xref: /freebsd/sys/dev/ppbus/pps.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 mtx	mtx;
50 	struct resource *intr_resource;	/* interrupt resource */
51 	void *intr_cookie;		/* interrupt registration cookie */
52 };
53 
54 static int	ppsintr(void *arg);
55 static void 	ppshcpoll(void *arg);
56 
57 #define DEVTOSOFTC(dev) \
58 	((struct pps_data *)device_get_softc(dev))
59 
60 static devclass_t pps_devclass;
61 
62 static	d_open_t	ppsopen;
63 static	d_close_t	ppsclose;
64 static	d_ioctl_t	ppsioctl;
65 
66 static struct cdevsw pps_cdevsw = {
67 	.d_version =	D_VERSION,
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 	mtx_init(&sc->mtx, device_get_nameunit(dev), "pps", MTX_SPIN);
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 == NULL)
124 		return (ENXIO);
125 
126 	sc->ppsdev = dev;
127 	sc->ppbus = ppbus;
128 	unit = device_get_unit(ppbus);
129 	d = make_dev(&pps_cdevsw, unit,
130 	    UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
131 	sc->devs[0] = d;
132 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
133 	d->si_drv1 = sc;
134 	d->si_drv2 = (void*)0;
135 	pps_init(&sc->pps[0]);
136 
137 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
138 		return (0);
139 
140 	do {
141 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
142 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
143 		if (i == -1)
144 			break;
145 		i = 0;
146 		ppb_wctr(ppbus, i);
147 		if (ppstry(ppbus, 0x00, 0x00))
148 			break;
149 		if (ppstry(ppbus, 0x55, 0x55))
150 			break;
151 		if (ppstry(ppbus, 0xaa, 0xaa))
152 			break;
153 		if (ppstry(ppbus, 0xff, 0xff))
154 			break;
155 
156 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
157 		ppb_wctr(ppbus, i);
158 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
159 		if (ppstry(ppbus, 0x00, 0x00))
160 			break;
161 		if (ppstry(ppbus, 0x55, 0x00))
162 			break;
163 		if (ppstry(ppbus, 0xaa, 0x00))
164 			break;
165 		if (ppstry(ppbus, 0xff, 0x00))
166 			break;
167 
168 		i = IRQENABLE | PCD | nINIT | SELECTIN;
169 		ppb_wctr(ppbus, i);
170 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
171 		ppstry(ppbus, 0x00, 0xff);
172 		ppstry(ppbus, 0x55, 0xff);
173 		ppstry(ppbus, 0xaa, 0xff);
174 		ppstry(ppbus, 0xff, 0xff);
175 
176 		for (i = 1; i < 9; i++) {
177 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
178 			  UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
179 			sc->devs[i] = d;
180 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
181 			d->si_drv1 = sc;
182 			d->si_drv2 = (void *)(intptr_t)i;
183 			pps_init(&sc->pps[i]);
184 		}
185 	} while (0);
186 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
187 	ppb_release_bus(ppbus, dev);
188 
189 	return (0);
190 }
191 
192 static	int
193 ppsopen(struct cdev *dev, int flags, int fmt, struct thread *td)
194 {
195 	struct pps_data *sc = dev->si_drv1;
196 	int subdev = (intptr_t)dev->si_drv2;
197 	int error, i;
198 
199 	if (!sc->busy) {
200 		device_t ppsdev = sc->ppsdev;
201 		device_t ppbus = sc->ppbus;
202 
203 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
204 			return (EINTR);
205 
206 		/* attach the interrupt handler */
207 		if ((error = bus_setup_intr(ppsdev, sc->intr_resource,
208 		    (INTR_TYPE_TTY | INTR_MPSAFE), ppsintr, NULL,
209 		    sc, &sc->intr_cookie))) {
210 			ppb_release_bus(ppbus, ppsdev);
211 			return (error);
212 		}
213 
214 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
215 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
216 
217 		i = IRQENABLE | PCD | nINIT | SELECTIN;
218 		ppb_wctr(ppbus, i);
219 	}
220 	if (subdev > 0 && !(sc->busy & ~1)) {
221 		sc->timeout = timeout(ppshcpoll, sc, 1);
222 		sc->lastdata = ppb_rdtr(sc->ppbus);
223 	}
224 	sc->busy |= (1 << subdev);
225 	return(0);
226 }
227 
228 static	int
229 ppsclose(struct cdev *dev, int flags, int fmt, struct thread *td)
230 {
231 	struct pps_data *sc = dev->si_drv1;
232 	int subdev = (intptr_t)dev->si_drv2;
233 
234 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
235 	sc->busy &= ~(1 << subdev);
236 	if (subdev > 0 && !(sc->busy & ~1))
237 		untimeout(ppshcpoll, sc, sc->timeout);
238 	if (!sc->busy) {
239 		device_t ppsdev = sc->ppsdev;
240 		device_t ppbus = sc->ppbus;
241 
242 		ppb_wdtr(ppbus, 0);
243 		ppb_wctr(ppbus, 0);
244 
245 		/* Note: the interrupt handler is automatically detached */
246 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
247 		ppb_release_bus(ppbus, ppsdev);
248 	}
249 	return(0);
250 }
251 
252 static void
253 ppshcpoll(void *arg)
254 {
255 	struct pps_data *sc = arg;
256 	int i, j, k, l;
257 
258 	if (!(sc->busy & ~1))
259 		return;
260 	mtx_lock_spin(&sc->mtx);
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 	mtx_unlock_spin(&sc->mtx);
277 }
278 
279 static int
280 ppsintr(void *arg)
281 {
282 	struct pps_data *sc = (struct pps_data *)arg;
283 
284 	pps_capture(&sc->pps[0]);
285 	if (!(ppb_rstr(sc->ppbus) & nACK))
286 		return (FILTER_STRAY);
287 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
288 		ppb_wctr(sc->ppbus, IRQENABLE | AUTOFEED);
289 	mtx_lock_spin(&sc->mtx);
290 	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
291 	mtx_unlock_spin(&sc->mtx);
292 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
293 		ppb_wctr(sc->ppbus, IRQENABLE);
294 	return (FILTER_HANDLED);
295 }
296 
297 static int
298 ppsioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
299 {
300 	struct pps_data *sc = dev->si_drv1;
301 	int subdev = (intptr_t)dev->si_drv2;
302 	int err;
303 
304 	mtx_lock_spin(&sc->mtx);
305 	err = pps_ioctl(cmd, data, &sc->pps[subdev]);
306 	mtx_unlock_spin(&sc->mtx);
307 	return (err);
308 }
309 
310 static device_method_t pps_methods[] = {
311 	/* device interface */
312 	DEVMETHOD(device_identify,	ppsidentify),
313 	DEVMETHOD(device_probe,		ppsprobe),
314 	DEVMETHOD(device_attach,	ppsattach),
315 
316 	{ 0, 0 }
317 };
318 
319 static driver_t pps_driver = {
320 	PPS_NAME,
321 	pps_methods,
322 	sizeof(struct pps_data),
323 };
324 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
325 MODULE_DEPEND(pps, ppbus, 1, 1, 1);
326