pcfclock.c revision 59391 
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 REGENTS 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 * $FreeBSD: head/sys/dev/ppbus/pcfclock.c 59391 2000-04-19 14:58:28Z phk $
25 *
26 */
27
28#include "opt_pcfclock.h"
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/bus.h>
33#include <sys/sockio.h>
34#include <sys/mbuf.h>
35#include <sys/kernel.h>
36#include <sys/conf.h>
37#include <sys/fcntl.h>
38#include <sys/uio.h>
39
40#include <machine/bus.h>
41#include <machine/resource.h>
42#include <machine/clock.h>      /* for DELAY */
43
44#include <dev/ppbus/ppbconf.h>
45#include <dev/ppbus/ppb_msq.h>
46#include <dev/ppbus/ppbio.h>
47
48#include "ppbus_if.h"
49
50#define PCFCLOCK_NAME "pcfclock"
51
52struct pcfclock_data {
53	int	count;
54	struct	ppb_device pcfclock_dev;
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
64static devclass_t pcfclock_devclass;
65
66static	d_open_t		pcfclock_open;
67static	d_close_t		pcfclock_close;
68static	d_read_t		pcfclock_read;
69
70#define CDEV_MAJOR 140
71static struct cdevsw pcfclock_cdevsw = {
72	/* open */	pcfclock_open,
73	/* close */	pcfclock_close,
74	/* read */	pcfclock_read,
75	/* write */	nowrite,
76	/* ioctl */	noioctl,
77	/* poll */	nopoll,
78	/* mmap */	nommap,
79	/* strategy */	nostrategy,
80	/* name */	PCFCLOCK_NAME,
81	/* maj */	CDEV_MAJOR,
82	/* dump */	nodump,
83	/* psize */	nopsize,
84	/* flags */	0,
85	/* bmaj */	-1
86};
87
88#ifndef PCFCLOCK_MAX_RETRIES
89#define PCFCLOCK_MAX_RETRIES 10
90#endif
91
92#define AFC_HI 0
93#define AFC_LO AUTOFEED
94
95/* AUTO FEED is used as clock */
96#define AUTOFEED_CLOCK(val) \
97	ctr = (ctr & ~(AUTOFEED)) ^ (val); ppb_wctr(ppbus, ctr)
98
99/* SLCT is used as clock */
100#define CLOCK_OK \
101	((ppb_rstr(ppbus) & SELECT) == (i & 1 ? SELECT : 0))
102
103/* PE is used as data */
104#define BIT_SET (ppb_rstr(ppbus)&PERROR)
105
106/* the first byte sent as reply must be 00001001b */
107#define PCFCLOCK_CORRECT_SYNC(buf) (buf[0] == 9)
108
109#define NR(buf, off) (buf[off+1]*10+buf[off])
110
111/* check for correct input values */
112#define PCFCLOCK_CORRECT_FORMAT(buf) (\
113	NR(buf, 14) <= 99 && \
114	NR(buf, 12) <= 12 && \
115	NR(buf, 10) <= 31 && \
116	NR(buf,  6) <= 23 && \
117	NR(buf,  4) <= 59 && \
118	NR(buf,  2) <= 59)
119
120#define PCFCLOCK_BATTERY_STATUS_LOW(buf) (buf[8] & 4)
121
122#define PCFCLOCK_CMD_TIME 0		/* send current time */
123#define PCFCLOCK_CMD_COPY 7 	/* copy received signal to PC */
124
125static void
126pcfclock_identify(driver_t *driver, device_t parent)
127{
128
129	BUS_ADD_CHILD(parent, 0, PCFCLOCK_NAME, 0);
130}
131
132static int
133pcfclock_probe(device_t dev)
134{
135	struct pcfclock_data *sc;
136
137	device_set_desc(dev, "PCF-1.0");
138
139	sc = DEVTOSOFTC(dev);
140	bzero(sc, sizeof(struct pcfclock_data));
141
142	return (0);
143}
144
145static int
146pcfclock_attach(device_t dev)
147{
148	int unit;
149
150	unit = device_get_unit(dev);
151
152	make_dev(&pcfclock_cdevsw, unit,
153			UID_ROOT, GID_WHEEL, 0444, PCFCLOCK_NAME "%d", unit);
154
155	return (0);
156}
157
158static int
159pcfclock_open(dev_t dev, int flag, int fms, struct proc *p)
160{
161	u_int unit = minor(dev);
162	struct pcfclock_data *sc = UNITOSOFTC(unit);
163	device_t pcfclockdev = UNITODEVICE(unit);
164	device_t ppbus = device_get_parent(pcfclockdev);
165	int res;
166
167	if (!sc)
168		return (ENXIO);
169
170	if ((res = ppb_request_bus(ppbus, pcfclockdev,
171		(flag & O_NONBLOCK) ? PPB_DONTWAIT : PPB_WAIT)))
172		return (res);
173
174	sc->count++;
175
176	return (0);
177}
178
179static int
180pcfclock_close(dev_t dev, int flags, int fmt, struct proc *p)
181{
182	u_int unit = minor(dev);
