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onewire.c revision 1.4 
      1 /* $NetBSD: onewire.c,v 1.4 2006/11/16 01:33:08 christos Exp $ */
      2 /*	$OpenBSD: onewire.c,v 1.1 2006/03/04 16:27:03 grange Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 2006 Alexander Yurchenko <grange (at) openbsd.org>
      6  *
      7  * Permission to use, copy, modify, and distribute this software for any
      8  * purpose with or without fee is hereby granted, provided that the above
      9  * copyright notice and this permission notice appear in all copies.
     10  *
     11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
     12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     18  */
     19 
     20 #include <sys/cdefs.h>
     21 __KERNEL_RCSID(0, "$NetBSD: onewire.c,v 1.4 2006/11/16 01:33:08 christos Exp $");
     22 
     23 /*
     24  * 1-Wire bus driver.
     25  */
     26 
     27 #include <sys/param.h>
     28 #include <sys/systm.h>
     29 #include <sys/conf.h>
     30 #include <sys/device.h>
     31 #include <sys/kernel.h>
     32 #include <sys/kthread.h>
     33 #include <sys/lock.h>
     34 #include <sys/malloc.h>
     35 #include <sys/proc.h>
     36 #include <sys/queue.h>
     37 
     38 #include <dev/onewire/onewirereg.h>
     39 #include <dev/onewire/onewirevar.h>
     40 
     41 #ifdef ONEWIRE_DEBUG
     42 #define DPRINTF(x) printf x
     43 #else
     44 #define DPRINTF(x)
     45 #endif
     46 
     47 //#define ONEWIRE_MAXDEVS		256
     48 #define ONEWIRE_MAXDEVS		8
     49 #define ONEWIRE_SCANTIME	3
     50 
     51 struct onewire_softc {
     52 	struct device			sc_dev;
     53 
     54 	struct onewire_bus *		sc_bus;
     55 	struct lock			sc_lock;
     56 	struct proc *			sc_thread;
     57 	TAILQ_HEAD(, onewire_device)	sc_devs;
     58 
     59 	int				sc_dying;
     60 };
     61 
     62 struct onewire_device {
     63 	TAILQ_ENTRY(onewire_device)	d_list;
     64 	struct device *			d_dev;
     65 	u_int64_t			d_rom;
     66 	int				d_present;
     67 };
     68 
     69 int	onewire_match(struct device *, struct cfdata *, void *);
     70 void	onewire_attach(struct device *, struct device *, void *);
     71 int	onewire_detach(struct device *, int);
     72 int	onewire_activate(struct device *, enum devact);
     73 int	onewire_print(void *, const char *);
     74 
     75 void	onewire_thread(void *);
     76 void	onewire_createthread(void *);
     77 void	onewire_scan(struct onewire_softc *);
     78 
     79 CFATTACH_DECL(onewire, sizeof(struct onewire_softc),
     80 	onewire_match, onewire_attach, onewire_detach, onewire_activate);
     81 
     82 const struct cdevsw onewire_cdevsw = {
     83 	noopen, noclose, noread, nowrite, noioctl, nostop, notty,
     84 	nopoll, nommap, nokqfilter, D_OTHER,
     85 };
     86 
     87 extern struct cfdriver onewire_cd;
     88 
     89 int
     90 onewire_match(struct device *parent, struct cfdata *cf,
     91     void *aux)
     92 {
     93 	return 1;
     94 }
     95 
     96 void
     97 onewire_attach(struct device *parent, struct device *self, void *aux)
     98 {
     99 	struct onewire_softc *sc = device_private(self);
    100 	struct onewirebus_attach_args *oba = aux;
    101 
    102 	sc->sc_bus = oba->oba_bus;
    103 	lockinit(&sc->sc_lock, PRIBIO, "owlock", 0, 0);
