pps.c revision 58377 
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 58377 2000-03-20 14:09:06Z 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 <sys/malloc.h>
27#include <machine/bus.h>
28#include <machine/resource.h>
29#include <sys/rman.h>
30
31#include <dev/ppbus/ppbconf.h>
32#include "ppbus_if.h"
33#include <dev/ppbus/ppbio.h>
34#include "pps.h"
35
36#define PPS_NAME	"pps"		/* our official name */
37
38struct pps_data {
39	int	pps_open;
40	struct	ppb_device pps_dev;
41	struct	pps_state pps;
42
43	struct resource *intr_resource;	/* interrupt resource */
44	void *intr_cookie;		/* interrupt registration cookie */
45};
46
47static void	ppsintr(void *arg);
48
49#define DEVTOSOFTC(dev) \
50	((struct pps_data *)device_get_softc(dev))
51#define UNITOSOFTC(unit) \
52	((struct pps_data *)devclass_get_softc(pps_devclass, (unit)))
53#define UNITODEVICE(unit) \
54	(devclass_get_device(pps_devclass, (unit)))
55
56static devclass_t pps_devclass;
57
58static	d_open_t	ppsopen;
59static	d_close_t	ppsclose;
60static	d_ioctl_t	ppsioctl;
61
62#define CDEV_MAJOR 89
63static struct cdevsw pps_cdevsw = {
64	/* open */	ppsopen,
65	/* close */	ppsclose,
66	/* read */	noread,
67	/* write */	nowrite,
68	/* ioctl */	ppsioctl,
69	/* poll */	nopoll,
70	/* mmap */	nommap,
71	/* strategy */	nostrategy,
72	/* name */	PPS_NAME,
73	/* maj */	CDEV_MAJOR,
74	/* dump */	nodump,
75	/* psize */	nopsize,
76	/* flags */	0,
77	/* bmaj */	-1
78};
79
80static void
81ppsidentify(driver_t *driver, device_t parent)
82{
83
84	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
85}
86
87static int
88ppsprobe(device_t ppsdev)
89{
90	struct pps_data *sc;
91	dev_t dev;
92	int unit;
93
94	sc = DEVTOSOFTC(ppsdev);
95	bzero(sc, sizeof(struct pps_data));
96
97	unit = device_get_unit(ppsdev);
98	dev = make_dev(&pps_cdevsw, unit,
99	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
100
101	device_set_desc(ppsdev, "Pulse per second Timing Interface");
102
103	sc->pps.ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
104	pps_init(&sc->pps);
105	return (0);
106}
107
108static int
109ppsattach(device_t dev)
110{
111	struct pps_data *sc = DEVTOSOFTC(dev);
112	device_t ppbus = device_get_parent(dev);
113	int irq, zero = 0;
114
115	/* retrieve the ppbus irq */
116	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
117
118	if (irq > 0) {
119		/* declare our interrupt handler */
120		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
121				       &zero, irq, irq, 1, RF_SHAREABLE);
122	}
123	/* interrupts seem mandatory */
124	if (sc->intr_resource == 0)
125		return (ENXIO);
126
127	return (0);
128}
129
130static	int
131ppsopen(dev_t dev, int flags, int fmt, struct proc *p)
132{
133	u_int unit = minor(dev);
134	struct pps_data *sc = UNITOSOFTC(unit);
135	device_t ppsdev = UNITODEVICE(unit);
136	device_t ppbus = device_get_parent(ppsdev);
137	int error;
138
139	if (!sc->pps_open) {
140		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
141			return (EINTR);
142
143		/* attach the interrupt handler */
144		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
145			       INTR_TYPE_TTY, ppsintr, ppsdev,
146			       &sc->intr_cookie))) {
147			ppb_release_bus(ppbus, ppsdev);
148			return (error);
149		}
150
151		ppb_wctr(ppbus, 0);
152		ppb_wctr(ppbus, IRQENABLE);
153		sc->pps_open = 1;
154	}
155
156	return(0);
157}
158
159static	int
160ppsclose(dev_t dev, int flags, int fmt, struct proc *p)
161{
162	u_int unit = minor(dev);
163	struct pps_data *sc = UNITOSOFTC(unit);
164	device_t ppsdev = UNITODEVICE(unit);
165	device_t ppbus = device_get_parent(ppsdev);
166
167	sc->pps.ppsparam.mode = 0;	/* PHK ??? */
168
169	ppb_wdtr(ppbus, 0);
170	ppb_wctr(ppbus, 0);
171
172	/* Note: the interrupt handler is automatically detached */
173	ppb_release_bus(ppbus, ppsdev);
174	sc->pps_open = 0;
175	return(0);
176}
177
178static void
179ppsintr(void *arg)
180{
181	device_t ppsdev = (device_t)arg;
182	device_t ppbus = device_get_parent(ppsdev);
183	struct pps_data *sc = DEVTOSOFTC(ppsdev);
184	struct timecounter *tc;
185	unsigned count;
186
187	tc = timecounter;
188	count = timecounter->tc_get_timecount(tc);
189	if (!(ppb_rstr(ppbus) & nACK))
190		return;
191	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
192		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
193	pps_event(&sc->pps, tc, count, PPS_CAPTUREASSERT);
194	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
195		ppb_wctr(ppbus, IRQENABLE);
196}
197
198static int
199ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
200{
201	u_int unit = minor(dev);
202	struct pps_data *sc = UNITOSOFTC(unit);
203
204	return (pps_ioctl(cmd, data, &sc->pps));
205}
206
207static device_method_t pps_methods[] = {
208	/* device interface */
209	DEVMETHOD(device_identify,	ppsidentify),
210	DEVMETHOD(device_probe,		ppsprobe),
211	DEVMETHOD(device_attach,	ppsattach),
212
213	{ 0, 0 }
214};
215
216static driver_t pps_driver = {
217	PPS_NAME,
218	pps_methods,
219	sizeof(struct pps_data),
220};
221DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
222