xref: /freebsd/sys/dev/ppbus/pps.c (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
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/lock.h>
22 #include <sys/kernel.h>
23 #include <sys/systm.h>
24 #include <sys/module.h>
25 #include <sys/sx.h>
26 #include <sys/bus.h>
27 #include <sys/conf.h>
28 #include <sys/timepps.h>
29 #include <machine/bus.h>
30 #include <machine/resource.h>
31 #include <sys/rman.h>
32 
33 #include <dev/ppbus/ppbconf.h>
34 #include "ppbus_if.h"
35 #include <dev/ppbus/ppbio.h>
36 
37 #define PPS_NAME	"pps"		/* our official name */
38 
39 #define PRVERBOSE(fmt, arg...)	if (bootverbose) printf(fmt, ##arg);
40 
41 struct pps_data {
42 	struct	ppb_device pps_dev;
43 	struct	pps_state pps[9];
44 	struct cdev *devs[9];
45 	device_t ppsdev;
46 	device_t ppbus;
47 	int	busy;
48 	struct callout timeout;
49 	int	lastdata;
50 
51 	struct sx lock;
52 	struct resource *intr_resource;	/* interrupt resource */
53 	void *intr_cookie;		/* interrupt registration cookie */
54 };
55 
56 static void	ppsintr(void *arg);
57 static void 	ppshcpoll(void *arg);
58 
59 #define DEVTOSOFTC(dev) \
60 	((struct pps_data *)device_get_softc(dev))
61 
62 static devclass_t pps_devclass;
63 
64 static	d_open_t	ppsopen;
65 static	d_close_t	ppsclose;
66 static	d_ioctl_t	ppsioctl;
67 
68 static struct cdevsw pps_cdevsw = {
69 	.d_version =	D_VERSION,
70 	.d_open =	ppsopen,
71 	.d_close =	ppsclose,
72 	.d_ioctl =	ppsioctl,
73 	.d_name =	PPS_NAME,
74 };
75 
76 static void
77 ppsidentify(driver_t *driver, device_t parent)
78 {
79 
80 	device_t dev;
81 
82 	dev = device_find_child(parent, PPS_NAME, -1);
83 	if (!dev)
84 		BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
85 }
86 
87 static int
88 ppstry(device_t ppbus, int send, int expect)
89 {
90 	int i;
91 
92 	ppb_wdtr(ppbus, send);
93 	i = ppb_rdtr(ppbus);
94 	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
95 	return (i != expect);
96 }
97 
98 static int
99 ppsprobe(device_t ppsdev)
100 {
101 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
102 
103 	return (0);
104 }
105 
106 static int
107 ppsattach(device_t dev)
108 {
109 	struct pps_data *sc = DEVTOSOFTC(dev);
110 	device_t ppbus = device_get_parent(dev);
111 	struct cdev *d;
112 	int error, i, unit, rid = 0;
113 
114 	/* declare our interrupt handler */
115 	sc->intr_resource = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
116 	    RF_SHAREABLE);
117 
118 	/* interrupts seem mandatory */
119 	if (sc->intr_resource == NULL) {
120 		device_printf(dev, "Unable to allocate interrupt resource\n");
121 		return (ENXIO);
122 	}
123 
124 	error = bus_setup_intr(dev, sc->intr_resource,
125 	    INTR_TYPE_TTY | INTR_MPSAFE, NULL, ppsintr,
126 	    sc, &sc->intr_cookie);
127 	if (error) {
128 		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->intr_resource);
129 		device_printf(dev, "Unable to register interrupt handler\n");
130 		return (error);
131 	}
132 
133 	sx_init(&sc->lock, "pps");
134 	ppb_init_callout(ppbus, &sc->timeout, 0);
135 	sc->ppsdev = dev;
136 	sc->ppbus = ppbus;
137 	unit = device_get_unit(ppbus);
138 	d = make_dev(&pps_cdevsw, unit,
139 	    UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
140 	sc->devs[0] = d;
141 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
142 	d->si_drv1 = sc;
143 	d->si_drv2 = (void*)0;
144 	pps_init(&sc->pps[0]);
145 
146 	ppb_lock(ppbus);
147 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) {
148 		ppb_unlock(ppbus);
149 		return (0);
150 	}
151 
152 	do {
153 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
154 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
155 		if (i == -1)
156 			break;
157 		i = 0;
158 		ppb_wctr(ppbus, i);
159 		if (ppstry(ppbus, 0x00, 0x00))
160 			break;
161 		if (ppstry(ppbus, 0x55, 0x55))
162 			break;
163 		if (ppstry(ppbus, 0xaa, 0xaa))
164 			break;
165 		if (ppstry(ppbus, 0xff, 0xff))
166 			break;
167 
168 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
169 		ppb_wctr(ppbus, i);
170 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
171 		if (ppstry(ppbus, 0x00, 0x00))
172 			break;
173 		if (ppstry(ppbus, 0x55, 0x00))
174 			break;
175 		if (ppstry(ppbus, 0xaa, 0x00))
176 			break;
177 		if (ppstry(ppbus, 0xff, 0x00))
178 			break;
179 
180 		i = IRQENABLE | PCD | nINIT | SELECTIN;
181 		ppb_wctr(ppbus, i);
182 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
183 		ppstry(ppbus, 0x00, 0xff);
184 		ppstry(ppbus, 0x55, 0xff);
185 		ppstry(ppbus, 0xaa, 0xff);
186 		ppstry(ppbus, 0xff, 0xff);
187 		ppb_unlock(ppbus);
188 
189 		for (i = 1; i < 9; i++) {
190 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
191 			  UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
192 			sc->devs[i] = d;
193 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
194 			d->si_drv1 = sc;
195 			d->si_drv2 = (void *)(intptr_t)i;
196 			pps_init(&sc->pps[i]);
197 		}
198 		ppb_lock(ppbus);
199 	} while (0);
200 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
201 	ppb_release_bus(ppbus, dev);
202 	ppb_unlock(ppbus);
203 
204 	return (0);
205 }
206 
207 static	int
208 ppsopen(struct cdev *dev, int flags, int fmt, struct thread *td)
209 {
210 	struct pps_data *sc = dev->si_drv1;
211 	device_t ppbus = sc->ppbus;
212 	int subdev = (intptr_t)dev->si_drv2;
213 	int i;
214 
215 	/*
216 	 * The sx lock is here solely to serialize open()'s to close
217 	 * the race of concurrent open()'s when pps(4) doesn't own the
218 	 * ppbus.
