))
60 #define UNITOSOFTC(unit) \
61 	((struct pcfclock_data *)devclass_get_softc(pcfclock_devclass, (unit)))
62 #define UNITODEVICE(unit) \
63 	(devclass_get_device(pcfclock_devclass, (unit)))
64 
65 static devclass_t pcfclock_devclass;
66 
67 static	d_open_t		pcfclock_open;
68 static	d_close_t		pcfclock_close;
69 static	d_read_t		pcfclock_read;
70 
71 static struct cdevsw pcfclock_cdevsw = {
72 	.d_version =	D_VERSION,
73 	.d_flags =	D_NEEDGIANT,
74 	.d_open =	pcfclock_open,
75 	.d_close =	pcfclock_close,
76 	.d_read =	pcfclock_read,
77 	.d_name =	PCFCLOCK_NAME,
78 };
79 
80 #ifndef PCFCLOCK_MAX_RETRIES
81 #define PCFCLOCK_MAX_RETRIES 10
82 #endif
83 
84 #define AFC_HI 0
85 #define AFC_LO AUTOFEED
86 
87 /* AUTO FEED is used as clock */
88 #define AUTOFEED_CLOCK(val) \
89 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
90 
91 /* SLCT is used as clock */
92 #define CLOCK_OK \
93 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
94 
95 /* PE is used as data */
96 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
97 
98 /* the first byte sent as reply must be 00001001b */
99 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
100 
101 #define NR(buf, off) (buf[off+1]*10+buf[off])
102 
103 /* check for correct input values */
104 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
105 	NR(buf, 14) <= 99 && \
106 	NR(buf, 12) <= 12 && \
107 	NR(buf, 10) <= 31 && \
108 	NR(buf,  6) <= 23 && \
109 	NR(buf,  4) <= 59 && \
110 	NR(buf,  2) <= 59)
111 
112 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
113 
114 #define PCFCLOCK_CMD_TIME 0		/* send current time */
115 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
116 
117 static void
118 pcfclock_identify(driver_t *driver, device_t parent)
119 {
120 
121 	device_t dev;
122 
123 	dev = device_find_child(parent, PCFCLOCK_NAME, 0);
124 	if (!dev)
125 		BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
126 }
127 
128 static int
129 pcfclock_probe(device_t dev)
130 {
131 	struct pcfclock_data *sc;
132 
133 	device_set_desc(dev, "PCF-1.0");
134 
135 	sc = DEVTOSOFTC(dev);
136 	bzero(sc, sizeof(struct pcfclock_data));
137 
138 	return (0);
139 }
140 
141 static int
142 pcfclock_attach(device_t dev)
143 {
144 	int unit;
145 
146 	unit = device_get_unit(dev);
147 
148 	make_dev(&pcfclock_cdevsw, unit,
149 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
150 
151 	return (0);
152 }
153 
154 static int
155 pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
156 {
157 	u_int unit = minor(dev);
158 	struct pcfclock_data *sc = UNITOSOFTC(unit);
159 	device_t pcfclockdev = UNITODEVICE(unit);
160 	device_t ppbus = device_get_parent(pcfclockdev);
161 	int res;
162 
163 	if (!sc)
164 		return (ENXIO);
165 
166 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
167 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
168 		return (res);
169 
170 	sc->count++;
171 
172 	return (0);
173 }
174 
175 static int
176 pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
177 {
178 	u_int unit = minor(dev);
179 	struct pcfclock_data *sc = UNITOSOFTC(unit);
180 	device_t pcfclockdev = UNITODEVICE(unit);
181 	device_t ppbus = device_get_parent(pcfclockdev);
182 
183 	sc->count--;
184 	if (sc->count == 0)
185 		ppb_release_bus(ppbus, pcfclockdev);
186 
187 	return (0);
188 }
189 
190 static void
191 pcfclock_write_cmd(struct cdev *dev, unsigned char command)
192 {
193 	u_int unit = minor(dev);
194 	device_t ppidev = UNITODEVICE(unit);
