pcfclock.c revision 187576 
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: head/sys/dev/ppbus/pcfclock.c 187576 2009-01-21 23:10:06Z jhb $");
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
54struct pcfclock_data {
55	device_t dev;
56	struct cdev *cdev;
57};
58
59static devclass_t pcfclock_devclass;
60
61static	d_open_t		pcfclock_open;
62static	d_close_t		pcfclock_close;
63static	d_read_t		pcfclock_read;
64
65static 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
110static void
111pcfclock_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
121static int
122pcfclock_probe(device_t dev)
123{
124
125	device_set_desc(dev, "PCF-1.0");
126	return (0);
127}
128
129static int
130pcfclock_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
149static int
150pcfclock_open(struct cdev *dev, int flag, int fms, struct thread *td)
151{
152	struct pcfclock_data *sc = dev->si_drv1;
153	device_t pcfclockdev = sc->dev;
154	device_t ppbus = device_get_parent(pcfclockdev);
155	int res;
156
157	if (!sc)
158		return (ENXIO);
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
167static int
168pcfclock_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
181static void
182pcfclock_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
201static void
202pcfclock_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
223static int
224pcfclock_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
262static int
263pcfclock_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
292static int
293pcfclock_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
319static 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
325	{ 0, 0 }
326};
327
328static driver_t pcfclock_driver = {
329	PCFCLOCK_NAME,
330	pcfclock_methods,
331	sizeof(struct pcfclock_data),
332};
333
334DRIVER_MODULE(pcfclock, ppbus, pcfclock_driver, pcfclock_devclass, 0, 0);
335