1 /*- 2 * Copyright (c) 2015 M. Warner Losh <imp@FreeBSD.org> 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice unmodified, this list of conditions, and the following 9 * disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include <sys/param.h> 27 #include <sys/systm.h> 28 #include <sys/kernel.h> 29 30 #include <sys/bus.h> 31 #include <sys/errno.h> 32 #include <sys/libkern.h> 33 #include <sys/lock.h> 34 #include <sys/malloc.h> 35 #include <sys/module.h> 36 #include <sys/mutex.h> 37 #include <sys/sbuf.h> 38 #include <sys/sysctl.h> 39 40 #include <dev/ow/ow.h> 41 #include <dev/ow/owll.h> 42 #include <dev/ow/own.h> 43 44 /* 45 * lldev - link level device 46 * ndev - network / transport device (this module) 47 * pdev - presentation device (children of this module) 48 */ 49 50 typedef int ow_enum_fn(device_t, device_t); 51 typedef int ow_found_fn(device_t, romid_t); 52 53 struct ow_softc 54 { 55 device_t dev; /* Newbus driver back pointer */ 56 struct mtx mtx; /* bus mutex */ 57 device_t owner; /* bus owner, if != NULL */ 58 }; 59 60 struct ow_devinfo 61 { 62 romid_t romid; 63 }; 64 65 static int ow_acquire_bus(device_t ndev, device_t pdev, int how); 66 static void ow_release_bus(device_t ndev, device_t pdev); 67 68 #define OW_LOCK(_sc) mtx_lock(&(_sc)->mtx) 69 #define OW_UNLOCK(_sc) mtx_unlock(&(_sc)->mtx) 70 #define OW_LOCK_DESTROY(_sc) mtx_destroy(&_sc->mtx) 71 #define OW_ASSERT_LOCKED(_sc) mtx_assert(&_sc->mtx, MA_OWNED) 72 #define OW_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->mtx, MA_NOTOWNED) 73 74 static MALLOC_DEFINE(M_OW, "ow", "House keeping data for 1wire bus"); 75 76 static const struct ow_timing timing_regular_min = { 77 .t_slot = 60, 78 .t_low0 = 60, 79 .t_low1 = 1, 80 .t_release = 0, 81 .t_rec = 1, 82 .t_rdv = 15, /* fixed */ 83 .t_rstl = 480, 84 .t_rsth = 480, 85 .t_pdl = 60, 86 .t_pdh = 15, 87 .t_lowr = 1, 88 }; 89 90 static const struct ow_timing timing_regular_max = { 91 .t_slot = 120, 92 .t_low0 = 120, 93 .t_low1 = 15, 94 .t_release = 45, 95 .t_rec = 960, /* infinity */ 96 .t_rdv = 15, /* fixed */ 97 .t_rstl = 960, /* infinity */ 98 .t_rsth = 960, /* infinity */ 99 .t_pdl = 240, /* 60us to 240us */ 100 .t_pdh = 60, /* 15us to 60us */ 101 .t_lowr = 15, /* 1us */ 102 }; 103 104 static struct ow_timing timing_regular = { 105 .t_slot = 60, /* 60 <= t < 120 */ 106 .t_low0 = 60, /* 60 <= t < t_slot < 120 */ 107 .t_low1 = 1, /* 1 <= t < 15 */ 108 .t_release = 45, /* 0 <= t < 45 */ 109 .t_rec = 15, /* 1 <= t < inf */ 110 .t_rdv = 15, /* t == 15 */ 111 .t_rstl = 480, /* 480 <= t < inf */ 112 .t_rsth = 480, /* 480 <= t < inf */ 113 .t_pdl = 60, /* 60 <= t < 240 */ 114 .t_pdh = 60, /* 15 <= t < 60 */ 115 .t_lowr = 1, /* 1 <= t < 15 */ 116 }; 117 118 /* NB: Untested */ 119 static const struct ow_timing timing_overdrive_min = { 120 .t_slot = 6, 121 .t_low0 = 6, 122 .t_low1 = 1, 123 .t_release = 0, 124 .t_rec = 1, 125 .t_rdv = 2, /* fixed */ 126 .t_rstl = 48, 127 .t_rsth = 48, 128 .t_pdl = 8, 129 .t_pdh = 2, 130 .t_lowr = 1, 131 }; 132 133 static const struct ow_timing timing_overdrive_max = { 134 .t_slot = 16, 135 .t_low0 = 16, 136 .t_low1 = 2, 137 .t_release = 4, 138 .t_rec = 960, /* infinity */ 139 .t_rdv = 2, /* fixed */ 140 .t_rstl = 80, 141 .t_rsth = 960, /* infinity */ 142 .t_pdl = 24, 143 .t_pdh = 6, 144 .t_lowr = 2, 145 }; 146 147 static struct ow_timing timing_overdrive = { 148 .t_slot = 11, /* 6 <= t < 16 */ 149 .t_low0 = 6, /* 6 <= t < t_slot < 16 */ 150 .t_low1 = 1, /* 1 <= t < 2 */ 151 .t_release = 4, /* 0 <= t < 4 */ 152 .t_rec = 1, /* 1 <= t < inf */ 153 .t_rdv = 2, /* t == 2 */ 154 .t_rstl = 48, /* 48 <= t < 80 */ 155 .t_rsth = 48, /* 48 <= t < inf */ 156 .t_pdl = 8, /* 8 <= t < 24 */ 157 .t_pdh = 2, /* 2 <= t < 6 */ 158 .t_lowr = 1, /* 1 <= t < 2 */ 159 }; 160 161 SYSCTL_NODE(_hw, OID_AUTO, ow, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 162 "1-Wire protocol"); 163 SYSCTL_NODE(_hw_ow, OID_AUTO, regular, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 164 "Regular mode timings"); 165 SYSCTL_NODE(_hw_ow, OID_AUTO, overdrive, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 166 "Overdrive mode timings"); 167 168 #define _OW_TIMING_SYSCTL(mode, param) \ 169 static int \ 170 sysctl_ow_timing_ ## mode ## _ ## param(SYSCTL_HANDLER_ARGS) \ 171 { \ 172 int val = timing_ ## mode.param; \ 173 int err; \ 174 err = sysctl_handle_int(oidp, &val, 0, req); \ 175 if (err != 0 || req->newptr == NULL) \ 176 return (err); \ 177 if (val < timing_ ## mode ## _min.param) \ 178 return (EINVAL); \ 179 else if (val >= timing_ ## mode ## _max.param) \ 180 return (EINVAL); \ 181 timing_ ## mode.param = val; \ 182 return (0); \ 183 } \ 184 SYSCTL_PROC(_hw_ow_ ## mode, OID_AUTO, param, \ 185 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), \ 186 sysctl_ow_timing_ ## mode ## _ ## param, "I", \ 187 "1-Wire timing parameter in microseconds (-1 resets to default)") 188 189 #define OW_TIMING_SYSCTL(param) \ 190 _OW_TIMING_SYSCTL(regular, param); \ 191 _OW_TIMING_SYSCTL(overdrive, param) 192 193 OW_TIMING_SYSCTL(t_slot); 194 OW_TIMING_SYSCTL(t_low0); 195 OW_TIMING_SYSCTL(t_low1); 196 OW_TIMING_SYSCTL(t_release); 197 OW_TIMING_SYSCTL(t_rec); 198 OW_TIMING_SYSCTL(t_rdv); 199 OW_TIMING_SYSCTL(t_rstl); 200 OW_TIMING_SYSCTL(t_rsth); 201 OW_TIMING_SYSCTL(t_pdl); 202 OW_TIMING_SYSCTL(t_pdh); 203 OW_TIMING_SYSCTL(t_lowr); 204 205 #undef _OW_TIMING_SYSCTL 206 #undef OW_TIMING_SYSCTL 207 208 static void 209 ow_send_byte(device_t lldev, struct ow_timing *t, uint8_t byte) 210 { 211 int i; 212 213 for (i = 0; i < 8; i++) 214 if (byte & (1 << i)) 215 OWLL_WRITE_ONE(lldev, t); 216 else 217 OWLL_WRITE_ZERO(lldev, t); 218 } 219 220 static void 221 ow_read_byte(device_t lldev, struct ow_timing *t, uint8_t *bytep) 222 { 223 int i; 224 uint8_t byte = 0; 225 int bit; 226 227 for (i = 0; i < 8; i++) { 228 OWLL_READ_DATA(lldev, t, &bit); 229 byte |= bit << i; 230 } 231 *bytep = byte; 232 } 233 234 static int 235 ow_send_command(device_t ndev, device_t pdev, struct ow_cmd *cmd) 236 { 237 int present, i, bit, tries; 238 device_t lldev; 239 struct ow_timing *t; 240 241 lldev = device_get_parent(ndev); 242 243 /* 244 * Retry the reset a couple of times before giving up. 245 */ 246 tries = 4; 247 do { 248 OWLL_RESET_AND_PRESENCE(lldev, &timing_regular, &present); 249 if (present == 1) 250 device_printf(ndev, "Reset said no device on bus?.\n"); 251 } while (present == 1 && tries-- > 0); 252 if (present == 1) { 253 device_printf(ndev, "Reset said the device wasn't there.