xref: /freebsd/sys/dev/ppbus/pps.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
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 	dev_t	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 #define CDEV_MAJOR 89
66 static struct cdevsw pps_cdevsw = {
67 	.d_open =	ppsopen,
68 	.d_close =	ppsclose,
69 	.d_ioctl =	ppsioctl,
70 	.d_name =	PPS_NAME,
71 	.d_maj =	CDEV_MAJOR,
72 };
73 
74 static void
75 ppsidentify(driver_t *driver, device_t parent)
76 {
77 
78 	BUS_ADD_CHILD(parent, 0, PPS_NAME, -1);
79 }
80 
81 static int
82 ppstry(device_t ppbus, int send, int expect)
83 {
84 	int i;
85 
86 	ppb_wdtr(ppbus, send);
87 	i = ppb_rdtr(ppbus);
88 	PRVERBOSE("S: %02x E: %02x G: %02x\n", send, expect, i);
89 	return (i != expect);
90 }
91 
92 static int
93 ppsprobe(device_t ppsdev)
94 {
95 	device_set_desc(ppsdev, "Pulse per second Timing Interface");
96 
97 	return (0);
98 }
99 
100 static int
101 ppsattach(device_t dev)
102 {
103 	struct pps_data *sc = DEVTOSOFTC(dev);
104 	device_t ppbus = device_get_parent(dev);
105 	dev_t d;
106 	intptr_t irq;
107 	int i, unit, zero = 0;
108 
109 	bzero(sc, sizeof(struct pps_data)); /* XXX doesn't newbus do this? */
110 
111 	/* retrieve the ppbus irq */
112 	BUS_READ_IVAR(ppbus, dev, PPBUS_IVAR_IRQ, &irq);
113 
114 	if (irq > 0) {
115 		/* declare our interrupt handler */
116 		sc->intr_resource = bus_alloc_resource(dev, SYS_RES_IRQ,
117 		    &zero, irq, irq, 1, RF_SHAREABLE);
118 	}
119 	/* interrupts seem mandatory */
120 	if (sc->intr_resource == NULL)
121 		return (ENXIO);
122 
123 	sc->ppsdev = dev;
124 	sc->ppbus = ppbus;
125 	unit = device_get_unit(ppbus);
126 	d = make_dev(&pps_cdevsw, unit,
127 	    UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%d", unit);
128 	sc->devs[0] = d;
129 	sc->pps[0].ppscap = PPS_CAPTUREASSERT | PPS_ECHOASSERT;
130 	d->si_drv1 = sc;
131 	d->si_drv2 = (void*)0;
132 	pps_init(&sc->pps[0]);
133 
134 	if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT))
135 		return (0);
136 
137 	do {
138 		i = ppb_set_mode(sc->ppbus, PPB_EPP);
139 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
140 		if (i == -1)
141 			break;
142 		i = 0;
143 		ppb_wctr(ppbus, i);
144 		if (ppstry(ppbus, 0x00, 0x00))
145 			break;
146 		if (ppstry(ppbus, 0x55, 0x55))
147 			break;
148 		if (ppstry(ppbus, 0xaa, 0xaa))
149 			break;
150 		if (ppstry(ppbus, 0xff, 0xff))
151 			break;
152 
153 		i = IRQENABLE | PCD | STROBE | nINIT | SELECTIN;
154 		ppb_wctr(ppbus, i);
155 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
156 		if (ppstry(ppbus, 0x00, 0x00))
157 			break;
158 		if (ppstry(ppbus, 0x55, 0x00))
159 			break;
160 		if (ppstry(ppbus, 0xaa, 0x00))
161 			break;
162 		if (ppstry(ppbus, 0xff, 0x00))
163 			break;
164 
165 		i = IRQENABLE | PCD | nINIT | SELECTIN;
166 		ppb_wctr(ppbus, i);
167 		PRVERBOSE("CTR = %02x (%02x)\n", ppb_rctr(ppbus), i);
168 		ppstry(ppbus, 0x00, 0xff);
169 		ppstry(ppbus, 0x55, 0xff);
170 		ppstry(ppbus, 0xaa, 0xff);
171 		ppstry(ppbus, 0xff, 0xff);
172 
173 		for (i = 1; i < 9; i++) {
174 			d = make_dev(&pps_cdevsw, unit + 0x10000 * i,
175 			  UID_ROOT, GID_WHEEL, 0600, PPS_NAME "%db%d", unit, i - 1);
176 			sc->devs[i] = d;
177 			sc->pps[i].ppscap = PPS_CAPTUREASSERT | PPS_CAPTURECLEAR;
178 			d->si_drv1 = sc;
179 			d->si_drv2 = (void *)(intptr_t)i;
180 			pps_init(&sc->pps[i]);
181 		}
182 	} while (0);
183 	i = ppb_set_mode(sc->ppbus, PPB_COMPATIBLE);
184 	ppb_release_bus(ppbus, dev);
