u-boot/include/mailbox.h

4  * SPDX-License-Identifier: GPL-2.0
11  * A mailbox is a hardware mechanism for transferring small fixed-size messages
12  * and/or notifications between the CPU on which U-Boot runs and some other
17  * FIFOs, rather than via RAM-based buffers. The mailbox API generally
19  * leaves any higher-level protocols to other layers.
21  * A mailbox channel is a bi-directional mechanism that can send a message or
29  * it manages often has this capability. mailbox-uclass.h describes the
39  * struct mbox_chan - A handle to a single mailbox channel.
68  * mbox_get_by_index - Get/request a mailbox by integer index
74  * device-tree properties, board-provided mapping tables, or some other
86  * mbox_get_by_name - Get/request a mailbox by name
92  * device-tree properties, board-provided mapping tables, or some other
105  * mbox_free - Free a previously requested mailbox channel.
114  * mbox_send - Send a message over a mailbox channel
130  * mbox_recv - Receive any available message from a mailbox channel
134  * into a caller-provided buffer.
143  *		micro-seconds. A value of 0 does not wait at all.
144  * @return 0 if OK, -ENODATA if no message was available, or a negative error