| 1 | /* $NetBSD: onewire.c,v 1.16 2014/07/25 08:10:38 dholland 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@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 1.16 2014/07/25 08:10:38 dholland 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/rwlock.h> |
| 34 | #include <sys/malloc.h> |
| 35 | #include <sys/proc.h> |
| 36 | #include <sys/queue.h> |
| 37 | #include <sys/module.h> |
| 38 | |
| 39 | #include <dev/onewire/onewirereg.h> |
| 40 | #include <dev/onewire/onewirevar.h> |
| 41 | |
| 42 | #ifdef ONEWIRE_DEBUG |
| 43 | #define DPRINTF(x) printf x |
| 44 | #else |
| 45 | #define DPRINTF(x) |
| 46 | #endif |
| 47 | |
| 48 | //#define ONEWIRE_MAXDEVS 256 |
| 49 | #define ONEWIRE_MAXDEVS 8 |
| 50 | #define ONEWIRE_SCANTIME 3 |
| 51 | |
| 52 | struct onewire_softc { |
| 53 | device_t sc_dev; |
| 54 | |
| 55 | struct onewire_bus * sc_bus; |
| 56 | krwlock_t sc_rwlock; |
| 57 | struct lwp * sc_thread; |
| 58 | TAILQ_HEAD(, onewire_device) sc_devs; |
| 59 | |
| 60 | int sc_dying; |
| 61 | }; |
| 62 | |
| 63 | struct onewire_device { |
| 64 | TAILQ_ENTRY(onewire_device) d_list; |
| 65 | device_t d_dev; |
| 66 | u_int64_t d_rom; |
| 67 | int d_present; |
| 68 | }; |
| 69 | |
| 70 | static int onewire_match(device_t, cfdata_t, void *); |
| 71 | static void onewire_attach(device_t, device_t, void *); |
| 72 | static int onewire_detach(device_t, int); |
| 73 | static int onewire_activate(device_t, enum devact); |
| 74 | int onewire_print(void *, const char *); |
| 75 | |
| 76 | static void onewire_thread(void *); |
| 77 | static void onewire_scan(struct onewire_softc *); |
| 78 | |
| 79 | CFATTACH_DECL_NEW(onewire, sizeof(struct onewire_softc), |
| 80 | onewire_match, onewire_attach, onewire_detach, onewire_activate); |
| 81 | |
| 82 | const struct cdevsw onewire_cdevsw = { |
| 83 | .d_open = noopen, |
| 84 | .d_close = noclose, |
| 85 | .d_read = noread, |
| 86 | .d_write = nowrite, |
| 87 | .d_ioctl = noioctl, |
| 88 | .d_stop = nostop, |
| 89 | .d_tty = notty, |
| 90 | .d_poll = nopoll, |
| 91 | .d_mmap = nommap, |
| 92 | .d_kqfilter = nokqfilter, |
| 93 | .d_discard = nodiscard, |
| 94 | .d_flag = D_OTHER |
| 95 | }; |
| 96 | |
| 97 | extern struct cfdriver onewire_cd; |
| 98 | |
| 99 | static int |
| 100 | onewire_match(device_t parent, cfdata_t cf, void *aux) |
| 101 | { |
| 102 | return 1; |
| 103 | } |
| 104 | |
| 105 | static void |
| 106 | onewire_attach(device_t parent, device_t self, void *aux) |
| 107 | { |
| 108 | struct onewire_softc *sc = device_private(self); |
| 109 | struct onewirebus_attach_args *oba = aux; |
| 110 | |
| 111 | sc->sc_dev = self; |
| 112 | sc->sc_bus = oba->oba_bus; |
| 113 | rw_init(&sc->sc_rwlock); |
| 114 | TAILQ_INIT(&sc->sc_devs); |
| 115 | |
| 116 | aprint_normal("\n" ); |
| 117 | |
| 118 | if (kthread_create(PRI_NONE, 0, NULL, onewire_thread, sc, |
| 119 | &sc->sc_thread, "%s" , device_xname(self)) != 0) |
| 120 | aprint_error_dev(self, "can't create kernel thread\n" ); |
| 121 | } |
| 122 | |
| 123 | static int |
| 124 | onewire_detach(device_t self, int flags) |
| 125 | { |
| 126 | struct onewire_softc *sc = device_private(self); |
| 127 | int rv; |
| 128 | |
| 129 | sc->sc_dying = 1; |
| 130 | if (sc->sc_thread != NULL) { |
| 131 | wakeup(sc->sc_thread); |
| 132 | tsleep(&sc->sc_dying, PWAIT, "owdt" , 0); |
