xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision dc08ffec870569914f44bcf26aa838310e343764)
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/conf.h>
39 #include <sys/fcntl.h>
40 #include <sys/uio.h>
41 
42 #include <machine/bus.h>
43 #include <machine/resource.h>
44 
45 #include <dev/ppbus/ppbconf.h>
46 #include <dev/ppbus/ppb_msq.h>
47 #include <dev/ppbus/ppbio.h>
48 
49 #include "ppbus_if.h"
50 
51 #define PCFCLOCK_NAME "pcfclock"
52 
53 struct pcfclock_data {
54 	int	count;
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 static struct cdevsw pcfclock_cdevsw = {
71 	.d_version =	D_VERSION,
72 	.d_flags =	D_NEEDGIANT,
73 	.d_open =	pcfclock_open,
74 	.d_close =	pcfclock_close,
75 	.d_read =	pcfclock_read,
76 	.d_name =	PCFCLOCK_NAME,
77 };
78 
79 #ifndef PCFCLOCK_MAX_RETRIES
80 #define PCFCLOCK_MAX_RETRIES 10
81 #endif
82 
83 #define AFC_HI 0
84 #define AFC_LO AUTOFEED
85 
86 /* AUTO FEED is used as clock */
87 #define AUTOFEED_CLOCK(val) \
88 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
89 
90 /* SLCT is used as clock */
91 #define CLOCK_OK \
92 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
93 
94 /* PE is used as data */
95 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
96 
97 /* the first byte sent as reply must be 00001001b */
98 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
99 
100 #define NR(buf, off) (buf[off+1]*10+buf[off])
101 
102 /* check for correct input values */
103 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
104 	NR(buf, 14) <= 99 && \
105 	NR(buf, 12) <= 12 && \
106 	NR(buf, 10) <= 31 && \
107 	NR(buf,  6) <= 23 && \
108 	NR(buf,  4) <= 59 && \
109 	NR(buf,  2) <= 59)
110 
111 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
112 
113 #define PCFCLOCK_CMD_TIME 0		/* send current time */
114 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
115 
116 static void
117 pcfclock_identify(driver_t *driver, device_t parent)
118 {
119 
120 	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
121 }
122 
123 static int
124 pcfclock_probe(device_t dev)
125 {
126 	struct pcfclock_data *sc;
127 
128 	device_set_desc(dev, "PCF-1.0");
129 
130 	sc = DEVTOSOFTC(dev);
131 	bzero(sc, sizeof(struct pcfclock_data));
132 
133 	return (0);
134 }
135 
136 static int
137 pcfclock_attach(device_t dev)
138 {
139 	int unit;
140 
141 	unit = device_get_unit(dev);
142 
143 	make_dev(&pcfclock_cdevsw, unit,
144 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
145 
146 	return (0);
147 }
148 
149 static int
150 pcfclock_open(dev_t dev, int flag, int fms, struct thread *td)
151 {
152 	u_int unit = minor(dev);
153 	struct pcfclock_data *sc = UNITOSOFTC(unit);
154 	device_t pcfclockdev = UNITODEVICE(unit);
155 	device_t ppbus = device_get_parent(pcfclockdev);
156 	int res;
157 
158 	if (!sc)
159 		return (ENXIO);
160 
161 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
162 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
163 		return (res);
164 
165 	sc->count++;
166 
167 	return (0);
168 }
169 
170 static int
171 pcfclock_close(dev_t dev, int flags, int fmt, struct thread *td)
172 {
173 	u_int unit = minor(dev);
174 	struct pcfclock_data *sc = UNITOSOFTC(unit);
175 	device_t pcfclockdev = UNITODEVICE(unit);
176 	device_t ppbus = device_get_parent(pcfclockdev);
177 
178 	sc->count--;
179 	if (sc->count == 0)
180 		ppb_release_bus(ppbus, pcfclockdev);
181 
182 	return (0);
183 }
184 
185 static void
186 pcfclock_write_cmd(dev_t dev, unsigned char command)
187 {
188 	u_int unit = minor(dev);
