xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 5956d97f4b3204318ceb6aa9c77bd0bc6ea87a41)
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	d_open_t		pcfclock_open;
62 static	d_close_t		pcfclock_close;
63 static	d_read_t		pcfclock_read;
64 
65 static struct cdevsw pcfclock_cdevsw = {
66 	.d_version =	D_VERSION,
67 	.d_open =	pcfclock_open,
68 	.d_close =	pcfclock_close,
69 	.d_read =	pcfclock_read,
70 	.d_name =	PCFCLOCK_NAME,
71 };
72 
73 #ifndef PCFCLOCK_MAX_RETRIES
74 #define PCFCLOCK_MAX_RETRIES 10
75 #endif
76 
77 #define AFC_HI 0
78 #define AFC_LO AUTOFEED
79 
80 /* AUTO FEED is used as clock */
81 #define AUTOFEED_CLOCK(val) \
82 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
83 
84 /* SLCT is used as clock */
85 #define CLOCK_OK \
86 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
87 
88 /* PE is used as data */
89 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
90 
91 /* the first byte sent as reply must be 00001001b */
92 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
93 
94 #define NR(buf, off) (buf[off+1]*10+buf[off])
95 
96 /* check for correct input values */
97 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
98 	NR(buf, 14) <= 99 && \
99 	NR(buf, 12) <= 12 && \
100 	NR(buf, 10) <= 31 && \
101 	NR(buf,  6) <= 23 && \
102 	NR(buf,  4) <= 59 && \
103 	NR(buf,  2) <= 59)
104 
105 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
106 
107 #define PCFCLOCK_CMD_TIME 0		/* send current time */
108 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
109 
110 static void
111 pcfclock_identify(driver_t *driver, device_t parent)
112 {
113 
114 	device_t dev;
115 
116 	dev = device_find_child(parent, PCFCLOCK_NAME, -1);
117 	if (!dev)
118 		BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
119 }
120 
121 static int
122 pcfclock_probe(device_t dev)
123 {
124 
125 	device_set_desc(dev, "PCF-1.0");
126 	return (0);
127 }
128 
129 static int
130 pcfclock_attach(device_t dev)
131 {
132 	struct pcfclock_data *sc = device_get_softc(dev);
133 	int unit;
134 
135 	unit = device_get_unit(dev);
136 
137 	sc->dev = dev;
138 	sc->cdev = make_dev(&pcfclock_cdevsw, unit,
139 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
140 	if (sc->cdev == NULL) {
141 		device_printf(dev, "Failed to create character device\n");
142 		return (ENXIO);
143 	}
144 	sc->cdev->si_drv1 = sc;
145 
146 	return (0);
147 }
148 
149 static int
150 pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
151 {
152 	struct pcfclock_data *sc = dev->si_drv1;
153 	device_t pcfclockdev;
154 	device_t ppbus;
155 	int res;
156 
157 	if (!sc)
158 		return (ENXIO);
159 	pcfclockdev = sc->dev;
160 	ppbus = device_get_parent(pcfclockdev);
161 
162 	ppb_lock(ppbus);
163 	res = ppb_request_bus(ppbus, pcfclockdev,
164 	    (flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT);
165 	ppb_unlock(ppbus);
166 	return (res);
167 }
168 
169 static int
170 pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
171 {
172 	struct pcfclock_data *sc = dev->si_drv1;
173 	device_t pcfclockdev = sc->dev;
174 	device_t ppbus = device_get_parent(pcfclockdev);
175 
176 	ppb_lock(ppbus);
177 	ppb_release_bus(ppbus, pcfclockdev);
178 	ppb_unlock(ppbus);
179 
180 	return (0);
181 }
182 
183 static void
184 pcfclock_write_cmd(struct cdev *dev, unsigned char command)
185 {
186 	struct pcfclock_data *sc = dev->si_drv1;
187 	device_t pcfclockdev = sc->dev;
188 	device_t ppbus = device_get_parent(pcfclockdev);
189 	unsigned char ctr = 14;
190 	char i;
191 
192 	for (i = 0; i <= 7; i++) {
193 		ppb_wdtr(ppbus, i);
194 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
195 		DELAY(3000);
196 	}
197 	ppb_wdtr(ppbus, command);
198 	AUTOFEED_CLOCK(AFC_LO);
199 	DELAY(3000);
200 	AUTOFEED_CLOCK(AFC_HI);
201 }
202 
203 static void
204 pcfclock_display_data(struct cdev *dev, char buf[18])
205 {
206 	struct pcfclock_data *sc = dev->si_drv1;
207 #ifdef PCFCLOCK_VERBOSE
208 	int year;
209 
210 	year = NR(buf, 14);
211 	if (year < 70)
212 		year += 100;
213 
214 	device_printf(sc->dev, "%02d.%02d.%4d %02d:%02d:%02d, "
215 			"battery status: %s\n",
216 			NR(buf, 10), NR(buf, 12), 1900 + year,
217 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
218 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
219 #else
220 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
221 		device_printf(sc->dev, "BATTERY STATUS LOW ON\n");
222 #endif
223 }
224 
225 static int
226 pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
227 {
228 	struct pcfclock_data *sc = dev->si_drv1;
229 	device_t pcfclockdev = sc->dev;
230 	device_t ppbus = device_get_parent(pcfclockdev);
231 	int i;
232 	char waitfor;
233 	int offset;
234 
235 	/* one byte per four bits */
236 	bzero(buf, ((bits + 3) >> 2) + 1);
237 
238 	waitfor = 100;
239 	for (i = 0; i <= bits; i++) {
240 		/* wait for clock, maximum (waitfor*100) usec */
241 		while (!CLOCK_OK && --waitfor > 0)
242 			DELAY(100);
243 
244 		/* timed out? */
245 		if (!waitfor)
246 			return (EIO);
247 
248 		waitfor = 100; /* reload */
249 
250 		/* give it some time */
251 		DELAY(500);
252 
253 		/* calculate offset into buffer */
254 		offset = i >> 2;
255 		buf[offset] <<= 1;
256 
257 		if (BIT_SET)
258 			buf[offset] |= 1;
259 	}
260 
261 	return (0);
262 }
263 
264 static int
265 pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
266 {
267 	struct pcfclock_data *sc = dev->si_drv1;
268 	device_t pcfclockdev = sc->dev;
269 	device_t ppbus = device_get_parent(pcfclockdev);
270 	int error = 0;
271 
272 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
273 
274 	while (--maxretries > 0) {
275 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
276 		if (pcfclock_read_data(dev, buf, 68))
277 			continue;
278 
279 		if (!PCFCLOCK_CORRECT_SYNC(buf))
280 			continue;
281 
282 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
283 			continue;
284 
285 		break;
286 	}
287 
288 	if (!maxretries)
289 		error = EIO;
290 
291 	return (error);
292 }
293 
294 static int
295 pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
296 {
297 	struct pcfclock_data *sc = dev->si_drv1;
298 	device_t ppbus;
299 	char buf[18];
300 	int error = 0;
301 
302 	if (uio->uio_resid < 18)
303 		return (ERANGE);
304 
305 	ppbus = device_get_parent(sc->dev);
306 	ppb_lock(ppbus);
307 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
308 	ppb_unlock(ppbus);
309 
310 	if (error) {
311 		device_printf(sc->dev, "no PCF found\n");
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 	{ 0, 0 }
327 };
328 
329 static driver_t pcfclock_driver = {
330 	PCFCLOCK_NAME,
331 	pcfclock_methods,
332 	sizeof(struct pcfclock_data),
333 };
334 
335 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, 0, 0);
336