xref: /freebsd/sys/dev/ppbus/pcfclock.c (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #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 	device_t dev;
56 	struct cdev *cdev;
57 };
58 
59 static	d_open_t		pcfclock_open;
60 static	d_close_t		pcfclock_close;
61 static	d_read_t		pcfclock_read;
62 
63 static struct cdevsw pcfclock_cdevsw = {
64 	.d_version =	D_VERSION,
65 	.d_open =	pcfclock_open,
66 	.d_close =	pcfclock_close,
67 	.d_read =	pcfclock_read,
68 	.d_name =	PCFCLOCK_NAME,
69 };
70 
71 #ifndef PCFCLOCK_MAX_RETRIES
72 #define PCFCLOCK_MAX_RETRIES 10
73 #endif
74 
75 #define AFC_HI 0
76 #define AFC_LO AUTOFEED
77 
78 /* AUTO FEED is used as clock */
79 #define AUTOFEED_CLOCK(val) \
80 	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
81 
82 /* SLCT is used as clock */
83 #define CLOCK_OK \
84 	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
85 
86 /* PE is used as data */
87 #define BIT_SET (ppb_rstr(ppbus)&PERROR)
88 
89 /* the first byte sent as reply must be 00001001b */
90 #define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
91 
92 #define NR(buf, off) (buf[off+1]*10+buf[off])
93 
94 /* check for correct input values */
95 #define PCFCLOCK_CORRECT_FORMAT(buf) (\
96 	NR(buf, 14) <= 99 && \
97 	NR(buf, 12) <= 12 && \
98 	NR(buf, 10) <= 31 && \
99 	NR(buf,  6) <= 23 && \
100 	NR(buf,  4) <= 59 && \
101 	NR(buf,  2) <= 59)
102 
103 #define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
104 
105 #define PCFCLOCK_CMD_TIME 0		/* send current time */
106 #define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
107 
108 static void
109 pcfclock_identify(driver_t *driver, device_t parent)
110 {
111 
112 	device_t dev;
113 
114 	dev = device_find_child(parent, PCFCLOCK_NAME, -1);
115 	if (!dev)
116 		BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, -1);
117 }
118 
119 static int
120 pcfclock_probe(device_t dev)
121 {
122 
123 	device_set_desc(dev, "PCF-1.0");
124 	return (0);
125 }
126 
127 static int
128 pcfclock_attach(device_t dev)
129 {
130 	struct pcfclock_data *sc = device_get_softc(dev);
131 	int unit;
132 
133 	unit = device_get_unit(dev);
134 
135 	sc->dev = dev;
136 	sc->cdev = make_dev(&pcfclock_cdevsw, unit,
137 			UID_ROOT, GID_WHEEL, 0400, PCFCLOCK_NAME "%d", unit);
138 	if (sc->cdev == NULL) {
139 		device_printf(dev, "Failed to create character device\n");
140 		return (ENXIO);
141 	}
142 	sc->cdev->si_drv1 = sc;
143 
144 	return (0);
145 }
146 
147 static int
148 pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
149 {
150 	struct pcfclock_data *sc = dev->si_drv1;
151 	device_t pcfclockdev;
152 	device_t ppbus;
153 	int res;
154 
155 	if (!sc)
156 		return (ENXIO);
157 	pcfclockdev = sc->dev;
158 	ppbus = device_get_parent(pcfclockdev);
159 
160 	ppb_lock(ppbus);
161 	res = ppb_request_bus(ppbus, pcfclockdev,
162 	    (flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT);
163 	ppb_unlock(ppbus);
164 	return (res);
165 }
166 
167 static int
168 pcfclock_close(struct cdev *dev, int flags, int fmt, struct thread *td)
169 {
170 	struct pcfclock_data *sc = dev->si_drv1;
171 	device_t pcfclockdev = sc->dev;
172 	device_t ppbus = device_get_parent(pcfclockdev);
173 
174 	ppb_lock(ppbus);
175 	ppb_release_bus(ppbus, pcfclockdev);
176 	ppb_unlock(ppbus);
177 
178 	return (0);
179 }
180 
181 static void
182 pcfclock_write_cmd(struct cdev *dev, unsigned char command)
183 {
184 	struct pcfclock_data *sc = dev->si_drv1;
185 	device_t pcfclockdev = sc->dev;
186 	device_t ppbus = device_get_parent(pcfclockdev);
