Index: sys/dev/acpi_support/acpi_cros_tbmc.c
===================================================================
--- /dev/null
+++ sys/dev/acpi_support/acpi_cros_tbmc.c
@@ -0,0 +1,179 @@
+/*-
+ * Copyright (c) 2019 Greg V <greg@unrelenting.technology>
+ *
+ * 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.
+ * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 "opt_acpi.h"
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/bus.h>
+#include <machine/cpufunc.h>
+
+#include <contrib/dev/acpica/include/acpi.h>
+#include <contrib/dev/acpica/include/accommon.h>
+
+#include "acpi_if.h"
+#include <sys/module.h>
+#include <dev/evdev/evdev.h>
+#include <dev/evdev/input.h>
+#include <dev/acpica/acpivar.h>
+
+ACPI_MODULE_NAME("CROS_TBMC")
+
+struct acpi_cros_tbmc_softc {
+	device_t	dev;
+	ACPI_HANDLE	handle;
+
+	struct evdev_dev	*evdev;
+};
+
+static void
+acpi_cros_tbmc_read_status(struct acpi_cros_tbmc_softc *sc)
+{
+	int32_t val = 0;
+
+	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
+
+	if (ACPI_FAILURE(acpi_GetInteger(sc->handle, "TBMC", &val))) {
+		device_printf(sc->dev, "ACPI failure\n");
+		return;
+	}
+
+	evdev_push_sw(sc->evdev, SW_TABLET_MODE, val);
+	evdev_sync(sc->evdev);
+}
+
+static void
+acpi_cros_tbmc_notify(ACPI_HANDLE h, UINT32 notify, void *context)
+{
+	device_t	dev = context;
+	struct acpi_cros_tbmc_softc *sc = device_get_softc(dev);
+
+	ACPI_FUNCTION_TRACE_U32((char *)(uintptr_t)__func__, notify);
+
+	if (notify != 0x80)
+		device_printf(dev, "Unknown notify\n");
+
+	acpi_cros_tbmc_read_status(sc);
+}
+
+static int
+acpi_cros_tbmc_resume(device_t dev)
+{
+	struct acpi_cros_tbmc_softc *sc = device_get_softc(dev);
+
+	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
+
+	acpi_cros_tbmc_read_status(sc);
+
+	return (0);
+}
+
+static char *cros_tbmc_ids[] = {"GOOG0006", NULL};
+
+static int
+acpi_cros_tbmc_probe(device_t dev)
+{
+	int rv;
+
+	if (acpi_disabled("cros_tbmc") ||
+	    device_get_unit(dev) != 0)
+		return (ENXIO);
+
+	rv = ACPI_ID_PROBE(device_get_parent(dev), dev, cros_tbmc_ids, NULL);
+
+	if (rv <= 0)
+		device_set_desc(dev, "Google Tablet Motion Control");
+
+	return (rv);
+}
+
+static int
+acpi_cros_tbmc_attach(device_t dev)
+{
+	struct acpi_cros_tbmc_softc	*sc;
+
+	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
+
+	sc = device_get_softc(dev);
+	sc->dev = dev;
+	sc->handle = acpi_get_handle(dev);
+
+	sc->evdev = evdev_alloc();
+	evdev_set_name(sc->evdev, device_get_desc(dev));
+	evdev_set_phys(sc->evdev, device_get_nameunit(dev));
+	evdev_set_id(sc->evdev, BUS_HOST, 0, 0, 1);
+	evdev_support_event(sc->evdev, EV_SYN);
+	evdev_support_event(sc->evdev, EV_SW);
+	evdev_support_sw(sc->evdev, SW_TABLET_MODE);
+
+	if (evdev_register(sc->evdev))
+		return (ENXIO);
+
+	AcpiInstallNotifyHandler(sc->handle, ACPI_ALL_NOTIFY,
+	    acpi_cros_tbmc_notify, dev);
+
+	acpi_cros_tbmc_read_status(sc);
+
+	return (0);
+}
+
+static int
+acpi_cros_tbmc_detach(device_t dev)
+{
+	ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
+
+	struct acpi_cros_tbmc_softc *sc = device_get_softc(dev);
+
+	evdev_free(sc->evdev);
+	AcpiRemoveNotifyHandler(sc->handle, ACPI_ALL_NOTIFY, acpi_cros_tbmc_notify);
+
+	return (0);
+}
+
+static device_method_t acpi_cros_tbmc_methods[] = {
+	/* Device interface */
+	DEVMETHOD(device_probe, acpi_cros_tbmc_probe),
+	DEVMETHOD(device_attach, acpi_cros_tbmc_attach),
+	DEVMETHOD(device_detach, acpi_cros_tbmc_detach),
+	DEVMETHOD(device_resume, acpi_cros_tbmc_resume),
+
+	DEVMETHOD_END
+};
+
+static driver_t	acpi_cros_tbmc_driver = {
+	"acpi_cros_tbmc",
+	acpi_cros_tbmc_methods,
+	sizeof(struct acpi_cros_tbmc_softc),
+};
+
+static devclass_t acpi_cros_tbmc_devclass;
+
+DRIVER_MODULE(acpi_cros_tbmc, acpi, acpi_cros_tbmc_driver, acpi_cros_tbmc_devclass,
+	      0, 0);
+MODULE_DEPEND(acpi_cros_tbmc, acpi, 1, 1, 1);
+MODULE_DEPEND(acpi_cros_tbmc, evdev, 1, 1, 1);
Index: sys/modules/acpi/acpi_cros_tbmc/Makefile
===================================================================
--- /dev/null
+++ sys/modules/acpi/acpi_cros_tbmc/Makefile
@@ -0,0 +1,7 @@
+# $FreeBSD$
+
+.PATH:		${SRCTOP}/sys/dev/acpi_support
+KMOD=		acpi_cros_tbmc
+SRCS=		acpi_cros_tbmc.c opt_acpi.h device_if.h bus_if.h acpi_if.h
+
+.include <bsd.kmod.mk>