xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2000 Sascha Schumann. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY SASCHA SCHUMANN ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
17  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
18  * EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
20  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
21  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
22  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
23  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
24  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  *
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_pcfclock.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/bus.h>
37 #include <sys/sockio.h>
38 #include <sys/mbuf.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/conf.h>
42 #include <sys/fcntl.h>
43 #include <sys/uio.h>
44 
45 #include <machine/bus.h>
46 #include <machine/resource.h>
47 
48 #include <dev/ppbus/ppbconf.h>
49 #include <dev/ppbus/ppb_msq.h>
50 #include <dev/ppbus/ppbio.h>
51 
52 #include "ppbus_if.h"
53 
54 #define PCFCLOCK_NAME "pcfclock"
55 
56 struct pcfclock_data {
57 	device_t dev;
58 	struct cdev *cdev;
59 };
60 
61 static devclass_t pcfclock_devclass;
62 
63 static	d_open_t		pcfclock_open;
64 static	d_close_t		pcfclock_close;
65 static	d_read_t		pcfclock_read;
66 
67 static struct cdevsw pcfclock_cdevsw = {
68 	.d_version =	D_VERSION,
69 	.d_open =	pcfclock_open,
70 	.d_close =	pcfclock_close,
71 	.d_read =	pcfclock_read,
72 	.d_name =	PCFCLOCK_NAME,
73 };
74 
75 #ifndef PCFCLOCK_MAX_RETRIES
76 #define PCFCLOCK_MAX_RETRIES 10
77 #endif
78 
79 #define AFC_HI 0
80 #define AFC_LO AUTOFEED
81 
82 /* AUTO FEED is used as clock */
83 #define AUTOFEED_CLOCK(val) \
84 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
85 
86 /* SLCT is used as clock */
87 #define CLOCK_OK \
88 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
89 
90 /* PE is used as data */
91 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
92 
93 /* the first byte sent as reply must be 00001001b */
94 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
95 
96 #define NR(buf, off) (buf[off+1]*10+buf[off])
97 
98 /* check for correct input values */
99 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
100 	NR(buf, 14) <= 99 && \
101 	NR(buf, 12) <= 12 && \
102 	NR(buf, 10) <= 31 && \
103 	NR(buf,  6) <= 23 && \
104 	NR(buf,  4) <= 59 && \
105 	NR(buf,  2) <= 59)
106 
107 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
108 
109 #define PCFCLOCK_CMD_TIME 0		/* send current time */
110 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
111 
112 static void
113 pcfclock_identify(driver_t *driver, device_t parent)
114 {
115 
116 	device_t dev;
117 
118 	dev = device_find_child(parent, PCFCLOCK_NAME, -1);
119 	if (!dev)
120 		BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
121 }
122 
123 static int
124 pcfclock_probe(device_t dev)
125 {
126 
127 	device_set_desc(dev, "PCF-1.0");
128 	return (0);
129 }
130 
131 static int
132 pcfclock_attach(device_t dev)
133 {
134 	struct pcfclock_data *sc = device_get_softc(dev);
135 	int unit;
136 
137 	unit = device_get_unit(dev);
138 
139 	sc->dev = dev;
140 	sc->cdev = make_dev(&pcfclock_cdevsw, unit,
141 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
142 	if (sc->cdev == NULL) {
143 		device_printf(dev, "Failed to create character device\n");
144 		return (ENXIO);
145 	}
146 	sc->cdev->si_drv1 = sc;
147 
148 	return (0);
149 }
150 
151 static int
152 pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
153 {
154 	struct pcfclock_data *sc = dev->si_drv1;
155 	device_t pcfclockdev;
156 	device_t ppbus;
157 	int res;
158 
159 	if (!sc)
160 		return (ENXIO);
161 	pcfclockdev = sc->dev;
162 	ppbus = device_get_parent(pcfclockdev);
163 
164 	ppb_lock(ppbus);
165 	res = ppb_request_bus(ppbus, pcfclockdev,
