xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 23f282aa31e9b6fceacd449020e936e98d6f2298)
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 REGENTS 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 #include <machine/clock.h>      /* for DELAY */
43 
44 #include <dev/ppbus/ppbconf.h>
45 #include <dev/ppbus/ppb_msq.h>
46 #include <dev/ppbus/ppbio.h>
47 
48 #include "ppbus_if.h"
49 
50 #define PCFCLOCK_NAME "pcfclock"
51 
52 struct pcfclock_data {
53 	int	count;
54 	struct	ppb_device pcfclock_dev;
55 };
56 
57 #define DEVTOSOFTC(dev) \
58 	((struct pcfclock_data *)device_get_softc(dev))
59 #define UNITOSOFTC(unit) \
60 	((struct pcfclock_data *)devclass_get_softc(pcfclock_devclass, (unit)))
61 #define UNITODEVICE(unit) \
62 	(devclass_get_device(pcfclock_devclass, (unit)))
63 
64 static devclass_t pcfclock_devclass;
65 
66 static	d_open_t		pcfclock_open;
67 static	d_close_t		pcfclock_close;
68 static	d_read_t		pcfclock_read;
69 
70 #define CDEV_MAJOR 140
71 static struct cdevsw pcfclock_cdevsw = {
72 	/* open */	pcfclock_open,
73 	/* close */	pcfclock_close,
74 	/* read */	pcfclock_read,
75 	/* write */	nowrite,
76 	/* ioctl */	noioctl,
77 	/* poll */	nopoll,
78 	/* mmap */	nommap,
79 	/* strategy */	nostrategy,
80 	/* name */	PCFCLOCK_NAME,
81 	/* maj */	CDEV_MAJOR,
82 	/* dump */	nodump,
83 	/* psize */	nopsize,
84 	/* flags */	0,
85 	/* bmaj */	-1
86 };
87 
88 #ifndef PCFCLOCK_MAX_RETRIES
89 #define PCFCLOCK_MAX_RETRIES 10
90 #endif
91 
92 #define AFC_HI 0
93 #define AFC_LO AUTOFEED
94 
95 /* AUTO FEED is used as clock */
96 #define AUTOFEED_CLOCK(val) \
97 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
98 
99 /* SLCT is used as clock */
100 #define CLOCK_OK \
101 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
102 
103 /* PE is used as data */
104 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
105 
106 /* the first byte sent as reply must be 00001001b */
107 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
108 
109 #define NR(buf, off) (buf[off+1]*10+buf[off])
110 
111 /* check for correct input values */
112 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
113 	NR(buf, 14) <= 99 && \
114 	NR(buf, 12) <= 12 && \
115 	NR(buf, 10) <= 31 && \
116 	NR(buf,  6) <= 23 && \
117 	NR(buf,  4) <= 59 && \
118 	NR(buf,  2) <= 59)
119 
120 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
121 
122 #define PCFCLOCK_CMD_TIME 0		/* send current time */
123 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
124 
125 static void
126 pcfclock_identify(driver_t *driver, device_t parent)
127 {
128 
129 	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, 0);
130 }
131 
132 static int
133 pcfclock_probe(device_t dev)
134 {
135 	struct pcfclock_data *sc;
136 
137 	device_set_desc(dev, "PCF-1.0");
138 
139 	sc = DEVTOSOFTC(dev);
140 	bzero(sc, sizeof(struct pcfclock_data));
141 
142 	return (0);
143 }
144 
145 static int
146 pcfclock_attach(device_t dev)
147 {
148 	int unit;
149 
150 	unit = device_get_unit(dev);
151 
152 	make_dev(&pcfclock_cdevsw, unit,
153 			UID_ROOT, GID_WHEEL, 0444, PCFCLOCK_NAME "%d", unit);
154 
155 	return (0);
156 }
157 
158 static int
159 pcfclock_open(dev_t dev, int flag, int fms, struct proc *p)
160 {
161 	u_int unit = minor(dev);
162 	struct pcfclock_data *sc = UNITOSOFTC(unit);
163 	device_t pcfclockdev = UNITODEVICE(unit);
164 	device_t ppbus = device_get_parent(pcfclockdev);
165 	int res;
166 
167 	if (!sc)
168 		return (ENXIO);
169 
170 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
171 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
172 		return (res);
173 
174 	sc->count++;
175 
176 	return (0);
177 }
178 
179 static int
180 pcfclock_close(dev_t dev, int flags, int fmt, struct proc *p)
181 {
182 	u_int unit = minor(dev);
183 	struct pcfclock_data *sc = UNITOSOFTC(unit);
184 	device_t pcfclockdev = UNITODEVICE(unit);
