xref: /freebsd/sys/dev/ppbus/pps.c (revision f9218d3d4fd34f082473b3a021c6d4d109fb47cf)
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/timepps.h>
25 #include <machine/bus.h>
26 #include <machine/resource.h>
27 #include <sys/rman.h>
28 
29 #include <dev/ppbus/ppbconf.h>
30 #include "ppbus_if.h"
31 #include <dev/ppbus/ppbio.h>
32 
33 #define PPS_NAME	"pps"		/* our official name */
34 
35 #define PRVERBOSE(fmt, arg...)	if (bootverbose) printf(fmt, ##arg);
36 
37 struct pps_data {
38 	struct	ppb_device pps_dev;
39 	struct	pps_state pps[9];
40 	dev_t	devs[9];
41 	device_t ppsdev;
42 	device_t ppbus;
43 	int	busy;
44 	struct callout_handle timeout;
45 	int	lastdata;
46 
47 	struct resource *intr_resource;	/* interrupt resource */
48 	void *intr_cookie;		/* interrupt registration cookie */
49 };
50 
51 static void	ppsintr(void *arg);
52 static void 	ppshcpoll(void *arg);
53 
54 #define DEVTOSOFTC(dev) \
55 	((struct pps_data *)device_get_softc(dev))
56 
57 static devclass_t pps_devclass;
58 
59 static	d_open_t	ppsopen;
60 static	d_close_t	ppsclose;
61 static	d_ioctl_t	ppsioctl;
62 
63 #define CDEV_MAJOR 89
64 static struct cdevsw pps_cdevsw = {
65 	.d_open =	ppsopen,
66 	.d_close =	ppsclose,
67 	.d_ioctl =	ppsioctl,
68 	.d_name =	PPS_NAME,
69 	.d_maj =	CDEV_MAJOR,
70 };
71 
72 static void
73 ppsidentify(driver_t *driver, device_t parent)
74 {
75 
76 	BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
77 }
78 
79 static int
80 ppstry(device_t ppbus, int send, int expect)
81 {
82 	int i;
83 
84 	ppb_wdtr(ppbus, send);
85 	i = ppb_rdtr(ppbus);
86 	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
87 	return (i != expect);
88 }
89 
90 static int
91 ppsprobe(device_t ppsdev)
92 {
93 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
94 
95 	return (0);
96 }
97 
98 static int
99 ppsattach(device_t dev)
100 {
101 	struct pps_data *sc = DEVTOSOFTC(dev);
102 	device_t ppbus = device_get_parent(dev);
103 	dev_t d;
104 	intptr_t irq;
105 	int i, unit, zero = 0;
106 
107 	bzero(sc, sizeof(struct pps_data)); /* XXX doesn't newbus do this? */
108 
109 	/* retrieve the ppbus irq */
110 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
111 
112 	if (irq > 0) {
113 		/* declare our interrupt handler */
114 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
115 		    &zero, irq, irq, 1, RF_SHAREABLE);
116 	}
117 	/* interrupts seem mandatory */
118 	if (sc->intr_resource == NULL)
119 		return (ENXIO);
120 
121 	sc->ppsdev = dev;
122 	sc->ppbus = ppbus;
123 	unit = device_get_unit(ppbus);
124 	d = make_dev(&pps_cdevsw, unit,
125 	    UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
126 	sc->devs[0] = d;
127 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
128 	d->si_drv1 = sc;
129 	d->si_drv2 = (void*)0;
130 	pps_init(&sc->pps[0]);
131 
132 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
133 		return (0);
134 
135 	do {
136 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
137 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
138 		if (i == -1)
139 			break;
140 		i = 0;
141 		ppb_wctr(ppbus, i);
142 		if (ppstry(ppbus, 0x00, 0x00))
143 			break;
144 		if (ppstry(ppbus, 0x55, 0x55))
145 			break;
146 		if (ppstry(ppbus, 0xaa, 0xaa))
147 			break;
148 		if (ppstry(ppbus, 0xff, 0xff))
149 			break;
150 
151 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
152 		ppb_wctr(ppbus, i);
153 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
154 		if (ppstry(ppbus, 0x00, 0x00))
155 			break;
156 		if (ppstry(ppbus, 0x55, 0x00))
157 			break;
158 		if (ppstry(ppbus, 0xaa, 0x00))
159 			break;
160 		if (ppstry(ppbus, 0xff, 0x00))
161 			break;
162 
163 		i = IRQENABLE | PCD | nINIT | SELECTIN;
164 		ppb_wctr(ppbus, i);
165 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
166 		ppstry(ppbus, 0x00, 0xff);
167 		ppstry(ppbus, 0x55, 0xff);
168 		ppstry(ppbus, 0xaa, 0xff);
169 		ppstry(ppbus, 0xff, 0xff);
170 
