1 files changed, 42 insertions, 0 deletions
diff --git a/driver/retimer/tdp142.c b/driver/retimer/tdp142.c
new file mode 100644
index 0000000000..e1632150d0
--- /dev/null
+++ b/driver/retimer/tdp142.c
@@ -0,0 +1,42 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Texas Instruments TDP142 DisplayPort Linear Redriver
+ */
+
+#include "common.h"
+#include "ec_commands.h"
+#include "i2c.h"
+#include "tdp142.h"
+
+static enum ec_error_list tdp142_write(int offset, int data)
+{
+	return i2c_write8(TDP142_I2C_PORT,
+			  TDP142_I2C_ADDR,
+			  offset, data);
+
+}
+
+static enum ec_error_list tdp142_read(int offset, int *regval)
+{
+	return i2c_read8(TDP142_I2C_PORT,
+			 TDP142_I2C_ADDR,
+			 offset, regval);
+
+}
+
+enum ec_error_list tdp142_set_ctlsel(enum tdp142_ctlsel selection)
+{
+	int regval;
+	enum ec_error_list rv;
+
+	rv = tdp142_read(TDP142_REG_GENERAL, &regval);
+	if (rv)
+		return rv;
+
+	regval &= ~TDP142_GENERAL_CTLSEL;
+	regval |= selection;
+
+	return tdp142_write(TDP142_REG_GENERAL, regval);
+}