\n"); 254 return ENOENT; /* No devices acked the RESET */ 255 } 256 if (present == -1) { 257 device_printf(ndev, "Reset discovered bus wired wrong.\n"); 258 return ENOENT; 259 } 260 261 for (i = 0; i < cmd->rom_len; i++) 262 ow_send_byte(lldev, &timing_regular, cmd->rom_cmd[i]); 263 for (i = 0; i < cmd->rom_read_len; i++) 264 ow_read_byte(lldev, &timing_regular, cmd->rom_read + i); 265 if (cmd->xpt_len) { 266 /* 267 * Per AN937, the reset pulse and ROM level are always 268 * done with the regular timings. Certain ROM commands 269 * put the device into overdrive mode for the remainder 270 * of the data transfer, which is why we have to pass the 271 * timings here. Commands that need to be handled like this 272 * are expected to be flagged by the client. 273 */ 274 t = (cmd->flags & OW_FLAG_OVERDRIVE) ? 275 &timing_overdrive : &timing_regular; 276 for (i = 0; i < cmd->xpt_len; i++) 277 ow_send_byte(lldev, t, cmd->xpt_cmd[i]); 278 if (cmd->flags & OW_FLAG_READ_BIT) { 279 memset(cmd->xpt_read, 0, (cmd->xpt_read_len + 7) / 8); 280 for (i = 0; i < cmd->xpt_read_len; i++) { 281 OWLL_READ_DATA(lldev, t, &bit); 282 cmd->xpt_read[i / 8] |= bit << (i % 8); 283 } 284 } else { 285 for (i = 0; i < cmd->xpt_read_len; i++) 286 ow_read_byte(lldev, t, cmd->xpt_read + i); 287 } 288 } 289 return 0; 290 } 291 292 static int 293 ow_search_rom(device_t lldev, device_t dev) 294 { 295 struct ow_cmd cmd; 296 297 memset(&cmd, 0, sizeof(cmd)); 298 cmd.rom_cmd[0] = SEARCH_ROM; 299 cmd.rom_len = 1; 300 return ow_send_command(lldev, dev, &cmd); 301 } 302 303 #if 0 304 static int 305 ow_alarm_search(device_t lldev, device_t dev) 306 { 307 struct ow_cmd cmd; 308 309 memset(&cmd, 0, sizeof(cmd)); 310 cmd.rom_cmd[0] = ALARM_SEARCH; 311 cmd.rom_len = 1; 312 return ow_send_command(lldev, dev, &cmd); 313 } 314 #endif 315 316 static int 317 ow_add_child(device_t dev, romid_t romid) 318 { 319 struct ow_devinfo *di; 320 device_t child; 321 322 di = malloc(sizeof(*di), M_OW, M_WAITOK); 323 di->romid = romid; 324 child = device_add_child(dev, NULL, DEVICE_UNIT_ANY); 325 if (child == NULL) { 326 free(di, M_OW); 327 return ENOMEM; 328 } 329 device_set_ivars(child, di); 330 return (0); 331 } 332 333 static void 334 ow_child_deleted(device_t dev, device_t child) 335 { 336 free(device_get_ivars(child), M_OW); 337 } 338 339 static device_t 340 ow_child_by_romid(device_t dev, romid_t romid) 341 { 342 device_t *children, retval, child; 343 int nkid, i; 344 struct ow_devinfo *di; 345 346 if (device_get_children(dev, &children, &nkid) != 0) 347 return (NULL); 348 retval = NULL; 349 for (i = 0; i < nkid; i++) { 350 child = children[i]; 351 di = device_get_ivars(child); 352 if (di->romid == romid) { 353 retval = child; 354 break; 355 } 356 } 357 free(children, M_TEMP); 358 359 return (retval); 360 } 361 362 /* 363 * CRC generator table -- taken from AN937 DOW CRC LOOKUP FUNCTION Table 2 364 */ 365 const uint8_t ow_crc_table[] = { 366 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, 367 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, 368 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, 369 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, 