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freebsd-skq/sys/dev/ow/ow.c

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/*-
* Copyright (c) 2015 M. Warner Losh <imp@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions, and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/errno.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <dev/ow/ow.h>
#include <dev/ow/owll.h>
#include <dev/ow/own.h>
/*
* lldev - link level device
* ndev - network / transport device (this module)
* pdev - presentation device (children of this module)
*/
typedef int ow_enum_fn(device_t, device_t);
typedef int ow_found_fn(device_t, romid_t);
struct ow_softc
{
device_t dev; /* Newbus driver back pointer */
struct mtx mtx; /* bus mutex */
device_t owner; /* bus owner, if != NULL */
};
struct ow_devinfo
{
romid_t romid;
};
static int ow_acquire_bus(device_t ndev, device_t pdev, int how);
static void ow_release_bus(device_t ndev, device_t pdev);
#define OW_LOCK(_sc) mtx_lock(&(_sc)->mtx)
#define OW_UNLOCK(_sc) mtx_unlock(&(_sc)->mtx)
#define OW_LOCK_DESTROY(_sc) mtx_destroy(&_sc->mtx)
#define OW_ASSERT_LOCKED(_sc) mtx_assert(&_sc->mtx, MA_OWNED)
#define OW_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->mtx, MA_NOTOWNED)
static MALLOC_DEFINE(M_OW, "ow", "House keeping data for 1wire bus");
static const struct ow_timing timing_regular_min = {
.t_slot = 60,
.t_low0 = 60,
.t_low1 = 1,
.t_release = 0,
.t_rec = 1,
.t_rdv = 15, /* fixed */
.t_rstl = 480,
.t_rsth = 480,
.t_pdl = 60,
.t_pdh = 15,
.t_lowr = 1,
};
static const struct ow_timing timing_regular_max = {
.t_slot = 120,
.t_low0 = 120,
.t_low1 = 15,
.t_release = 45,
.t_rec = 960, /* infinity */
.t_rdv = 15, /* fixed */
.t_rstl = 960, /* infinity */
.t_rsth = 960, /* infinity */
.t_pdl = 240, /* 60us to 240us */
.t_pdh = 60, /* 15us to 60us */
.t_lowr = 15, /* 1us */
};
static struct ow_timing timing_regular = {
.t_slot = 60, /* 60 <= t < 120 */
.t_low0 = 60, /* 60 <= t < t_slot < 120 */
.t_low1 = 1, /* 1 <= t < 15 */
.t_release = 45, /* 0 <= t < 45 */
.t_rec = 15, /* 1 <= t < inf */
.t_rdv = 15, /* t == 15 */
.t_rstl = 480, /* 480 <= t < inf */
.t_rsth = 480, /* 480 <= t < inf */
.t_pdl = 60, /* 60 <= t < 240 */
.t_pdh = 60, /* 15 <= t < 60 */
.t_lowr = 1, /* 1 <= t < 15 */
};
/* NB: Untested */
static const struct ow_timing timing_overdrive_min = {
.t_slot = 6,
.t_low0 = 6,
.t_low1 = 1,
.t_release = 0,
.t_rec = 1,
.t_rdv = 2, /* fixed */
.t_rstl = 48,
.t_rsth = 48,
.t_pdl = 8,
.t_pdh = 2,
.t_lowr = 1,
};
static const struct ow_timing timing_overdrive_max = {
.t_slot = 16,
.t_low0 = 16,
.t_low1 = 2,
.t_release = 4,
.t_rec = 960, /* infinity */
.t_rdv = 2, /* fixed */
.t_rstl = 80,
.t_rsth = 960, /* infinity */
.t_pdl = 24,
.t_pdh = 6,
.t_lowr = 2,
};
static struct ow_timing timing_overdrive = {
.t_slot = 11, /* 6 <= t < 16 */
.t_low0 = 6, /* 6 <= t < t_slot < 16 */
.t_low1 = 1, /* 1 <= t < 2 */
.t_release = 4, /* 0 <= t < 4 */
.t_rec = 1, /* 1 <= t < inf */
.t_rdv = 2, /* t == 2 */
.t_rstl = 48, /* 48 <= t < 80 */
