xref: /freebsd/sys/dev/ppbus/pps.c (revision eacee0ff7ec955b32e09515246bd97b6edcd2b0f)
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/timetc.h>
25 #include <sys/timepps.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 
34 #define PPS_NAME	"pps"		/* our official name */
35 
36 #define PRVERBOSE(arg...)	if (bootverbose) printf(##arg);
37 
38 struct pps_data {
39 	struct	ppb_device pps_dev;
40 	struct	pps_state pps[9];
41 	dev_t	devs[9];
42 	device_t ppsdev;
43 	device_t ppbus;
44 	int	busy;
45 	struct callout_handle timeout;
46 	int	lastdata;
47 
48 	struct resource *intr_resource;	/* interrupt resource */
49 	void *intr_cookie;		/* interrupt registration cookie */
50 };
51 
52 static void	ppsintr(void *arg);
53 static void 	ppshcpoll(void *arg);
54 
55 #define DEVTOSOFTC(dev) \
56 	((struct pps_data *)device_get_softc(dev))
57 
58 static devclass_t pps_devclass;
59 
60 static	d_open_t	ppsopen;
61 static	d_close_t	ppsclose;
62 static	d_ioctl_t	ppsioctl;
63 
64 #define CDEV_MAJOR 89
65 static struct cdevsw pps_cdevsw = {
66 	/* open */	ppsopen,
67 	/* close */	ppsclose,
68 	/* read */	noread,
69 	/* write */	nowrite,
70 	/* ioctl */	ppsioctl,
71 	/* poll */	nopoll,
72 	/* mmap */	nommap,
73 	/* strategy */	nostrategy,
74 	/* name */	PPS_NAME,
75 	/* maj */	CDEV_MAJOR,
76 	/* dump */	nodump,
77 	/* psize */	nopsize,
78 	/* flags */	0,
79 };
80 
81 static void
82 ppsidentify(driver_t *driver, device_t parent)
83 {
84 
85 	BUS_ADD_CHILD(parent, 0, PPS_NAME, 0);
86 }
87 
88 static int
89 ppstry(device_t ppbus, int send, int expect)
90 {
91 	int i;
92 
93 	ppb_wdtr(ppbus, send);
94 	i = ppb_rdtr(ppbus);
95 	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
96 	return (i != expect);
97 }
98 
99 static int
100 ppsprobe(device_t ppsdev)
101 {
102 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
103 
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 	dev_t d;
114 	int unit, i;
115 
116 	bzero(sc, sizeof(struct pps_data)); /* XXX doesn't newbus do this? */
117 
118 	/* retrieve the ppbus irq */
119 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
120 
121 	if (irq > 0) {
122 		/* declare our interrupt handler */
123 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
124 		    &zero, irq, irq, 1, RF_SHAREABLE);
125 	}
126 	/* interrupts seem mandatory */
127 	if (sc->intr_resource == NULL)
128 		return (ENXIO);
129 
130 	sc->ppsdev = dev;
131 	sc->ppbus = ppbus;
132 	unit = device_get_unit(ppbus);
133 	d = make_dev(&pps_cdevsw, unit,
134 	    UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%d", unit);
135 	sc->devs[0] = d;
136 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
137 	d->si_drv1 = sc;
138 	d->si_drv2 = (void*)0;
139 	pps_init(&sc->pps[0]);
140 
141 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
142 		return (0);
143 
144 	do {
145 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
146 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
147 		if (i == -1)
148 			break;
149 		i = 0;
150 		ppb_wctr(ppbus, i);
151 		if (ppstry(ppbus, 0x00, 0x00))
152 			break;
153 		if (ppstry(ppbus, 0x55, 0x55))
154 			break;
155 		if (ppstry(ppbus, 0xaa, 0xaa))
156 			break;
157 		if (ppstry(ppbus, 0xff, 0xff))
158 			break;
159 
160 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
161 		ppb_wctr(ppbus, i);
162 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
163 		if (ppstry(ppbus, 0x00, 0x00))
164 			break;
165 		if (ppstry(ppbus, 0x55, 0x00))
166 			break;
167 		if (ppstry(ppbus, 0xaa, 0x00))
168 			break;
169 		if (ppstry(ppbus, 0xff, 0x00))
170 			break;
171 
172 		i = IRQENABLE | PCD | nINIT | SELECTIN;
173 		ppb_wctr(ppbus, i);
174 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
175 		ppstry(ppbus, 0x00, 0xff);
176 		ppstry(ppbus, 0x55, 0xff);
177 		ppstry(ppbus, 0xaa, 0xff);
178 		ppstry(ppbus, 0xff, 0xff);
179 
180 		for (i = 1; i < 9; i++) {
181 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
182 			  UID_ROOT, GID_WHEEL, 0644, PPS_NAME "%db%d", unit, i - 1);
