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 <scmi_protocols.h> 14 #include <asm/types.h> 15 16 struct udevice; 17 struct scmi_channel; 18 19 /** 20 * struct scmi_agent_proto_priv - Private data in device for SCMI agent 21 * @channel: Reference to the SCMI channel to use 22 */ 23 struct scmi_agent_proto_priv { 24 struct scmi_channel *channel; 25 }; 26 27 /* 28 * struct scmi_msg - Context of a SCMI message sent and the response received 29 * 30 * @protocol_id: SCMI protocol ID 31 * @message_id: SCMI message ID for a defined protocol ID 32 * @in_msg: Pointer to the message payload sent by the driver 33 * @in_msg_sz: Byte size of the message payload sent 34 * @out_msg: Pointer to buffer to store response message payload 35 * @out_msg_sz: Byte size of the response buffer and response payload 36 */ 37 struct scmi_msg { 38 unsigned int protocol_id; 39 unsigned int message_id; 40 u8 *in_msg; 41 size_t in_msg_sz; 42 u8 *out_msg; 43 size_t out_msg_sz; 44 }; 45 46 /* Helper macro to match a message on input/output array references */ 47 #define SCMI_MSG_IN(_protocol, _message, _in_array, _out_array) \ 48 (struct scmi_msg){ \ 49 .protocol_id = (_protocol), \ 50 .message_id = (_message), \ 51 .in_msg = (uint8_t *)&(_in_array), \ 52 .in_msg_sz = sizeof(_in_array), \ 53 .out_msg = (uint8_t *)&(_out_array), \ 54 .out_msg_sz = sizeof(_out_array), \ 55 } 56 57 /** 58 * devm_scmi_of_get_channel() - Get SCMI channel handle from SCMI agent DT node 59 * 60 * @dev: Device requesting a channel 61 * @return 0 on success and a negative errno on failure 62 */ 63 int devm_scmi_of_get_channel(struct udevice *dev); 64 65 /** 66 * devm_scmi_process_msg() - Send and process an SCMI message 67 * 68 * Send a message to an SCMI server through a target SCMI agent device. 69 * Caller sets scmi_msg::out_msg_sz to the output message buffer size. 70 * On return, scmi_msg::out_msg_sz stores the response payload size. 71 * 72 * @dev: SCMI device 73 * @msg: Message structure reference 74 * Return: 0 on success and a negative errno on failure 75 */ 76 int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg); 77 78 /** 79 * scmi_get_protocol() - get protocol instance 80 * 81 * @dev: SCMI agent device 82 * @id: SCMI protocol ID 83 * 84 * Obtain the device instance for given protocol ID, @id. 85 * 86 * Return: Pointer to the device if found, null otherwise 87 */ 88 struct udevice *scmi_get_protocol(struct udevice *dev, 89 enum scmi_std_protocol id); 90 91 /** 92 * scmi_to_linux_errno() - Convert an SCMI error code into a Linux errno code 93 * 94 * @scmi_errno: SCMI error code value 95 * Return: 0 for successful status and a negative errno otherwise 96 */ 97 int scmi_to_linux_errno(s32 scmi_errno); 98 99 #endif /* SCMI_H */ 100