    104 	TAILQ_INIT(&sc->sc_devs);
    105 
    106 	printf("\n");
    107 
    108 	kthread_create(onewire_createthread, sc);
    109 }
    110 
    111 int
    112 onewire_detach(struct device *self, int flags)
    113 {
    114 	struct onewire_softc *sc = device_private(self);
    115 	int rv;
    116 
    117 	sc->sc_dying = 1;
    118 	if (sc->sc_thread != NULL) {
    119 		wakeup(sc->sc_thread);
    120 		tsleep(&sc->sc_dying, PWAIT, "owdt", 0);
    121 	}
    122 
    123 	onewire_lock(sc, 0);
    124 	//rv = config_detach_children(self, flags);
    125 	rv = 0;  /* XXX riz */
    126 	onewire_unlock(sc);
    127 
    128 	return (rv);
    129 }
    130 
    131 int
    132 onewire_activate(struct device *self, enum devact act)
    133 {
    134 	struct onewire_softc *sc = device_private(self);
    135 	int rv = 0;
    136 
    137 	switch (act) {
    138 	case DVACT_ACTIVATE:
    139 		rv = EOPNOTSUPP;
    140 		break;
    141 	case DVACT_DEACTIVATE:
    142 		sc->sc_dying = 1;
    143 		break;
    144 	}
    145 
    146 	//return (config_activate_children(self, act));
    147 	return rv;
    148 }
    149 
    150 int
    151 onewire_print(void *aux, const char *pnp)
    152 {
    153 	struct onewire_attach_args *oa = aux;
    154 	const char *famname;
    155 
    156 	if (pnp == NULL)
    157 		printf(" ");
    158 
    159 	famname = onewire_famname(ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom));
    160 	if (famname == NULL)
    161 		printf("family 0x%02x", (uint)ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom));
    162 	else
    163 		printf("\"%s\"", famname);
    164 	printf(" sn %012llx", ONEWIRE_ROM_SN(oa->oa_rom));
    165 
    166 	if (pnp != NULL)
    167 		printf(" at %s", pnp);
    168 
    169 	return (UNCONF);
    170 }
    171 
    172 int
    173 onewirebus_print(void *aux, const char *pnp)
    174 {
    175 	if (pnp != NULL)
    176 		printf("onewire at %s", pnp);
    177 
    178 	return (UNCONF);
    179 }
    180 
    181 int
    182 onewire_lock(void *arg, int flags)
    183 {
    184 	struct onewire_softc *sc = arg;
    185 	int lflags = LK_EXCLUSIVE;
    186 
    187 	if (flags & ONEWIRE_NOWAIT)
    188 		lflags |= LK_NOWAIT;
    189 
    190 	return (lockmgr(&sc->sc_lock, lflags, NULL));
    191 }
    192 
    193 void
    194 onewire_unlock(void *arg)
    195 {
    196 	struct onewire_softc *sc = arg;
    197 
    198 	lockmgr(&sc->sc_lock, LK_RELEASE, NULL);
    199 }
    200 
    201 int
    202 onewire_reset(void *arg)
    203 {
    204 	struct onewire_softc *sc = arg;
    205 	struct onewire_bus *bus = sc->sc_bus;
    206 
    207 	return (bus->bus_reset(bus->bus_cookie));
    208 }
    209 
    210 int
    211 onewire_bit(void *arg, int value)
    212 {
    213 	struct onewire_softc *sc = arg;
    214 	struct onewire_bus *bus = sc->sc_bus;
    215 
    216 	return (bus->bus_bit(bus->bus_cookie, value));
    217 }
    218 
    219 int
    220 onewire_read_byte(void *arg)
    221 {
    222 	struct onewire_softc *sc = arg;
    223 	struct onewire_bus *bus = sc->sc_bus;
    224 	u_int8_t value = 0;
    225 	int i;
    226 
    227 	if (bus->bus_read_byte != NULL)
    228 		return (bus->bus_read_byte(bus->bus_cookie));
    229 
    230 	for (i = 0; i < 8; i++)
