driver: misc: Add MU and S400 API to communicate with Sentinel

Add MU driver and S400 API. Need enable MISC driver to work

Signed-off-by: Ye Li <ye.li@nxp.com>
diff --git a/drivers/misc/imx8ulp/s400_api.c b/drivers/misc/imx8ulp/s400_api.c
new file mode 100644
index 0000000..82fd311
--- /dev/null
+++ b/drivers/misc/imx8ulp/s400_api.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 NXP
+ *
+ */
+
+#include <common.h>
+#include <hang.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <asm/arch/s400_api.h>
+#include <misc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int ahab_release_rdc(u8 core_id)
+{
+	struct udevice *dev = gd->arch.s400_dev;
+	int size = sizeof(struct imx8ulp_s400_msg);
+	struct imx8ulp_s400_msg msg;
+	int ret;
+
+	if (!dev) {
+		printf("s400 dev is not initialized\n");
+		return -ENODEV;
+	}
+
+	msg.version = AHAB_VERSION;
+	msg.tag = AHAB_CMD_TAG;
+	msg.size = 2;
+	msg.command = AHAB_RELEASE_RDC_REQ_CID;
+	msg.data[0] = core_id;
+
+	ret = misc_call(dev, false, &msg, size, &msg, size);
+	if (ret)
+		printf("Error: %s: ret %d, core id %u, response 0x%x\n",
+		       __func__, ret, core_id, msg.data[0]);
+
+	return ret;
+}