.t_rsth = 48, /* 48 <= t < inf */
.t_pdl = 8, /* 8 <= t < 24 */
.t_pdh = 2, /* 2 <= t < 6 */
.t_lowr = 1, /* 1 <= t < 2 */
};
SYSCTL_NODE(_hw, OID_AUTO, ow, CTLFLAG_RD, 0, "1-Wire protocol");
SYSCTL_NODE(_hw_ow, OID_AUTO, regular, CTLFLAG_RD, 0,
"Regular mode timings");
SYSCTL_NODE(_hw_ow, OID_AUTO, overdrive, CTLFLAG_RD, 0,
"Overdrive mode timings");
#define _OW_TIMING_SYSCTL(mode, param) \
static int \
sysctl_ow_timing_ ## mode ## _ ## param(SYSCTL_HANDLER_ARGS) \
{ \
int val = timing_ ## mode.param; \
int err; \
err = sysctl_handle_int(oidp, &val, 0, req); \
if (err != 0 || req->newptr == NULL) \
return (err); \
if (val < timing_ ## mode ## _min.param) \
return (EINVAL); \
else if (val >= timing_ ## mode ## _max.param) \
return (EINVAL); \
timing_ ## mode.param = val; \
return (0); \
} \
SYSCTL_PROC(_hw_ow_ ## mode, OID_AUTO, param, \
CTLTYPE_INT | CTLFLAG_RWTUN, 0, sizeof(int), \
sysctl_ow_timing_ ## mode ## _ ## param, "I", \
"1-Wire timing parameter in microseconds (-1 resets to default)")
#define OW_TIMING_SYSCTL(param) \
_OW_TIMING_SYSCTL(regular, param); \
_OW_TIMING_SYSCTL(overdrive, param)
OW_TIMING_SYSCTL(t_slot);
OW_TIMING_SYSCTL(t_low0);
OW_TIMING_SYSCTL(t_low1);
OW_TIMING_SYSCTL(t_release);
OW_TIMING_SYSCTL(t_rec);
OW_TIMING_SYSCTL(t_rdv);
OW_TIMING_SYSCTL(t_rstl);
OW_TIMING_SYSCTL(t_rsth);
OW_TIMING_SYSCTL(t_pdl);
OW_TIMING_SYSCTL(t_pdh);
OW_TIMING_SYSCTL(t_lowr);
#undef _OW_TIMING_SYSCTL
#undef OW_TIMING_SYSCTL
static void
ow_send_byte(device_t lldev, struct ow_timing *t, uint8_t byte)
{
int i;
for (i = 0; i < 8; i++)
if (byte & (1 << i))
OWLL_WRITE_ONE(lldev, t);
else
OWLL_WRITE_ZERO(lldev, t);
}
static void
ow_read_byte(device_t lldev, struct ow_timing *t, uint8_t *bytep)
{
int i;
uint8_t byte = 0;
int bit;
for (i = 0; i < 8; i++) {
OWLL_READ_DATA(lldev, t, &bit);
byte |= bit << i;
}
*bytep = byte;
}
static int
ow_send_command(device_t ndev, device_t pdev, struct ow_cmd *cmd)
{
int present, i, bit, tries;
device_t lldev;
struct ow_timing *t;
lldev = device_get_parent(ndev);
/*
* Retry the reset a couple of times before giving up.
*/
tries = 4;
do {
OWLL_RESET_AND_PRESENCE(lldev, &timing_regular, &present);
if (present == 1)
device_printf(ndev, "Reset said no device on bus?.\n");
} while (present == 1 && tries-- > 0);
if (present == 1) {
device_printf(ndev, "Reset said the device wasn't there.\n");
return ENOENT; /* No devices acked the RESET */
}
if (present == -1) {
device_printf(ndev, "Reset discovered bus wired wrong.\n");
return ENOENT;
}
for (i = 0; i < cmd->rom_len; i++)
ow_send_byte(lldev, &timing_regular, cmd->rom_cmd[i]);
for (i = 0; i < cmd->rom_read_len; i++)
ow_read_byte(lldev, &timing_regular, cmd->rom_read + i);
if (cmd->xpt_len) {
/*
* Per AN937, the reset pulse and ROM level are always
* done with the regular timings. Certain ROM commands
* put the device into overdrive mode for the remainder
* of the data transfer, which is why we have to pass the
* timings here. Commands that need to be handled like this
* are expected to be flagged by the client.
