1 /* 2 * Copyright (c) 2022, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #ifndef MHU_H 8 #define MHU_H 9 10 #include <stddef.h> 11 #include <stdint.h> 12 13 /** 14 * Generic MHU error enumeration types. 15 */ 16 enum mhu_error_t { 17 MHU_ERR_NONE = 0, 18 MHU_ERR_NOT_INIT = -1, 19 MHU_ERR_ALREADY_INIT = -2, 20 MHU_ERR_UNSUPPORTED_VERSION = -3, 21 MHU_ERR_UNSUPPORTED = -4, 22 MHU_ERR_INVALID_ARG = -5, 23 MHU_ERR_BUFFER_TOO_SMALL = -6, 24 MHU_ERR_GENERAL = -7, 25 }; 26 27 /** 28 * Initializes sender MHU. 29 * 30 * mhu_sender_base Base address of sender MHU. 31 * 32 * Returns mhu_error_t error code. 33 * 34 * This function must be called before mhu_send_data(). 35 */ 36 enum mhu_error_t mhu_init_sender(uintptr_t mhu_sender_base); 37 38 39 /** 40 * Initializes receiver MHU. 41 * 42 * mhu_receiver_base Base address of receiver MHU. 43 * 44 * Returns mhu_error_t error code. 45 * 46 * This function must be called before mhu_receive_data(). 47 */ 48 enum mhu_error_t mhu_init_receiver(uintptr_t mhu_receiver_base); 49 50 /** 51 * Sends data over MHU. 52 * 53 * send_buffer Pointer to buffer containing the data to be transmitted. 54 * size Size of the data to be transmitted in bytes. 55 * 56 * Returns mhu_error_t error code. 57 * 58 * The send_buffer must be 4-byte aligned and its length must be at least 59 * (4 - (size % 4)) bytes bigger than the data size to prevent buffer 60 * over-reading. 61 */ 62 enum mhu_error_t mhu_send_data(const uint8_t *send_buffer, size_t size); 63 64 /** 65 * Receives data from MHU. 66 * 67 * receive_buffer Pointer the buffer where to store the received data. 68 * size As input the size of the receive_buffer, as output the 69 * number of bytes received. As a limitation, 70 * the size of the buffer must be a multiple of 4. 71 * 72 * Returns mhu_error_t error code. 73 * 74 * The receive_buffer must be 4-byte aligned and its length must be a 75 * multiple of 4. 76 */ 77 enum mhu_error_t mhu_receive_data(uint8_t *receive_buffer, size_t *size); 78 79 /** 80 * Gets the maximum amount of bytes that can be transmitted in a single send by MHU. 81 * 82 * Returns The amount of bytes that can be sent or received in a single message. 83 */ 84 size_t mhu_get_max_message_size(void); 85 86 #endif /* MHU_H */ 87