| 133 | } |
| 134 | |
| 135 | onewire_lock(sc); |
| 136 | //rv = config_detach_children(self, flags); |
| 137 | rv = 0; /* XXX riz */ |
| 138 | onewire_unlock(sc); |
| 139 | rw_destroy(&sc->sc_rwlock); |
| 140 | |
| 141 | return rv; |
| 142 | } |
| 143 | |
| 144 | static int |
| 145 | onewire_activate(device_t self, enum devact act) |
| 146 | { |
| 147 | struct onewire_softc *sc = device_private(self); |
| 148 | |
| 149 | switch (act) { |
| 150 | case DVACT_DEACTIVATE: |
| 151 | sc->sc_dying = 1; |
| 152 | return 0; |
| 153 | default: |
| 154 | return EOPNOTSUPP; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | int |
| 159 | onewire_print(void *aux, const char *pnp) |
| 160 | { |
| 161 | struct onewire_attach_args *oa = aux; |
| 162 | const char *famname; |
| 163 | |
| 164 | if (pnp == NULL) |
| 165 | aprint_normal(" " ); |
| 166 | |
| 167 | famname = onewire_famname(ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom)); |
| 168 | if (famname == NULL) |
| 169 | aprint_normal("family 0x%02x" , |
| 170 | (uint)ONEWIRE_ROM_FAMILY_TYPE(oa->oa_rom)); |
| 171 | else |
| 172 | aprint_normal("\"%s\"" , famname); |
| 173 | aprint_normal(" sn %012llx" , ONEWIRE_ROM_SN(oa->oa_rom)); |
| 174 | |
| 175 | if (pnp != NULL) |
| 176 | aprint_normal(" at %s" , pnp); |
| 177 | |
| 178 | return UNCONF; |
| 179 | } |
| 180 | |
| 181 | int |
| 182 | onewirebus_print(void *aux, const char *pnp) |
| 183 | { |
| 184 | if (pnp != NULL) |
| 185 | aprint_normal("onewire at %s" , pnp); |
| 186 | |
| 187 | return UNCONF; |
| 188 | } |
| 189 | |
| 190 | void |
| 191 | onewire_lock(void *arg) |
| 192 | { |
| 193 | struct onewire_softc *sc = arg; |
| 194 | |
| 195 | rw_enter(&sc->sc_rwlock, RW_WRITER); |
| 196 | } |
| 197 | |
| 198 | void |
| 199 | onewire_unlock(void *arg) |
| 200 | { |
| 201 | struct onewire_softc *sc = arg; |
| 202 | |
| 203 | rw_exit(&sc->sc_rwlock); |
| 204 | } |
| 205 | |
| 206 | int |
| 207 | onewire_reset(void *arg) |
| 208 | { |
| 209 | struct onewire_softc *sc = arg; |
| 210 | struct onewire_bus *bus = sc->sc_bus; |
| 211 | |
| 212 | return bus->bus_reset(bus->bus_cookie); |
| 213 | } |
| 214 | |
| 215 | int |
| 216 | onewire_bit(void *arg, int value) |
| 217 | { |
| 218 | struct onewire_softc *sc = arg; |
| 219 | struct onewire_bus *bus = sc->sc_bus; |
| 220 | |
| 221 | return bus->bus_bit(bus->bus_cookie, value); |
| 222 | } |
| 223 | |
| 224 | int |
| 225 | onewire_read_byte(void *arg) |
| 226 | { |
| 227 | struct onewire_softc *sc = arg; |
| 228 | struct onewire_bus *bus = sc->sc_bus; |
| 229 | uint8_t value = 0; |
| 230 | int i; |
| 231 | |
| 232 | if (bus->bus_read_byte != NULL) |
| 233 | return bus->bus_read_byte(bus->bus_cookie); |
| 234 | |
| 235 | for (i = 0; i < 8; i++) |
| 236 | value |= (bus->bus_bit(bus->bus_cookie, 1) << i); |
| 237 | |
| 238 | return value; |
| 239 | } |
| 240 | |
| 241 | void |
| 242 | onewire_write_byte(void *arg, int value) |
| 243 | { |
| 244 | struct onewire_softc *sc = arg; |
| 245 | struct onewire_bus *bus = sc->sc_bus; |
| 246 | int i; |
| 247 | |
| 248 | if (bus->bus_write_byte != NULL) |
| 249 | return bus->bus_write_byte(bus->bus_cookie, value); |
| 250 | |
| 251 | for (i = 0; i < 8; i++) |
| 252 | bus->bus_bit(bus->bus_cookie, (value >> i) & 0x1); |
| 253 | } |
| 254 | |
| 255 | int |
