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/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 #include <sys/param.h> 30 #include <sys/systm.h> 31 #include <sys/kernel.h> 32 33 #include <sys/bus.h> 34 #include <sys/errno.h> 35 #include <sys/libkern.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/module.h> 39 #include <sys/mutex.h> 40 #include <sys/sbuf.h> 41 #include <sys/sysctl.h> 42 43 #include <dev/ow/ow.h> 44 #include <dev/ow/owll.h> 45 #include <dev/ow/own.h> 46 47 /* 48 * lldev - link level device 49 * ndev - network / transport device (this module) 50 * pdev - presentation device (children of this module) 51 */ 52 53 typedef int ow_enum_fn(device_t, device_t); 54 typedef int ow_found_fn(device_t, romid_t); 55 56 struct ow_softc 57 { 58 device_t dev; /* Newbus driver back pointer */ 59 struct mtx mtx; /* bus mutex */ 60 device_t owner; /* bus owner, if != NULL */ 61 }; 62 63 struct ow_devinfo 64 { 65 romid_t romid; 66 }; 67 68 static int ow_acquire_bus(device_t ndev, device_t pdev, int how); 69 static void ow_release_bus(device_t ndev, device_t pdev); 70 71 #define OW_LOCK(_sc) mtx_lock(&(_sc)->mtx) 72 #define OW_UNLOCK(_sc) mtx_unlock(&(_sc)->mtx) 73 #define OW_LOCK_DESTROY(_sc) mtx_destroy(&_sc->mtx) 74 #define OW_ASSERT_LOCKED(_sc) mtx_assert(&_sc->mtx, MA_OWNED) 75 #define OW_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->mtx, MA_NOTOWNED) 76 77 static MALLOC_DEFINE(M_OW, "ow", "House keeping data for 1wire bus"); 78 79 static const struct ow_timing timing_regular_min = { 80 .t_slot = 60, 81 .t_low0 = 60, 82 .t_low1 = 1, 83 .t_release = 0, 84 .t_rec = 1, 85 .t_rdv = 15, /* fixed */ 86 .t_rstl = 480, 87 .t_rsth = 480, 88 .t_pdl = 60, 89 .t_pdh = 15, 90 .t_lowr = 1, 91 }; 92 93 static const struct ow_timing timing_regular_max = { 94 .t_slot = 120, 95 .t_low0 = 120, 96 .t_low1 = 15, 97 .t_release = 45, 98 .t_rec = 960, /* infinity */ 99 .t_rdv = 15, /* fixed */ 100 .t_rstl = 960, /* infinity */ 101 .t_rsth = 960, /* infinity */ 102 .t_pdl = 240, /* 60us to 240us */ 103 .t_pdh = 60, /* 15us to 60us */ 104 .t_lowr = 15, /* 1us */ 105 }; 106 107 static struct ow_timing timing_regular = { 108 .t_slot = 60, /* 60 <= t < 120 */ 109 .t_low0 = 60, /* 60 <= t < t_slot < 120 */ 110 .t_low1 = 1, /* 1 <= t < 15 */ 111 .t_release = 45, /* 0 <= t < 45 */ 112 .t_rec = 15, /* 1 <= t < inf */ 113 .t_rdv = 15, /* t == 15 */ 114 .t_rstl = 480, /* 480 <= t < inf */ 115 .t_rsth = 480, /* 480 <= t < inf */ 116 .t_pdl = 60, /* 60 <= t < 240 */ 117 .t_pdh = 60, /* 15 <= t < 60 */ 118 .t_lowr = 1, /* 1 <= t < 15 */ 119 }; 120 121 /* NB: Untested */ 122 static const struct ow_timing timing_overdrive_min = { 123 .t_slot = 6, 124 .t_low0 = 6, 125 .t_low1 = 1, 126 .t_release = 0, 127 .t_rec = 1, 128 .t_rdv = 2, /* fixed */ 129 .t_rstl = 48, 130 .t_rsth = 48, 131 .t_pdl = 8, 132 .t_pdh = 2, 133 .t_lowr = 1, 134 }; 135 136 static const struct ow_timing timing_overdrive_max = { 137 .t_slot = 16, 138 .t_low0 = 16, 139 .t_low1 = 2, 140 .t_release = 4, 141 .t_rec = 960, /* infinity */ 142 .t_rdv = 2, /* fixed */ 143 .t_rstl = 80, 144 .t_rsth = 960, /* infinity */ 145 .t_pdl = 24, 146 .t_pdh = 6, 147 .t_lowr = 2, 148 }; 149 150 static struct ow_timing timing_overdrive = { 151 .t_slot = 11, /* 6 <= t < 16 */ 152 .t_low0 = 6, /* 6 <= t < t_slot < 16 */ 153 .t_low1 = 1, /* 1 <= t < 2 */ 154 .t_release = 4, /* 0 <= t < 4 */ 155 .t_rec = 1, /* 1 <= t < inf */ 156 .t_rdv = 2, /* t == 2 */ 157 .t_rstl = 48, /* 48 <= t < 80 */ 158 .t_rsth = 48, /* 48 <= t < inf */ 159 .t_pdl = 8, /* 8 <= t < 24 */ 160 .t_pdh = 2, /* 2 <= t < 6 */ 161 .t_lowr = 1, /* 1 <= t < 2 */ 162 }; 163 164 SYSCTL_NODE(_hw, OID_AUTO, ow, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 165 "1-Wire protocol"); 166 SYSCTL_NODE(_hw_ow, OID_AUTO, regular, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 167 "Regular mode timings"); 168 SYSCTL_NODE(_hw_ow, OID_AUTO, overdrive, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, 169 "Overdrive mode timings"); 170 171 #define _OW_TIMING_SYSCTL(mode, param) \ 172 static int \ 173 sysctl_ow_timing_ ## mode ## _ ## param(SYSCTL_HANDLER_ARGS) \ 174 { \ 175 int val = timing_ ## mode.param; \ 176 int err; \ 177 err = sysctl_handle_int(oidp, &val, 0, req); \ 178 if (err != 0 || req->newptr == NULL) \ 179 return (err); \ 180 if (val < timing_ ## mode ## _min.param) \ 181 return (EINVAL); \ 182 else if (val >= timing_ ## mode ## _max.param) \ 183 return (EINVAL); \ 184 timing_ ## mode.param = val; \ 185 return (0); \ 186 } \ 187 SYSCTL_PROC(_hw_ow_ ## mode, OID_AUTO, param, \ 188 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), \ 189 sysctl_ow_timing_ ## mode ## _ ## param, "I", \ 190 "1-Wire timing parameter in microseconds (-1 resets to default)") 191 192 #define OW_TIMING_SYSCTL(param) \ 193 _OW_TIMING_SYSCTL(regular, param); \ 194 _OW_TIMING_SYSCTL(overdrive, param) 195 196 OW_TIMING_SYSCTL(t_slot); 197 OW_TIMING_SYSCTL(t_low0); 198 OW_TIMING_SYSCTL(t_low1); 199 OW_TIMING_SYSCTL(t_release); 200 OW_TIMING_SYSCTL(t_rec); 201 OW_TIMING_SYSCTL(t_rdv); 202 OW_TIMING_SYSCTL(t_rstl); 203 OW_TIMING_SYSCTL(t_rsth); 204 OW_TIMING_SYSCTL(t_pdl); 205 OW_TIMING_SYSCTL(t_pdh); 206 OW_TIMING_SYSCTL(t_lowr); 207 208 #undef _OW_TIMING_SYSCTL 209 #undef OW_TIMING_SYSCTL 210 211 static void 212 ow_send_byte(device_t lldev, struct ow_timing *t, uint8_t byte) 213 { 214 int i; 215 216 for (i = 0; i < 8; i++) 217 if (byte & (1 << i)) 218 OWLL_WRITE_ONE(lldev, t); 219 else 220 OWLL_WRITE_ZERO(lldev, t); 221 } 222 223 static void 224 ow_read_byte(device_t lldev, struct ow_timing *t, uint8_t *bytep) 225 { 226 int i; 227 uint8_t byte = 0; 228 int bit; 229 230 for (i = 0; i < 8; i++) { 231 OWLL_READ_DATA(lldev, t, &bit); 232 byte |= bit << i; 233 } 234 *bytep = byte; 235 } 236 237 static int 238 ow_send_command(device_t ndev, device_t pdev, struct ow_cmd *cmd) 239 { 240 int present, i, bit, tries; 241 device_t lldev; 242 struct ow_timing *t; 243 244 lldev = device_get_parent(ndev); 245 246 /* 247 * Retry the reset a couple of times before giving up. 248 */ 249 tries = 4; 250 do { 251 OWLL_RESET_AND_PRESENCE(lldev, &timing_regular, &present); 252 if (present == 1) 253 device_printf(ndev, "Reset said no device on bus?.\n"); 254 } while (present == 1 && tries-- > 0); 255 if (present == 1) { 256 device_printf(ndev, "Reset said the device wasn't there.\n"); 257 return ENOENT; /* No devices acked the RESET */ 258 } 259 if (present == -1) { 260 device_printf(ndev, "Reset discovered bus wired wrong.