219 	 */
220 	sx_xlock(&sc->lock);
221 	ppb_lock(ppbus);
222 	if (!sc->busy) {
223 		device_t ppsdev = sc->ppsdev;
224 
225 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR)) {
226 			ppb_unlock(ppbus);
227 			sx_xunlock(&sc->lock);
228 			return (EINTR);
229 		}
230 
231 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
232 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
233 
234 		i = IRQENABLE | PCD | nINIT | SELECTIN;
235 		ppb_wctr(ppbus, i);
236 	}
237 	if (subdev > 0 && !(sc->busy & ~1)) {
238 		/* XXX: Timeout of 1?  hz/100 instead perhaps? */
239 		callout_reset(&sc->timeout, 1, ppshcpoll, sc);
240 		sc->lastdata = ppb_rdtr(sc->ppbus);
241 	}
242 	sc->busy |= (1 << subdev);
243 	ppb_unlock(ppbus);
244 	sx_xunlock(&sc->lock);
245 	return(0);
246 }
247 
248 static	int
249 ppsclose(struct cdev *dev, int flags, int fmt, struct thread *td)
250 {
251 	struct pps_data *sc = dev->si_drv1;
252 	int subdev = (intptr_t)dev->si_drv2;
253 
254 	sx_xlock(&sc->lock);
255 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
256 	ppb_lock(sc->ppbus);
257 	sc->busy &= ~(1 << subdev);
258 	if (subdev > 0 && !(sc->busy & ~1))
259 		callout_stop(&sc->timeout);
260 	if (!sc->busy) {
261 		device_t ppsdev = sc->ppsdev;
262 		device_t ppbus = sc->ppbus;
263 
264 		ppb_wdtr(ppbus, 0);
265 		ppb_wctr(ppbus, 0);
266 
267 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
268 		ppb_release_bus(ppbus, ppsdev);
269 	}
270 	ppb_unlock(sc->ppbus);
271 	sx_xunlock(&sc->lock);
272 	return(0);
273 }
274 
275 static void
276 ppshcpoll(void *arg)
277 {
278 	struct pps_data *sc = arg;
279 	int i, j, k, l;
280 
281 	KASSERT(sc->busy & ~1, ("pps polling w/o opened devices"));
282 	i = ppb_rdtr(sc->ppbus);
283 	if (i == sc->lastdata)
284 		return;
285 	l = sc->lastdata ^ i;
286 	k = 1;
287 	for (j = 1; j < 9; j ++) {
288 		if (l & k) {
289 			pps_capture(&sc->pps[j]);
290 			pps_event(&sc->pps[j],
291 			    i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
292 		}
293 		k += k;
294 	}
295 	sc->lastdata = i;
296 	callout_reset(&sc->timeout, 1, ppshcpoll, sc);
297 }
298 
299 static void
300 ppsintr(void *arg)
301 {
302 	struct pps_data *sc = (struct pps_data *)arg;
303 
304 	ppb_assert_locked(sc->ppbus);
305 	pps_capture(&sc->pps[0]);
306 	if (!(ppb_rstr(sc->ppbus) & nACK))
307 		return;
308 
309 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
310 		ppb_wctr(sc->ppbus, IRQENABLE | AUTOFEED);
311 	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
312 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
313 		ppb_wctr(sc->ppbus, IRQENABLE);
314 }
315 
316 static int
317 ppsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
318 {
319 	struct pps_data *sc = dev->si_drv1;
320 	int subdev = (intptr_t)dev->si_drv2;
321 	int err;
322 
323 	ppb_lock(sc->ppbus);
324 	err = pps_ioctl(cmd, data, &sc->pps[subdev]);
325 	ppb_unlock(sc->ppbus);
326 	return (err);
327 }
328 
329 static device_method_t pps_methods[] = {
330 	/* device interface */
331 	DEVMETHOD(device_identify,	ppsidentify),
332 	DEVMETHOD(device_probe,		ppsprobe),
333 	DEVMETHOD(device_attach,	ppsattach),
334 
335 	{ 0, 0 }
336 };
337 
338 static driver_t pps_driver = {
339 	PPS_NAME,
340 	pps_methods,
341 	sizeof(struct pps_data),
342 };
343 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
344 MODULE_DEPEND(pps, ppbus, 1, 1, 1);
345