370 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, 371 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, 372 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, 373 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, 374 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205, 375 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80, 376 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238, 377 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, 378 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, 379 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, 380 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, 381 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 382 }; 383 384 /* 385 * Converted from DO_CRC page 131 ANN937 386 */ 387 static uint8_t 388 ow_crc(device_t ndev, device_t pdev, uint8_t *buffer, size_t len) 389 { 390 uint8_t crc = 0; 391 int i; 392 393 for (i = 0; i < len; i++) 394 crc = ow_crc_table[crc ^ buffer[i]]; 395 return crc; 396 } 397 398 static int 399 ow_check_crc(romid_t romid) 400 { 401 return ow_crc(NULL, NULL, (uint8_t *)&romid, sizeof(romid)) == 0; 402 } 403 404 static int 405 ow_device_found(device_t dev, romid_t romid) 406 { 407 408 /* XXX Move this up into enumerate? */ 409 /* 410 * All valid ROM IDs have a valid CRC. Check that first. 411 */ 412 if (!ow_check_crc(romid)) { 413 device_printf(dev, "Device romid %8D failed CRC.\n", 414 &romid, ":"); 415 return EINVAL; 416 } 417 418 /* 419 * If we've seen this child before, don't add a new one for it. 420 */ 421 if (ow_child_by_romid(dev, romid) != NULL) 422 return 0; 423 424 return ow_add_child(dev, romid); 425 } 426 427 static int 428 ow_enumerate(device_t dev, ow_enum_fn *enumfp, ow_found_fn *foundfp) 429 { 430 device_t lldev = device_get_parent(dev); 431 int first, second, i, dir, prior, last, err, retries; 432 uint64_t probed, last_mask; 433 int sanity = 10; 434 435 prior = -1; 436 last_mask = 0; 437 retries = 0; 438 last = -2; 439 err = ow_acquire_bus(dev, dev, OWN_DONTWAIT); 440 if (err != 0) 441 return err; 442 while (last != -1) { 443 if (sanity-- < 0) { 444 printf("Reached the sanity limit\n"); 445 return EIO; 446 } 447 again: 448 probed = 0; 449 last = -1; 450 451 /* 452 * See AN397 section 5.II.C.3 for the algorithm (though a bit 453 * poorly stated). The search command forces each device to 454 * send ROM ID bits one at a time (first the bit, then the 455 * complement) the master (us) sends back a bit. If the 456 * device's bit doesn't match what we send back, that device 457 * stops sending bits back. So each time through we remember 458 * where we made the last decision (always 0). If there's a 459 * conflict there this time (and there will be in the absence 460 * of a hardware failure) we go with 1. This way, we prune the 461 * devices on the bus and wind up with a unique ROM. We know 462 * we're done when we detect no new conflicts. The same 463 * algorithm is used for devices in alarm state as well. 464 * 465 * In addition, experience has shown that sometimes devices 466 * stop responding in the middle of enumeration, so try this 467 * step again a few times when that happens. It is unclear if 468 * this is due to a nosiy electrical environment or some odd 469 * timing issue. 