one wire counter driver 2nd rev, from John L. Scarfone" <j0@cox.net> PR 6422

ok miod

7 files changed, 386 insertions, 9 deletions

diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index fc6b21adb49..feda76c49d9 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.510 2010/07/03 03:59:16 krw Exp $
+#	$OpenBSD: Makefile,v 1.511 2010/07/06 19:59:58 deraadt Exp $
 
 MAN=	aac.4 ac97.4 acphy.4 \
 	acpi.4 acpiac.4 acpiasus.4 acpibat.4 acpibtn.4 acpicpu.4 acpidock.4 \
@@ -37,7 +37,7 @@ MAN=	aac.4 ac97.4 acphy.4 \
 	ne.4 neo.4 netintro.4 nfe.4 nge.4 nmea.4 \
 	noct.4 nofn.4 nsclpcsio.4 nsgphy.4 nsphy.4 nsphyter.4 null.4 nviic.4 \
 	ohci.4 opl.4 options.4 onewire.4 oosiop.4 osiop.4 otus.4 \
-	owid.4 owsbm.4 \
+	owid.4 owctr.4 owsbm.4 \
 	owtemp.4 pcagpio.4 pcaled.4 pcdisplay.4 pchb.4 pci.4 pcib.4 pcfadc.4 \
 	pcfiic.4 pciide.4 pckbc.4 pckbd.4 pcmcia.4 pcn.4 pcppi.4 pcscp.4 \
 	pf.4 pflog.4 pflow.4 pfsync.4 pgt.4 piixpm.4 pim.4 \
diff --git a/share/man/man4/onewire.4 b/share/man/man4/onewire.4
index 66b53541a99..8fa5288e091 100644
--- a/share/man/man4/onewire.4
+++ b/share/man/man4/onewire.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: onewire.4,v 1.8 2009/11/16 20:13:12 miod Exp $
+.\"	$OpenBSD: onewire.4,v 1.9 2010/07/06 19:59:58 deraadt Exp $
 .\"
 .\" Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 16 2009 $
+.Dd $Mdocdate: July 6 2010 $
 .Dt ONEWIRE 4
 .Os
 .Sh NAME
@@ -57,6 +57,8 @@ Octane core system widget
 .El
 .Sh SUPPORTED SLAVES
 .Bl -tag -width 11n -offset ind -compact
+.It Xr owctr 4
+1-Wire counter device
 .It Xr owid 4
 1-Wire ID device
 .It Xr owmac 4
diff --git a/share/man/man4/owctr.4 b/share/man/man4/owctr.4
new file mode 100644
index 00000000000..aa81c3544f3
--- /dev/null
+++ b/share/man/man4/owctr.4
@@ -0,0 +1,55 @@
+.\" Copyright (c) 2010 John L. Scarfone <john@scarfone.net>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: July 6 2010 $
+.Dt OWCTR 4
+.Os
+.Sh NAME
+.Nm owctr
+.Nd 1-Wire counter device
+.Sh SYNOPSIS
+.Cd "owctr* at onewire?"
+.Sh DESCRIPTION
+The
+.Nm
+driver provides support for the externally triggered counters in the
+DS2423 chip.
+The supported chip contains a 4096 bit SRAM and four 32-bit counters.
+The two externally triggered counters are accessible by the
+.Xr sysctl 8
+interface.
+.Pp
+The following chips are supported by the driver:
+.Pp
+.Bl -bullet -compact -offset indent
+.It
+Maxim/Dallas DS2423
+.El
+.Sh SEE ALSO
+.Xr intro 4 ,
+.Xr onewire 4 ,
+.Xr owsbm 4 ,
+.Xr owtemp 4 ,
+.Xr sysctl 8
+.Sh HISTORY
+The
+.Nm
+driver first appeared in
+.Ox 4.8 .
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+driver was written by
+.An John L. Scarfone Aq john@scarfone.net .
diff --git a/sys/dev/onewire/files.onewire b/sys/dev/onewire/files.onewire
index dae25b7a87a..cca6b8db363 100644
--- a/sys/dev/onewire/files.onewire
+++ b/sys/dev/onewire/files.onewire
@@ -1,4 +1,4 @@
-# $OpenBSD: files.onewire,v 1.2 2007/02/28 21:54:43 grange Exp $
+# $OpenBSD: files.onewire,v 1.3 2010/07/06 19:59:59 deraadt Exp $
 
