xref: /dragonfly/sys/dev/misc/pps/pps.c (revision 6b5c5d0d)
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: src/sys/dev/ppbus/pps.c,v 1.24.2.1 2000/05/24 00:20:57 n_hibma Exp $
10  * $DragonFly: src/sys/dev/misc/pps/pps.c,v 1.17 2006/10/25 20:55:55 dillon Exp $
11  *
12  * This driver implements a draft-mogul-pps-api-02.txt PPS source.
13  *
14  * The input pin is pin#10
15  * The echo output pin is pin#14
16  *
17  */
18 
19 #include "use_pps.h"
20 
21 #include <sys/param.h>
22 #include <sys/kernel.h>
23 #include <sys/systm.h>
24 #include <sys/conf.h>
25 #include <sys/device.h>
26 #include <sys/module.h>
27 #include <sys/bus.h>
28 #include <sys/timepps.h>
29 #include <sys/rman.h>
30 
31 #include <bus/ppbus/ppbconf.h>
32 #include <bus/ppbus/ppbio.h>
33 
34 #include "ppbus_if.h"
35 
36 #define PPS_NAME	"pps"		/* our official name */
37 
38 struct 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 
47 static 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 
56 static devclass_t pps_devclass;
57 
58 static	d_open_t	ppsopen;
59 static	d_close_t	ppsclose;
60 static	d_ioctl_t	ppsioctl;
61 
62 #define CDEV_MAJOR 89
63 static struct dev_ops pps_ops = {
64 	{ PPS_NAME, CDEV_MAJOR, 0 },
65 	.d_open =	ppsopen,
66 	.d_close =	ppsclose,
67 	.d_ioctl =	ppsioctl,
68 };
69 
70 static int
71 ppsprobe(device_t ppsdev)
72 {
73 	struct pps_data *sc;
74 
75 	sc = DEVTOSOFTC(ppsdev);
76 	bzero(sc, sizeof(struct pps_data));
77 
78 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
79 
80 	sc->pps.ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
81 	pps_init(&sc->pps);
82 	return (0);
83 }
84 
85 static int
86 ppsattach(device_t ppsdev)
87 {
88 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
89 	device_t ppbus = device_get_parent(ppsdev);
90 	int irq;
91 	int unit;
92 	int zero = 0;
93 
94 	/* retrieve the ppbus irq */
95 	BUS_READ_IVAR(ppbus, ppsdev, PPBUS_IVAR_IRQ, &irq);
96 
97 	if (irq > 0) {
98 		/* declare our interrupt handler */
99 		sc->intr_resource = bus_alloc_resource(ppsdev, SYS_RES_IRQ,
100 				       &zero, irq, irq, 1, RF_SHAREABLE);
101 	}
102 	/* interrupts seem mandatory */
103 	if (sc->intr_resource == 0)
104 		return (ENXIO);
105 
106 	unit = device_get_unit(ppsdev);
107 	dev_ops_add(&pps_ops, -1, unit);
108 	make_dev(&pps_ops, unit, UID_ROOT, GID_WHEEL, 0644,
109 		    PPS_NAME "%d", unit);
110 	return (0);
111 }
112 
113 static	int
114 ppsopen(struct dev_open_args *ap)
115 {
116 	cdev_t dev = ap->a_head.a_dev;
117 	u_int unit = minor(dev);
118 	struct pps_data *sc = UNITOSOFTC(unit);
119 	device_t ppsdev = UNITODEVICE(unit);
120 	device_t ppbus = device_get_parent(ppsdev);
121 	int error;
122 
123 	if (!sc->pps_open) {
124 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
125 			return (EINTR);
126 
127 		/* attach the interrupt handler */
128 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
129 			       0, ppsintr, ppsdev,
130 			       &sc->intr_cookie, NULL))) {
131 			ppb_release_bus(ppbus, ppsdev);
132 			return (error);
133 		}
134 
135 		ppb_wctr(ppbus, 0);
136 		ppb_wctr(ppbus, IRQENABLE);
137 		sc->pps_open = 1;
138 	}
139 
140 	return(0);
141 }
142 
143 static	int
144 ppsclose(struct dev_close_args *ap)
145 {
146 	cdev_t dev = ap->a_head.a_dev;
147 	u_int unit = minor(dev);
148 	struct pps_data *sc = UNITOSOFTC(unit);
149 	device_t ppsdev = UNITODEVICE(unit);
150 	device_t ppbus = device_get_parent(ppsdev);
151 
152 	sc->pps.ppsparam.mode = 0;	/* PHK ??? */
153 
154 	ppb_wdtr(ppbus, 0);
155 	ppb_wctr(ppbus, 0);
156 
157 	/* Note: the interrupt handler is automatically detached */
158 	ppb_release_bus(ppbus, ppsdev);
159 	sc->pps_open = 0;
160 	return(0);
161 }
162 
163 static void
164 ppsintr(void *arg)
165 {
166 	device_t ppsdev = (device_t)arg;
167 	device_t ppbus = device_get_parent(ppsdev);
168 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
169 	sysclock_t count;
170 
171 	count = sys_cputimer->count();
172 	if (!(ppb_rstr(ppbus) & nACK))
173 		return;
174 	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
175 		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
176 	pps_event(&sc->pps, count, PPS_CAPTUREASSERT);
177 	if (sc->pps.ppsparam.mode & PPS_ECHOASSERT)
178 		ppb_wctr(ppbus, IRQENABLE);
179 }
180 
181 static int
182 ppsioctl(struct dev_ioctl_args *ap)
183 {
184 	cdev_t dev = ap->a_head.a_dev;
185 	u_int unit = minor(dev);
186 	struct pps_data *sc = UNITOSOFTC(unit);
187 
188 	return (pps_ioctl(ap->a_cmd, ap->a_data, &sc->pps));
189 }
190 
191 /*
192  * Becuase pps is a static device under any attached ppbus, and not scanned
193  * by the ppbus, we need an identify function to create the device.
194  */
195 static device_method_t pps_methods[] = {
196 	/* device interface */
197 	DEVMETHOD(device_identify,	bus_generic_identify),
198 	DEVMETHOD(device_probe,		ppsprobe),
199 	DEVMETHOD(device_attach,	ppsattach),
200 
201 	{ 0, 0 }
202 };
203 
204 static driver_t pps_driver = {
205 	PPS_NAME,
206 	pps_methods,
207 	sizeof(struct pps_data),
208 };
209 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
210