1 files changed, 86 insertions, 0 deletions
diff --git a/include/drivers/arm/mhu.h b/include/drivers/arm/mhu.h
new file mode 100644
index 0000000..31c6a81
--- /dev/null
+++ b/include/drivers/arm/mhu.h
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MHU_H
+#define MHU_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/**
+ * Generic MHU error enumeration types.
+ */
+enum mhu_error_t {
+	MHU_ERR_NONE			=  0,
+	MHU_ERR_NOT_INIT		= -1,
+	MHU_ERR_ALREADY_INIT		= -2,
+	MHU_ERR_UNSUPPORTED_VERSION	= -3,
+	MHU_ERR_UNSUPPORTED		= -4,
+	MHU_ERR_INVALID_ARG		= -5,
+	MHU_ERR_BUFFER_TOO_SMALL	= -6,
+	MHU_ERR_GENERAL			= -7,
+};
+
+/**
+ * Initializes sender MHU.
+ *
+ * mhu_sender_base	Base address of sender MHU.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * This function must be called before mhu_send_data().
+ */
+enum mhu_error_t mhu_init_sender(uintptr_t mhu_sender_base);
+
+
+/**
+ * Initializes receiver MHU.
+ *
+ * mhu_receiver_base	Base address of receiver MHU.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * This function must be called before mhu_receive_data().
+ */
+enum mhu_error_t mhu_init_receiver(uintptr_t mhu_receiver_base);
+
+/**
+ * Sends data over MHU.
+ *
+ * send_buffer		Pointer to buffer containing the data to be transmitted.
+ * size			Size of the data to be transmitted in bytes.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * The send_buffer must be 4-byte aligned and its length must be at least
+ * (4 - (size % 4)) bytes bigger than the data size to prevent buffer
+ * over-reading.
+ */
+enum mhu_error_t mhu_send_data(const uint8_t *send_buffer, size_t size);
+
+/**
+ * Receives data from MHU.
+ *
+ * receive_buffer	Pointer the buffer where to store the received data.
+ * size			As input the size of the receive_buffer, as output the
+ *			number of bytes received. As a limitation,
+ *			the size of the buffer must be a multiple of 4.
+ *
+ * Returns mhu_error_t error code.
+ *
+ * The receive_buffer must be 4-byte aligned and its length must be a
+ * multiple of 4.
+ */
+enum mhu_error_t mhu_receive_data(uint8_t *receive_buffer, size_t *size);
+
+/**
+ * Gets the maximum amount of bytes that can be transmitted in a single send by MHU.
+ *
+ * Returns The amount of bytes that can be sent or received in a single message.
+ */
+size_t mhu_get_max_message_size(void);
+
+#endif /* MHU_H */