 define	onewire {}
 
@@ -23,3 +23,8 @@ file	dev/onewire/owsbm.c		owsbm
 device	owtemp
 attach	owtemp at onewire
 file	dev/onewire/owtemp.c		owtemp
+
+# Counter family type device
+device	owctr
+attach	owctr at onewire
+file	dev/onewire/owctr.c		owctr
diff --git a/sys/dev/onewire/onewire_subr.c b/sys/dev/onewire/onewire_subr.c
index ccb24a0868f..d4de7965fb7 100644
--- a/sys/dev/onewire/onewire_subr.c
+++ b/sys/dev/onewire/onewire_subr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: onewire_subr.c,v 1.2 2007/02/28 22:31:32 deraadt Exp $	*/
+/*	$OpenBSD: onewire_subr.c,v 1.3 2010/07/06 19:59:59 deraadt Exp $	*/
 
 /*
  * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
@@ -32,7 +32,7 @@
 #include <dev/onewire/onewiredevs_data.h>
 #endif
 
-static const u_int8_t crctable[] = {
+static const u_int8_t crc8_table[] = {
 	0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
 	0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41,
 	0x9d, 0xc3, 0x21, 0x7f, 0xfc, 0xa2, 0x40, 0x1e,
@@ -67,6 +67,76 @@ static const u_int8_t crctable[] = {
 	0xb6, 0xe8, 0x0a, 0x54, 0xd7, 0x89, 0x6b, 0x35
 };
 
