xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 817420dc8eac7df799c78f5309b75092b7f7cd40)
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 
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 	struct	ppb_device pcfclock_dev;
54 };
55 
56 #define DEVTOSOFTC(dev) \
57 	((struct pcfclock_data *)device_get_softc(dev))
58 #define UNITOSOFTC(unit) \
59 	((struct pcfclock_data *)devclass_get_softc(pcfclock_devclass, (unit)))
60 #define UNITODEVICE(unit) \
61 	(devclass_get_device(pcfclock_devclass, (unit)))
62 
63 static devclass_t pcfclock_devclass;
64 
65 static	d_open_t		pcfclock_open;
66 static	d_close_t		pcfclock_close;
67 static	d_read_t		pcfclock_read;
68 
69 #define CDEV_MAJOR 140
70 static struct cdevsw pcfclock_cdevsw = {
71 	/* open */	pcfclock_open,
72 	/* close */	pcfclock_close,
73 	/* read */	pcfclock_read,
74 	/* write */	nowrite,
75 	/* ioctl */	noioctl,
76 	/* poll */	nopoll,
77 	/* mmap */	nommap,
78 	/* strategy */	nostrategy,
79 	/* name */	PCFCLOCK_NAME,
80 	/* maj */	CDEV_MAJOR,
81 	/* dump */	nodump,
82 	/* psize */	nopsize,
83 	/* flags */	0,
84 	/* bmaj */	-1
85 };
86 
87 #ifndef PCFCLOCK_MAX_RETRIES
88 #define PCFCLOCK_MAX_RETRIES 10
89 #endif
90 
91 #define AFC_HI 0
92 #define AFC_LO AUTOFEED
93 
94 /* AUTO FEED is used as clock */
95 #define AUTOFEED_CLOCK(val) \
96 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
97 
98 /* SLCT is used as clock */
99 #define CLOCK_OK \
100 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
101 
102 /* PE is used as data */
103 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
104 
105 /* the first byte sent as reply must be 00001001b */
106 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
107 
108 #define NR(buf, off) (buf[off+1]*10+buf[off])
109 
110 /* check for correct input values */
111 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
112 	NR(buf, 14) <= 99 && \
113 	NR(buf, 12) <= 12 && \
114 	NR(buf, 10) <= 31 && \
115 	NR(buf,  6) <= 23 && \
116 	NR(buf,  4) <= 59 && \
117 	NR(buf,  2) <= 59)
118 
119 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
120 
121 #define PCFCLOCK_CMD_TIME 0		/* send current time */
122 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
123 
124 static void
125 pcfclock_identify(driver_t *driver, device_t parent)
126 {
127 
128 	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, 0);
129 }
130 
131 static int
132 pcfclock_probe(device_t dev)
133 {
134 	struct pcfclock_data *sc;
135 
136 	device_set_desc(dev, "PCF-1.0");
137 
138 	sc = DEVTOSOFTC(dev);
139 	bzero(sc, sizeof(struct pcfclock_data));
140 
141 	return (0);
142 }
143 
144 static int
145 pcfclock_attach(device_t dev)
146 {
147 	int unit;
148 
149 	unit = device_get_unit(dev);
150 
151 	make_dev(&pcfclock_cdevsw, unit,
152 			UID_ROOT, GID_WHEEL, 0444, PCFCLOCK_NAME "%d", unit);
153 
154 	return (0);
155 }
156 
157 static int
158 pcfclock_open(dev_t dev, int flag, int fms, struct proc *p)
159 {
160 	u_int unit = minor(dev);
161 	struct pcfclock_data *sc = UNITOSOFTC(unit);
162 	device_t pcfclockdev = UNITODEVICE(unit);
163 	device_t ppbus = device_get_parent(pcfclockdev);
164 	int res;
165 
166 	if (!sc)
167 		return (ENXIO);
168 
169 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
170 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
171 		return (res);
172 
173 	sc->count++;
174 
175 	return (0);
176 }
177 
178 static int
179 pcfclock_close(dev_t dev, int flags, int fmt, struct proc *p)
180 {
181 	u_int unit = minor(dev);
182 	struct pcfclock_data *sc = UNITOSOFTC(unit);
183 	device_t pcfclockdev = UNITODEVICE(unit);
184 	device_t ppbus = device_get_parent(pcfclockdev);
185 
186 	sc->count--;
187 	if (sc->count == 0) {
