1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * System Control and Management Interface (SCMI) Message Protocol
  4 * driver common header file containing some definitions, structures
  5 * and function prototypes used in all the different SCMI protocols.
  6 *
  7 * Copyright (C) 2018 ARM Ltd.
  8 */
  9
 10#include <linux/bitfield.h>
 11#include <linux/completion.h>
 12#include <linux/device.h>
 13#include <linux/errno.h>
 14#include <linux/kernel.h>
 15#include <linux/scmi_protocol.h>
 16#include <linux/types.h>
 17
 18#include <asm/unaligned.h>
 19
 20#define PROTOCOL_REV_MINOR_MASK	GENMASK(15, 0)
 21#define PROTOCOL_REV_MAJOR_MASK	GENMASK(31, 16)
 22#define PROTOCOL_REV_MAJOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MAJOR_MASK, (x)))
 23#define PROTOCOL_REV_MINOR(x)	(u16)(FIELD_GET(PROTOCOL_REV_MINOR_MASK, (x)))
 24#define MAX_PROTOCOLS_IMP	16
 25#define MAX_OPPS		16
 26
 27enum scmi_common_cmd {
 28	PROTOCOL_VERSION = 0x0,
 29	PROTOCOL_ATTRIBUTES = 0x1,
 30	PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
 31};
 32
 33/**
 34 * struct scmi_msg_resp_prot_version - Response for a message
 35 *
 36 * @major_version: Major version of the ABI that firmware supports
 37 * @minor_version: Minor version of the ABI that firmware supports
 38 *
 39 * In general, ABI version changes follow the rule that minor version increments
 40 * are backward compatible. Major revision changes in ABI may not be
 41 * backward compatible.
 42 *
 43 * Response to a generic message with message type SCMI_MSG_VERSION
 44 */
 45struct scmi_msg_resp_prot_version {
 46	__le16 minor_version;
 47	__le16 major_version;
 48};
 49
 50/**
 51 * struct scmi_msg_hdr - Message(Tx/Rx) header
 52 *
 53 * @id: The identifier of the message being sent
 54 * @protocol_id: The identifier of the protocol used to send @id message
 55 * @seq: The token to identify the message. When a message returns, the
 56 *	platform returns the whole message header unmodified including the
 57 *	token
 58 * @status: Status of the transfer once it's complete
 59 * @poll_completion: Indicate if the transfer needs to be polled for
 60 *	completion or interrupt mode is used
 61 */
 62struct scmi_msg_hdr {
 63	u8 id;
 64	u8 protocol_id;
 65	u16 seq;
 66	u32 status;
 67	bool poll_completion;
 68};
 69
 70/**
 71 * struct scmi_msg - Message(Tx/Rx) structure
 72 *
 73 * @buf: Buffer pointer
 74 * @len: Length of data in the Buffer
 75 */
 76struct scmi_msg {
 77	void *buf;
 78	size_t len;
 79};
 80
 81/**
 82 * struct scmi_xfer - Structure representing a message flow
 83 *
 84 * @hdr: Transmit message header
 85 * @tx: Transmit message
 86 * @rx: Receive message, the buffer should be pre-allocated to store
 87 *	message. If request-ACK protocol is used, we can reuse the same
 88 *	buffer for the rx path as we use for the tx path.
 89 * @done: command message transmit completion event
 90 * @async: pointer to delayed response message received event completion
 91 */
 92struct scmi_xfer {
 93	struct scmi_msg_hdr hdr;
 94	struct scmi_msg tx;
 95	struct scmi_msg rx;
 96	struct completion done;
 97	struct completion *async_done;
 98};
 99
100void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
101int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
102int scmi_do_xfer_with_response(const struct scmi_handle *h,
103			       struct scmi_xfer *xfer);
104int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
105		       size_t tx_size, size_t rx_size, struct scmi_xfer **p);
106int scmi_handle_put(const struct scmi_handle *handle);
107struct scmi_handle *scmi_handle_get(struct device *dev);
108void scmi_set_handle(struct scmi_device *scmi_dev);
109int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
110void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
111				     u8 *prot_imp);
112
113int scmi_base_protocol_init(struct scmi_handle *h);