+static const u_int8_t crc16_table_low[] = {
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x00, 0xc1, 0x81, 0x40, 0x01, 0xc0, 0x80, 0x41,
+	0x01, 0xc0, 0x80, 0x41, 0x00, 0xc1, 0x81, 0x40
+};
+
+static const u_int8_t crc16_table_high[] = {
+	0x00, 0xc0, 0xc1, 0x01, 0xc3, 0x03, 0x02, 0xc2,
+	0xc6, 0x06, 0x07, 0xc7, 0x05, 0xc5, 0xc4, 0x04,
+	0xcc, 0x0c, 0x0d, 0xcd, 0x0f, 0xcf, 0xce, 0x0e,
+	0x0a, 0xca, 0xcb, 0x0b, 0xc9, 0x09, 0x08, 0xc8,
+	0xd8, 0x18, 0x19, 0xd9, 0x1b, 0xdb, 0xda, 0x1a,
+	0x1e, 0xde, 0xdf, 0x1f, 0xdd, 0x1d, 0x1c, 0xdc,
+	0x14, 0xd4, 0xd5, 0x15, 0xd7, 0x17, 0x16, 0xd6,
+	0xd2, 0x12, 0x13, 0xd3, 0x11, 0xd1, 0xd0, 0x10,
+	0xf0, 0x30, 0x31, 0xf1, 0x33, 0xf3, 0xf2, 0x32,
+	0x36, 0xf6, 0xf7, 0x37, 0xf5, 0x35, 0x34, 0xf4,
+	0x3c, 0xfc, 0xfd, 0x3d, 0xff, 0x3f, 0x3e, 0xfe,
+	0xfa, 0x3a, 0x3b, 0xfb, 0x39, 0xf9, 0xf8, 0x38,
+	0x28, 0xe8, 0xe9, 0x29, 0xeb, 0x2b, 0x2a, 0xea,
+	0xee, 0x2e, 0x2f, 0xef, 0x2d, 0xed, 0xec, 0x2c,
+	0xe4, 0x24, 0x25, 0xe5, 0x27, 0xe7, 0xe6, 0x26,
+	0x22, 0xe2, 0xe3, 0x23, 0xe1, 0x21, 0x20, 0xe0,
+	0xa0, 0x60, 0x61, 0xa1, 0x63, 0xa3, 0xa2, 0x62,
+	0x66, 0xa6, 0xa7, 0x67, 0xa5, 0x65, 0x64, 0xa4,
+	0x6c, 0xac, 0xad, 0x6d, 0xaf, 0x6f, 0x6e, 0xae,
+	0xaa, 0x6a, 0x6b, 0xab, 0x69, 0xa9, 0xa8, 0x68,
+	0x78, 0xb8, 0xb9, 0x79, 0xbb, 0x7b, 0x7a, 0xba,
+	0xbe, 0x7e, 0x7f, 0xbf, 0x7d, 0xbd, 0xbc, 0x7c,
+	0xb4, 0x74, 0x75, 0xb5, 0x77, 0xb7, 0xb6, 0x76,
+	0x72, 0xb2, 0xb3, 0x73, 0xb1, 0x71, 0x70, 0xb0,
+	0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
+	0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54,
+	0x9c, 0x5c, 0x5d, 0x9d, 0x5f, 0x9f, 0x9e, 0x5e,
+	0x5a, 0x9a, 0x9b, 0x5b, 0x99, 0x59, 0x58, 0x98,
+	0x88, 0x48, 0x49, 0x89, 0x4b, 0x8b, 0x8a, 0x4a,
+	0x4e, 0x8e, 0x8f, 0x4f, 0x8d, 0x4d, 0x4c, 0x8c,
+	0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86,
+	0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40
+};
+
 int
 onewire_crc(const void *buf, int len)
 {
@@ -74,11 +144,23 @@ onewire_crc(const void *buf, int len)
 	u_int8_t crc = 0;
 
 	while (len--)
-		crc = crctable[crc ^ *p++];
+		crc = crc8_table[crc ^ *p++];
 
 	return (crc);
 }
 
+u_int16_t
+onewire_crc16(u_int16_t crc16, u_int8_t data)
+{
+	int idx;
+	u_int16_t newcrc16;
+
+	idx = (crc16 & 0xff) ^ data;
+	newcrc16 = crc16_table_high[idx] << 8;
+	newcrc16 |= crc16_table_low[idx] ^ (crc16 >> 8);
+	return (newcrc16);
+}
+
 const char *
 onewire_famname(int type)
 {
diff --git a/sys/dev/onewire/onewirevar.h b/sys/dev/onewire/onewirevar.h
index 1aa084f61ea..296c951498d 100644
--- a/sys/dev/onewire/onewirevar.h
+++ b/sys/dev/onewire/onewirevar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: onewirevar.h,v 1.5 2008/04/07 22:50:41 miod Exp $	*/
+/*	$OpenBSD: onewirevar.h,v 1.6 2010/07/06 19:59:59 deraadt Exp $	*/
 
 /*
  * Copyright (c) 2006 Alexander Yurchenko <grange@openbsd.org>
@@ -77,6 +77,7 @@ struct onewire_matchfam {
 
