u-boot/drivers/firmware/scmi/smt.h
Etienne Carriere 240720e905 firmware: scmi: mailbox/smt agent device
This change implements a mailbox transport using SMT format for SCMI
exchanges. This implementation follows the Linux kernel and
SCP-firmware [1] as references implementation for SCMI message
processing using SMT format for communication channel meta-data.

Use of mailboxes in SCMI FDT bindings are defined in the Linux kernel
DT bindings since v4.17.

Links: [1] https://github.com/ARM-software/SCP-firmware
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2020-09-30 11:55:23 -04:00

86 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
* Copyright (C) 2019-2020 Linaro Limited.
*/
#ifndef SCMI_SMT_H
#define SCMI_SMT_H
#include <asm/types.h>
/**
* struct scmi_smt_header - Description of the shared memory message buffer
*
* SMT stands for Shared Memory based Transport.
* SMT uses 28 byte header prior message payload to handle the state of
* the communication channel realized by the shared memory area and
* to define SCMI protocol information the payload relates to.
*/
struct scmi_smt_header {
__le32 reserved;
__le32 channel_status;
#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR BIT(1)
#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE BIT(0)
__le32 reserved1[2];
__le32 flags;
#define SCMI_SHMEM_FLAG_INTR_ENABLED BIT(0)
__le32 length;
__le32 msg_header;
u8 msg_payload[0];
};
#define SMT_HEADER_TOKEN(token) (((token) << 18) & GENMASK(31, 18))
#define SMT_HEADER_PROTOCOL_ID(proto) (((proto) << 10) & GENMASK(17, 10))
#define SMT_HEADER_MESSAGE_TYPE(type) (((type) << 18) & GENMASK(9, 8))
#define SMT_HEADER_MESSAGE_ID(id) ((id) & GENMASK(7, 0))
/**
* struct scmi_smt - Description of a SMT memory buffer
* @buf: Shared memory base address
* @size: Shared memory byte size
*/
struct scmi_smt {
u8 *buf;
size_t size;
};
static inline bool scmi_smt_channel_is_free(struct scmi_smt *smt)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
}
static inline bool scmi_smt_channel_reports_error(struct scmi_smt *smt)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
return hdr->channel_status & SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
}
static inline void scmi_smt_get_channel(struct scmi_smt *smt)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
}
static inline void scmi_smt_put_channel(struct scmi_smt *smt)
{
struct scmi_smt_header *hdr = (void *)smt->buf;
hdr->channel_status |= SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE;
hdr->channel_status &= ~SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR;
}
int scmi_dt_get_smt_buffer(struct udevice *dev, struct scmi_smt *smt);
int scmi_write_msg_to_smt(struct udevice *dev, struct scmi_smt *smt,
struct scmi_msg *msg);
int scmi_read_resp_from_smt(struct udevice *dev, struct scmi_smt *smt,
struct scmi_msg *msg);
void scmi_clear_smt_channel(struct scmi_smt *smt);
#endif /* SCMI_SMT_H */