    231 		value |= (bus->bus_bit(bus->bus_cookie, 1) << i);
    232 
    233 	return (value);
    234 }
    235 
    236 void
    237 onewire_write_byte(void *arg, int value)
    238 {
    239 	struct onewire_softc *sc = arg;
    240 	struct onewire_bus *bus = sc->sc_bus;
    241 	int i;
    242 
    243 	if (bus->bus_write_byte != NULL)
    244 		return (bus->bus_write_byte(bus->bus_cookie, value));
    245 
    246 	for (i = 0; i < 8; i++)
    247 		bus->bus_bit(bus->bus_cookie, (value >> i) & 0x1);
    248 }
    249 
    250 int
    251 onewire_triplet(void *arg, int dir)
    252 {
    253 	struct onewire_softc *sc = arg;
    254 	struct onewire_bus *bus = sc->sc_bus;
    255 	int rv;
    256 
    257 	if (bus->bus_triplet != NULL)
    258 		return (bus->bus_triplet(bus->bus_cookie, dir));
    259 
    260 	rv = bus->bus_bit(bus->bus_cookie, 1);
    261 	rv <<= 1;
    262 	rv |= bus->bus_bit(bus->bus_cookie, 1);
    263 
    264 	switch (rv) {
    265 	case 0x0:
    266 		bus->bus_bit(bus->bus_cookie, dir);
    267 		break;
    268 	case 0x1:
    269 		bus->bus_bit(bus->bus_cookie, 0);
    270 		break;
    271 	default:
    272 		bus->bus_bit(bus->bus_cookie, 1);
    273 	}
    274 
    275 	return (rv);
    276 }
    277 
    278 void
    279 onewire_read_block(void *arg, void *buf, int len)
    280 {
    281 	u_int8_t *p = buf;
    282 
    283 	while (len--)
    284 		*p++ = onewire_read_byte(arg);
    285 }
    286 
    287 void
    288 onewire_write_block(void *arg, const void *buf, int len)
    289 {
    290 	const u_int8_t *p = buf;
    291 
    292 	while (len--)
    293 		onewire_write_byte(arg, *p++);
    294 }
    295 
    296 void
    297 onewire_matchrom(void *arg, u_int64_t rom)
    298 {
    299 	int i;
    300 
    301 	onewire_write_byte(arg, ONEWIRE_CMD_MATCH_ROM);
    302 	for (i = 0; i < 8; i++)
    303 		onewire_write_byte(arg, (rom >> (i * 8)) & 0xff);
    304 }
    305 
    306 void
    307 onewire_thread(void *arg)
    308 {
    309 	struct onewire_softc *sc = arg;
    310 
    311 	while (!sc->sc_dying) {
    312 		onewire_scan(sc);
    313 		tsleep(sc->sc_thread, PWAIT, "owidle", ONEWIRE_SCANTIME * hz);
    314 	}
    315 
    316 	sc->sc_thread = NULL;
    317 	wakeup(&sc->sc_dying);
    318 	kthread_exit(0);
    319 }
    320 
    321 void
    322 onewire_createthread(void *arg)
    323 {
    324 	struct onewire_softc *sc = arg;
    325 
    326 	if (kthread_create1(onewire_thread, sc, &sc->sc_thread,
    327 	    "%s", sc->sc_dev.dv_xname) != 0)
    328 		printf("%s: can't create kernel thread\n",
    329 		    sc->sc_dev.dv_xname);
    330 }
    331 
    332 void
    333 onewire_scan(struct onewire_softc *sc)
    334 {
    335 	struct onewire_device *d, *next, *nd;
    336 	struct onewire_attach_args oa;
    337 	struct device *dev;
    338 	int search = 1, count = 0, present;
    339 	int dir, rv;
    340 	u_int64_t mask, rom = 0, lastrom;
    341 	u_int8_t data[8];
    342 	int i, i0 = -1, lastd = -1;
    343 
    344 	TAILQ_FOREACH(d, &sc->sc_devs, d_list)
    345 		d->d_present = 0;
    346 
    347 	while (search && count++ < ONEWIRE_MAXDEVS) {
    348 		/* XXX: yield processor */
    349 		tsleep(sc, PWAIT, "owscan", hz / 10);
    350 
    351 		/*
    352 		 * Reset the bus. If there's no presence pulse
    353 		 * don't search for any devices.