189 	device_t ppidev = UNITODEVICE(unit);
190         device_t ppbus = device_get_parent(ppidev);
191 	unsigned char ctr = 14;
192 	char i;
193 
194 	for (i = 0; i <= 7; i++) {
195 		ppb_wdtr(ppbus, i);
196 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
197 		DELAY(3000);
198 	}
199 	ppb_wdtr(ppbus, command);
200 	AUTOFEED_CLOCK(AFC_LO);
201 	DELAY(3000);
202 	AUTOFEED_CLOCK(AFC_HI);
203 }
204 
205 static void
206 pcfclock_display_data(dev_t dev, char buf[18])
207 {
208 	u_int unit = minor(dev);
209 #ifdef PCFCLOCK_VERBOSE
210 	int year;
211 
212 	year = NR(buf, 14);
213 	if (year < 70)
214 		year += 100;
215 
216 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
217 			"battery status: %s\n",
218 			unit,
219 			NR(buf, 10), NR(buf, 12), 1900 + year,
220 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
221 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
222 #else
223 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
224 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
225 				unit);
226 #endif
227 }
228 
229 static int
230 pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
231 {
232 	u_int unit = minor(dev);
233 	device_t ppidev = UNITODEVICE(unit);
234         device_t ppbus = device_get_parent(ppidev);
235 	int i;
236 	char waitfor;
237 	int offset;
238 
239 	/* one byte per four bits */
240 	bzero(buf, ((bits + 3) >> 2) + 1);
241 
242 	waitfor = 100;
243 	for (i = 0; i <= bits; i++) {
244 		/* wait for clock, maximum (waitfor*100) usec */
245 		while(!CLOCK_OK && --waitfor > 0)
246 			DELAY(100);
247 
248 		/* timed out? */
249 		if (!waitfor)
250 			return (EIO);
251 
252 		waitfor = 100; /* reload */
253 
254 		/* give it some time */
255 		DELAY(500);
256 
257 		/* calculate offset into buffer */
258 		offset = i >> 2;
259 		buf[offset] <<= 1;
260 
261 		if (BIT_SET)
262 			buf[offset] |= 1;
263 	}
264 
265 	return (0);
266 }
267 
268 static int
269 pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
270 {
271 	u_int unit = minor(dev);
272 	device_t ppidev = UNITODEVICE(unit);
273         device_t ppbus = device_get_parent(ppidev);
274 	int error = 0;
275 
276 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
277 
278 	while (--maxretries > 0) {
279 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
280 		if (pcfclock_read_data(dev, buf, 68))
281 			continue;
282 
283 		if (!PCFCLOCK_CORRECT_SYNC(buf))
284 			continue;
285 
286 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
287 			continue;
288 
289 		break;
290 	}
291 
292 	if (!maxretries)
293 		error = EIO;
294 
295 	return (error);
296 }
297 
298 static int
299 pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
300 {
301 	u_int unit = minor(dev);
302 	char buf[18];
303 	int error = 0;
304 
305 	if (uio->uio_resid < 18)
306 		return (ERANGE);
307 
308 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
309 
310 	if (error) {
311 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
312 	} else {
313 		pcfclock_display_data(dev, buf);
314 
315 		uiomove(buf, 18, uio);
316 	}
317 
318 	return (error);
319 }
320 
321 static device_method_t pcfclock_methods[] = {
322 	/* device interface */
323 	DEVMETHOD(device_identify,	pcfclock_identify),
324 	DEVMETHOD(device_probe,		pcfclock_probe),
325 	DEVMETHOD(device_attach,	pcfclock_attach),
326 
327 	{ 0, 0 }
328 };
329 
330 static driver_t pcfclock_driver = {
331 	PCFCLOCK_NAME,
332 	pcfclock_methods,
333 	sizeof(struct pcfclock_data),
334 };
335 
336 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
337