xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 
137 	return (0);
138 }
139 
140 static int
141 pcfclock_attach(device_t dev)
142 {
143 	int unit;
144 
145 	unit = device_get_unit(dev);
146 
147 	make_dev(&pcfclock_cdevsw, unit,
148 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
149 
150 	return (0);
151 }
152 
153 static int
154 pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
155 {
156 	u_int unit = minor(dev);
157 	struct pcfclock_data *sc = UNITOSOFTC(unit);
158 	device_t pcfclockdev = UNITODEVICE(unit);
159 	device_t ppbus = device_get_parent(pcfclockdev);
160 	int res;
161 
162 	if (!sc)
163 		return (ENXIO);
164 
165 	if ((res = ppb_request_bus(ppbus, pcfclockdev,
166 		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
167 		return (res);
168 
169 	sc->count++;
170 
171 	return (0);
172 }
173 
174 static int
175 pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
176 {
177 	u_int unit = minor(dev);
178 	struct pcfclock_data *sc = UNITOSOFTC(unit);
179 	device_t pcfclockdev = UNITODEVICE(unit);
180 	device_t ppbus = device_get_parent(pcfclockdev);
181 
182 	sc->count--;
183 	if (sc->count == 0)
184 		ppb_release_bus(ppbus, pcfclockdev);
185 
186 	return (0);
187 }
188 
189 static void
190 pcfclock_write_cmd(struct cdev *dev, unsigned char command)
191 {
192 	u_int unit = minor(dev);
193 	device_t ppidev = UNITODEVICE(unit);
194         device_t ppbus = device_get_parent(ppidev);
195 	unsigned char ctr = 14;
196 	char i;
197 
198 	for (i = 0; i <= 7; i++) {
199 		ppb_wdtr(ppbus, i);
200 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
201 		DELAY(3000);
202 	}
203 	ppb_wdtr(ppbus, command);
204 	AUTOFEED_CLOCK(AFC_LO);
205 	DELAY(3000);
206 	AUTOFEED_CLOCK(AFC_HI);
207 }
208 
209 static void
210 pcfclock_display_data(struct cdev *dev, char buf[18])
211 {
212 	u_int unit = minor(dev);
213 #ifdef PCFCLOCK_VERBOSE
214 	int year;
215 
216 	year = NR(buf, 14);
217 	if (year < 70)
218 		year += 100;
219 
220 	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
221 			"battery status: %s\n",
222 			unit,
223 			NR(buf, 10), NR(buf, 12), 1900 + year,
224 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
225 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
226 #else
227 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
228 		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
229 				unit);
230 #endif
231 }
232 
233 static int
234 pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
235 {
236 	u_int unit = minor(dev);
237 	device_t ppidev = UNITODEVICE(unit);
238         device_t ppbus = device_get_parent(ppidev);
239 	int i;
240 	char waitfor;
241 	int offset;
242 
243 	/* one byte per four bits */
244 	bzero(buf, ((bits + 3) >> 2) + 1);
245 
246 	waitfor = 100;
247 	for (i = 0; i <= bits; i++) {
248 		/* wait for clock, maximum (waitfor*100) usec */
249 		while(!CLOCK_OK && --waitfor > 0)
250 			DELAY(100);
251 
252 		/* timed out? */
253 		if (!waitfor)
254 			return (EIO);
255 
256 		waitfor = 100; /* reload */
257 
258 		/* give it some time */
259 		DELAY(500);
260 
261 		/* calculate offset into buffer */
262 		offset = i >> 2;
263 		buf[offset] <<= 1;
264 
265 		if (BIT_SET)
266 			buf[offset] |= 1;
267 	}
268 
269 	return (0);
270 }
271 
272 static int
273 pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
274 {
275 	u_int unit = minor(dev);
276 	device_t ppidev = UNITODEVICE(unit);
277         device_t ppbus = device_get_parent(ppidev);
278 	int error = 0;
279 
280 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
281 
282 	while (--maxretries > 0) {
283 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
284 		if (pcfclock_read_data(dev, buf, 68))
285 			continue;
286 
287 		if (!PCFCLOCK_CORRECT_SYNC(buf))
288 			continue;
289 
290 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
291 			continue;
292 
293 		break;
294 	}
295 
296 	if (!maxretries)
297 		error = EIO;
298 
299 	return (error);
300 }
301 
302 static int
303 pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
304 {
305 	u_int unit = minor(dev);
306 	char buf[18];
307 	int error = 0;
308 
309 	if (uio->uio_resid < 18)
310 		return (ERANGE);
311 
312 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
313 
314 	if (error) {
315 		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
316 	} else {
317 		pcfclock_display_data(dev, buf);
318 
319 		uiomove(buf, 18, uio);
320 	}
321 
322 	return (error);
323 }
324 
325 static device_method_t pcfclock_methods[] = {
326 	/* device interface */
327 	DEVMETHOD(device_identify,	pcfclock_identify),
328 	DEVMETHOD(device_probe,		pcfclock_probe),
329 	DEVMETHOD(device_attach,	pcfclock_attach),
330 
331 	{ 0, 0 }
332 };
333 
334 static driver_t pcfclock_driver = {
335 	PCFCLOCK_NAME,
336 	pcfclock_methods,
337 	sizeof(struct pcfclock_data),
338 };
339 
340 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
341