u-boot/drivers/firmware/scmi/mailbox_agent.c
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

102 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020 Linaro Limited.
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <mailbox.h>
#include <scmi_agent.h>
#include <scmi_agent-uclass.h>
#include <dm/devres.h>
#include <linux/compat.h>
#include "smt.h"
#define TIMEOUT_US_10MS 10000
/**
* struct scmi_mbox_channel - Description of an SCMI mailbox transport
* @smt: Shared memory buffer
* @mbox: Mailbox channel description
* @timeout_us: Timeout in microseconds for the mailbox transfer
*/
struct scmi_mbox_channel {
struct scmi_smt smt;
struct mbox_chan mbox;
ulong timeout_us;
};
static int scmi_mbox_process_msg(struct udevice *dev, struct scmi_msg *msg)
{
struct scmi_mbox_channel *chan = dev_get_priv(dev);
int ret;
ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
if (ret)
return ret;
/* Give shm addr to mbox in case it is meaningful */
ret = mbox_send(&chan->mbox, chan->smt.buf);
if (ret) {
dev_err(dev, "Message send failed: %d\n", ret);
goto out;
}
/* Receive the response */
ret = mbox_recv(&chan->mbox, chan->smt.buf, chan->timeout_us);
if (ret) {
dev_err(dev, "Response failed: %d, abort\n", ret);
goto out;
}
ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
out:
scmi_clear_smt_channel(&chan->smt);
return ret;
}
int scmi_mbox_probe(struct udevice *dev)
{
struct scmi_mbox_channel *chan = dev_get_priv(dev);
int ret;
chan->timeout_us = TIMEOUT_US_10MS;
ret = mbox_get_by_index(dev, 0, &chan->mbox);
if (ret) {
dev_err(dev, "Failed to find mailbox: %d\n", ret);
goto out;
}
ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
if (ret)
dev_err(dev, "Failed to get shm resources: %d\n", ret);
out:
if (ret)
devm_kfree(dev, chan);
return ret;
}
static const struct udevice_id scmi_mbox_ids[] = {
{ .compatible = "arm,scmi" },
{ }
};
static const struct scmi_agent_ops scmi_mbox_ops = {
.process_msg = scmi_mbox_process_msg,
};
U_BOOT_DRIVER(scmi_mbox) = {
.name = "scmi-over-mailbox",
.id = UCLASS_SCMI_AGENT,
.of_match = scmi_mbox_ids,
.priv_auto_alloc_size = sizeof(struct scmi_mbox_channel),
.probe = scmi_mbox_probe,
.ops = &scmi_mbox_ops,
};