| 256 | onewire_triplet(void *arg, int dir) |
| 257 | { |
| 258 | struct onewire_softc *sc = arg; |
| 259 | struct onewire_bus *bus = sc->sc_bus; |
| 260 | int rv; |
| 261 | |
| 262 | if (bus->bus_triplet != NULL) |
| 263 | return bus->bus_triplet(bus->bus_cookie, dir); |
| 264 | |
| 265 | rv = bus->bus_bit(bus->bus_cookie, 1); |
| 266 | rv <<= 1; |
| 267 | rv |= bus->bus_bit(bus->bus_cookie, 1); |
| 268 | |
| 269 | switch (rv) { |
| 270 | case 0x0: |
| 271 | bus->bus_bit(bus->bus_cookie, dir); |
| 272 | break; |
| 273 | case 0x1: |
| 274 | bus->bus_bit(bus->bus_cookie, 0); |
| 275 | break; |
| 276 | default: |
| 277 | bus->bus_bit(bus->bus_cookie, 1); |
| 278 | } |
| 279 | |
| 280 | return rv; |
| 281 | } |
| 282 | |
| 283 | void |
| 284 | onewire_read_block(void *arg, void *buf, int len) |
| 285 | { |
| 286 | uint8_t *p = buf; |
| 287 | |
| 288 | while (len--) |
| 289 | *p++ = onewire_read_byte(arg); |
| 290 | } |
| 291 | |
| 292 | void |
| 293 | onewire_write_block(void *arg, const void *buf, int len) |
| 294 | { |
| 295 | const uint8_t *p = buf; |
| 296 | |
| 297 | while (len--) |
| 298 | onewire_write_byte(arg, *p++); |
| 299 | } |
| 300 | |
| 301 | void |
| 302 | onewire_matchrom(void *arg, u_int64_t rom) |
| 303 | { |
| 304 | int i; |
| 305 | |
| 306 | onewire_write_byte(arg, ONEWIRE_CMD_MATCH_ROM); |
| 307 | for (i = 0; i < 8; i++) |
| 308 | onewire_write_byte(arg, (rom >> (i * 8)) & 0xff); |
| 309 | } |
| 310 | |
| 311 | static void |
| 312 | onewire_thread(void *arg) |
| 313 | { |
| 314 | struct onewire_softc *sc = arg; |
| 315 | |
| 316 | while (!sc->sc_dying) { |
| 317 | onewire_scan(sc); |
| 318 | tsleep(sc->sc_thread, PWAIT, "owidle" , ONEWIRE_SCANTIME * hz); |
| 319 | } |
| 320 | |
| 321 | sc->sc_thread = NULL; |
| 322 | wakeup(&sc->sc_dying); |
| 323 | kthread_exit(0); |
| 324 | } |
| 325 | |
| 326 | static void |
| 327 | onewire_scan(struct onewire_softc *sc) |
| 328 | { |
| 329 | struct onewire_device *d, *next, *nd; |
| 330 | struct onewire_attach_args oa; |
| 331 | device_t dev; |
| 332 | int search = 1, count = 0, present; |
| 333 | int dir, rv; |
| 334 | uint64_t mask, rom = 0, lastrom; |
| 335 | uint8_t data[8]; |
| 336 | int i, i0 = -1, lastd = -1; |
| 337 | |
| 338 | TAILQ_FOREACH(d, &sc->sc_devs, d_list) |
| 339 | d->d_present = 0; |
| 340 | |
| 341 | while (search && count++ < ONEWIRE_MAXDEVS) { |
| 342 | /* XXX: yield processor */ |
| 343 | tsleep(sc, PWAIT, "owscan" , hz / 10); |
| 344 | |
| 345 | /* |
| 346 | * Reset the bus. If there's no presence pulse |
| 347 | * don't search for any devices. |
| 348 | */ |
| 349 | onewire_lock(sc); |
| 350 | if (onewire_reset(sc) != 0) { |
| 351 | DPRINTF(("%s: scan: no presence pulse\n" , |
| 352 | device_xname(sc->sc_dev))); |
| 353 | onewire_unlock(sc); |
| 354 | break; |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Start new search. Go through the previous path to |
| 359 | * the point we made a decision last time and make an |
| 360 | * opposite decision. If we didn't make any decision |
| 361 | * stop searching. |
| 362 | */ |
| 363 | search = 0; |
| 364 | lastrom = rom; |
| 365 | rom = 0; |
| 366 | onewire_write_byte(sc, ONEWIRE_CMD_SEARCH_ROM); |
| 367 | for (i = 0,i0 = -1; i < 64; i++) { |
| 368 | dir = (lastrom >> i) & 0x1; |
| 369 | if (i == lastd) |
| 370 | dir = 1; |
| 371 | else if (i > lastd) |
