LXR uboot/drivers/firmware/scmi/smt.h

   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