185 
186 	return (0);
187 }
188 
189 static	int
190 ppsopen(dev_t dev, int flags, int fmt, struct thread *td)
191 {
192 	struct pps_data *sc = dev->si_drv1;
193 	int subdev = (intptr_t)dev->si_drv2;
194 	int error, i;
195 
196 	if (!sc->busy) {
197 		device_t ppsdev = sc->ppsdev;
198 		device_t ppbus = sc->ppbus;
199 
200 		if (ppb_request_bus(ppbus, ppsdev, PPB_WAIT|PPB_INTR))
201 			return (EINTR);
202 
203 		/* attach the interrupt handler */
204 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
205 			       INTR_TYPE_TTY, ppsintr, ppsdev,
206 			       &sc->intr_cookie))) {
207 			ppb_release_bus(ppbus, ppsdev);
208 			return (error);
209 		}
210 
211 		i = ppb_set_mode(sc->ppbus, PPB_PS2);
212 		PRVERBOSE("EPP: %d %d\n", i, PPB_IN_EPP_MODE(sc->ppbus));
213 
214 		i = IRQENABLE | PCD | nINIT | SELECTIN;
215 		ppb_wctr(ppbus, i);
216 	}
217 	if (subdev > 0 && !(sc->busy & ~1)) {
218 		sc->timeout = timeout(ppshcpoll, sc, 1);
219 		sc->lastdata = ppb_rdtr(sc->ppbus);
220 	}
221 	sc->busy |= (1 << subdev);
222 	return(0);
223 }
224 
225 static	int
226 ppsclose(dev_t dev, int flags, int fmt, struct thread *td)
227 {
228 	struct pps_data *sc = dev->si_drv1;
229 	int subdev = (intptr_t)dev->si_drv2;
230 
231 	sc->pps[subdev].ppsparam.mode = 0;	/* PHK ??? */
232 	sc->busy &= ~(1 << subdev);
233 	if (subdev > 0 && !(sc->busy & ~1))
234 		untimeout(ppshcpoll, sc, sc->timeout);
235 	if (!sc->busy) {
236 		device_t ppsdev = sc->ppsdev;
237 		device_t ppbus = sc->ppbus;
238 
239 		ppb_wdtr(ppbus, 0);
240 		ppb_wctr(ppbus, 0);
241 
242 		/* Note: the interrupt handler is automatically detached */
243 		ppb_set_mode(ppbus, PPB_COMPATIBLE);
244 		ppb_release_bus(ppbus, ppsdev);
245 	}
246 	return(0);
247 }
248 
249 static void
250 ppshcpoll(void *arg)
251 {
252 	struct pps_data *sc = arg;
253 	int i, j, k, l;
254 
255 	if (!(sc->busy & ~1))
256 		return;
257 	sc->timeout = timeout(ppshcpoll, sc, 1);
258 	i = ppb_rdtr(sc->ppbus);
259 	if (i == sc->lastdata)
260 		return;
261 	l = sc->lastdata ^ i;
262 	k = 1;
263 	for (j = 1; j < 9; j ++) {
264 		if (l & k) {
265 			pps_capture(&sc->pps[j]);
266 			pps_event(&sc->pps[j],
267 			    i & k ? PPS_CAPTUREASSERT : PPS_CAPTURECLEAR);
268 		}
269 		k += k;
270 	}
271 	sc->lastdata = i;
272 }
273 
274 static void
275 ppsintr(void *arg)
276 {
277 	device_t ppsdev = (device_t)arg;
278 	struct pps_data *sc = DEVTOSOFTC(ppsdev);
279 	device_t ppbus = sc->ppbus;
280 
281 	pps_capture(&sc->pps[0]);
282 	if (!(ppb_rstr(ppbus) & nACK))
283 		return;
284 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
285 		ppb_wctr(ppbus, IRQENABLE | AUTOFEED);
286 	pps_event(&sc->pps[0], PPS_CAPTUREASSERT);
287 	if (sc->pps[0].ppsparam.mode & PPS_ECHOASSERT)
288 		ppb_wctr(ppbus, IRQENABLE);
289 }
290 
291 static int
292 ppsioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct thread *td)
293 {
294 	struct pps_data *sc = dev->si_drv1;
295 	int subdev = (intptr_t)dev->si_drv2;
296 
297 	return (pps_ioctl(cmd, data, &sc->pps[subdev]));
298 }
299 
300 static device_method_t pps_methods[] = {
301 	/* device interface */
302 	DEVMETHOD(device_identify,	ppsidentify),
303 	DEVMETHOD(device_probe,		ppsprobe),
304 	DEVMETHOD(device_attach,	ppsattach),
305 
306 	{ 0, 0 }
307 };
308 
309 static driver_t pps_driver = {
310 	PPS_NAME,
311 	pps_methods,
312 	sizeof(struct pps_data),
313 };
314 DRIVER_MODULE(pps, ppbus, pps_driver, pps_devclass, 0, 0);
315