187 	unsigned char ctr = 14;
188 	char i;
189 
190 	for (i = 0; i <= 7; i++) {
191 		ppb_wdtr(ppbus, i);
192 		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
193 		DELAY(3000);
194 	}
195 	ppb_wdtr(ppbus, command);
196 	AUTOFEED_CLOCK(AFC_LO);
197 	DELAY(3000);
198 	AUTOFEED_CLOCK(AFC_HI);
199 }
200 
201 static void
202 pcfclock_display_data(struct cdev *dev, char buf[18])
203 {
204 	struct pcfclock_data *sc = dev->si_drv1;
205 #ifdef PCFCLOCK_VERBOSE
206 	int year;
207 
208 	year = NR(buf, 14);
209 	if (year < 70)
210 		year += 100;
211 
212 	device_printf(sc->dev, "%02d.%02d.%4d %02d:%02d:%02d, "
213 			"battery status: %s\n",
214 			NR(buf, 10), NR(buf, 12), 1900 + year,
215 			NR(buf, 6), NR(buf, 4), NR(buf, 2),
216 			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
217 #else
218 	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
219 		device_printf(sc->dev, "BATTERY STATUS LOW ON\n");
220 #endif
221 }
222 
223 static int
224 pcfclock_read_data(struct cdev *dev, char *buf, ssize_t bits)
225 {
226 	struct pcfclock_data *sc = dev->si_drv1;
227 	device_t pcfclockdev = sc->dev;
228 	device_t ppbus = device_get_parent(pcfclockdev);
229 	int i;
230 	char waitfor;
231 	int offset;
232 
233 	/* one byte per four bits */
234 	bzero(buf, ((bits + 3) >> 2) + 1);
235 
236 	waitfor = 100;
237 	for (i = 0; i <= bits; i++) {
238 		/* wait for clock, maximum (waitfor*100) usec */
239 		while (!CLOCK_OK && --waitfor > 0)
240 			DELAY(100);
241 
242 		/* timed out? */
243 		if (!waitfor)
244 			return (EIO);
245 
246 		waitfor = 100; /* reload */
247 
248 		/* give it some time */
249 		DELAY(500);
250 
251 		/* calculate offset into buffer */
252 		offset = i >> 2;
253 		buf[offset] <<= 1;
254 
255 		if (BIT_SET)
256 			buf[offset] |= 1;
257 	}
258 
259 	return (0);
260 }
261 
262 static int
263 pcfclock_read_dev(struct cdev *dev, char *buf, int maxretries)
264 {
265 	struct pcfclock_data *sc = dev->si_drv1;
266 	device_t pcfclockdev = sc->dev;
267 	device_t ppbus = device_get_parent(pcfclockdev);
268 	int error = 0;
269 
270 	ppb_set_mode(ppbus, PPB_COMPATIBLE);
271 
272 	while (--maxretries > 0) {
273 		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
274 		if (pcfclock_read_data(dev, buf, 68))
275 			continue;
276 
277 		if (!PCFCLOCK_CORRECT_SYNC(buf))
278 			continue;
279 
280 		if (!PCFCLOCK_CORRECT_FORMAT(buf))
281 			continue;
282 
283 		break;
284 	}
285 
286 	if (!maxretries)
287 		error = EIO;
288 
289 	return (error);
290 }
291 
292 static int
293 pcfclock_read(struct cdev *dev, struct uio *uio, int ioflag)
294 {
295 	struct pcfclock_data *sc = dev->si_drv1;
296 	device_t ppbus;
297 	char buf[18];
298 	int error = 0;
299 
300 	if (uio->uio_resid < 18)
301 		return (ERANGE);
302 
303 	ppbus = device_get_parent(sc->dev);
304 	ppb_lock(ppbus);
305 	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
306 	ppb_unlock(ppbus);
307 
308 	if (error) {
309 		device_printf(sc->dev, "no PCF found\n");
310 	} else {
311 		pcfclock_display_data(dev, buf);
312 
313 		uiomove(buf, 18, uio);
314 	}
315 
316 	return (error);
317 }
318 
319 static device_method_t pcfclock_methods[] = {
320 	/* device interface */
321 	DEVMETHOD(device_identify,	pcfclock_identify),
322 	DEVMETHOD(device_probe,		pcfclock_probe),
323 	DEVMETHOD(device_attach,	pcfclock_attach),
324 	{ 0, 0 }
325 };
326 
327 static driver_t pcfclock_driver = {
328 	PCFCLOCK_NAME,
329 	pcfclock_methods,
330 	sizeof(struct pcfclock_data),
331 };
332 
333 DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, 0, 0);
334