\n"); 261 return ENOENT; 262 } 263 264 for (i = 0; i < cmd->rom_len; i++) 265 ow_send_byte(lldev, &timing_regular, cmd->rom_cmd[i]); 266 for (i = 0; i < cmd->rom_read_len; i++) 267 ow_read_byte(lldev, &timing_regular, cmd->rom_read + i); 268 if (cmd->xpt_len) { 269 /* 270 * Per AN937, the reset pulse and ROM level are always 271 * done with the regular timings. Certain ROM commands 272 * put the device into overdrive mode for the remainder 273 * of the data transfer, which is why we have to pass the 274 * timings here. Commands that need to be handled like this 275 * are expected to be flagged by the client. 276 */ 277 t = (cmd->flags & OW_FLAG_OVERDRIVE) ? 278 &timing_overdrive : &timing_regular; 279 for (i = 0; i < cmd->xpt_len; i++) 280 ow_send_byte(lldev, t, cmd->xpt_cmd[i]); 281 if (cmd->flags & OW_FLAG_READ_BIT) { 282 memset(cmd->xpt_read, 0, (cmd->xpt_read_len + 7) / 8); 283 for (i = 0; i < cmd->xpt_read_len; i++) { 284 OWLL_READ_DATA(lldev, t, &bit); 285 cmd->xpt_read[i / 8] |= bit << (i % 8); 286 } 287 } else { 288 for (i = 0; i < cmd->xpt_read_len; i++) 289 ow_read_byte(lldev, t, cmd->xpt_read + i); 290 } 291 } 292 return 0; 293 } 294 295 static int 296 ow_search_rom(device_t lldev, device_t dev) 297 { 298 struct ow_cmd cmd; 299 300 memset(&cmd, 0, sizeof(cmd)); 301 cmd.rom_cmd[0] = SEARCH_ROM; 302 cmd.rom_len = 1; 303 return ow_send_command(lldev, dev, &cmd); 304 } 305 306 #if 0 307 static int 308 ow_alarm_search(device_t lldev, device_t dev) 309 { 310 struct ow_cmd cmd; 311 312 memset(&cmd, 0, sizeof(cmd)); 313 cmd.rom_cmd[0] = ALARM_SEARCH; 314 cmd.rom_len = 1; 315 return ow_send_command(lldev, dev, &cmd); 316 } 317 #endif 318 319 static int 320 ow_add_child(device_t dev, romid_t romid) 321 { 322 struct ow_devinfo *di; 323 device_t child; 324 325 di = malloc(sizeof(*di), M_OW, M_WAITOK); 326 di->romid = romid; 327 child = device_add_child(dev, NULL, -1); 328 if (child == NULL) { 329 free(di, M_OW); 330 return ENOMEM; 331 } 332 device_set_ivars(child, di); 333 return (0); 334 } 335 336 static device_t 337 ow_child_by_romid(device_t dev, romid_t romid) 338 { 339 device_t *children, retval, child; 340 int nkid, i; 341 struct ow_devinfo *di; 342 343 if (device_get_children(dev, &children, &nkid) != 0) 344 return (NULL); 345 retval = NULL; 346 for (i = 0; i < nkid; i++) { 347 child = children[i]; 348 di = device_get_ivars(child); 349 if (di->romid == romid) { 350 retval = child; 351 break; 352 } 353 } 354 free(children, M_TEMP); 355 356 return (retval); 357 } 358 359 /* 360 * CRC generator table -- taken from AN937 DOW CRC LOOKUP FUNCTION Table 2 361 */ 362 const uint8_t ow_crc_table[] = { 363 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65, 364 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220, 365 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98, 366 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255, 367 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7, 368 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154, 369 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36, 370 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185, 371 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205, 372 