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 */ 19struct 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 */ 38struct 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 */ 53struct scmi_smt { 54 u8 *buf; 55 size_t size; 56}; 57 58static 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 65static 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 72static 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 79static 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 87int 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 */ 95int 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 */ 104int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt, 105 struct scmi_msg *msg); 106 107void 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 */ 116int 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 */ 126int 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