185 	device_t ppbus = device_get_parent(pcfclockdev);
186 
187 	sc->count--;
188 	if (sc->count == 0) {
189 		ppb_release_bus(ppbus, pcfclockdev);
190 	}
191 
192 	return (0);
193 }
194 
195 static void
196 pcfclock_write_cmd(dev_t dev, unsigned char command)
197 {
198 	u_int unit = minor(dev);
199 	device_t ppidev = UNITODEVICE(unit);
200         device_t ppbus = device_get_parent(ppidev);
201 	unsigned char ctr = 14;
202 	char i;
203 
204 	for (i = 0; i <= 7; i++) {
205 		ppb_wdtr(ppbus, i);
206 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
207 		DELAY(3000);
208 	}
209 	ppb_wdtr(ppbus, command);
210 	AUTOFEED_CLOCK(AFC_LO);
211 	DELAY(3000);
212 	AUTOFEED_CLOCK(AFC_HI);
213 }
214 
215 static void
216 pcfclock_display_data(dev_t dev, char buf[18])
217 {
218 	u_int unit = minor(dev);
219 #ifdef PCFCLOCK_VERBOSE
220 	int year;
221 
222 	year = NR(buf, 14);
223 	if (year < 70)
224 		year += 100;
225 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
226 			"battery status: %s\n",
227 			unit,
228 			NR(buf, 10), NR(buf, 12), 1900 + year,
229 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
230 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
231 #else
232 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
233 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
234 				unit);
235 #endif
236 }
237 
238 static int
239 pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
240 {
241 	u_int unit = minor(dev);
242 	device_t ppidev = UNITODEVICE(unit);
243         device_t ppbus = device_get_parent(ppidev);
244 	int i;
245 	char waitfor;
246 	int offset;
247 
248 	/* one byte per four bits */
249 	bzero(buf, ((bits + 3) >> 2) + 1);
250 
251 	waitfor = 100;
252 	for (i = 0; i <= bits; i++) {
253 		/* wait for clock, maximum (waitfor*100) usec */
254 		while(!CLOCK_OK && --waitfor > 0)
255 			DELAY(100);
256 
257 		/* timed out? */
258 		if (!waitfor)
259 			return (EIO);
260 
261 		waitfor = 100; /* reload */
262 
263 		/* give it some time */
264 		DELAY(500);
265 
266 		/* calculate offset into buffer */
267 		offset = i >> 2;
268 		buf[offset] <<= 1;
269 
270 		if (BIT_SET)
271 			buf[offset] |= 1;
272 	}
273 
274 	return (0);
275 }
276 
277 static int
278 pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
279 {
280 	u_int unit = minor(dev);
281 	device_t ppidev = UNITODEVICE(unit);
282         device_t ppbus = device_get_parent(ppidev);
283 	int error = 0;
284 
285 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
286 
287 	while (--maxretries > 0) {
288 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
289 		if (pcfclock_read_data(dev, buf, 68))
290 			continue;
291 
292 		if (!PCFCLOCK_CORRECT_SYNC(buf))
293 			continue;
294 
295 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
296 			continue;
297 
298 		break;
299 	}
300 
301 	if (!maxretries)
302 		error = EIO;
303 
304 	return (error);
305 }
306 
307 static ssize_t
308 pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
309 {
310 	u_int unit = minor(dev);
311 	char buf[18];
312 	int error = 0;
313 
314 	if (uio->uio_resid < 18)
315 		return (ERANGE);
316 
317 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
318 
319 	if (error) {
320 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
321 	} else {
322 		pcfclock_display_data(dev, buf);
323 
324 		uiomove(buf, 18, uio);
325 	}
326 
327 	return (error);
328 }
329 
330 static device_method_t pcfclock_methods[] = {
331 	/* device interface */
332 	DEVMETHOD(device_identify,	pcfclock_identify),
333 	DEVMETHOD(device_probe,		pcfclock_probe),
334 	DEVMETHOD(device_attach,	pcfclock_attach),
335 
336 	{ 0, 0 }
337 };
338 
339 static driver_t pcfclock_driver = {
340 	PCFCLOCK_NAME,
341 	pcfclock_methods,
342 	sizeof(struct pcfclock_data),
343 };
344 
345 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
346