2 * Copyright (c) 2015 M. Warner Losh <imp@freebsd.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice unmodified, this list of conditions, and the following
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
35 #include <sys/errno.h>
36 #include <sys/libkern.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
40 #include <dev/ow/ow.h>
41 #include <dev/ow/owll.h>
42 #include <dev/ow/own.h>
45 * lldev - link level device
46 * ndev - network / transport device (this module)
47 * pdev - presentation device (children of this module)
50 typedef int ow_enum_fn(device_t, device_t);
51 typedef int ow_found_fn(device_t, romid_t);
55 device_t dev; /* Newbus driver back pointer */
56 struct mtx mtx; /* bus mutex */
57 device_t owner; /* bus owner, if != NULL */
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);
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)
74 static MALLOC_DEFINE(M_OW, "ow", "House keeping data for 1wire bus");
76 static struct ow_timing timing_regular = {
77 .t_slot = 60, /* 60 to 120 */
78 .t_low0 = 60, /* really 60 to 120 */
79 .t_low1 = 1, /* really 1 to 15 */
80 .t_release = 45, /* <= 45us */
81 .t_rec = 1, /* at least 1us */
82 .t_rdv = 15, /* 15us */
83 .t_rstl = 480, /* 480us or more */
84 .t_rsth = 480, /* 480us or more */
85 .t_pdl = 60, /* 60us to 240us */
86 .t_pdh = 60, /* 15us to 60us */
87 .t_lowr = 1, /* 1us */
91 static struct ow_timing timing_overdrive = {
92 .t_slot = 11, /* 6us to 16us */
93 .t_low0 = 6, /* really 6 to 16 */
94 .t_low1 = 1, /* really 1 to 2 */
95 .t_release = 4, /* <= 4us */
96 .t_rec = 1, /* at least 1us */
98 .t_rstl = 48, /* 48us to 80us */
99 .t_rsth = 48, /* 48us or more */
100 .t_pdl = 8, /* 8us to 24us */
101 .t_pdh = 2, /* 2us to 6us */
102 .t_lowr = 1, /* 1us */
106 ow_send_byte(device_t lldev, struct ow_timing *t, uint8_t byte)
110 for (i = 0; i < 8; i++)
112 OWLL_WRITE_ONE(lldev, t);
114 OWLL_WRITE_ZERO(lldev, t);
118 ow_read_byte(device_t lldev, struct ow_timing *t, uint8_t *bytep)
124 for (i = 0; i < 8; i++) {
125 OWLL_READ_DATA(lldev, t, &bit);
132 ow_send_command(device_t ndev, device_t pdev, struct ow_cmd *cmd)
134 int present, i, bit, tries;
138 lldev = device_get_parent(ndev);
141 * Retry the reset a couple of times before giving up.
145 OWLL_RESET_AND_PRESENCE(lldev, &timing_regular, &present);
147 device_printf(ndev, "Reset said no device on bus?.\n");
148 } while (present == 1 && tries-- > 0);
150 device_printf(ndev, "Reset said the device wasn't there.\n");
151 return ENOENT; /* No devices acked the RESET */
154 device_printf(ndev, "Reset discovered bus wired wrong.\n");
158 for (i = 0; i < cmd->rom_len; i++)
159 ow_send_byte(lldev, &timing_regular, cmd->rom_cmd[i]);
160 for (i = 0; i < cmd->rom_read_len; i++)
161 ow_read_byte(lldev, &timing_regular, cmd->rom_read + i);
164 * Per AN937, the reset pulse and ROM level are always
165 * done with the regular timings. Certain ROM commands
166 * put the device into overdrive mode for the remainder
167 * of the data transfer, which is why we have to pass the
168 * timings here. Commands that need to be handled like this
169 * are expected to be flagged by the client.
171 t = (cmd->flags & OW_FLAG_OVERDRIVE) ?