*/
t = (cmd->flags & OW_FLAG_OVERDRIVE) ?
&timing_overdrive : &timing_regular;
for (i = 0; i < cmd->xpt_len; i++)
ow_send_byte(lldev, t, cmd->xpt_cmd[i]);
if (cmd->flags & OW_FLAG_READ_BIT) {
memset(cmd->xpt_read, 0, (cmd->xpt_read_len + 7) / 8);
for (i = 0; i < cmd->xpt_read_len; i++) {
OWLL_READ_DATA(lldev, t, &bit);
cmd->xpt_read[i / 8] |= bit << (i % 8);
}
} else {
for (i = 0; i < cmd->xpt_read_len; i++)
ow_read_byte(lldev, t, cmd->xpt_read + i);
}
}
return 0;
}
static int
ow_search_rom(device_t lldev, device_t dev)
{
struct ow_cmd cmd;
memset(&cmd, 0, sizeof(cmd));
cmd.rom_cmd[0] = SEARCH_ROM;
cmd.rom_len = 1;
return ow_send_command(lldev, dev, &cmd);
}
#if 0
static int
ow_alarm_search(device_t lldev, device_t dev)
{
struct ow_cmd cmd;
memset(&cmd, 0, sizeof(cmd));
cmd.rom_cmd[0] = ALARM_SEARCH;
cmd.rom_len = 1;
return ow_send_command(lldev, dev, &cmd);
}
#endif
static int
ow_add_child(device_t dev, romid_t romid)
{
struct ow_devinfo *di;
device_t child;
di = malloc(sizeof(*di), M_OW, M_WAITOK);
di->romid = romid;
child = device_add_child(dev, NULL, -1);
if (child == NULL) {
free(di, M_OW);
return ENOMEM;
}
device_set_ivars(child, di);
return (0);
}
static device_t
ow_child_by_romid(device_t dev, romid_t romid)
{
device_t *children, retval, child;
int nkid, i;
struct ow_devinfo *di;
if (device_get_children(dev, &children, &nkid) != 0)
return (NULL);
retval = NULL;
for (i = 0; i < nkid; i++) {
child = children[i];
di = device_get_ivars(child);
if (di->romid == romid) {
retval = child;
break;
}
}
free(children, M_TEMP);
return (retval);
}
/*
* CRC generator table -- taken from AN937 DOW CRC LOOKUP FUNCTION Table 2
*/
const uint8_t ow_crc_table[] = {
0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
219, 133,103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
140,210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113,147, 205,
17, 79, 173, 243, 112, 46, 204, 146, 211,141, 111, 49, 178, 236, 14, 80,
175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82,176, 238,
50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53
};
/*
* Converted from DO_CRC page 131 ANN937
*/
static uint8_t
ow_crc(device_t ndev, device_t pdev, uint8_t *buffer, size_t len)
{
uint8_t crc = 0;
int i;
for (i = 0; i < len; i++)
crc = ow_crc_table[crc ^ buffer[i]];
return crc;
}
static int
ow_check_crc(romid_t romid)
{
return ow_crc(NULL, NULL, (uint8_t *)&romid, sizeof(romid)) == 0;
}
static int
ow_device_found(device_t dev, romid_t romid)
{
/* XXX Move this up into enumerate? */
/*
* All valid ROM IDs have a valid CRC. Check that first.
*/
if (!ow_check_crc(romid)) {
device_printf(dev, "Device romid %8D failed CRC.\n",
&romid, ":");
return EINVAL;
}
/*
* If we've seen this child before, don't add a new one for it.
