diff --git a/sys/dev/acpi_support/acpi_hp.c b/sys/dev/acpi_support/acpi_hp.c
index b0e85be..edc04b7 100644
--- a/sys/dev/acpi_support/acpi_hp.c
+++ b/sys/dev/acpi_support/acpi_hp.c
@@ -116,7 +116,6 @@ struct acpi_hp_inst_seq_pair {
 
 struct acpi_hp_softc {
 	device_t	dev;
-	ACPI_HANDLE	handle;
 	device_t	wmi_dev;
 	int		has_notify;		/* notification GUID found */
 	int		has_cmi;		/* CMI GUID found */
@@ -289,6 +288,7 @@ static struct {
 
 ACPI_SERIAL_DECL(hp, "HP ACPI-WMI Mapping");
 
+static void	acpi_hp_identify(driver_t *driver, device_t parent);
 static int	acpi_hp_probe(device_t dev);
 static int	acpi_hp_attach(device_t dev);
 static int	acpi_hp_detach(device_t dev);
@@ -320,6 +320,7 @@ static struct cdevsw hpcmi_cdevsw = {
 };
 
 static device_method_t acpi_hp_methods[] = {
+	DEVMETHOD(device_identify, acpi_hp_identify),
 	DEVMETHOD(device_probe, acpi_hp_probe),
 	DEVMETHOD(device_attach, acpi_hp_attach),
 	DEVMETHOD(device_detach, acpi_hp_detach),
@@ -334,7 +335,7 @@ static driver_t	acpi_hp_driver = {
 
 static devclass_t acpi_hp_devclass;
 
-DRIVER_MODULE(acpi_hp, acpi, acpi_hp_driver, acpi_hp_devclass,
+DRIVER_MODULE(acpi_hp, acpi_wmi, acpi_hp_driver, acpi_hp_devclass,
 		0, 0);
 MODULE_DEPEND(acpi_hp, acpi_wmi, 1, 1, 1);
 MODULE_DEPEND(acpi_hp, acpi, 1, 1, 1);
@@ -405,7 +406,7 @@ acpi_hp_evaluate_auto_on_off(struct acpi_hp_softc *sc)
 			    	    "WLAN on air changed to %i "
 			    	    "(new_wlan_status is %i)\n",
 			    	    sc->was_wlan_on_air, new_wlan_status);
-			acpi_UserNotify("HP", sc->handle,
+			acpi_UserNotify("HP", ACPI_ROOT_OBJECT,
 			    0xc0+sc->was_wlan_on_air);
 		}
 	}
@@ -420,7 +421,7 @@ acpi_hp_evaluate_auto_on_off(struct acpi_hp_softc *sc)
 				    " to %i (new_bluetooth_status is %i)\n",
 				    sc->was_bluetooth_on_air,
 				    new_bluetooth_status);
-			acpi_UserNotify("HP", sc->handle,
+			acpi_UserNotify("HP", ACPI_ROOT_OBJECT,
 			    0xd0+sc->was_bluetooth_on_air);
 		}
 	}
@@ -433,19 +434,33 @@ acpi_hp_evaluate_auto_on_off(struct acpi_hp_softc *sc)
 				    "WWAN on air changed to %i"
 			    	    " (new_wwan_status is %i)\n",
 				    sc->was_wwan_on_air, new_wwan_status);
-			acpi_UserNotify("HP", sc->handle,
+			acpi_UserNotify("HP", ACPI_ROOT_OBJECT,
 			    0xe0+sc->was_wwan_on_air);
 		}
 	}
 }
 
+static void
+acpi_hp_identify(driver_t *driver, device_t parent)
+{
+
+	/* Don't do anything if driver is disabled. */
+	if (acpi_disabled("hp"))
+		return;
+
+	/* Add only a single device instance. */
+	if (device_find_child(parent, "acpi_hp", -1) != NULL)
+		return;
+
+	if (BUS_ADD_CHILD(parent, 0, "acpi_hp", -1) == NULL)
+		device_printf(parent, "add acpi_hp child failed\n");
+}
+
 static int
 acpi_hp_probe(device_t dev)
 {
-	if (acpi_disabled("hp") || device_get_unit(dev) != 0)
-		return (ENXIO);
-	device_set_desc(dev, "HP ACPI-WMI Mapping");
 
+	device_set_desc(dev, "HP ACPI-WMI Mapping");
 	return (0);
 }
 
@@ -453,14 +468,12 @@ static int
 acpi_hp_attach(device_t dev)
 {
 	struct acpi_hp_softc	*sc;
-	devclass_t		wmi_devclass;
 	int			arg;
 
 	ACPI_FUNCTION_TRACE((char *)(uintptr_t) __func__);
 
 	sc = device_get_softc(dev);
 	sc->dev = dev;
-	sc->handle = acpi_get_handle(dev);
 	sc->has_notify = 0;
 	sc->has_cmi = 0;
 	sc->bluetooth_enable_if_radio_on = 0;
@@ -477,14 +490,7 @@ acpi_hp_attach(device_t dev)
 	sc->verbose = 0;
 	memset(sc->cmi_order, 0, sizeof(sc->cmi_order));
 
-	if (!(wmi_devclass = devclass_find ("acpi_wmi"))) {
-		device_printf(dev, "Couldn't find acpi_wmi devclass\n");
-		return (EINVAL);
-	}
-	if (!(sc->wmi_dev = devclass_get_device(wmi_devclass, 0))) {
-		device_printf(dev, "Couldn't find acpi_wmi device\n");
-		return (EINVAL);
-	}
+	sc->wmi_dev = device_get_parent(dev);
 	if (!ACPI_WMI_PROVIDES_GUID_STRING(sc->wmi_dev,
 	    ACPI_HP_WMI_BIOS_GUID)) {
 		device_printf(dev,
diff --git a/sys/dev/acpi_support/acpi_wmi.c b/sys/dev/acpi_support/acpi_wmi.c
index 14d8d69..04e74ba 100644
--- a/sys/dev/acpi_support/acpi_wmi.c
+++ b/sys/dev/acpi_support/acpi_wmi.c
@@ -280,6 +280,11 @@ acpi_wmi_attach(device_t dev)
 	}
 	ACPI_SERIAL_END(acpi_wmi);
 
+	if (ret == 0) {
+		bus_generic_probe(dev);
+		ret = bus_generic_attach(dev);
+	}
+
 	return (ret);
 }