| 372 | dir = 0; |
| 373 | rv = onewire_triplet(sc, dir); |
| 374 | switch (rv) { |
| 375 | case 0x0: |
| 376 | if (i != lastd) { |
| 377 | if (dir == 0) |
| 378 | i0 = i; |
| 379 | search = 1; |
| 380 | } |
| 381 | mask = dir; |
| 382 | break; |
| 383 | case 0x1: |
| 384 | mask = 0; |
| 385 | break; |
| 386 | case 0x2: |
| 387 | mask = 1; |
| 388 | break; |
| 389 | default: |
| 390 | DPRINTF(("%s: scan: triplet error 0x%x, " |
| 391 | "step %d\n" , |
| 392 | device_xname(sc->sc_dev), rv, i)); |
| 393 | onewire_unlock(sc); |
| 394 | return; |
| 395 | } |
| 396 | rom |= (mask << i); |
| 397 | } |
| 398 | lastd = i0; |
| 399 | onewire_unlock(sc); |
| 400 | |
| 401 | if (rom == 0) |
| 402 | continue; |
| 403 | |
| 404 | /* |
| 405 | * The last byte of the ROM code contains a CRC calculated |
| 406 | * from the first 7 bytes. Re-calculate it to make sure |
| 407 | * we found a valid device. |
| 408 | */ |
| 409 | for (i = 0; i < 8; i++) |
| 410 | data[i] = (rom >> (i * 8)) & 0xff; |
| 411 | if (onewire_crc(data, 7) != data[7]) |
| 412 | continue; |
| 413 | |
| 414 | /* |
| 415 | * Go through the list of attached devices to see if we |
| 416 | * found a new one. |
| 417 | */ |
| 418 | present = 0; |
| 419 | TAILQ_FOREACH(d, &sc->sc_devs, d_list) { |
| 420 | if (d->d_rom == rom) { |
| 421 | d->d_present = 1; |
| 422 | present = 1; |
| 423 | break; |
| 424 | } |
| 425 | } |
| 426 | if (!present) { |
| 427 | memset(&oa, 0, sizeof(oa)); |
| 428 | oa.oa_onewire = sc; |
| 429 | oa.oa_rom = rom; |
| 430 | if ((dev = config_found(sc->sc_dev, &oa, |
| 431 | onewire_print)) == NULL) |
| 432 | continue; |
| 433 | |
| 434 | nd = malloc(sizeof(struct onewire_device), |
| 435 | M_DEVBUF, M_NOWAIT); |
| 436 | if (nd == NULL) |
| 437 | continue; |
| 438 | nd->d_dev = dev; |
| 439 | nd->d_rom = rom; |
| 440 | nd->d_present = 1; |
| 441 | TAILQ_INSERT_TAIL(&sc->sc_devs, nd, d_list); |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | /* Detach disappeared devices */ |
| 446 | onewire_lock(sc); |
| 447 | for (d = TAILQ_FIRST(&sc->sc_devs); |
| 448 | d != NULL; d = next) { |
| 449 | next = TAILQ_NEXT(d, d_list); |
| 450 | if (!d->d_present) { |
| 451 | config_detach(d->d_dev, DETACH_FORCE); |
| 452 | TAILQ_REMOVE(&sc->sc_devs, d, d_list); |
| 453 | free(d, M_DEVBUF); |
| 454 | } |
| 455 | } |
| 456 | onewire_unlock(sc); |
| 457 | } |
| 458 | |
| 459 | MODULE(MODULE_CLASS_DRIVER, onewire, NULL); |
| 460 | |
| 461 | #ifdef _MODULE |
| 462 | #include "ioconf.c" |
| 463 | #endif |
| 464 | |
| 465 | static int |
| 466 | onewire_modcmd(modcmd_t cmd, void *opaque) |
| 467 | { |
| 468 | int error; |
| 469 | |
| 470 | error = 0; |
| 471 | switch (cmd) { |
| 472 | case MODULE_CMD_INIT: |
| 473 | #ifdef _MODULE |
| 474 | error = config_init_component(cfdriver_ioconf_onewire, |
| 475 | cfattach_ioconf_onewire, cfdata_ioconf_onewire); |
| 476 | if (error) |
| 477 | aprint_error("%s: unable to init component\n" , |
| 478 | onewire_cd.cd_name); |
| 479 | #endif |
| 480 | break; |
| 481 | case MODULE_CMD_FINI: |
| 482 | #ifdef _MODULE |
| 483 | config_fini_component(cfdriver_ioconf_onewire, |
| 484 | cfattach_ioconf_onewire, cfdata_ioconf_onewire); |
| 485 | #endif |
| 486 | break; |
| 487 | default: |
| 488 | error = ENOTTY; |
| 489 | } |
| 490 | return error; |
| 491 | } |
| 492 | |