1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
4 * Copyright (C) 2019-2020 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 #define SMT_HEADER_TOKEN(token) (((token) << 18) & GENMASK(31, 18))
33 #define SMT_HEADER_PROTOCOL_ID(proto) (((proto) << 10) & GENMASK(17, 10))
34 #define SMT_HEADER_MESSAGE_TYPE(type) (((type) << 18) & GENMASK(9, 8))
35 #define SMT_HEADER_MESSAGE_ID(id) ((id) & GENMASK(7, 0))
36
37 /**
38 * struct scmi_smt - Description of a SMT memory buffer
39 * @buf: Shared memory base address
40 * @size: Shared memory byte size
41 */
42 struct scmi_smt {
43 u8 *buf;
44 size_t size;
45 };
46
scmi_smt_channel_is_free(struct scmi_smt * smt)47 static inline bool scmi_smt_channel_is_free(struct scmi_smt *smt)
48 {
49 struct scmi_smt_header *hdr = (void *)smt->buf;
50
51 return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
52 }
53
scmi_smt_channel_reports_error(struct scmi_smt * smt)54 static inline bool scmi_smt_channel_reports_error(struct scmi_smt *smt)
55 {
56 struct scmi_smt_header *hdr = (void *)smt->buf;
57
58 return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
59 }
60
scmi_smt_get_channel(struct scmi_smt * smt)61 static inline void scmi_smt_get_channel(struct scmi_smt *smt)
62 {
63 struct scmi_smt_header *hdr = (void *)smt->buf;
64
65 hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
66 }
67
scmi_smt_put_channel(struct scmi_smt * smt)68 static inline void scmi_smt_put_channel(struct scmi_smt *smt)
69 {
70 struct scmi_smt_header *hdr = (void *)smt->buf;
71
72 hdr->channel_status |= SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
73 hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
74 }
75
76 int scmi_dt_get_smt_buffer(struct udevice *dev, struct scmi_smt *smt);
77
78 int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
79 struct scmi_msg *msg);
80
81 int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
82 struct scmi_msg *msg);
83
84 void scmi_clear_smt_channel(struct scmi_smt *smt);
85
86 #endif /* SCMI_SMT_H */
87