1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/media/dvb-frontends/cxd2880/cxd2880_common.c b/drivers/media/dvb-frontends/cxd2880/cxd2880_common.c
new file mode 100644
index 000000000..d6f5af660
--- /dev/null
+++ b/drivers/media/dvb-frontends/cxd2880/cxd2880_common.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * cxd2880_common.c
+ * Sony CXD2880 DVB-T2/T tuner + demodulator driver
+ * common functions
+ *
+ * Copyright (C) 2016, 2017, 2018 Sony Semiconductor Solutions Corporation
+ */
+
+#include "cxd2880_common.h"
+
+int cxd2880_convert2s_complement(u32 value, u32 bitlen)
+{
+	if (!bitlen || bitlen >= 32)
+		return (int)value;
+
+	if (value & (u32)(1 << (bitlen - 1)))
+		return (int)(GENMASK(31, bitlen) | value);
+	else
+		return (int)(GENMASK(bitlen - 1, 0) & value);
+}