 /* Miscellaneous routines */
 int		onewire_crc(const void *, int);
+u_int16_t	onewire_crc16(u_int16_t, u_int8_t);
 const char *	onewire_famname(int);
 int		onewire_matchbyfam(struct onewire_attach_args *,
 		    const struct onewire_matchfam *, int);
diff --git a/sys/dev/onewire/owctr.c b/sys/dev/onewire/owctr.c
new file mode 100644
index 00000000000..dd63b8a32a2
--- /dev/null
+++ b/sys/dev/onewire/owctr.c
@@ -0,0 +1,232 @@
+/*
+ * Copyright (c) 2010 John L. Scarfone <john@scarfone.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * DS2423 1-Wire 4kbit SRAM with Counter family type device driver.
+ * Provides 4096 bits of SRAM and four 32-bit, read-only counters.
+ * This driver provides access to the two externally triggered
+ * counters.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/rwlock.h>
+#include <sys/sensors.h>
+
+#include <dev/onewire/onewiredevs.h>
+#include <dev/onewire/onewirereg.h>
+#include <dev/onewire/onewirevar.h>
+
+/* Commands */
+#define	DSCTR_CMD_READ_MEMCOUNTER	0xa5
+
+/* External counter banks */
+#define DS2423_COUNTER_BANK_A		0x1c0
+#define DS2423_COUNTER_BANK_B		0x1e0
+
+struct owctr_softc {
+	struct device		sc_dev;
+
+	void *			sc_onewire;
+	u_int64_t		sc_rom;
+
+	struct ksensordev	sc_sensordev;
+
+	struct ksensor		sc_counterA;
+	struct ksensor		sc_counterB;
+
+	struct sensor_task	*sc_sensortask;
+
+	struct rwlock		sc_lock;
+};
+
+int	owctr_match(struct device *, void *, void *);
+void	owctr_attach(struct device *, struct device *, void *);
+int	owctr_detach(struct device *, int);
+int	owctr_activate(struct device *, int);
+
+void	owctr_update(void *);
+void	owctr_update_counter(void *, int);
+
+struct cfattach owctr_ca = {
+	sizeof(struct owctr_softc),
+	owctr_match,
+	owctr_attach,
+	owctr_detach,
+	owctr_activate
+};
+
+struct cfdriver owctr_cd = {
+	NULL, "owctr", DV_DULL
+};
+
+static const struct onewire_matchfam owctr_fams[] = {
+	{ ONEWIRE_FAMILY_DS2423 }
+};
+
+int
+owctr_match(struct device *parent, void *match, void *aux)
+{
+	return (onewire_matchbyfam(aux, owctr_fams,
+		sizeof(owctr_fams) /sizeof(owctr_fams[0])));
+}
+
+void
+owctr_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct owctr_softc *sc = (struct owctr_softc *)self;
+	struct onewire_attach_args *oa = aux;
+
+	sc->sc_onewire = oa->oa_onewire;
+	sc->sc_rom = oa->oa_rom;
+
+	/* Initialize counter sensors */
+	strlcpy(sc->sc_sensordev.xname, sc->sc_dev.dv_xname,
+		sizeof(sc->sc_sensordev.xname));
+	sc->sc_counterA.type = SENSOR_INTEGER;
+	snprintf(sc->sc_counterA.desc, sizeof(sc->sc_counterA.desc),
+		"Counter A sn %012llx", ONEWIRE_ROM_SN(oa->oa_rom));
+	sensor_attach(&sc->sc_sensordev, &sc->sc_counterA);
+	sc->sc_counterB.type = SENSOR_INTEGER;
+	snprintf(sc->sc_counterB.desc, sizeof(sc->sc_counterB.desc),
+		"Counter B sn %012llx", ONEWIRE_ROM_SN(oa->oa_rom));
+	sensor_attach(&sc->sc_sensordev, &sc->sc_counterB);
+
+	sc->sc_sensortask = sensor_task_register(sc, owctr_update, 10);
