Add BL31 support for Broadcom stingray platform

Change-Id: Icfef5b6923dc292e637001045a334c499d346fe9
Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
diff --git a/plat/brcm/board/stingray/src/ncsi.c b/plat/brcm/board/stingray/src/ncsi.c
new file mode 100644
index 0000000..58ea9e2
--- /dev/null
+++ b/plat/brcm/board/stingray/src/ncsi.c
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2019-2020, Broadcom
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdbool.h>
+
+#include <common/debug.h>
+#include <lib/mmio.h>
+
+#include <ncsi.h>
+#include <sr_def.h>
+#include <sr_utils.h>
+
+static const char *const io_drives[] = {
+	"2mA", "4mA", "6mA", "8mA",
+	"10mA", "12mA", "14mA", "16mA"
+};
+
+void brcm_stingray_ncsi_init(void)
+{
+	unsigned int i = 0;
+	unsigned int selx = 0;
+
+#if NCSI_IO_DRIVE_STRENGTH_MA == 2
+	selx = 0x0;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 4
+	selx = 0x1;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 6
+	selx = 0x2;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 8
+	selx = 0x3;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 10
+	selx = 0x4;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 12
+	selx = 0x5;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 14
+	selx = 0x6;
+#elif NCSI_IO_DRIVE_STRENGTH_MA == 16
+	selx = 0x7;
+#else
+	ERROR("Unsupported NCSI_IO_DRIVE_STRENGTH_MA. Please check it.\n");
+	return;
+#endif
+	INFO("ncsi io drives: %s\n", io_drives[selx]);
+
+	for (i = 0; i < NITRO_NCSI_IOPAD_CONTROL_NUM; i++) {
+		mmio_clrsetbits_32((NITRO_NCSI_IOPAD_CONTROL_BASE + (i * 4)),
+				   PAD_SELX_MASK, PAD_SELX_VALUE(selx));
+	}
+
+	INFO("ncsi init done\n");
+}