pps.c revision 97228 
1/*
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 *
9 * $FreeBSD: head/sys/dev/ppbus/pps.c 97228 2002-05-24 06:32:18Z peter $
10 *
11 * This driver implements a draft-mogul-pps-api-02.txt PPS source.
12 *
13 * The input pin is pin#10
14 * The echo output pin is pin#14
15 *
16 */
17
18#include <sys/param.h>
19#include <sys/kernel.h>
20#include <sys/systm.h>
21#include <sys/module.h>
22#include <sys/bus.h>
23#include <sys/conf.h>
24#include <sys/timepps.h>
25#include <machine/bus.h>
26#include <machine/resource.h>
27#include <sys/rman.h>
28
29#include <dev/ppbus/ppbconf.h>
30#include "ppbus_if.h"
31#include <dev/ppbus/ppbio.h>
32
33#define PPS_NAME	"pps"		/* our official name */
34
35#define PRVERBOSE(fmt, arg...)	if (bootverbose) printf(fmt, ##arg);
36
37struct pps_data {
38	struct	ppb_device pps_dev;
39	struct	pps_state pps[9];
40	dev_t	devs[9];
41	device_t ppsdev;
42	device_t ppbus;
43	int	busy;
44	struct callout_handle timeout;
45	int	lastdata;
46
47	struct resource *intr_resource;	/* interrupt resource */
48	void *intr_cookie;		/* interrupt registration cookie */
49};
50
51static void	ppsintr(void *arg);
52static void 	ppshcpoll(void *arg);
53
54#define DEVTOSOFTC(dev) \
55	((struct pps_data *)device_get_softc(dev))
56
57static devclass_t pps_devclass;
58
59static	d_open_t	ppsopen;
60static	d_close_t	ppsclose;
61static	d_ioctl_t	ppsioctl;
62
63#define CDEV_MAJOR 89
64static struct cdevsw pps_cdevsw = {
65	/* open */	ppsopen,
66	/* close */	ppsclose,
67	/* read */	noread,
68	/* write */	nowrite,
69	/* ioctl */	ppsioctl,
70	/* poll */	nopoll,
71	/* mmap */	nommap,
72	/* strategy */	nostrategy,
73	/* name */	PPS_NAME,
74	/* maj */	CDEV_MAJOR,
75	/* dump */	nodump,
76	/* psize */	nopsize,
77	/* flags */	0,
78};
79
80static void
81ppsidentify(driver_t *driver, device_t parent)
82{
83
84	BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
85}
86
87static int
88ppstry(device_t ppbus, int send, int expect)
89{
90	int i;
91
92	ppb_wdtr(ppbus, send);
93	i = ppb_rdtr(ppbus);
94	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
95	return (i != expect);
96}
97
98static int
99ppsprobe(device_t ppsdev)
100{
101	device_set_desc(ppsdev, "Pulse per second Timing Interface");
102
103	return (0);
104}
105
106static int
107ppsattach(device_t dev)
108{
109	struct pps_data *sc = DEVTOSOFTC(dev);
110	device_t ppbus = device_get_parent(dev);
111	int irq, zero = 0;
112	dev_t d;
113	int unit, i;
114
115	bzero(sc, sizeof(struct pps_data)); /* XXX doesn't newbus do this? */
116
117	/* retrieve the ppbus irq */
118	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
119
120	if (irq > 0) {
121		/* declare our interrupt handler */
122		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
123		    &zero, irq, irq, 1, RF_SHAREABLE);
124	}
125	/* interrupts seem mandatory */
126	if (sc->intr_resource == NULL)
127		return (ENXIO);
128
129	sc->ppsdev = dev;
130	sc->ppbus = ppbus;
131	unit = device_get_unit(ppbus);
132	d = make_dev(&pps_cdevsw, unit,
133	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
134	sc->devs[0] = d;
135	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
136	d->si_drv1 = sc;
137	d->si_drv2 = (void*)0;
138	pps_init(&sc->pps[0]);
139
140	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
141		return (0);
142
143	do {
144		i = ppb_set_mode(sc->ppbus, PPB_EPP);
145		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
146		if (i == -1)
147			break;
148		i = 0;
149		ppb_wctr(ppbus, i);
150		if (ppstry(ppbus, 0x00, 0x00))
151			break;
152		if (ppstry(ppbus, 0x55, 0x55))
153			break;
154		if (ppstry(ppbus, 0xaa, 0xaa))
155			break;
156		if (ppstry(ppbus, 0xff, 0xff))
157			break;
158
159		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
160		ppb_wctr(ppbus, i);
161		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
162		if (ppstry(ppbus, 0x00, 0x00))
163			break;
164		if (ppstry(ppbus, 0x55, 0x00))
165			break;
166		if (ppstry(ppbus, 0xaa, 0x00))
167			break;
168		if (ppstry(ppbus, 0xff, 0x00))
169			break;