183	struct pcfclock_data *sc = UNITOSOFTC(unit);
184	device_t pcfclockdev = UNITODEVICE(unit);
185	device_t ppbus = device_get_parent(pcfclockdev);
186
187	sc->count--;
188	if (sc->count == 0) {
189		ppb_release_bus(ppbus, pcfclockdev);
190	}
191
192	return (0);
193}
194
195static void
196pcfclock_write_cmd(dev_t dev, unsigned char command)
197{
198	u_int unit = minor(dev);
199	device_t ppidev = UNITODEVICE(unit);
200        device_t ppbus = device_get_parent(ppidev);
201	unsigned char ctr = 14;
202	char i;
203
204	for (i = 0; i <= 7; i++) {
205		ppb_wdtr(ppbus, i);
206		AUTOFEED_CLOCK(i & 1 ? AFC_HI : AFC_LO);
207		DELAY(3000);
208	}
209	ppb_wdtr(ppbus, command);
210	AUTOFEED_CLOCK(AFC_LO);
211	DELAY(3000);
212	AUTOFEED_CLOCK(AFC_HI);
213}
214
215static void
216pcfclock_display_data(dev_t dev, char buf[18])
217{
218	u_int unit = minor(dev);
219#ifdef PCFCLOCK_VERBOSE
220	int year;
221
222	year = NR(buf, 14);
223	if (year < 70)
224		year += 100;
225	printf(PCFCLOCK_NAME "%d: %02d.%02d.%4d %02d:%02d:%02d, "
226			"battery status: %s\n",
227			unit,
228			NR(buf, 10), NR(buf, 12), 1900 + year,
229			NR(buf, 6), NR(buf, 4), NR(buf, 2),
230			PCFCLOCK_BATTERY_STATUS_LOW(buf) ? "LOW" : "ok");
231#else
232	if (PCFCLOCK_BATTERY_STATUS_LOW(buf))
233		printf(PCFCLOCK_NAME "%d: BATTERY STATUS LOW ON\n",
234				unit);
235#endif
236}
237
238static int
239pcfclock_read_data(dev_t dev, char *buf, ssize_t bits)
240{
241	u_int unit = minor(dev);
242	device_t ppidev = UNITODEVICE(unit);
243        device_t ppbus = device_get_parent(ppidev);
244	int i;
245	char waitfor;
246	int offset;
247
248	/* one byte per four bits */
249	bzero(buf, ((bits + 3) >> 2) + 1);
250
251	waitfor = 100;
252	for (i = 0; i <= bits; i++) {
253		/* wait for clock, maximum (waitfor*100) usec */
254		while(!CLOCK_OK && --waitfor > 0)
255			DELAY(100);
256
257		/* timed out? */
258		if (!waitfor)
259			return (EIO);
260
261		waitfor = 100; /* reload */
262
263		/* give it some time */
264		DELAY(500);
265
266		/* calculate offset into buffer */
267		offset = i >> 2;
268		buf[offset] <<= 1;
269
270		if (BIT_SET)
271			buf[offset] |= 1;
272	}
273
274	return (0);
275}
276
277static int
278pcfclock_read_dev(dev_t dev, char *buf, int maxretries)
279{
280	u_int unit = minor(dev);
281	device_t ppidev = UNITODEVICE(unit);
282        device_t ppbus = device_get_parent(ppidev);
283	int error = 0;
284
285	ppb_set_mode(ppbus, PPB_COMPATIBLE);
286
287	while (--maxretries > 0) {
288		pcfclock_write_cmd(dev, PCFCLOCK_CMD_TIME);
289		if (pcfclock_read_data(dev, buf, 68))
290			continue;
291
292		if (!PCFCLOCK_CORRECT_SYNC(buf))
293			continue;
294
295		if (!PCFCLOCK_CORRECT_FORMAT(buf))
296			continue;
297
298		break;
299	}
300
301	if (!maxretries)
302		error = EIO;
303
304	return (error);
305}
306
307static ssize_t
308pcfclock_read(dev_t dev, struct uio *uio, int ioflag)
309{
310	u_int unit = minor(dev);
311	char buf[18];
312	int error = 0;
313
314	if (uio->uio_resid < 18)
315		return (ERANGE);
316
317	error = pcfclock_read_dev(dev, buf, PCFCLOCK_MAX_RETRIES);
318
319	if (error) {
320		printf(PCFCLOCK_NAME "%d: no PCF found\n", unit);
321	} else {
322		pcfclock_display_data(dev, buf);
323
324		uiomove(buf, 18, uio);
325	}
326
327	return (error);
328}
329
330static device_method_t pcfclock_methods[] = {
331	/* device interface */
332	DEVMETHOD(device_identify,	pcfclock_identify),
333	DEVMETHOD(device_probe,		pcfclock_probe),
334	DEVMETHOD(device_attach,	pcfclock_attach),
335
336	{ 0, 0 }
337};
338
339static driver_t pcfclock_driver = {
340	PCFCLOCK_NAME,
341	pcfclock_methods,
342	sizeof(struct pcfclock_data),
343};
344
345DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
346