188 		ppb_release_bus(ppbus, pcfclockdev);
189 	}
190 
191 	return (0);
192 }
193 
194 static void
195 pcfclock_write_cmd(dev_t dev, unsigned char command)
196 {
197 	u_int unit = minor(dev);
198 	device_t ppidev = UNITODEVICE(unit);
199         device_t ppbus = device_get_parent(ppidev);
200 	unsigned char ctr = 14;
201 	char i;
202 
203 	for (i = 0; i <= 7; i++) {
204 		ppb_wdtr(ppbus, i);
205 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
206 		DELAY(3000);
207 	}
208 	ppb_wdtr(ppbus, command);
209 	AUTOFEED_CLOCK(AFC_LO);
210 	DELAY(3000);
211 	AUTOFEED_CLOCK(AFC_HI);
212 }
213 
214 static void
215 pcfclock_display_data(dev_t dev, char buf[18])
216 {
217 	u_int unit = minor(dev);
218 #ifdef PCFCLOCK_VERBOSE
219 	int year;
220 
221 	year = NR(buf, 14);
222 	if (year < 70)
223 		year += 100;
224 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
225 			"battery status: %s\n",
226 			unit,
227 			NR(buf, 10), NR(buf, 12), 1900 + year,
228 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
229 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
230 #else
231 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
232 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
233 				unit);
234 #endif
235 }
236 
237 static int
238 pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
239 {
240 	u_int unit = minor(dev);
241 	device_t ppidev = UNITODEVICE(unit);
242         device_t ppbus = device_get_parent(ppidev);
243 	int i;
244 	char waitfor;
245 	int offset;
246 
247 	/* one byte per four bits */
248 	bzero(buf, ((bits + 3) >> 2) + 1);
249 
250 	waitfor = 100;
251 	for (i = 0; i <= bits; i++) {
252 		/* wait for clock, maximum (waitfor*100) usec */
253 		while(!CLOCK_OK && --waitfor > 0)
254 			DELAY(100);
255 
256 		/* timed out? */
257 		if (!waitfor)
258 			return (EIO);
259 
260 		waitfor = 100; /* reload */
261 
262 		/* give it some time */
263 		DELAY(500);
264 
265 		/* calculate offset into buffer */
266 		offset = i >> 2;
267 		buf[offset] <<= 1;
268 
269 		if (BIT_SET)
270 			buf[offset] |= 1;
271 	}
272 
273 	return (0);
274 }
275 
276 static int
277 pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
278 {
279 	u_int unit = minor(dev);
280 	device_t ppidev = UNITODEVICE(unit);
281         device_t ppbus = device_get_parent(ppidev);
282 	int error = 0;
283 
284 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
285 
286 	while (--maxretries > 0) {
287 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
288 		if (pcfclock_read_data(dev, buf, 68))
289 			continue;
290 
291 		if (!PCFCLOCK_CORRECT_SYNC(buf))
292 			continue;
293 
294 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
295 			continue;
296 
297 		break;
298 	}
299 
300 	if (!maxretries)
301 		error = EIO;
302 
303 	return (error);
304 }
305 
306 static ssize_t
307 pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
308 {
309 	u_int unit = minor(dev);
310 	char buf[18];
311 	int error = 0;
312 
313 	if (uio->uio_resid < 18)
314 		return (ERANGE);
315 
316 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
317 
318 	if (error) {
319 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
320 	} else {
321 		pcfclock_display_data(dev, buf);
322 
323 		uiomove(buf, 18, uio);
324 	}
325 
326 	return (error);
327 }
328 
329 static device_method_t pcfclock_methods[] = {
330 	/* device interface */
331 	DEVMETHOD(device_identify,	pcfclock_identify),
332 	DEVMETHOD(device_probe,		pcfclock_probe),
333 	DEVMETHOD(device_attach,	pcfclock_attach),
334 
335 	{ 0, 0 }
336 };
337 
338 static driver_t pcfclock_driver = {
339 	PCFCLOCK_NAME,
340 	pcfclock_methods,
341 	sizeof(struct pcfclock_data),
342 };
343 
344 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
345