172 &timing_overdrive : &timing_regular;
173 for (i = 0; i < cmd->xpt_len; i++)
174 ow_send_byte(lldev, t, cmd->xpt_cmd[i]);
175 if (cmd->flags & OW_FLAG_READ_BIT) {
176 memset(cmd->xpt_read, 0, (cmd->xpt_read_len + 7) / 8);
177 for (i = 0; i < cmd->xpt_read_len; i++) {
178 OWLL_READ_DATA(lldev, t, &bit);
179 cmd->xpt_read[i / 8] |= bit << (i % 8);
182 for (i = 0; i < cmd->xpt_read_len; i++)
183 ow_read_byte(lldev, t, cmd->xpt_read + i);
190 ow_search_rom(device_t lldev, device_t dev)
194 memset(&cmd, 0, sizeof(cmd));
195 cmd.rom_cmd[0] = SEARCH_ROM;
197 return ow_send_command(lldev, dev, &cmd);
202 ow_alarm_search(device_t lldev, device_t dev)
206 memset(&cmd, 0, sizeof(cmd));
207 cmd.rom_cmd[0] = ALARM_SEARCH;
209 return ow_send_command(lldev, dev, &cmd);
214 ow_add_child(device_t dev, romid_t romid)
216 struct ow_devinfo *di;
219 di = malloc(sizeof(*di), M_OW, M_WAITOK);
221 child = device_add_child(dev, NULL, -1);
226 device_set_ivars(child, di);
231 ow_child_by_romid(device_t dev, romid_t romid)
233 device_t *children, retval, child;
235 struct ow_devinfo *di;
237 if (device_get_children(dev, &children, &nkid) != 0)
240 for (i = 0; i < nkid; i++) {
242 di = device_get_ivars(child);
243 if (di->romid == romid) {
248 free(children, M_TEMP);
254 * CRC generator table -- taken from AN937 DOW CRC LOOKUP FUNCTION Table 2
256 const uint8_t ow_crc_table[] = {
257 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
258 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
259 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
260 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
261 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
262 219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
263 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
264 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
265 140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205,
266 17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80,
267 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238,
268 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
269 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
270 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
271 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
272 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53
276 * Converted from DO_CRC page 131 ANN937
279 ow_crc(device_t ndev, device_t pdev, uint8_t *buffer, size_t len)
284 for (i = 0; i < len; i++)
285 crc = ow_crc_table[crc ^ buffer[i]];
290 ow_check_crc(romid_t romid)
292 return ow_crc(NULL, NULL, (uint8_t *)&romid, sizeof(romid)) == 0;
296 ow_device_found(device_t dev, romid_t romid)
299 /* XXX Move this up into enumerate? */
301 * All valid ROM IDs have a valid CRC. Check that first.
303 if (!ow_check_crc(romid)) {
304 device_printf(dev, "Device romid %8D failed CRC.\n",
310 * If we've seen this child before, don't add a new one for it.
312 if (ow_child_by_romid(dev, romid) != NULL)
315 return ow_add_child(dev, romid);
319 ow_enumerate(device_t dev, ow_enum_fn *enumfp, ow_found_fn *foundfp)
321 device_t lldev = device_get_parent(dev);
322 int first, second, i, dir, prior, last, err, retries;
323 uint64_t probed, last_mask;
330 err = ow_acquire_bus(dev, dev, OWN_DONTWAIT);
335 printf("Reached the sanity limit\n");
343 * See AN397 section 5.II.C.3 for the algorithm (though a bit
344 * poorly stated). The search command forces each device to
345 * send ROM ID bits one at a time (first the bit, then the
346 * complement) the the master (us) sends back a bit. If the
347 * device's bit doesn't match what we send back, that device
348 * stops sending bits back. So each time through we remember
349 * where we made the last decision (always 0). If there's a
350 * conflict there this time (and there will be in the absence
351 * of a hardware failure) we go with 1. This way, we prune the
352 * devices on the bus and wind up with a unique ROM. We know
353 * we're done when we detect no new conflicts. The same
354 * algorithm is used for devices in alarm state as well.
356 * In addition, experience has shown that sometimes devices
357 * stop responding in the middle of enumeration, so try this
358 * step again a few times when that happens. It is unclear if
359 * this is due to a nosiy electrical environment or some odd
364 * The enumeration command should be successfully sent, if not,
365 * we have big issues on the bus so punt. Lower layers report
366 * any unusual errors, so we don't need to here.
368 err = enumfp(dev, dev);
372 for (i = 0; i < 64; i++) {
373 OWLL_READ_DATA(lldev, &timing_regular, &first);
374 OWLL_READ_DATA(lldev, &timing_regular, &second);
375 switch (first | second << 1) {
376 case 0: /* Conflict */
378 dir = (last_mask >> i) & 1;
385 case 1: /* 1 then 0 -> 1 for all */
388 case 2: /* 0 then 1 -> 0 for all */
393 * No device responded. This is unexpected, but
394 * experience has shown that on some platforms
395 * we miss a timing window, or otherwise have
396 * an issue. Start this step over. Since we've
397 * not updated prior yet, we can just jump to
398 * the top of the loop for a re-do of this step.
400 printf("oops, starting over\n");
406 OWLL_WRITE_ONE(lldev, &timing_regular);
409 OWLL_WRITE_ZERO(lldev, &timing_regular);
413 foundfp(dev, probed);
417 ow_release_bus(dev, dev);
423 ow_probe(device_t dev)
426 device_set_desc(dev, "1 Wire Bus");
427 return (BUS_PROBE_GENERIC);
431 ow_attach(device_t ndev)
436 * Find all the devices on the bus. We don't probe / attach them in the
437 * enumeration phase. We do this because we want to allow the probe /
438 * attach routines of the child drivers to have as full an access to the
439 * bus as possible. While we reset things before the next step of the
440 * search (so it would likely be OK to allow access by the clients to
441 * the bus), it is more conservative to find them all, then to do the
442 * attach of the devices. This also allows the child devices to have
443 * more knowledge of the bus. We also ignore errors from the enumeration
444 * because they might happen after we've found a few devices.