    354 		 */
    355 		onewire_lock(sc, 0);
    356 		if (onewire_reset(sc) != 0) {
    357 			DPRINTF(("%s: scan: no presence pulse\n",
    358 			    sc->sc_dev.dv_xname));
    359 			onewire_unlock(sc);
    360 			break;
    361 		}
    362 
    363 		/*
    364 		 * Start new search. Go through the previous path to
    365 		 * the point we made a decision last time and make an
    366 		 * opposite decision. If we didn't make any decision
    367 		 * stop searching.
    368 		 */
    369 		search = 0;
    370 		lastrom = rom;
    371 		rom = 0;
    372 		onewire_write_byte(sc, ONEWIRE_CMD_SEARCH_ROM);
    373 		for (i = 0,i0 = -1; i < 64; i++) {
    374 			dir = (lastrom >> i) & 0x1;
    375 			if (i == lastd)
    376 				dir = 1;
    377 			else if (i > lastd)
    378 				dir = 0;
    379 			rv = onewire_triplet(sc, dir);
    380 			switch (rv) {
    381 			case 0x0:
    382 				if (i != lastd) {
    383 					if (dir == 0)
    384 						i0 = i;
    385 					search = 1;
    386 				}
    387 				mask = dir;
    388 				break;
    389 			case 0x1:
    390 				mask = 0;
    391 				break;
    392 			case 0x2:
    393 				mask = 1;
    394 				break;
    395 			default:
    396 				DPRINTF(("%s: scan: triplet error 0x%x, "
    397 				    "step %d\n",
    398 				    sc->sc_dev.dv_xname, rv, i));
    399 				onewire_unlock(sc);
    400 				return;
    401 			}
    402 			rom |= (mask << i);
    403 		}
    404 		lastd = i0;
    405 		onewire_unlock(sc);
    406 
    407 		if (rom == 0)
    408 			continue;
    409 
    410 		/*
    411 		 * The last byte of the ROM code contains a CRC calculated
    412 		 * from the first 7 bytes. Re-calculate it to make sure
    413 		 * we found a valid device.
    414 		 */
    415 		for (i = 0; i < 8; i++)
    416 			data[i] = (rom >> (i * 8)) & 0xff;
    417 		if (onewire_crc(data, 7) != data[7])
    418 			continue;
    419 
    420 		/*
    421 		 * Go through the list of attached devices to see if we
    422 		 * found a new one.
    423 		 */
    424 		present = 0;
    425 		TAILQ_FOREACH(d, &sc->sc_devs, d_list) {
    426 			if (d->d_rom == rom) {
    427 				d->d_present = 1;
    428 				present = 1;
    429 				break;
    430 			}
    431 		}
    432 		if (!present) {
    433 			bzero(&oa, sizeof(oa));
    434 			oa.oa_onewire = sc;
    435 			oa.oa_rom = rom;
    436 			if ((dev = config_found(&sc->sc_dev, &oa,
    437 			    onewire_print)) == NULL)
    438 				continue;
    439 
    440 			MALLOC(nd, struct onewire_device *,
    441 			    sizeof(struct onewire_device), M_DEVBUF, M_NOWAIT);
    442 			if (nd == NULL)
    443 				continue;
    444 			nd->d_dev = dev;
    445 			nd->d_rom = rom;
    446 			nd->d_present = 1;
    447 			TAILQ_INSERT_TAIL(&sc->sc_devs, nd, d_list);
    448 		}
    449 	}
    450 
    451 	/* Detach disappeared devices */
    452 	onewire_lock(sc, 0);
    453 	for (d = TAILQ_FIRST(&sc->sc_devs);
    454 	    d != NULL; d = next) {
    455 		next = TAILQ_NEXT(d, d_list);
    456 		if (!d->d_present) {
    457 			config_detach(d->d_dev, DETACH_FORCE);
    458 			TAILQ_REMOVE(&sc->sc_devs, d, d_list);
    459 			FREE(d, M_DEVBUF);
    460 		}
    461 	}
    462 	onewire_unlock(sc);
    463 }
    464