*/
if (ow_child_by_romid(dev, romid) != NULL)
return 0;
return ow_add_child(dev, romid);
}
static int
ow_enumerate(device_t dev, ow_enum_fn *enumfp, ow_found_fn *foundfp)
{
device_t lldev = device_get_parent(dev);
int first, second, i, dir, prior, last, err, retries;
uint64_t probed, last_mask;
int sanity = 10;
prior = -1;
last_mask = 0;
retries = 0;
last = -2;
err = ow_acquire_bus(dev, dev, OWN_DONTWAIT);
if (err != 0)
return err;
while (last != -1) {
if (sanity-- < 0) {
printf("Reached the sanity limit\n");
return EIO;
}
again:
probed = 0;
last = -1;
/*
* See AN397 section 5.II.C.3 for the algorithm (though a bit
* poorly stated). The search command forces each device to
* send ROM ID bits one at a time (first the bit, then the
* complement) the master (us) sends back a bit. If the
* device's bit doesn't match what we send back, that device
* stops sending bits back. So each time through we remember
* where we made the last decision (always 0). If there's a
* conflict there this time (and there will be in the absence
* of a hardware failure) we go with 1. This way, we prune the
* devices on the bus and wind up with a unique ROM. We know
* we're done when we detect no new conflicts. The same
* algorithm is used for devices in alarm state as well.
*
* In addition, experience has shown that sometimes devices
* stop responding in the middle of enumeration, so try this
* step again a few times when that happens. It is unclear if
* this is due to a nosiy electrical environment or some odd
* timing issue.
*/
/*
* The enumeration command should be successfully sent, if not,
* we have big issues on the bus so punt. Lower layers report
* any unusual errors, so we don't need to here.
*/
err = enumfp(dev, dev);
if (err != 0)
return (err);
for (i = 0; i < 64; i++) {
OWLL_READ_DATA(lldev, &timing_regular, &first);
OWLL_READ_DATA(lldev, &timing_regular, &second);
switch (first | second << 1) {
case 0: /* Conflict */
if (i < prior)
dir = (last_mask >> i) & 1;
else
dir = i == prior;
if (dir == 0)
last = i;
break;
case 1: /* 1 then 0 -> 1 for all */
dir = 1;
break;
case 2: /* 0 then 1 -> 0 for all */
dir = 0;
break;
case 3:
/*
* No device responded. This is unexpected, but
* experience has shown that on some platforms
* we miss a timing window, or otherwise have
* an issue. Start this step over. Since we've
* not updated prior yet, we can just jump to
* the top of the loop for a re-do of this step.
*/
printf("oops, starting over\n");
if (++retries > 5)
return (EIO);
goto again;
default: /* NOTREACHED */
__unreachable();
}
if (dir) {
OWLL_WRITE_ONE(lldev, &timing_regular);
probed |= 1ull << i;
} else {
OWLL_WRITE_ZERO(lldev, &timing_regular);
}
}
retries = 0;
foundfp(dev, probed);
last_mask = probed;
prior = last;
}
ow_release_bus(dev, dev);
return (0);
}
static int
ow_probe(device_t dev)
{
device_set_desc(dev, "1 Wire Bus");
return (BUS_PROBE_GENERIC);
}
static int
ow_attach(device_t ndev)
{
struct ow_softc *sc;
/*
* Find all the devices on the bus. We don't probe / attach them in the
* enumeration phase. We do this because we want to allow the probe /
* attach routines of the child drivers to have as full an access to the
* bus as possible. While we reset things before the next step of the
* search (so it would likely be OK to allow access by the clients to
* the bus), it is more conservative to find them all, then to do the
* attach of the devices. This also allows the child devices to have
* more knowledge of the bus. We also ignore errors from the enumeration
* because they might happen after we've found a few devices.
*/
sc = device_get_softc(ndev);
sc->dev = ndev;
mtx_init(&sc->mtx, device_get_nameunit(sc->dev), "ow", MTX_DEF);
ow_enumerate(ndev, ow_search_rom, ow_device_found);
return bus_generic_attach(ndev);
}
static int
ow_detach(device_t ndev)
{
device_t *children, child;
int nkid, i;
struct ow_devinfo *di;
struct ow_softc *sc;
sc = device_get_softc(ndev);
/*
* detach all the children first. This is blocking until any threads
* have stopped, etc.
*/
bus_generic_detach(ndev);
/*
* We delete all the children, and free up the ivars
*/
if (device_get_children(ndev, &children, &nkid) != 0)
return ENOMEM;
for (i = 0; i < nkid; i++) {
child = children[i];
di = device_get_ivars(child);
free(di, M_OW);
device_delete_child(ndev, child);
}
free(children, M_TEMP);
OW_LOCK_DESTROY(sc);
return 0;
}
/*
* Not sure this is really needed. I'm having trouble figuring out what
* location means in the context of the one wire bus.
