iio: vcnl4000: warn on incorrectly specified device id

We can detect incorrectly specified device id for some chips, so warn
user in that case.
Signed-off-by: Tomas Novotny <tomas@novotny.cz>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/vcnl4000.c

@@ -84,8 +84,20 @@ static int vcnl4000_init(struct vcnl4000_data *data)
 		return ret;
 
 	prod_id = ret >> 4;
-	if (prod_id != VCNL4010_PROD_ID && prod_id != VCNL4000_PROD_ID)
+	switch (prod_id) {
+	case VCNL4000_PROD_ID:
+		if (data->id != VCNL4000)
+			dev_warn(&data->client->dev,
+					"wrong device id, use vcnl4000");
+		break;
+	case VCNL4010_PROD_ID:
+		if (data->id != VCNL4010)
+			dev_warn(&data->client->dev,
+					"wrong device id, use vcnl4010/4020");
+		break;
+	default:
 		return -ENODEV;
+	}
 
 	data->rev = ret & 0xf;
 	data->al_scale = 250000;