171 		for (i = 1; i < 9; i++) {
172 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
173 			  UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
174 			sc->devs[i] = d;
175 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
176 			d->si_drv1 = sc;
177 			d->si_drv2 = (void *)(intptr_t)i;
178 			pps_init(&sc->pps[i]);
179 		}
180 	} while (0);
181 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
182 	ppb_release_bus(ppbus, dev);
183 
184 	return (0);
185 }
186 
187 static	int
188 ppsopen(dev_t dev, int flags, int fmt, struct thread *td)
189 {
190 	struct pps_data *sc = dev->si_drv1;
191 	int subdev = (intptr_t)dev->si_drv2;
192 	int error, i;
193 
194 	if (!sc->busy) {
195 		device_t ppsdev = sc->ppsdev;
196 		device_t ppbus = sc->ppbus;
197 
198 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
199 			return (EINTR);
200 
201 		/* attach the interrupt handler */
202 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
203 			       INTR_TYPE_TTY, ppsintr, ppsdev,
204 			       &sc->intr_cookie))) {
205 			ppb_release_bus(ppbus, ppsdev);
206 			return (error);
207 		}
208 
209 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
210 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
211 
212 		i = IRQENABLE | PCD | nINIT | SELECTIN;
213 		ppb_wctr(ppbus, i);
214 	}
215 	if (subdev > 0 && !(sc->busy & ~1)) {
216 		sc->timeout = timeout(ppshcpoll, sc, 1);
217 		sc->lastdata = ppb_rdtr(sc->ppbus);
218 	}
219 	sc->busy |= (1 << subdev);
220 	return(0);
221 }
222 
223 static	int
224 ppsclose(dev_t dev, int flags, int fmt, struct thread *td)
225 {
226 	struct pps_data *sc = dev->si_drv1;
227 	int subdev = (intptr_t)dev->si_drv2;
228 
229 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
230 	sc->busy &= ~(1 << subdev);
231 	if (subdev > 0 && !(sc->busy & ~1))
232 		untimeout(ppshcpoll, sc, sc->timeout);
233 	if (!sc->busy) {
234 		device_t ppsdev = sc->ppsdev;
235 		device_t ppbus = sc->ppbus;
236 
237 		ppb_wdtr(ppbus, 0);
238 		ppb_wctr(ppbus, 0);
239 
240 		/* Note: the interrupt handler is automatically detached */
241 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
242 		ppb_release_bus(ppbus, ppsdev);
243 	}
244 	return(0);
245 }
246 
247 static void
248 ppshcpoll(void *arg)
249 {
250 	struct pps_data *sc = arg;
251 	int i, j, k, l;
252 
253 	if (!(sc->busy & ~1))
254 		return;
255 	sc->timeout = timeout(ppshcpoll, sc, 1);
256 	i = ppb_rdtr(sc->ppbus);
257 	if (i == sc->lastdata)
258 		return;
259 	l = sc->lastdata ^ i;
260 	k = 1;
261 	for (j = 1; j < 9; j ++) {
262 		if (l & k) {
263 			pps_capture(&sc->pps[j]);
264 			pps_event(&sc->pps[j],
265 			    i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
266 		}
267 		k += k;
268 	}
269 	sc->lastdata = i;
270 }
271 
272 static void
273 ppsintr(void *arg)
274 {
275 	device_t ppsdev = (device_t)arg;
276 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
277 	device_t ppbus = sc->ppbus;
278 
279 	pps_capture(&sc->pps[0]);
280 	if (!(ppb_rstr(ppbus) & nACK))
281 		return;
282 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
283 		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
284 	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
285 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
286 		ppb_wctr(ppbus, IRQENABLE);
287 }
288 
289 static int
290 ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
291 {
292 	struct pps_data *sc = dev->si_drv1;
293 	int subdev = (intptr_t)dev->si_drv2;
294 
295 	return (pps_ioctl(cmd, data, &sc->pps[subdev]));
296 }
297 
298 static device_method_t pps_methods[] = {
299 	/* device interface */
300 	DEVMETHOD(device_identify,	ppsidentify),
301 	DEVMETHOD(device_probe,		ppsprobe),
302 	DEVMETHOD(device_attach,	ppsattach),
303 
304 	{ 0, 0 }
305 };
306 
307 static driver_t pps_driver = {
308 	PPS_NAME,
309 	pps_methods,
310 	sizeof(struct pps_data),
311 };
312 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
313