1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2 /*
3  * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
4  * Copyright (C) 2019-2020, Linaro Limited
5  *
6  * An SCMI agent device represent on communication path from a
7  * device driver to the remote SCMI server which driver sends
8  * messages to and receives response messages from.
9  */
10 #ifndef SCMI_AGENT_H
11 #define SCMI_AGENT_H
12 
13 #include <asm/types.h>
14 
15 struct udevice;
16 
17 /*
18  * struct scmi_msg - Context of a SCMI message sent and the response received
19  *
20  * @protocol_id:	SCMI protocol ID
21  * @message_id:		SCMI message ID for a defined protocol ID
22  * @in_msg:		Pointer to the message payload sent by the driver
23  * @in_msg_sz:		Byte size of the message payload sent
24  * @out_msg:		Pointer to buffer to store response message payload
25  * @out_msg_sz:		Byte size of the response buffer and response payload
26  */
27 struct scmi_msg {
28 	unsigned int protocol_id;
29 	unsigned int message_id;
30 	u8 *in_msg;
31 	size_t in_msg_sz;
32 	u8 *out_msg;
33 	size_t out_msg_sz;
34 };
35 
36 /* Helper macro to match a message on input/output array references */
37 #define SCMI_MSG_IN(_protocol, _message, _in_array, _out_array) \
38 	(struct scmi_msg){			\
39 		.protocol_id = (_protocol),	\
40 		.message_id = (_message),	\
41 		.in_msg = (uint8_t *)&(_in_array),	\
42 		.in_msg_sz = sizeof(_in_array),	\
43 		.out_msg = (uint8_t *)&(_out_array),	\
44 		.out_msg_sz = sizeof(_out_array),	\
45 	}
46 
47 /**
48  * scmi_send_and_process_msg() - send and process a SCMI message
49  *
50  * Send a message to a SCMI server through a target SCMI agent device.
51  * Caller sets scmi_msg::out_msg_sz to the output message buffer size.
52  * On return, scmi_msg::out_msg_sz stores the response payload size.
53  *
54  * @dev:	SCMI agent device
55  * @msg:	Message structure reference
56  * @return 0 on success and a negative errno on failure
57  */
58 int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg);
59 
60 /**
61  * scmi_to_linux_errno() - Convert an SCMI error code into a Linux errno code
62  *
63  * @scmi_errno:	SCMI error code value
64  * @return 0 for successful status and a negative errno otherwise
65  */
66 int scmi_to_linux_errno(s32 scmi_errno);
67 
68 #endif /* SCMI_H */
69