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80, 373 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238, 374 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115, 375 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139, 376 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22, 377 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168, 378 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53 379 }; 380 381 /* 382 * Converted from DO_CRC page 131 ANN937 383 */ 384 static uint8_t 385 ow_crc(device_t ndev, device_t pdev, uint8_t *buffer, size_t len) 386 { 387 uint8_t crc = 0; 388 int i; 389 390 for (i = 0; i < len; i++) 391 crc = ow_crc_table[crc ^ buffer[i]]; 392 return crc; 393 } 394 395 static int 396 ow_check_crc(romid_t romid) 397 { 398 return ow_crc(NULL, NULL, (uint8_t *)&romid, sizeof(romid)) == 0; 399 } 400 401 static int 402 ow_device_found(device_t dev, romid_t romid) 403 { 404 405 /* XXX Move this up into enumerate? */ 406 /* 407 * All valid ROM IDs have a valid CRC. Check that first. 408 */ 409 if (!ow_check_crc(romid)) { 410 device_printf(dev, "Device romid %8D failed CRC.\n", 411 &romid, ":"); 412 return EINVAL; 413 } 414 415 /* 416 * If we've seen this child before, don't add a new one for it. 417 */ 418 if (ow_child_by_romid(dev, romid) != NULL) 419 return 0; 420 421 return ow_add_child(dev, romid); 422 } 423 424 static int 425 ow_enumerate(device_t dev, ow_enum_fn *enumfp, ow_found_fn *foundfp) 426 { 427 device_t lldev = device_get_parent(dev); 428 int first, second, i, dir, prior, last, err, retries; 429 uint64_t probed, last_mask; 430 int sanity = 10; 431 432 prior = -1; 433 last_mask = 0; 434 retries = 0; 435 last = -2; 436 err = ow_acquire_bus(dev, dev, OWN_DONTWAIT); 437 if (err != 0) 438 return err; 439 while (last != -1) { 440 if (sanity-- < 0) { 441 printf("Reached the sanity limit\n"); 442 return EIO; 443 } 444 again: 445 probed = 0; 446 last = -1; 447 448 /* 449 * See AN397 section 5.II.C.3 for the algorithm (though a bit 450 * poorly stated). The search command forces each device to 451 * send ROM ID bits one at a time (first the bit, then the 452 * complement) the master (us) sends back a bit. If the 453 * device's bit doesn't match what we send back, that device 454 * stops sending bits back. So each time through we remember 455 * where we made the last decision (always 0). If there's a 456 * conflict there this time (and there will be in the absence 457 * of a hardware failure) we go with 1. This way, we prune the 458 * devices on the bus and wind up with a unique ROM. We know 459 * we're done when we detect no new conflicts. The same 460 * algorithm is used for devices in alarm state as well. 461 * 462 * In addition, experience has shown that sometimes devices 463 * stop responding in the middle of enumeration, so try this 464 * step again a few times when that happens. It is unclear if 465 * this is due to a nosiy electrical environment or some odd 466 * timing issue. 