*/
static int
ow_child_location_str(device_t dev, device_t child, char *buf,
size_t buflen)
{
*buf = '\0';
return (0);
}
static int
ow_child_pnpinfo_str(device_t dev, device_t child, char *buf,
size_t buflen)
{
struct ow_devinfo *di;
di = device_get_ivars(child);
snprintf(buf, buflen, "romid=%8D", &di->romid, ":");
return (0);
}
static int
ow_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
{
struct ow_devinfo *di;
romid_t **ptr;
di = device_get_ivars(child);
switch (which) {
case OW_IVAR_FAMILY:
*result = di->romid & 0xff;
break;
case OW_IVAR_ROMID:
ptr = (romid_t **)result;
*ptr = &di->romid;
break;
default:
return EINVAL;
}
return 0;
}
static int
ow_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
{
return EINVAL;
}
static int
ow_print_child(device_t ndev, device_t pdev)
{
int retval = 0;
struct ow_devinfo *di;
di = device_get_ivars(pdev);
retval += bus_print_child_header(ndev, pdev);
retval += printf(" romid %8D", &di->romid, ":");
retval += bus_print_child_footer(ndev, pdev);
return retval;
}
static void
ow_probe_nomatch(device_t ndev, device_t pdev)
{
struct ow_devinfo *di;
di = device_get_ivars(pdev);
device_printf(ndev, "romid %8D: no driver\n", &di->romid, ":");
}
static int
ow_acquire_bus(device_t ndev, device_t pdev, int how)
{
struct ow_softc *sc;
sc = device_get_softc(ndev);
OW_ASSERT_UNLOCKED(sc);
OW_LOCK(sc);
if (sc->owner != NULL) {
if (sc->owner == pdev)
panic("%s: %s recursively acquiring the bus.\n",
device_get_nameunit(ndev),
device_get_nameunit(pdev));
if (how == OWN_DONTWAIT) {
OW_UNLOCK(sc);
return EWOULDBLOCK;
}
while (sc->owner != NULL)
mtx_sleep(sc, &sc->mtx, 0, "owbuswait", 0);
}
sc->owner = pdev;
OW_UNLOCK(sc);
return 0;
}
static void
ow_release_bus(device_t ndev, device_t pdev)
{
struct ow_softc *sc;
sc = device_get_softc(ndev);
OW_ASSERT_UNLOCKED(sc);
OW_LOCK(sc);
if (sc->owner == NULL)
panic("%s: %s releasing unowned bus.", device_get_nameunit(ndev),
device_get_nameunit(pdev));
if (sc->owner != pdev)
panic("%s: %s don't own the bus. %s does. game over.",
device_get_nameunit(ndev), device_get_nameunit(pdev),
device_get_nameunit(sc->owner));
sc->owner = NULL;
wakeup(sc);
OW_UNLOCK(sc);
}
devclass_t ow_devclass;
static device_method_t ow_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, ow_probe),
DEVMETHOD(device_attach, ow_attach),
DEVMETHOD(device_detach, ow_detach),
/* Bus interface */
DEVMETHOD(bus_child_pnpinfo_str, ow_child_pnpinfo_str),
DEVMETHOD(bus_child_location_str, ow_child_location_str),
DEVMETHOD(bus_read_ivar, ow_read_ivar),
DEVMETHOD(bus_write_ivar, ow_write_ivar),
DEVMETHOD(bus_print_child, ow_print_child),
DEVMETHOD(bus_probe_nomatch, ow_probe_nomatch),
/* One Wire Network/Transport layer interface */
DEVMETHOD(own_send_command, ow_send_command),
DEVMETHOD(own_acquire_bus, ow_acquire_bus),
DEVMETHOD(own_release_bus, ow_release_bus),
DEVMETHOD(own_crc, ow_crc),
{ 0, 0 }
};
static driver_t ow_driver = {
"ow",
ow_methods,
sizeof(struct ow_softc),
};
DRIVER_MODULE(ow, owc, ow_driver, ow_devclass, 0, 0);
MODULE_VERSION(ow, 1);
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