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
27 enum 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 */
45 struct 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 */
62 struct 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 */
76 struct 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 */
92 struct 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
100 void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
101 int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
102 int scmi_do_xfer_with_response(const struct scmi_handle *h,
103 struct scmi_xfer *xfer);
104 int 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);
106 int scmi_handle_put(const struct scmi_handle *handle);
107 struct scmi_handle *scmi_handle_get(struct device *dev);
108 void scmi_set_handle(struct scmi_device *scmi_dev);
109 int scmi_version_get(const struct scmi_handle *h, u8 protocol, u32 *version);
110 void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
111 u8 *prot_imp);
112
113 int scmi_base_protocol_init(struct scmi_handle *h);