+	if (sc->sc_sensortask == NULL) {
+		printf(": unable to register update task\n");
+		return;
+	}
+
+	sensordev_install(&sc->sc_sensordev);
+
+	rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
+	printf("\n");
+}
+
+int
+owctr_detach(struct device *self, int flags)
+{
+	struct owctr_softc *sc = (struct owctr_softc *)self;
+
+	rw_enter_write(&sc->sc_lock);
+	sensordev_deinstall(&sc->sc_sensordev);
+	if (sc->sc_sensortask != NULL)
+		sensor_task_unregister(sc->sc_sensortask);
+	rw_exit_write(&sc->sc_lock);
+
+	return (0);
+}
+
+int
+owctr_activate(struct device *self, int act)
+{
+	return (0);
+}
+
+void
+owctr_update(void *arg)
+{
+	owctr_update_counter(arg, DS2423_COUNTER_BANK_A);
+	owctr_update_counter(arg, DS2423_COUNTER_BANK_B);
+}
+
+void
+owctr_update_counter(void *arg, int bank)
+{
+	struct owctr_softc *sc = arg;
+	u_int32_t counter;
+	u_int16_t crc;
+	int data;
+	int i;
+
+	rw_enter_write(&sc->sc_lock);
+	onewire_lock(sc->sc_onewire, 0);
+	if (onewire_reset(sc->sc_onewire) != 0)
+		goto done;
+
+	onewire_matchrom(sc->sc_onewire, sc->sc_rom);
+	onewire_write_byte(sc->sc_onewire, DSCTR_CMD_READ_MEMCOUNTER);
+	crc = onewire_crc16(0, DSCTR_CMD_READ_MEMCOUNTER);
+	onewire_write_byte(sc->sc_onewire, bank);
+	crc = onewire_crc16(crc, bank);
+	onewire_write_byte(sc->sc_onewire, bank >> 8);
+	crc = onewire_crc16(crc, bank >> 8);
+	for (i=0; i<32; ++i)
+	{
+		data = onewire_read_byte(sc->sc_onewire);
+		crc = onewire_crc16(crc, data);
+	}
+	data = onewire_read_byte(sc->sc_onewire);
+	crc = onewire_crc16(crc, data);
+	counter = data;
+	data = onewire_read_byte(sc->sc_onewire);
+	crc = onewire_crc16(crc, data);
+	counter |= data << 8;
+	data = onewire_read_byte(sc->sc_onewire);
+	crc = onewire_crc16(crc, data);
+	counter |= data << 16;
+	data = onewire_read_byte(sc->sc_onewire);
+	crc = onewire_crc16(crc, data);
+	counter |= data << 24;
+	for (i=0; i<4; ++i)
+	{
+		onewire_read_byte(sc->sc_onewire);
+		crc = onewire_crc16(crc, data);
+	}
+	data = onewire_read_byte(sc->sc_onewire);
+	crc ^= data;
+	data = onewire_read_byte(sc->sc_onewire);
+	crc ^= data << 8;
+	if ( crc != 0xffff)
+	{
+		printf("%s: invalid CRC\n", sc->sc_dev.dv_xname);
+		if (bank == DS2423_COUNTER_BANK_A) {
+			sc->sc_counterA.value = 0;
+			sc->sc_counterA.status = SENSOR_S_UNKNOWN;
+			sc->sc_counterA.flags |= SENSOR_FUNKNOWN;
+		}
+		else
+		{
+			sc->sc_counterB.value = 0;
+			sc->sc_counterB.status = SENSOR_S_UNKNOWN;
+			sc->sc_counterB.flags |= SENSOR_FUNKNOWN;
+		}
+	}
+	else
+	{
+		if (bank == DS2423_COUNTER_BANK_A)
+		{
+			sc->sc_counterA.value = counter;
+			sc->sc_counterA.status = SENSOR_S_UNSPEC;
+			sc->sc_counterA.flags &= ~SENSOR_FUNKNOWN;
+		}
+		else
+		{
+			sc->sc_counterB.value = counter;
+			sc->sc_counterB.status = SENSOR_S_UNSPEC;
+			sc->sc_counterB.flags &= ~SENSOR_FUNKNOWN;
+		}
+	}
+	onewire_reset(sc->sc_onewire);
+
+done:
+	onewire_unlock(sc->sc_onewire);
+	rw_exit_write(&sc->sc_lock);
+}