pps.c revision 83366 
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 83366 2001-09-12 08:38:13Z julian $
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/timetc.h>
25#include <sys/timepps.h>
26#include <machine/bus.h>
27#include <machine/resource.h>
28#include <sys/rman.h>
29
30#include <dev/ppbus/ppbconf.h>
31#include "ppbus_if.h"
32#include <dev/ppbus/ppbio.h>
33
34#define PPS_NAME	"pps"		/* our official name */
35
36struct pps_data {
37	int	pps_open;
38	struct	ppb_device pps_dev;
39	struct	pps_state pps;
40
41	struct resource *intr_resource;	/* interrupt resource */
42	void *intr_cookie;		/* interrupt registration cookie */
43};
44
45static void	ppsintr(void *arg);
46
47#define DEVTOSOFTC(dev) \
48	((struct pps_data *)device_get_softc(dev))
49#define UNITOSOFTC(unit) \
50	((struct pps_data *)devclass_get_softc(pps_devclass, (unit)))
51#define UNITODEVICE(unit) \
52	(devclass_get_device(pps_devclass, (unit)))
53
54static devclass_t pps_devclass;
55
56static	d_open_t	ppsopen;
57static	d_close_t	ppsclose;
58static	d_ioctl_t	ppsioctl;
59
60#define CDEV_MAJOR 89
61static struct cdevsw pps_cdevsw = {
62	/* open */	ppsopen,
63	/* close */	ppsclose,
64	/* read */	noread,
65	/* write */	nowrite,
66	/* ioctl */	ppsioctl,
67	/* poll */	nopoll,
68	/* mmap */	nommap,
69	/* strategy */	nostrategy,
70	/* name */	PPS_NAME,
71	/* maj */	CDEV_MAJOR,
72	/* dump */	nodump,
73	/* psize */	nopsize,
74	/* flags */	0,
75};
76
77static void
78ppsidentify(driver_t *driver, device_t parent)
79{
80
81	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
82}
83
84static int
85ppsprobe(device_t ppsdev)
86{
87	struct pps_data *sc;
88	dev_t dev;
89	int unit;
90
91	sc = DEVTOSOFTC(ppsdev);
92	bzero(sc, sizeof(struct pps_data));
93
94	unit = device_get_unit(ppsdev);
95	dev = make_dev(&pps_cdevsw, unit,
96	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
97
98	device_set_desc(ppsdev, "Pulse per second Timing Interface");
99
100	sc->pps.ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
101	pps_init(&sc->pps);
102	return (0);
103}
104
105static int
106ppsattach(device_t dev)
107{
108	struct pps_data *sc = DEVTOSOFTC(dev);
109	device_t ppbus = device_get_parent(dev);
110	int irq, zero = 0;
111
112	/* retrieve the ppbus irq */
113	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
114
115	if (irq > 0) {
116		/* declare our interrupt handler */
117		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
118				       &zero, irq, irq, 1, RF_SHAREABLE);
119	}
120	/* interrupts seem mandatory */
121	if (sc->intr_resource == 0)
122		return (ENXIO);
123
124	return (0);
125}
126
127static	int
128ppsopen(dev_t dev, int flags, int fmt, struct thread *td)
129{
130	u_int unit = minor(dev);
131	struct pps_data *sc = UNITOSOFTC(unit);
132	device_t ppsdev = UNITODEVICE(unit);
133	device_t ppbus = device_get_parent(ppsdev);
134	int error;
135
136	if (!sc->pps_open) {
137		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
138			return (EINTR);
139
140		/* attach the interrupt handler */
141		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
142			       INTR_TYPE_TTY, ppsintr, ppsdev,
143			       &sc->intr_cookie))) {
144			ppb_release_bus(ppbus, ppsdev);
145			return (error);
146		}
147
148		ppb_wctr(ppbus, 0);
149		ppb_wctr(ppbus, IRQENABLE);
150		sc->pps_open = 1;
151	}
152
153	return(0);
154}
155
156static	int
157ppsclose(dev_t dev, int flags, int fmt, struct thread *td)
158{
159	u_int unit = minor(dev);
160	struct pps_data *sc = UNITOSOFTC(unit);
161	device_t ppsdev = UNITODEVICE(unit);
162	device_t ppbus = device_get_parent(ppsdev);
163
164	sc->pps.ppsparam.mode = 0;	/* PHK ??? */
165
166	ppb_wdtr(ppbus, 0);
167	ppb_wctr(ppbus, 0);
168
169	/* Note: the interrupt handler is automatically detached */
170	ppb_release_bus(ppbus, ppsdev);
171	sc->pps_open = 0;
172	return(0);
173}
174
175static void
176ppsintr(void *arg)
177{
178	device_t ppsdev = (device_t)arg;
179	device_t ppbus = device_get_parent(ppsdev);
180	struct pps_data *sc = DEVTOSOFTC(ppsdev);
181	struct timecounter *tc;
182	unsigned count;
183
184	tc = timecounter;
185	count = timecounter->tc_get_timecount(tc);
186	if (!(ppb_rstr(ppbus) & nACK))
187		return;
188	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
189		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
190	pps_event(&sc->pps, tc, count, PPS_CAPTUREASSERT);
191	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
192		ppb_wctr(ppbus, IRQENABLE);
193}
194
195static int
196ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
197{
198	u_int unit = minor(dev);
199	struct pps_data *sc = UNITOSOFTC(unit);
200
201	return (pps_ioctl(cmd, data, &sc->pps));
202}
203
204static device_method_t pps_methods[] = {
205	/* device interface */
206	DEVMETHOD(device_identify,	ppsidentify),
207	DEVMETHOD(device_probe,		ppsprobe),
208	DEVMETHOD(device_attach,	ppsattach),
209
210	{ 0, 0 }
211};
212
213static driver_t pps_driver = {
214	PPS_NAME,
215	pps_methods,
216	sizeof(struct pps_data),
217};
218DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
219