470 */ 471 472 /* 473 * The enumeration command should be successfully sent, if not, 474 * we have big issues on the bus so punt. Lower layers report 475 * any unusual errors, so we don't need to here. 476 */ 477 err = enumfp(dev, dev); 478 if (err != 0) 479 return (err); 480 481 for (i = 0; i < 64; i++) { 482 OWLL_READ_DATA(lldev, &timing_regular, &first); 483 OWLL_READ_DATA(lldev, &timing_regular, &second); 484 switch (first | second << 1) { 485 case 0: /* Conflict */ 486 if (i < prior) 487 dir = (last_mask >> i) & 1; 488 else 489 dir = i == prior; 490 491 if (dir == 0) 492 last = i; 493 break; 494 case 1: /* 1 then 0 -> 1 for all */ 495 dir = 1; 496 break; 497 case 2: /* 0 then 1 -> 0 for all */ 498 dir = 0; 499 break; 500 case 3: 501 /* 502 * No device responded. This is unexpected, but 503 * experience has shown that on some platforms 504 * we miss a timing window, or otherwise have 505 * an issue. Start this step over. Since we've 506 * not updated prior yet, we can just jump to 507 * the top of the loop for a re-do of this step. 508 */ 509 printf("oops, starting over\n"); 510 if (++retries > 5) 511 return (EIO); 512 goto again; 513 default: /* NOTREACHED */ 514 __assert_unreachable(); 515 } 516 if (dir) { 517 OWLL_WRITE_ONE(lldev, &timing_regular); 518 probed |= 1ull << i; 519 } else { 520 OWLL_WRITE_ZERO(lldev, &timing_regular); 521 } 522 } 523 retries = 0; 524 foundfp(dev, probed); 525 last_mask = probed; 526 prior = last; 527 } 528 ow_release_bus(dev, dev); 529 530 return (0); 531 } 532 533 static int 534 ow_probe(device_t dev) 535 { 536 537 device_set_desc(dev, "1 Wire Bus"); 538 return (BUS_PROBE_GENERIC); 539 } 540 541 static int 542 ow_attach(device_t ndev) 543 { 544 struct ow_softc *sc; 545 546 /* 547 * Find all the devices on the bus. We don't probe / attach them in the 548 * enumeration phase. We do this because we want to allow the probe / 549 * attach routines of the child drivers to have as full an access to the 550 * bus as possible. While we reset things before the next step of the 551 * search (so it would likely be OK to allow access by the clients to 552 * the bus), it is more conservative to find them all, then to do the 553 * attach of the devices. This also allows the child devices to have 554 * more knowledge of the bus. We also ignore errors from the enumeration 555 * because they might happen after we've found a few devices. 556 */ 557 sc = device_get_softc(ndev); 558 sc->dev = ndev; 559 mtx_init(&sc->mtx, device_get_nameunit(sc->dev), "ow", MTX_DEF); 560 ow_enumerate(ndev, ow_search_rom, ow_device_found); 561 bus_attach_children(ndev); 562 return (0); 563 } 564 565 static int 566 ow_detach(device_t ndev) 567 { 568 struct ow_softc *sc; 569 570 sc = device_get_softc(ndev); 571 /* 572 * detach all the children first. This is blocking until any threads 573 * have stopped, etc. 574 */ 575 bus_generic_detach(ndev); 576 577 OW_LOCK_DESTROY(sc); 578 return 0; 579 } 580 581 static int 582 ow_child_pnpinfo(device_t dev, device_t child, struct sbuf *sb) 583 { 584 struct ow_devinfo *di; 585 586 di = device_get_ivars(child); 587 sbuf_printf(sb, "romid=%8D", &di->romid, ":"); 588 return (0); 