pps.c revision 61490 
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 61490 2000-06-10 11:14:19Z 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/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	/* bmaj */	-1
76};
77
78static void
79ppsidentify(driver_t *driver, device_t parent)
80{
81
82	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
83}
84
85static int
86ppsprobe(device_t ppsdev)
87{
88	struct pps_data *sc;
89	dev_t dev;
90	int unit;
91
92	sc = DEVTOSOFTC(ppsdev);
93	bzero(sc, sizeof(struct pps_data));
94
95	unit = device_get_unit(ppsdev);
96	dev = make_dev(&pps_cdevsw, unit,
97	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
98
99	device_set_desc(ppsdev, "Pulse per second Timing Interface");
100
101	sc->pps.ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
102	pps_init(&sc->pps);
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
113	/* retrieve the ppbus irq */
114	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
115
116	if (irq > 0) {
117		/* declare our interrupt handler */
118		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
119				       &zero, irq, irq, 1, RF_SHAREABLE);
120	}
121	/* interrupts seem mandatory */
122	if (sc->intr_resource == 0)
123		return (ENXIO);
124
125	return (0);
126}
127
128static	int
129ppsopen(dev_t dev, int flags, int fmt, struct proc *p)
130{
131	u_int unit = minor(dev);
132	struct pps_data *sc = UNITOSOFTC(unit);
133	device_t ppsdev = UNITODEVICE(unit);
134	device_t ppbus = device_get_parent(ppsdev);
135	int error;
136
137	if (!sc->pps_open) {
138		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
139			return (EINTR);
140
141		/* attach the interrupt handler */
142		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
143			       INTR_TYPE_TTY, ppsintr, ppsdev,
144			       &sc->intr_cookie))) {
145			ppb_release_bus(ppbus, ppsdev);
146			return (error);
147		}
148
149		ppb_wctr(ppbus, 0);
150		ppb_wctr(ppbus, IRQENABLE);
151		sc->pps_open = 1;
152	}
153
154	return(0);
155}
156
157static	int
158ppsclose(dev_t dev, int flags, int fmt, struct proc *p)
159{
160	u_int unit = minor(dev);
161	struct pps_data *sc = UNITOSOFTC(unit);
162	device_t ppsdev = UNITODEVICE(unit);
163	device_t ppbus = device_get_parent(ppsdev);
164
165	sc->pps.ppsparam.mode = 0;	/* PHK ??? */
166
167	ppb_wdtr(ppbus, 0);
168	ppb_wctr(ppbus, 0);
169
170	/* Note: the interrupt handler is automatically detached */
171	ppb_release_bus(ppbus, ppsdev);
172	sc->pps_open = 0;
173	return(0);
174}
175
176static void
177ppsintr(void *arg)
178{
179	device_t ppsdev = (device_t)arg;
180	device_t ppbus = device_get_parent(ppsdev);
181	struct pps_data *sc = DEVTOSOFTC(ppsdev);
182	struct timecounter *tc;
183	unsigned count;
184
185	tc = timecounter;
186	count = timecounter->tc_get_timecount(tc);
187	if (!(ppb_rstr(ppbus) & nACK))
188		return;
189	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
190		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
191	pps_event(&sc->pps, tc, count, PPS_CAPTUREASSERT);
192	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
193		ppb_wctr(ppbus, IRQENABLE);
194}
195
196static int
197ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
198{
199	u_int unit = minor(dev);
200	struct pps_data *sc = UNITOSOFTC(unit);
201
202	return (pps_ioctl(cmd, data, &sc->pps));
203}
204
205static device_method_t pps_methods[] = {
206	/* device interface */
207	DEVMETHOD(device_identify,	ppsidentify),
208	DEVMETHOD(device_probe,		ppsprobe),
209	DEVMETHOD(device_attach,	ppsattach),
210
211	{ 0, 0 }
212};
213
214static driver_t pps_driver = {
215	PPS_NAME,
216	pps_methods,
217	sizeof(struct pps_data),
218};
219DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
220