1 files changed, 40 insertions, 0 deletions
diff --git a/src/mainboard/lowrisc/nexys4ddr/uart.c b/src/mainboard/lowrisc/nexys4ddr/uart.c
new file mode 100644
index 0000000000..e3c233f80b
--- /dev/null
+++ b/src/mainboard/lowrisc/nexys4ddr/uart.c
@@ -0,0 +1,40 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2016 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <types.h>
+#include <console/uart.h>
+#include <arch/io.h>
+#include <boot/coreboot_tables.h>
+#include <spike_util.h>
+
+uintptr_t uart_platform_base(int idx)
+{
+	return (uintptr_t) 0x42000000;
+}
+
+/* these are currently not quite right but they are here for reference
+ * and will be fixed when lowrisc gives us a standard clock
+ * and set of values. */
+// divisor = clk_freq / (16 * Baud)
+unsigned int uart_input_clock_divider(void)
+{
+	return (25 * 1000 * 1000u / (16u * 115200u)) % 0x100;
+}
+
+// System clock 25 MHz, 115200 baud rate
+unsigned int uart_platform_refclk(void)
+{
+	return (25 * 1000 * 1000u / (16u * 115200u)) >> 8;
+}