xref: /freebsd/sys/dev/ppbus/pps.c (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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  *
10  * This driver implements a draft-mogul-pps-api-02.txt PPS source.
11  *
12  * The input pin is pin#10
13  * The echo output pin is pin#14
14  *
15  */
16 
17 #include <sys/cdefs.h>
18 __FBSDID("$FreeBSD$");
19 
20 #include <sys/param.h>
21 #include <sys/kernel.h>
22 #include <sys/systm.h>
23 #include <sys/module.h>
24 #include <sys/bus.h>
25 #include <sys/conf.h>
26 #include <sys/timepps.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 
35 #define PPS_NAME	"pps"		/* our official name */
36 
37 #define PRVERBOSE(fmt, arg...)	if (bootverbose) printf(fmt, ##arg);
38 
39 struct pps_data {
40 	struct	ppb_device pps_dev;
41 	struct	pps_state pps[9];
42 	struct cdev *devs[9];
43 	device_t ppsdev;
44 	device_t ppbus;
45 	int	busy;
46 	struct callout_handle timeout;
47 	int	lastdata;
48 
49 	struct resource *intr_resource;	/* interrupt resource */
50 	void *intr_cookie;		/* interrupt registration cookie */
51 };
52 
53 static void	ppsintr(void *arg);
54 static void 	ppshcpoll(void *arg);
55 
56 #define DEVTOSOFTC(dev) \
57 	((struct pps_data *)device_get_softc(dev))
58 
59 static devclass_t pps_devclass;
60 
61 static	d_open_t	ppsopen;
62 static	d_close_t	ppsclose;
63 static	d_ioctl_t	ppsioctl;
64 
65 static struct cdevsw pps_cdevsw = {
66 	.d_version =	D_VERSION,
67 	.d_flags =	D_NEEDGIANT,
68 	.d_open =	ppsopen,
69 	.d_close =	ppsclose,
70 	.d_ioctl =	ppsioctl,
71 	.d_name =	PPS_NAME,
72 };
73 
74 static void
75 ppsidentify(driver_t *driver, device_t parent)
76 {
77 
78 	device_t dev;
79 
80 	dev = device_find_child(parent, PPS_NAME, 0);
81 	if (!dev)
82 		BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
83 }
84 
85 static int
86 ppstry(device_t ppbus, int send, int expect)
87 {
88 	int i;
89 
90 	ppb_wdtr(ppbus, send);
91 	i = ppb_rdtr(ppbus);
92 	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
93 	return (i != expect);
94 }
95 
96 static int
97 ppsprobe(device_t ppsdev)
98 {
99 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
100 
101 	return (0);
102 }
103 
104 static int
105 ppsattach(device_t dev)
106 {
107 	struct pps_data *sc = DEVTOSOFTC(dev);
108 	device_t ppbus = device_get_parent(dev);
109 	struct cdev *d;
110 	intptr_t irq;
111 	int i, unit, zero = 0;
112 
113 	bzero(sc, sizeof(struct pps_data)); /* XXX doesn't newbus do this? */
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 == NULL)
125 		return (ENXIO);
126 
127 	sc->ppsdev = dev;
128 	sc->ppbus = ppbus;
129 	unit = device_get_unit(ppbus);
130 	d = make_dev(&pps_cdevsw, unit,
131 	    UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
132 	sc->devs[0] = d;
133 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
134 	d->si_drv1 = sc;
135 	d->si_drv2 = (void*)0;
136 	pps_init(&sc->pps[0]);
137 
138 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
139 		return (0);
140 
141 	do {
142 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
143 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
144 		if (i == -1)
145 			break;
146 		i = 0;
147 		ppb_wctr(ppbus, i);
148 		if (ppstry(ppbus, 0x00, 0x00))
149 			break;
150 		if (ppstry(ppbus, 0x55, 0x55))
151 			break;
152 		if (ppstry(ppbus, 0xaa, 0xaa))
153 			break;
154 		if (ppstry(ppbus, 0xff, 0xff))
155 			break;
156 
157 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
158 		ppb_wctr(ppbus, i);
159 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
160 		if (ppstry(ppbus, 0x00, 0x00))
161 			break;
162 		if (ppstry(ppbus, 0x55, 0x00))
163 			break;
164 		if (ppstry(ppbus, 0xaa, 0x00))
165 			break;
166 		if (ppstry(ppbus, 0xff, 0x00))
167 			break;
168 
169 		i = IRQENABLE | PCD | nINIT | SELECTIN;
170 		ppb_wctr(ppbus, i);
171 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
172 		ppstry(ppbus, 0x00, 0xff);
173 		ppstry(ppbus, 0x55, 0xff);
174 		ppstry(ppbus, 0xaa, 0xff);
