xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 41466b50c1d5bfd1cf6adaae547a579a75d7c04e)
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 	/* open */	pcfclock_open,
71 	/* close */	pcfclock_close,
72 	/* read */	pcfclock_read,
73 	/* write */	nowrite,
74 	/* ioctl */	noioctl,
75 	/* poll */	nopoll,
76 	/* mmap */	nommap,
77 	/* strategy */	nostrategy,
78 	/* name */	PCFCLOCK_NAME,
79 	/* maj */	CDEV_MAJOR,
80 	/* dump */	nodump,
81 	/* psize */	nopsize,
82 	/* flags */	0,
83 };
84 
85 #ifndef PCFCLOCK_MAX_RETRIES
86 #define PCFCLOCK_MAX_RETRIES 10
87 #endif
88 
89 #define AFC_HI 0
90 #define AFC_LO AUTOFEED
91 
92 /* AUTO FEED is used as clock */
93 #define AUTOFEED_CLOCK(val) \
94 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
95 
96 /* SLCT is used as clock */
97 #define CLOCK_OK \
98 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
99 
100 /* PE is used as data */
101 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
102 
103 /* the first byte sent as reply must be 00001001b */
104 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
105 
106 #define NR(buf, off) (buf[off+1]*10+buf[off])
107 
108 /* check for correct input values */
109 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
110 	NR(buf, 14) <= 99 && \
111 	NR(buf, 12) <= 12 && \
112 	NR(buf, 10) <= 31 && \
113 	NR(buf,  6) <= 23 && \
114 	NR(buf,  4) <= 59 && \
115 	NR(buf,  2) <= 59)
116 
117 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
118 
119 #define PCFCLOCK_CMD_TIME 0		/* send current time */
120 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
121 
122 static void
123 pcfclock_identify(driver_t *driver, device_t parent)
124 {
125 
126 	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, 0);
127 }
128 
129 static int
130 pcfclock_probe(device_t dev)
131 {
132 	struct pcfclock_data *sc;
133 
134 	device_set_desc(dev, "PCF-1.0");
135 
136 	sc = DEVTOSOFTC(dev);
137 	bzero(sc, sizeof(struct pcfclock_data));
138 
139 	return (0);
140 }
141 
142 static int
143 pcfclock_attach(device_t dev)
144 {
145 	int unit;
146 
147 	unit = device_get_unit(dev);
148 
149 	make_dev(&pcfclock_cdevsw, unit,
150 			UID_ROOT, GID_WHEEL, 0444, PCFCLOCK_NAME "%d", unit);
151 
152 	return (0);
153 }
154 
155 static int
156 pcfclock_open(dev_t dev, int flag, int fms, struct thread *td)
157 {
158 	u_int unit = minor(dev);
159 	struct pcfclock_data *sc = UNITOSOFTC(unit);
160 	device_t pcfclockdev = UNITODEVICE(unit);
161 	device_t ppbus = device_get_parent(pcfclockdev);
162 	int res;
163 
164 	if (!sc)
165 		return (ENXIO);
166 
167 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
168 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
169 		return (res);
170 
171 	sc->count++;
172 
173 	return (0);
174 }
175 
176 static int
177 pcfclock_close(dev_t dev, int flags, int fmt, struct thread *td)
178 {
179 	u_int unit = minor(dev);
180 	struct pcfclock_data *sc = UNITOSOFTC(unit);
181 	device_t pcfclockdev = UNITODEVICE(unit);
182 	device_t ppbus = device_get_parent(pcfclockdev);
183 
184 	sc->count--;
185 	if (sc->count == 0)
186 		ppb_release_bus(ppbus, pcfclockdev);
187 
188 	return (0);
189 }
190 
191 static void
192 pcfclock_write_cmd(dev_t dev, unsigned char command)
193 {
194 	u_int unit = minor(dev);
195 	device_t ppidev = UNITODEVICE(unit);
196         device_t ppbus = device_get_parent(ppidev);
197 	unsigned char ctr = 14;
198 	char i;
199 
200 	for (i = 0; i <= 7; i++) {
201 		ppb_wdtr(ppbus, i);
202 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
203 		DELAY(3000);
204 	}
205 	ppb_wdtr(ppbus, command);
206 	AUTOFEED_CLOCK(AFC_LO);
207 	DELAY(3000);
208 	AUTOFEED_CLOCK(AFC_HI);
209 }
210 
211 static void
212 pcfclock_display_data(dev_t dev, char buf[18])
213 {
214 	u_int unit = minor(dev);
215 #ifdef PCFCLOCK_VERBOSE
216 	int year;
217 
218 	year = NR(buf, 14);
219 	if (year < 70)
220 		year += 100;
221 
222 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
223 			"battery status: %s\n",
224 			unit,
225 			NR(buf, 10), NR(buf, 12), 1900 + year,
226 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
227 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
228 #else
229 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
230 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
231 				unit);
232 #endif
233 }
234 
235 static int
236 pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
237 {
238 	u_int unit = minor(dev);
239 	device_t ppidev = UNITODEVICE(unit);
240         device_t ppbus = device_get_parent(ppidev);
241 	int i;
242 	char waitfor;
243 	int offset;
244 
245 	/* one byte per four bits */
246 	bzero(buf, ((bits + 3) >> 2) + 1);
247 
248 	waitfor = 100;
249 	for (i = 0; i <= bits; i++) {
250 		/* wait for clock, maximum (waitfor*100) usec */
251 		while(!CLOCK_OK && --waitfor > 0)
252 			DELAY(100);
253 
254 		/* timed out? */
255 		if (!waitfor)
256 			return (EIO);
257 
258 		waitfor = 100; /* reload */
259 
260 		/* give it some time */
261 		DELAY(500);
262 
263 		/* calculate offset into buffer */
264 		offset = i >> 2;
265 		buf[offset] <<= 1;
266 
267 		if (BIT_SET)
268 			buf[offset] |= 1;
269 	}
270 
271 	return (0);
272 }
273 
274 static int
275 pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
276 {
277 	u_int unit = minor(dev);
278 	device_t ppidev = UNITODEVICE(unit);
279         device_t ppbus = device_get_parent(ppidev);
280 	int error = 0;
281 
282 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
283 
284 	while (--maxretries > 0) {
285 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
286 		if (pcfclock_read_data(dev, buf, 68))
287 			continue;
288 
289 		if (!PCFCLOCK_CORRECT_SYNC(buf))
290 			continue;
291 
292 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
293 			continue;
294 
295 		break;
296 	}
297 
298 	if (!maxretries)
299 		error = EIO;
300 
301 	return (error);
302 }
303 
304 static ssize_t
305 pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
306 {
307 	u_int unit = minor(dev);
308 	char buf[18];
309 	int error = 0;
310 
311 	if (uio->uio_resid < 18)
312 		return (ERANGE);
313 
314 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
315 
316 	if (error) {
317 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
318 	} else {
319 		pcfclock_display_data(dev, buf);
320 
321 		uiomove(buf, 18, uio);
322 	}
323 
324 	return (error);
325 }
326 
327 static device_method_t pcfclock_methods[] = {
328 	/* device interface */
329 	DEVMETHOD(device_identify,	pcfclock_identify),
330 	DEVMETHOD(device_probe,		pcfclock_probe),
331 	DEVMETHOD(device_attach,	pcfclock_attach),
332 
333 	{ 0, 0 }
334 };
335 
336 static driver_t pcfclock_driver = {
337 	PCFCLOCK_NAME,
338 	pcfclock_methods,
339 	sizeof(struct pcfclock_data),
340 };
341 
342 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
343