195         device_t ppbus = device_get_parent(ppidev);
196 	unsigned char ctr = 14;
197 	char i;
198 
199 	for (i = 0; i <= 7; i++) {
200 		ppb_wdtr(ppbus, i);
201 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
202 		DELAY(3000);
203 	}
204 	ppb_wdtr(ppbus, command);
205 	AUTOFEED_CLOCK(AFC_LO);
206 	DELAY(3000);
207 	AUTOFEED_CLOCK(AFC_HI);
208 }
209 
210 static void
211 pcfclock_display_data(struct cdev *dev, char buf[18])
212 {
213 	u_int unit = minor(dev);
214 #ifdef PCFCLOCK_VERBOSE
215 	int year;
216 
217 	year = NR(buf, 14);
218 	if (year < 70)
219 		year += 100;
220 
221 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
222 			"battery status: %s\n",
223 			unit,
224 			NR(buf, 10), NR(buf, 12), 1900 + year,
225 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
226 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
227 #else
228 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
229 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
230 				unit);
231 #endif
232 }
233 
234 static int
235 pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
236 {
237 	u_int unit = minor(dev);
238 	device_t ppidev = UNITODEVICE(unit);
239         device_t ppbus = device_get_parent(ppidev);
240 	int i;
241 	char waitfor;
242 	int offset;
243 
244 	/* one byte per four bits */
245 	bzero(buf, ((bits + 3) >> 2) + 1);
246 
247 	waitfor = 100;
248 	for (i = 0; i <= bits; i++) {
249 		/* wait for clock, maximum (waitfor*100) usec */
250 		while(!CLOCK_OK && --waitfor > 0)
251 			DELAY(100);
252 
253 		/* timed out? */
254 		if (!waitfor)
255 			return (EIO);
256 
257 		waitfor = 100; /* reload */
258 
259 		/* give it some time */
260 		DELAY(500);
261 
262 		/* calculate offset into buffer */
263 		offset = i >> 2;
264 		buf[offset] <<= 1;
265 
266 		if (BIT_SET)
267 			buf[offset] |= 1;
268 	}
269 
270 	return (0);
271 }
272 
273 static int
274 pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
275 {
276 	u_int unit = minor(dev);
277 	device_t ppidev = UNITODEVICE(unit);
278         device_t ppbus = device_get_parent(ppidev);
279 	int error = 0;
280 
281 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
282 
283 	while (--maxretries > 0) {
284 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
285 		if (pcfclock_read_data(dev, buf, 68))
286 			continue;
287 
288 		if (!PCFCLOCK_CORRECT_SYNC(buf))
289 			continue;
290 
291 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
292 			continue;
293 
294 		break;
295 	}
296 
297 	if (!maxretries)
298 		error = EIO;
299 
300 	return (error);
301 }
302 
303 static int
304 pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
305 {
306 	u_int unit = minor(dev);
307 	char buf[18];
308 	int error = 0;
309 
310 	if (uio->uio_resid < 18)
311 		return (ERANGE);
312 
313 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
314 
315 	if (error) {
316 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
317 	} else {
318 		pcfclock_display_data(dev, buf);
319 
320 		uiomove(buf, 18, uio);
321 	}
322 
323 	return (error);
324 }
325 
326 static device_method_t pcfclock_methods[] = {
327 	/* device interface */
328 	DEVMETHOD(device_identify,	pcfclock_identify),
329 	DEVMETHOD(device_probe,		pcfclock_probe),
330 	DEVMETHOD(device_attach,	pcfclock_attach),
331 
332 	{ 0, 0 }
333 };
334 
335 static driver_t pcfclock_driver = {
336 	PCFCLOCK_NAME,
337 	pcfclock_methods,
338 	sizeof(struct pcfclock_data),
339 };
340 
341 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
342