170
171		i = IRQENABLE | PCD | nINIT | SELECTIN;
172		ppb_wctr(ppbus, i);
173		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
174		ppstry(ppbus, 0x00, 0xff);
175		ppstry(ppbus, 0x55, 0xff);
176		ppstry(ppbus, 0xaa, 0xff);
177		ppstry(ppbus, 0xff, 0xff);
178
179		for (i = 1; i < 9; i++) {
180			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
181			  UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%db%d", unit, i - 1);
182			sc->devs[i] = d;
183			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
184			d->si_drv1 = sc;
185			d->si_drv2 = (void*)i;
186			pps_init(&sc->pps[i]);
187		}
188	} while (0);
189	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
190	ppb_release_bus(ppbus, dev);
191
192	return (0);
193}
194
195static	int
196ppsopen(dev_t dev, int flags, int fmt, struct thread *td)
197{
198	struct pps_data *sc = dev->si_drv1;
199	int subdev = (int)dev->si_drv2;
200	int error, i;
201
202	if (!sc->busy) {
203		device_t ppsdev = sc->ppsdev;
204		device_t ppbus = sc->ppbus;
205
206		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
207			return (EINTR);
208
209		/* attach the interrupt handler */
210		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
211			       INTR_TYPE_TTY, ppsintr, ppsdev,
212			       &sc->intr_cookie))) {
213			ppb_release_bus(ppbus, ppsdev);
214			return (error);
215		}
216
217		i = ppb_set_mode(sc->ppbus, PPB_PS2);
218		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
219
220		i = IRQENABLE | PCD | nINIT | SELECTIN;
221		ppb_wctr(ppbus, i);
222	}
223	if (subdev > 0 && !(sc->busy & ~1)) {
224		sc->timeout = timeout(ppshcpoll, sc, 1);
225		sc->lastdata = ppb_rdtr(sc->ppbus);
226	}
227	sc->busy |= (1 << subdev);
228	return(0);
229}
230
231static	int
232ppsclose(dev_t dev, int flags, int fmt, struct thread *td)
233{
234	struct pps_data *sc = dev->si_drv1;
235	int subdev = (int)dev->si_drv2;
236
237	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
238	sc->busy &= ~(1 << subdev);
239	if (subdev > 0 && !(sc->busy & ~1))
240		untimeout(ppshcpoll, sc, sc->timeout);
241	if (!sc->busy) {
242		device_t ppsdev = sc->ppsdev;
243		device_t ppbus = sc->ppbus;
244
245		ppb_wdtr(ppbus, 0);
246		ppb_wctr(ppbus, 0);
247
248		/* Note: the interrupt handler is automatically detached */
249		ppb_set_mode(ppbus, PPB_COMPATIBLE);
250		ppb_release_bus(ppbus, ppsdev);
251	}
252	return(0);
253}
254
255static void
256ppshcpoll(void *arg)
257{
258	struct pps_data *sc = arg;
259	int i, j, k, l;
260
261	if (!(sc->busy & ~1))
262		return;
263	sc->timeout = timeout(ppshcpoll, sc, 1);
264	i = ppb_rdtr(sc->ppbus);
265	if (i == sc->lastdata)
266		return;
267	l = sc->lastdata ^ i;
268	k = 1;
269	for (j = 1; j < 9; j ++) {
270		if (l & k) {
271			pps_capture(&sc->pps[j]);
272			pps_event(&sc->pps[j],
273			    i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
274		}
275		k += k;
276	}
277	sc->lastdata = i;
278}
279
280static void
281ppsintr(void *arg)
282{
283	device_t ppsdev = (device_t)arg;
284	struct pps_data *sc = DEVTOSOFTC(ppsdev);
285	device_t ppbus = sc->ppbus;
286
287	pps_capture(&sc->pps[0]);
288	if (!(ppb_rstr(ppbus) & nACK))
289		return;
290	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
291		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
292	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
293	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
294		ppb_wctr(ppbus, IRQENABLE);
295}
296
297static int
298ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
299{
300	struct pps_data *sc = dev->si_drv1;
301	int subdev = (int)dev->si_drv2;
302
303	return (pps_ioctl(cmd, data, &sc->pps[subdev]));
304}
305
306static device_method_t pps_methods[] = {
307	/* device interface */
308	DEVMETHOD(device_identify,	ppsidentify),
309	DEVMETHOD(device_probe,		ppsprobe),
310	DEVMETHOD(device_attach,	ppsattach),
311
312	{ 0, 0 }
313};
314
315static driver_t pps_driver = {
316	PPS_NAME,
317	pps_methods,
318	sizeof(struct pps_data),
319};
320DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
321