183 			sc->devs[i] = d;
184 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
185 			d->si_drv1 = sc;
186 			d->si_drv2 = (void*)i;
187 			pps_init(&sc->pps[i]);
188 		}
189 	} while (0);
190 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
191 	ppb_release_bus(ppbus, dev);
192 
193 	return (0);
194 }
195 
196 static	int
197 ppsopen(dev_t dev, int flags, int fmt, struct thread *td)
198 {
199 	struct pps_data *sc = dev->si_drv1;
200 	int subdev = (int)dev->si_drv2;
201 	int error, i;
202 
203 	if (!sc->busy) {
204 		device_t ppsdev = sc->ppsdev;
205 		device_t ppbus = sc->ppbus;
206 
207 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
208 			return (EINTR);
209 
210 		/* attach the interrupt handler */
211 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
212 			       INTR_TYPE_TTY, ppsintr, ppsdev,
213 			       &sc->intr_cookie))) {
214 			ppb_release_bus(ppbus, ppsdev);
215 			return (error);
216 		}
217 
218 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
219 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
220 
221 		i = IRQENABLE | PCD | nINIT | SELECTIN;
222 		ppb_wctr(ppbus, i);
223 	}
224 	if (subdev > 0 && !(sc->busy & ~1)) {
225 		sc->timeout = timeout(ppshcpoll, sc, 1);
226 		sc->lastdata = ppb_rdtr(sc->ppbus);
227 	}
228 	sc->busy |= (1 << subdev);
229 	return(0);
230 }
231 
232 static	int
233 ppsclose(dev_t dev, int flags, int fmt, struct thread *td)
234 {
235 	struct pps_data *sc = dev->si_drv1;
236 	int subdev = (int)dev->si_drv2;
237 
238 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
239 	sc->busy &= ~(1 << subdev);
240 	if (subdev > 0 && !(sc->busy & ~1))
241 		untimeout(ppshcpoll, sc, sc->timeout);
242 	if (!sc->busy) {
243 		device_t ppsdev = sc->ppsdev;
244 		device_t ppbus = sc->ppbus;
245 
246 		ppb_wdtr(ppbus, 0);
247 		ppb_wctr(ppbus, 0);
248 
249 		/* Note: the interrupt handler is automatically detached */
250 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
251 		ppb_release_bus(ppbus, ppsdev);
252 	}
253 	return(0);
254 }
255 
256 static void
257 ppshcpoll(void *arg)
258 {
259 	struct pps_data *sc = arg;
260 	int i, j, k, l;
261 	struct timecounter *tc;
262 	unsigned count;
263 
264 	if (!(sc->busy & ~1))
265 		return;
266 	sc->timeout = timeout(ppshcpoll, sc, 1);
267 	i = ppb_rdtr(sc->ppbus);
268 	if (i == sc->lastdata)
269 		return;
270 	tc = timecounter;
271 	count = timecounter->tc_get_timecount(tc);
272 	l = sc->lastdata ^ i;
273 	k = 1;
274 	for (j = 1; j < 9; j ++) {
275 		if (l & k)
276 			pps_event(&sc->pps[j], tc, count,
277 			    i & k ?
278 			    PPS_CAPTUREASSERT : PPS_CAPTURECLEAR
279 			);
280 		k += k;
281 	}
282 	sc->lastdata = i;
283 }
284 
285 static void
286 ppsintr(void *arg)
287 {
288 	device_t ppsdev = (device_t)arg;
289 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
290 	device_t ppbus = sc->ppbus;
291 	struct timecounter *tc;
292 	unsigned count;
293 
294 	tc = timecounter;
295 	count = timecounter->tc_get_timecount(tc);
296 	if (!(ppb_rstr(ppbus) & nACK))
297 		return;
298 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
299 		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
300 	pps_event(&sc->pps[0], tc, count, PPS_CAPTUREASSERT);
301 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
302 		ppb_wctr(ppbus, IRQENABLE);
303 }
304 
305 static int
306 ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
307 {
308 	struct pps_data *sc = dev->si_drv1;
309 	int subdev = (int)dev->si_drv2;
310 
311 	return (pps_ioctl(cmd, data, &sc->pps[subdev]));
312 }
313 
314 static device_method_t pps_methods[] = {
315 	/* device interface */
316 	DEVMETHOD(device_identify,	ppsidentify),
317 	DEVMETHOD(device_probe,		ppsprobe),
318 	DEVMETHOD(device_attach,	ppsattach),
319 
320 	{ 0, 0 }
321 };
322 
323 static driver_t pps_driver = {
324 	PPS_NAME,
325 	pps_methods,
326 	sizeof(struct pps_data),
327 };
328 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
329