Index: sys/dev/gpio/gpioths.c
===================================================================
--- sys/dev/gpio/gpioths.c
+++ sys/dev/gpio/gpioths.c
@@ -137,7 +137,7 @@
 	}
 
 	/*
-	 * According to specifications we need to wait no more than 18ms
+	 * According to specifications we need to wait no less than 18ms
 	 * to start data transfer
 	 */
 	DELAY(GPIOTHS_DHT_STARTCYCLE);
@@ -170,14 +170,21 @@
 
 	sc = device_get_softc(dev);
 
+	/*
+	 * Mark thread as in critical section to avoid preemption during GPIO
+	 * manipulations & measurements
+	 */
+	critical_enter();
 	err = gpioths_dht_initread(bus,dev);
 	if (err) {
+		critical_exit();
 		device_printf(dev, "gpioths_dht_initread error = %d\n", err);
 		goto error;
 	}
 
 	err = gpioths_dht_timeuntil(bus, dev, GPIO_PIN_LOW, NULL);
 	if (err) {
+		critical_exit();
 		device_printf(dev, "err(START) = %d\n", err);
 		goto error;
 	}
@@ -187,12 +194,14 @@
 		err = gpioths_dht_timeuntil(bus, dev, GPIO_PIN_HIGH,
 		          &calibrations[i]);
 		if (err) {
+			critical_exit();
 			device_printf(dev, "err(CAL, %d) = %d\n", i, err);
 			goto error;
 		}
 		err = gpioths_dht_timeuntil(bus, dev, GPIO_PIN_LOW,
 			  &intervals[i]);
 		if (err) {
+			critical_exit();
 			device_printf(dev, "err(INTERVAL, %d) = %d\n", i, err);
 			goto error;
 		}
@@ -200,10 +209,11 @@
 
 	err = GPIOBUS_PIN_SETFLAGS(bus, dev, 0, GPIO_PIN_OUTPUT);
 	if (err != 0) {
+		critical_exit();
 		device_printf(dev, "err(FINAL_SETFLAGS, OUT) = %d\n", err);
 		goto error;
 	}
-	DELAY(1);
+	critical_exit();
 
 	/* Calculate average data calibration cycle length */
 	avglen = 0;
@@ -352,6 +362,16 @@
 static int
 gpioths_detach(device_t dev)
 {
+	struct gpioths_softc	*sc;
+
+	sc = device_get_softc(dev);
+	callout_drain(&sc->callout);
+
+	/*
+	 * gpioths_detach process doesn't touch sysctl because they're are
+	 * located under oid "dev.<driver>" and this oid has been already
+	 * removed before gpioths_detach is called
+	 */
 
 	return (0);
 }
Index: sys/modules/gpio/Makefile
===================================================================
--- sys/modules/gpio/Makefile
+++ sys/modules/gpio/Makefile
@@ -25,7 +25,7 @@
 # SUCH DAMAGE.
 #
 
-SUBDIR = gpiobus gpioiic gpioled gpiospi
+SUBDIR = gpiobus gpioiic gpioled gpiospi gpioths
 
 .if !empty(OPT_FDT)
 SUBDIR += gpiokeys gpiopps
Index: sys/modules/gpio/gpioths/Makefile
===================================================================
--- /dev/null
+++ sys/modules/gpio/gpioths/Makefile
@@ -0,0 +1,39 @@
+#
+# Copyright (c) 2016 Michael Zhilin, <mizhka@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, this list of conditions and the following disclaimer,
+#    without modification.
+# 2. Redistributions in binary form must reproduce at minimum a disclaimer
+#    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+#    redistribution must be conditioned upon including a substantially
+#    similar Disclaimer requirement for further binary redistribution.
+#
+# NO WARRANTY
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+# AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+# THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
+#
+# $FreeBSD$
+#
+
+.PATH:	${.CURDIR}/../../../dev/gpio/
+
+KMOD=	gpioths
+SRCS=	gpioths.c bus_if.h gpiobus_if.h
+
+CFLAGS+=  -I. -I${.CURDIR}/../../../dev/gpio/
+
+.include <bsd.kmod.mk>