467 */ 468 469 /* 470 * The enumeration command should be successfully sent, if not, 471 * we have big issues on the bus so punt. Lower layers report 472 * any unusual errors, so we don't need to here. 473 */ 474 err = enumfp(dev, dev); 475 if (err != 0) 476 return (err); 477 478 for (i = 0; i < 64; i++) { 479 OWLL_READ_DATA(lldev, &timing_regular, &first); 480 OWLL_READ_DATA(lldev, &timing_regular, &second); 481 switch (first | second << 1) { 482 case 0: /* Conflict */ 483 if (i < prior) 484 dir = (last_mask >> i) & 1; 485 else 486 dir = i == prior; 487 488 if (dir == 0) 489 last = i; 490 break; 491 case 1: /* 1 then 0 -> 1 for all */ 492 dir = 1; 493 break; 494 case 2: /* 0 then 1 -> 0 for all */ 495 dir = 0; 496 break; 497 case 3: 498 /* 499 * No device responded. This is unexpected, but 500 * experience has shown that on some platforms 501 * we miss a timing window, or otherwise have 502 * an issue. Start this step over. Since we've 503 * not updated prior yet, we can just jump to 504 * the top of the loop for a re-do of this step. 505 */ 506 printf("oops, starting over\n"); 507 if (++retries > 5) 508 return (EIO); 509 goto again; 510 default: /* NOTREACHED */ 511 __assert_unreachable(); 512 } 513 if (dir) { 514 OWLL_WRITE_ONE(lldev, &timing_regular); 515 probed |= 1ull << i; 516 } else { 517 OWLL_WRITE_ZERO(lldev, &timing_regular); 518 } 519 } 520 retries = 0; 521 foundfp(dev, probed); 522 last_mask = probed; 523 prior = last; 524 } 525 ow_release_bus(dev, dev); 526 527 return (0); 528 } 529 530 static int 531 ow_probe(device_t dev) 532 { 533 534 device_set_desc(dev, "1 Wire Bus"); 535 return (BUS_PROBE_GENERIC); 536 } 537 538 static int 539 ow_attach(device_t ndev) 540 { 541 struct ow_softc *sc; 542 543 /* 544 * Find all the devices on the bus. We don't probe / attach them in the 545 * enumeration phase. We do this because we want to allow the probe / 546 * attach routines of the child drivers to have as full an access to the 547 * bus as possible. While we reset things before the next step of the 548 * search (so it would likely be OK to allow access by the clients to 549 * the bus), it is more conservative to find them all, then to do the 550 * attach of the devices. This also allows the child devices to have 551 * more knowledge of the bus. We also ignore errors from the enumeration 552 * because they might happen after we've found a few devices. 553 */ 554 sc = device_get_softc(ndev); 555 sc->dev = ndev; 556 mtx_init(&sc->mtx, device_get_nameunit(sc->dev), "ow", MTX_DEF); 557 ow_enumerate(ndev, ow_search_rom, ow_device_found); 558 return bus_generic_attach(ndev); 559 } 560 561 static int 562 ow_detach(device_t ndev) 563 { 564 device_t *children, child; 565 int nkid, i; 566 struct ow_devinfo *di; 567 struct ow_softc *sc; 568 569 sc = device_get_softc(ndev); 570 /* 571 * detach all the children first. This is blocking until any threads 572 * have stopped, etc. 573 */ 574 bus_generic_detach(ndev); 575 576 /* 577 * We delete all the children, and free up the ivars 578 */ 579 if (device_get_children(ndev, &children, &nkid) != 0) 580 return ENOMEM; 581 for (i = 0; i < nkid; i++) { 582 child = children[i]; 583 di = device_get_ivars(child); 584 free(di, M_OW); 585 device_delete_child(ndev, child); 586 } 587 free(children, M_TEMP); 588 589 OW_LOCK_DESTROY(sc); 590 return 0; 591 } 592 593 static int 594 ow_child_pnpinfo(device_t dev, device_t child, struct sbuf *sb) 595 { 596 struct ow_devinfo *di; 597 598 di = device_get_ivars(child); 