166 	    (flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT);
167 	ppb_unlock(ppbus);
168 	return (res);
169 }
170 
171 static int
172 pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
173 {
174 	struct pcfclock_data *sc = dev->si_drv1;
175 	device_t pcfclockdev = sc->dev;
176 	device_t ppbus = device_get_parent(pcfclockdev);
177 
178 	ppb_lock(ppbus);
179 	ppb_release_bus(ppbus, pcfclockdev);
180 	ppb_unlock(ppbus);
181 
182 	return (0);
183 }
184 
185 static void
186 pcfclock_write_cmd(struct cdev *dev, unsigned char command)
187 {
188 	struct pcfclock_data *sc = dev->si_drv1;
189 	device_t pcfclockdev = sc->dev;
190 	device_t ppbus = device_get_parent(pcfclockdev);
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(struct cdev *dev, char buf[18])
207 {
208 	struct pcfclock_data *sc = dev->si_drv1;
209 #ifdef PCFCLOCK_VERBOSE
210 	int year;
211 
212 	year = NR(buf, 14);
213 	if (year < 70)
214 		year += 100;
215 
216 	device_printf(sc->dev, "%02d.%02d.%4d %02d:%02d:%02d, "
217 			"battery status: %s\n",
218 			NR(buf, 10), NR(buf, 12), 1900 + year,
219 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
220 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
221 #else
222 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
223 		device_printf(sc->dev, "BATTERY STATUS LOW ON\n");
224 #endif
225 }
226 
227 static int
228 pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
229 {
230 	struct pcfclock_data *sc = dev->si_drv1;
231 	device_t pcfclockdev = sc->dev;
232 	device_t ppbus = device_get_parent(pcfclockdev);
233 	int i;
234 	char waitfor;
235 	int offset;
236 
237 	/* one byte per four bits */
238 	bzero(buf, ((bits + 3) >> 2) + 1);
239 
240 	waitfor = 100;
241 	for (i = 0; i <= bits; i++) {
242 		/* wait for clock, maximum (waitfor*100) usec */
243 		while (!CLOCK_OK && --waitfor > 0)
244 			DELAY(100);
245 
246 		/* timed out? */
247 		if (!waitfor)
248 			return (EIO);
249 
250 		waitfor = 100; /* reload */
251 
252 		/* give it some time */
253 		DELAY(500);
254 
255 		/* calculate offset into buffer */
256 		offset = i >> 2;
257 		buf[offset] <<= 1;
258 
259 		if (BIT_SET)
260 			buf[offset] |= 1;
261 	}
262 
263 	return (0);
264 }
265 
266 static int
267 pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
268 {
269 	struct pcfclock_data *sc = dev->si_drv1;
270 	device_t pcfclockdev = sc->dev;
271 	device_t ppbus = device_get_parent(pcfclockdev);
272 	int error = 0;
273 
274 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
275 
276 	while (--maxretries > 0) {
277 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
278 		if (pcfclock_read_data(dev, buf, 68))
279 			continue;
280 
281 		if (!PCFCLOCK_CORRECT_SYNC(buf))
282 			continue;
283 
284 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
285 			continue;
286 
287 		break;
288 	}
289 
290 	if (!maxretries)
291 		error = EIO;
292 
293 	return (error);
294 }
295 
296 static int
297 pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
298 {
299 	struct pcfclock_data *sc = dev->si_drv1;
300 	device_t ppbus;
301 	char buf[18];
302 	int error = 0;
303 
304 	if (uio->uio_resid < 18)
305 		return (ERANGE);
306 
307 	ppbus = device_get_parent(sc->dev);
308 	ppb_lock(ppbus);
309 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
310 	ppb_unlock(ppbus);
311 
312 	if (error) {
313 		device_printf(sc->dev, "no PCF found\n");
314 	} else {
315 		pcfclock_display_data(dev, buf);
316 
317 		uiomove(buf, 18, uio);
318 	}
319 
320 	return (error);
321 }
322 
323 static device_method_t pcfclock_methods[] = {
324 	/* device interface */
325 	DEVMETHOD(device_identify,	pcfclock_identify),
326 	DEVMETHOD(device_probe,		pcfclock_probe),
327 	DEVMETHOD(device_attach,	pcfclock_attach),
328 	{ 0, 0 }
329 };
330 
331 static driver_t pcfclock_driver = {
332 	PCFCLOCK_NAME,
333 	pcfclock_methods,
334 	sizeof(struct pcfclock_data),
335 };
336 
337 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
338