1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
4 * Copyright (C) 2019-2022 Linaro Limited.
5 */
6 #ifndef SCMI_SMT_H
7 #define SCMI_SMT_H
8
9 #include <asm/types.h>
10
11 /**
12 * struct scmi_smt_header - Description of the shared memory message buffer
13 *
14 * SMT stands for Shared Memory based Transport.
15 * SMT uses 28 byte header prior message payload to handle the state of
16 * the communication channel realized by the shared memory area and
17 * to define SCMI protocol information the payload relates to.
18 */
19 struct scmi_smt_header {
20 __le32 reserved;
21 __le32 channel_status;
22 #define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1)
23 #define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0)
24 __le32 reserved1[2];
25 __le32 flags;
26 #define SCMI_SHMEM_FLAG_INTR_ENABLED BIT(0)
27 __le32 length;
28 __le32 msg_header;
29 u8 msg_payload[0];
30 };
31
32 /**
33 * struct scmi_msg_header - Description of a MSG shared memory message buffer
34 *
35 * MSG communication protocol uses a 32bit header memory cell to store SCMI
36 * protocol data followed by the exchange SCMI message payload.
37 */
38 struct scmi_smt_msg_header {
39 __le32 msg_header;
40 u8 msg_payload[0];
41 };
42
43 #define SMT_HEADER_TOKEN(token) (((token) << 18) & GENMASK(31, 18))
44 #define SMT_HEADER_PROTOCOL_ID(proto) (((proto) << 10) & GENMASK(17, 10))
45 #define SMT_HEADER_MESSAGE_TYPE(type) (((type) << 18) & GENMASK(9, 8))
46 #define SMT_HEADER_MESSAGE_ID(id) ((id) & GENMASK(7, 0))
47
48 /**
49 * struct scmi_smt - Description of a SMT memory buffer
50 * @buf: Shared memory base address
51 * @size: Shared memory byte size
52 */
53 struct scmi_smt {
54 u8 *buf;
55 size_t size;
56 };
57
scmi_smt_channel_is_free(struct scmi_smt * smt)58 static inline bool scmi_smt_channel_is_free(struct scmi_smt *smt)
59 {
60 struct scmi_smt_header *hdr = (void *)smt->buf;
61
62 return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
63 }
64
scmi_smt_channel_reports_error(struct scmi_smt * smt)65 static inline bool scmi_smt_channel_reports_error(struct scmi_smt *smt)
66 {
67 struct scmi_smt_header *hdr = (void *)smt->buf;
68
69 return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
70 }
71
scmi_smt_get_channel(struct scmi_smt * smt)72 static inline void scmi_smt_get_channel(struct scmi_smt *smt)
73 {
74 struct scmi_smt_header *hdr = (void *)smt->buf;
75
76 hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
77 }
78
scmi_smt_put_channel(struct scmi_smt * smt)79 static inline void scmi_smt_put_channel(struct scmi_smt *smt)
80 {
81 struct scmi_smt_header *hdr = (void *)smt->buf;
82
83 hdr->channel_status |= SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
84 hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
85 }
86
87 int scmi_dt_get_smt_buffer(struct udevice *dev, struct scmi_smt *smt);
88
89 /*
90 * Write SCMI message to a SMT shared memory
91 * @dev: SCMI device
92 * @smt: Reference to shared memory using SMT header
93 * @msg: Input SCMI message transmitted
94 */
95 int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
96 struct scmi_msg *msg);
97
98 /*
99 * Read SCMI message from a SMT shared memory
100 * @dev: SCMI device
101 * @smt: Reference to shared memory using SMT header
102 * @msg: Output SCMI message received
103 */
104 int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
105 struct scmi_msg *msg);
106
107 void scmi_clear_smt_channel(struct scmi_smt *smt);
108
109 /*
110 * Write SCMI message to SMT_MSG shared memory
111 * @dev: SCMI device
112 * @smt: Reference to shared memory using SMT_MSG header
113 * @msg: Input SCMI message transmitted
114 * @buf_size: Size of the full SMT_MSG buffer transmitted
115 */
116 int scmi_msg_to_smt_msg(struct udevice *dev, struct scmi_smt *smt,
117 struct scmi_msg *msg, size_t *buf_size);
118
119 /*
120 * Read SCMI message from SMT_MSG shared memory
121 * @dev: SCMI device
122 * @smt: Reference to shared memory using SMT_MSG header
123 * @msg: Output SCMI message received
124 * @buf_size: Size of the full SMT_MSG buffer received
125 */
126 int scmi_msg_from_smt_msg(struct udevice *dev, struct scmi_smt *smt,
127 struct scmi_msg *msg, size_t buf_size);
128
129 #endif /* SCMI_SMT_H */
130