HID: hid-sony.c: Use devm_ api to simplify sony_register_touchpad()

HID: hid-sony.c: Use devm_ api to simplify sony_register_touchpad()

Using devm_ calls, the resources of the Sony game devices's features are
tied to the main device handle, making it easier to handle errors and
teardown inside the device driver. Altogether, this reduces complexity
of the driver source.
Signed-off-by: Hanno Zulla <kontakt@hanno.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-sony.c

@@ -1353,7 +1353,7 @@ static int sony_register_touchpad(struct sony_sc *sc, int touch_count,
 	char *name;
 	int ret;
 
-	sc->touchpad = input_allocate_device();
+	sc->touchpad = devm_input_allocate_device(&sc->hdev->dev);
 	if (!sc->touchpad)
 		return -ENOMEM;
 
@@ -1370,11 +1370,9 @@ static int sony_register_touchpad(struct sony_sc *sc, int touch_count,
 	 * DS4 compatible non-Sony devices with different names.
 	 */
 	name_sz = strlen(sc->hdev->name) + sizeof(DS4_TOUCHPAD_SUFFIX);
-	name = kzalloc(name_sz, GFP_KERNEL);
-	if (!name) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	name = devm_kzalloc(&sc->hdev->dev, name_sz, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
 	snprintf(name, name_sz, "%s" DS4_TOUCHPAD_SUFFIX, sc->hdev->name);
 	sc->touchpad->name = name;
 
@@ -1403,34 +1401,13 @@ static int sony_register_touchpad(struct sony_sc *sc, int touch_count,
 
 	ret = input_mt_init_slots(sc->touchpad, touch_count, INPUT_MT_POINTER);
 	if (ret < 0)
-		goto err;
+		return ret;
 
 	ret = input_register_device(sc->touchpad);
 	if (ret < 0)
-		goto err;
+		return ret;
 
 	return 0;
-
-err:
-	kfree(sc->touchpad->name);
-	sc->touchpad->name = NULL;
-
-	input_free_device(sc->touchpad);
-	sc->touchpad = NULL;
-
-	return ret;
-}
-
-static void sony_unregister_touchpad(struct sony_sc *sc)
-{
-	if (!sc->touchpad)
-		return;
-
-	kfree(sc->touchpad->name);
-	sc->touchpad->name = NULL;
-
-	input_unregister_device(sc->touchpad);
-	sc->touchpad = NULL;
 }
 
 static int sony_register_sensors(struct sony_sc *sc)
@@ -2883,8 +2860,6 @@ static int sony_input_configured(struct hid_device *hdev,
 		sony_leds_remove(sc);
 	if (sc->quirks & SONY_BATTERY_SUPPORT)
 		sony_battery_remove(sc);
-	if (sc->touchpad)
-		sony_unregister_touchpad(sc);
 	if (sc->sensor_dev)
 		sony_unregister_sensors(sc);
 	sony_cancel_work_sync(sc);
@@ -2971,9 +2946,6 @@ static void sony_remove(struct hid_device *hdev)
 	if (sc->quirks & SONY_BATTERY_SUPPORT)
 		sony_battery_remove(sc);
 
-	if (sc->touchpad)
-		sony_unregister_touchpad(sc);
-
 	if (sc->sensor_dev)
 		sony_unregister_sensors(sc);