pps.c revision 59391 
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 59391 2000-04-19 14:58:28Z phk $
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#include "pps.h"
34
35#define PPS_NAME	"pps"		/* our official name */
36
37struct pps_data {
38	int	pps_open;
39	struct	ppb_device pps_dev;
40	struct	pps_state pps;
41
42	struct resource *intr_resource;	/* interrupt resource */
43	void *intr_cookie;		/* interrupt registration cookie */
44};
45
46static void	ppsintr(void *arg);
47
48#define DEVTOSOFTC(dev) \
49	((struct pps_data *)device_get_softc(dev))
50#define UNITOSOFTC(unit) \
51	((struct pps_data *)devclass_get_softc(pps_devclass, (unit)))
52#define UNITODEVICE(unit) \
53	(devclass_get_device(pps_devclass, (unit)))
54
55static devclass_t pps_devclass;
56
57static	d_open_t	ppsopen;
58static	d_close_t	ppsclose;
59static	d_ioctl_t	ppsioctl;
60
61#define CDEV_MAJOR 89
62static struct cdevsw pps_cdevsw = {
63	/* open */	ppsopen,
64	/* close */	ppsclose,
65	/* read */	noread,
66	/* write */	nowrite,
67	/* ioctl */	ppsioctl,
68	/* poll */	nopoll,
69	/* mmap */	nommap,
70	/* strategy */	nostrategy,
71	/* name */	PPS_NAME,
72	/* maj */	CDEV_MAJOR,
73	/* dump */	nodump,
74	/* psize */	nopsize,
75	/* flags */	0,
76	/* bmaj */	-1
77};
78
79static void
80ppsidentify(driver_t *driver, device_t parent)
81{
82
83	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
84}
85
86static int
87ppsprobe(device_t ppsdev)
88{
89	struct pps_data *sc;
90	dev_t dev;
91	int unit;
92
93	sc = DEVTOSOFTC(ppsdev);
94	bzero(sc, sizeof(struct pps_data));
95
96	unit = device_get_unit(ppsdev);
97	dev = make_dev(&pps_cdevsw, unit,
98	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
99
100	device_set_desc(ppsdev, "Pulse per second Timing Interface");
101
102	sc->pps.ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
103	pps_init(&sc->pps);
104	return (0);
105}
106
107static int
108ppsattach(device_t dev)
109{
110	struct pps_data *sc = DEVTOSOFTC(dev);
111	device_t ppbus = device_get_parent(dev);
112	int irq, zero = 0;
113
114	/* retrieve the ppbus irq */
115	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
116
117	if (irq > 0) {
118		/* declare our interrupt handler */
119		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
120				       &zero, irq, irq, 1, RF_SHAREABLE);
121	}
122	/* interrupts seem mandatory */
123	if (sc->intr_resource == 0)
124		return (ENXIO);
125
126	return (0);
127}
128
129static	int
130ppsopen(dev_t dev, int flags, int fmt, struct proc *p)
131{
132	u_int unit = minor(dev);
133	struct pps_data *sc = UNITOSOFTC(unit);
134	device_t ppsdev = UNITODEVICE(unit);
135	device_t ppbus = device_get_parent(ppsdev);
136	int error;
137
138	if (!sc->pps_open) {
139		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
140			return (EINTR);
141
142		/* attach the interrupt handler */
143		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
144			       INTR_TYPE_TTY, ppsintr, ppsdev,
145			       &sc->intr_cookie))) {
146			ppb_release_bus(ppbus, ppsdev);
147			return (error);
148		}
149
150		ppb_wctr(ppbus, 0);
151		ppb_wctr(ppbus, IRQENABLE);
152		sc->pps_open = 1;
153	}
154
155	return(0);
156}
157
158static	int
159ppsclose(dev_t dev, int flags, int fmt, struct proc *p)
160{
161	u_int unit = minor(dev);
162	struct pps_data *sc = UNITOSOFTC(unit);
163	device_t ppsdev = UNITODEVICE(unit);
164	device_t ppbus = device_get_parent(ppsdev);
165
166	sc->pps.ppsparam.mode = 0;	/* PHK ??? */
167
168	ppb_wdtr(ppbus, 0);
169	ppb_wctr(ppbus, 0);
170
171	/* Note: the interrupt handler is automatically detached */
172	ppb_release_bus(ppbus, ppsdev);
173	sc->pps_open = 0;
174	return(0);
175}
176
177static void
178ppsintr(void *arg)
179{
180	device_t ppsdev = (device_t)arg;
181	device_t ppbus = device_get_parent(ppsdev);
182	struct pps_data *sc = DEVTOSOFTC(ppsdev);
183	struct timecounter *tc;
184	unsigned count;
185
186	tc = timecounter;
187	count = timecounter->tc_get_timecount(tc);
188	if (!(ppb_rstr(ppbus) & nACK))
189		return;
190	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
191		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
192	pps_event(&sc->pps, tc, count, PPS_CAPTUREASSERT);
193	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
194		ppb_wctr(ppbus, IRQENABLE);
195}
196
197static int
198ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
199{
200	u_int unit = minor(dev);
201	struct pps_data *sc = UNITOSOFTC(unit);
202
203	return (pps_ioctl(cmd, data, &sc->pps));
204}
205
206static device_method_t pps_methods[] = {
207	/* device interface */
208	DEVMETHOD(device_identify,	ppsidentify),
209	DEVMETHOD(device_probe,		ppsprobe),
210	DEVMETHOD(device_attach,	ppsattach),
211
212	{ 0, 0 }
213};
214
215static driver_t pps_driver = {
216	PPS_NAME,
217	pps_methods,
218	sizeof(struct pps_data),
219};
220DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
221