589 } 590 591 static int 592 ow_read_ivar(device_t dev, device_t child, int which, uintptr_t *result) 593 { 594 struct ow_devinfo *di; 595 romid_t **ptr; 596 597 di = device_get_ivars(child); 598 switch (which) { 599 case OW_IVAR_FAMILY: 600 *result = di->romid & 0xff; 601 break; 602 case OW_IVAR_ROMID: 603 ptr = (romid_t **)result; 604 *ptr = &di->romid; 605 break; 606 default: 607 return EINVAL; 608 } 609 610 return 0; 611 } 612 613 static int 614 ow_write_ivar(device_t dev, device_t child, int which, uintptr_t value) 615 { 616 617 return EINVAL; 618 } 619 620 static int 621 ow_print_child(device_t ndev, device_t pdev) 622 { 623 int retval = 0; 624 struct ow_devinfo *di; 625 626 di = device_get_ivars(pdev); 627 628 retval += bus_print_child_header(ndev, pdev); 629 retval += printf(" romid %8D", &di->romid, ":"); 630 retval += bus_print_child_footer(ndev, pdev); 631 632 return retval; 633 } 634 635 static void 636 ow_probe_nomatch(device_t ndev, device_t pdev) 637 { 638 struct ow_devinfo *di; 639 640 di = device_get_ivars(pdev); 641 device_printf(ndev, "romid %8D: no driver\n", &di->romid, ":"); 642 } 643 644 static int 645 ow_acquire_bus(device_t ndev, device_t pdev, int how) 646 { 647 struct ow_softc *sc; 648 649 sc = device_get_softc(ndev); 650 OW_ASSERT_UNLOCKED(sc); 651 OW_LOCK(sc); 652 if (sc->owner != NULL) { 653 if (sc->owner == pdev) 654 panic("%s: %s recursively acquiring the bus.\n", 655 device_get_nameunit(ndev), 656 device_get_nameunit(pdev)); 657 if (how == OWN_DONTWAIT) { 658 OW_UNLOCK(sc); 659 return EWOULDBLOCK; 660 } 661 while (sc->owner != NULL) 662 mtx_sleep(sc, &sc->mtx, 0, "owbuswait", 0); 663 } 664 sc->owner = pdev; 665 OW_UNLOCK(sc); 666 667 return 0; 668 } 669 670 static void 671 ow_release_bus(device_t ndev, device_t pdev) 672 { 673 struct ow_softc *sc; 674 675 sc = device_get_softc(ndev); 676 OW_ASSERT_UNLOCKED(sc); 677 OW_LOCK(sc); 678 if (sc->owner == NULL) 679 panic("%s: %s releasing unowned bus.", device_get_nameunit(ndev), 680 device_get_nameunit(pdev)); 681 if (sc->owner != pdev) 682 panic("%s: %s don't own the bus. %s does. game over.", 683 device_get_nameunit(ndev), device_get_nameunit(pdev), 684 device_get_nameunit(sc->owner)); 685 sc->owner = NULL; 686 wakeup(sc); 687 OW_UNLOCK(sc); 688 } 689 690 static device_method_t ow_methods[] = { 691 /* Device interface */ 692 DEVMETHOD(device_probe, ow_probe), 693 DEVMETHOD(device_attach, ow_attach), 694 DEVMETHOD(device_detach, ow_detach), 695 696 /* Bus interface */ 697 DEVMETHOD(bus_child_deleted, ow_child_deleted), 698 DEVMETHOD(bus_child_pnpinfo, ow_child_pnpinfo), 699 DEVMETHOD(bus_read_ivar, ow_read_ivar), 700 DEVMETHOD(bus_write_ivar, ow_write_ivar), 701 DEVMETHOD(bus_print_child, ow_print_child), 702 DEVMETHOD(bus_probe_nomatch, ow_probe_nomatch), 703 704 /* One Wire Network/Transport layer interface */ 705 DEVMETHOD(own_send_command, ow_send_command), 706 DEVMETHOD(own_acquire_bus, ow_acquire_bus), 707 DEVMETHOD(own_release_bus, ow_release_bus), 708 DEVMETHOD(own_crc, ow_crc), 709 { 0, 0 } 710 }; 711 712 static driver_t ow_driver = { 713 "ow", 714 ow_methods, 715 sizeof(struct ow_softc), 716 }; 717 718 DRIVER_MODULE(ow, owc, ow_driver, 0, 0); 719 MODULE_VERSION(ow, 1); 720