446 sc = device_get_softc(ndev);
448 mtx_init(&sc->mtx, device_get_nameunit(sc->dev), "ow", MTX_DEF);
449 ow_enumerate(ndev, ow_search_rom, ow_device_found);
450 return bus_generic_attach(ndev);
454 ow_detach(device_t ndev)
456 device_t *children, child;
458 struct ow_devinfo *di;
461 sc = device_get_softc(ndev);
463 * detach all the children first. This is blocking until any threads
466 bus_generic_detach(ndev);
469 * We delete all the children, and free up the ivars
471 if (device_get_children(ndev, &children, &nkid) != 0)
473 for (i = 0; i < nkid; i++) {
475 di = device_get_ivars(child);
477 device_delete_child(ndev, child);
479 free(children, M_TEMP);
486 * Not sure this is really needed. I'm having trouble figuring out what
487 * location means in the context of the one wire bus.
490 ow_child_location_str(device_t dev, device_t child, char *buf,
499 ow_child_pnpinfo_str(device_t dev, device_t child, char *buf,
502 struct ow_devinfo *di;
504 di = device_get_ivars(child);
505 snprintf(buf, buflen, "romid=%8D", &di->romid, ":");
510 ow_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
512 struct ow_devinfo *di;
515 di = device_get_ivars(child);
518 *result = di->romid & 0xff;
521 ptr = (romid_t **)result;
532 ow_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
539 ow_print_child(device_t ndev, device_t pdev)
542 struct ow_devinfo *di;
544 di = device_get_ivars(pdev);
546 retval += bus_print_child_header(ndev, pdev);
547 retval += printf(" romid %8D", &di->romid, ":");
548 retval += bus_print_child_footer(ndev, pdev);
554 ow_probe_nomatch(device_t ndev, device_t pdev)
556 struct ow_devinfo *di;
558 di = device_get_ivars(pdev);
559 device_printf(ndev, "romid %8D: no driver\n", &di->romid, ":");
563 ow_acquire_bus(device_t ndev, device_t pdev, int how)
567 sc = device_get_softc(ndev);
568 OW_ASSERT_UNLOCKED(sc);
570 if (sc->owner != NULL) {
571 if (sc->owner == pdev)
572 panic("%s: %s recursively acquiring the bus.\n",
573 device_get_nameunit(ndev),
574 device_get_nameunit(pdev));
575 if (how == OWN_DONTWAIT) {
579 while (sc->owner != NULL)
580 mtx_sleep(sc, &sc->mtx, 0, "owbuswait", 0);
589 ow_release_bus(device_t ndev, device_t pdev)
593 sc = device_get_softc(ndev);
594 OW_ASSERT_UNLOCKED(sc);
596 if (sc->owner == NULL)
597 panic("%s: %s releasing unowned bus.", device_get_nameunit(ndev),
598 device_get_nameunit(pdev));
599 if (sc->owner != pdev)
600 panic("%s: %s don't own the bus. %s does. game over.",
601 device_get_nameunit(ndev), device_get_nameunit(pdev),
602 device_get_nameunit(sc->owner));
608 devclass_t ow_devclass;
610 static device_method_t ow_methods[] = {
611 /* Device interface */
612 DEVMETHOD(device_probe, ow_probe),
613 DEVMETHOD(device_attach, ow_attach),
614 DEVMETHOD(device_detach, ow_detach),
617 DEVMETHOD(bus_child_pnpinfo_str, ow_child_pnpinfo_str),
618 DEVMETHOD(bus_child_location_str, ow_child_location_str),
619 DEVMETHOD(bus_read_ivar, ow_read_ivar),
620 DEVMETHOD(bus_write_ivar, ow_write_ivar),
621 DEVMETHOD(bus_print_child, ow_print_child),
622 DEVMETHOD(bus_probe_nomatch, ow_probe_nomatch),
624 /* One Wire Network/Transport layer interface */
625 DEVMETHOD(own_send_command, ow_send_command),
626 DEVMETHOD(own_acquire_bus, ow_acquire_bus),
627 DEVMETHOD(own_release_bus, ow_release_bus),
628 DEVMETHOD(own_crc, ow_crc),
632 static driver_t ow_driver = {
635 sizeof(struct ow_softc),
638 DRIVER_MODULE(ow, owc, ow_driver, ow_devclass, 0, 0);
639 MODULE_VERSION(ow, 1);