175 		ppstry(ppbus, 0xff, 0xff);
176 
177 		for (i = 1; i < 9; i++) {
178 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
179 			  UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
180 			sc->devs[i] = d;
181 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
182 			d->si_drv1 = sc;
183 			d->si_drv2 = (void *)(intptr_t)i;
184 			pps_init(&sc->pps[i]);
185 		}
186 	} while (0);
187 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
188 	ppb_release_bus(ppbus, dev);
189 
190 	return (0);
191 }
192 
193 static	int
194 ppsopen(struct cdev *dev, int flags, int fmt, struct thread *td)
195 {
196 	struct pps_data *sc = dev->si_drv1;
197 	int subdev = (intptr_t)dev->si_drv2;
198 	int error, i;
199 
200 	if (!sc->busy) {
201 		device_t ppsdev = sc->ppsdev;
202 		device_t ppbus = sc->ppbus;
203 
204 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
205 			return (EINTR);
206 
207 		/* attach the interrupt handler */
208 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
209 			       INTR_TYPE_TTY, ppsintr, ppsdev,
210 			       &sc->intr_cookie))) {
211 			ppb_release_bus(ppbus, ppsdev);
212 			return (error);
213 		}
214 
215 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
216 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
217 
218 		i = IRQENABLE | PCD | nINIT | SELECTIN;
219 		ppb_wctr(ppbus, i);
220 	}
221 	if (subdev > 0 && !(sc->busy & ~1)) {
222 		sc->timeout = timeout(ppshcpoll, sc, 1);
223 		sc->lastdata = ppb_rdtr(sc->ppbus);
224 	}
225 	sc->busy |= (1 << subdev);
226 	return(0);
227 }
228 
229 static	int
230 ppsclose(struct cdev *dev, int flags, int fmt, struct thread *td)
231 {
232 	struct pps_data *sc = dev->si_drv1;
233 	int subdev = (intptr_t)dev->si_drv2;
234 
235 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
236 	sc->busy &= ~(1 << subdev);
237 	if (subdev > 0 && !(sc->busy & ~1))
238 		untimeout(ppshcpoll, sc, sc->timeout);
239 	if (!sc->busy) {
240 		device_t ppsdev = sc->ppsdev;
241 		device_t ppbus = sc->ppbus;
242 
243 		ppb_wdtr(ppbus, 0);
244 		ppb_wctr(ppbus, 0);
245 
246 		/* Note: the interrupt handler is automatically detached */
247 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
248 		ppb_release_bus(ppbus, ppsdev);
249 	}
250 	return(0);
251 }
252 
253 static void
254 ppshcpoll(void *arg)
255 {
256 	struct pps_data *sc = arg;
257 	int i, j, k, l;
258 
259 	if (!(sc->busy & ~1))
260 		return;
261 	sc->timeout = timeout(ppshcpoll, sc, 1);
262 	i = ppb_rdtr(sc->ppbus);
263 	if (i == sc->lastdata)
264 		return;
265 	l = sc->lastdata ^ i;
266 	k = 1;
267 	for (j = 1; j < 9; j ++) {
268 		if (l & k) {
269 			pps_capture(&sc->pps[j]);
270 			pps_event(&sc->pps[j],
271 			    i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
272 		}
273 		k += k;
274 	}
275 	sc->lastdata = i;
276 }
277 
278 static void
279 ppsintr(void *arg)
280 {
281 	device_t ppsdev = (device_t)arg;
282 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
283 	device_t ppbus = sc->ppbus;
284 
285 	pps_capture(&sc->pps[0]);
286 	if (!(ppb_rstr(ppbus) & nACK))
287 		return;
288 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
289 		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
290 	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
291 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
292 		ppb_wctr(ppbus, IRQENABLE);
293 }
294 
295 static int
296 ppsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
297 {
298 	struct pps_data *sc = dev->si_drv1;
299 	int subdev = (intptr_t)dev->si_drv2;
300 
301 	return (pps_ioctl(cmd, data, &sc->pps[subdev]));
302 }
303 
304 static device_method_t pps_methods[] = {
305 	/* device interface */
306 	DEVMETHOD(device_identify,	ppsidentify),
307 	DEVMETHOD(device_probe,		ppsprobe),
308 	DEVMETHOD(device_attach,	ppsattach),
309 
310 	{ 0, 0 }
311 };
312 
313 static driver_t pps_driver = {
314 	PPS_NAME,
315 	pps_methods,
316 	sizeof(struct pps_data),
317 };
318 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
319