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 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 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 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 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