xref: /freebsd/sys/dev/ppbus/pps.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
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  * $FreeBSD$
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 <sys/malloc.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 
37 struct 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 
46 static 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 
55 static devclass_t pps_devclass;
56 
57 static	d_open_t	ppsopen;
58 static	d_close_t	ppsclose;
59 static	d_ioctl_t	ppsioctl;
60 
61 #define CDEV_MAJOR 89
62 static 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 
79 static void
80 ppsidentify(driver_t *driver, device_t parent)
81 {
82 
83 	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
84 }
85 
86 static int
87 ppsprobe(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 
107 static int
108 ppsattach(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 
129 static	int
130 ppsopen(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 
158 static	int
159 ppsclose(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 
177 static void
178 ppsintr(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 
197 static int
198 ppsioctl(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 
206 static 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 
215 static driver_t pps_driver = {
216 	PPS_NAME,
217 	pps_methods,
218 	sizeof(struct pps_data),
219 };
220 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
221