amd/pi/hudson: Add GPIO get function

Add a basic GPIO get function.

Note that GPIO set, ACPI/GPE, and other features should come
in future commits. Future changes to be modeled on the other soc/
gpio functions.

Change-Id: I8f681865715ab947b525320a6f9fc63af1334b59
Signed-off-by: Marc Jones <marcj303@gmail.com>
Reviewed-on: https://review.coreboot.org/19159
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/southbridge/amd/pi/hudson/gpio.c b/src/southbridge/amd/pi/hudson/gpio.c
new file mode 100644
index 0000000000..5b2eb4c161
--- /dev/null
+++ b/src/southbridge/amd/pi/hudson/gpio.c
@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2015 Google Inc.
+ * Copyright (C) 2015 Intel Corporation
+ * Copyright (C) 2017 Advanced Micro Devices, 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 <arch/io.h>
+#include "gpio.h"
+
+int gpio_get(gpio_t gpio_num)
+{
+	uint32_t reg;
+
+	reg = read32((void*)(uintptr_t)gpio_num);
+
+	return !!(reg & GPIO_PIN_STS);
+}