599 sbuf_printf(sb, "romid=%8D", &di->romid, ":"); 600 return (0); 601 } 602 603 static int 604 ow_read_ivar(device_t dev, device_t child, int which, uintptr_t *result) 605 { 606 struct ow_devinfo *di; 607 romid_t **ptr; 608 609 di = device_get_ivars(child); 610 switch (which) { 611 case OW_IVAR_FAMILY: 612 *result = di->romid & 0xff; 613 break; 614 case OW_IVAR_ROMID: 615 ptr = (romid_t **)result; 616 *ptr = &di->romid; 617 break; 618 default: 619 return EINVAL; 620 } 621 622 return 0; 623 } 624 625 static int 626 ow_write_ivar(device_t dev, device_t child, int which, uintptr_t value) 627 { 628 629 return EINVAL; 630 } 631 632 static int 633 ow_print_child(device_t ndev, device_t pdev) 634 { 635 int retval = 0; 636 struct ow_devinfo *di; 637 638 di = device_get_ivars(pdev); 639 640 retval += bus_print_child_header(ndev, pdev); 641 retval += printf(" romid %8D", &di->romid, ":"); 642 retval += bus_print_child_footer(ndev, pdev); 643 644 return retval; 645 } 646 647 static void 648 ow_probe_nomatch(device_t ndev, device_t pdev) 649 { 650 struct ow_devinfo *di; 651 652 di = device_get_ivars(pdev); 653 device_printf(ndev, "romid %8D: no driver\n", &di->romid, ":"); 654 } 655 656 static int 657 ow_acquire_bus(device_t ndev, device_t pdev, int how) 658 { 659 struct ow_softc *sc; 660 661 sc = device_get_softc(ndev); 662 OW_ASSERT_UNLOCKED(sc); 663 OW_LOCK(sc); 664 if (sc->owner != NULL) { 665 if (sc->owner == pdev) 666 panic("%s: %s recursively acquiring the bus.\n", 667 device_get_nameunit(ndev), 668 device_get_nameunit(pdev)); 669 if (how == OWN_DONTWAIT) { 670 OW_UNLOCK(sc); 671 return EWOULDBLOCK; 672 } 673 while (sc->owner != NULL) 674 mtx_sleep(sc, &sc->mtx, 0, "owbuswait", 0); 675 } 676 sc->owner = pdev; 677 OW_UNLOCK(sc); 678 679 return 0; 680 } 681 682 static void 683 ow_release_bus(device_t ndev, device_t pdev) 684 { 685 struct ow_softc *sc; 686 687 sc = device_get_softc(ndev); 688 OW_ASSERT_UNLOCKED(sc); 689 OW_LOCK(sc); 690 if (sc->owner == NULL) 691 panic("%s: %s releasing unowned bus.", device_get_nameunit(ndev), 692 device_get_nameunit(pdev)); 693 if (sc->owner != pdev) 694 panic("%s: %s don't own the bus. %s does. game over.", 695 device_get_nameunit(ndev), device_get_nameunit(pdev), 696 device_get_nameunit(sc->owner)); 697 sc->owner = NULL; 698 wakeup(sc); 699 OW_UNLOCK(sc); 700 } 701 702 static device_method_t ow_methods[] = { 703 /* Device interface */ 704 DEVMETHOD(device_probe, ow_probe), 705 DEVMETHOD(device_attach, ow_attach), 706 DEVMETHOD(device_detach, ow_detach), 707 708 /* Bus interface */ 709 DEVMETHOD(bus_child_pnpinfo, ow_child_pnpinfo), 710 DEVMETHOD(bus_read_ivar, ow_read_ivar), 711 DEVMETHOD(bus_write_ivar, ow_write_ivar), 712 DEVMETHOD(bus_print_child, ow_print_child), 713 DEVMETHOD(bus_probe_nomatch, ow_probe_nomatch), 714 715 /* One Wire Network/Transport layer interface */ 716 DEVMETHOD(own_send_command, ow_send_command), 717 DEVMETHOD(own_acquire_bus, ow_acquire_bus), 718 DEVMETHOD(own_release_bus, ow_release_bus), 719 DEVMETHOD(own_crc, ow_crc), 720 { 0, 0 } 721 }; 722 723 static driver_t ow_driver = { 724 "ow", 725 ow_methods, 726 sizeof(struct ow_softc), 727 }; 728 729 DRIVER_MODULE(ow, owc, ow_driver, 0, 0); 730 MODULE_VERSION(ow, 1); 731