u-boot/drivers/firmware/scmi/mailbox_agent.c
AKASHI Takahiro 689204be97 firmware: scmi: use a protocol's own channel if assigned
SCMI specification allows any protocol to have its own channel for
the transport. While the current SCMI driver may assign its channel
from a device tree, the core function, devm_scmi_process_msg(), doesn't
use a protocol's channel, but always use an agent's channel.

With this commit, devm_scmi_process_msg() tries to find and use
a protocol's channel. If it doesn't exist, use an agent's.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2023-10-13 16:59:23 -04:00

151 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2020 Linaro Limited.
*/
#define LOG_CATEGORY UCLASS_SCMI_AGENT
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <mailbox.h>
#include <scmi_agent.h>
#include <scmi_agent-uclass.h>
#include <dm/device_compat.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;
};
/**
* struct scmi_channel - Channel instance referenced in SCMI drivers
* @ref: Reference to local channel instance
**/
struct scmi_channel {
struct scmi_mbox_channel ref;
};
static int scmi_mbox_process_msg(struct udevice *dev,
struct scmi_channel *channel,
struct scmi_msg *msg)
{
struct scmi_mbox_channel *chan = &channel->ref;
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;
}
static int setup_channel(struct udevice *dev, struct scmi_mbox_channel *chan)
{
int ret;
ret = mbox_get_by_index(dev, 0, &chan->mbox);
if (ret) {
dev_err(dev, "Failed to find mailbox: %d\n", ret);
return ret;
}
ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
if (ret) {
dev_err(dev, "Failed to get shm resources: %d\n", ret);
return ret;
}
chan->timeout_us = TIMEOUT_US_10MS;
return 0;
}
static int scmi_mbox_get_channel(struct udevice *dev,
struct udevice *protocol,
struct scmi_channel **channel)
{
struct scmi_mbox_channel *base_chan = dev_get_plat(dev);
struct scmi_mbox_channel *chan;
int ret;
if (!dev_read_prop(protocol, "shmem", NULL)) {
/* Uses agent base channel */
*channel = container_of(base_chan, struct scmi_channel, ref);
return 0;
}
chan = calloc(1, sizeof(*chan));
if (!chan)
return -ENOMEM;
/* Setup a dedicated channel for the protocol */
ret = setup_channel(protocol, chan);
if (ret) {
free(chan);
return ret;
}
*channel = (void *)chan;
return 0;
}
int scmi_mbox_of_to_plat(struct udevice *dev)
{
struct scmi_mbox_channel *chan = dev_get_plat(dev);
return setup_channel(dev, chan);
}
static const struct udevice_id scmi_mbox_ids[] = {
{ .compatible = "arm,scmi" },
{ }
};
static const struct scmi_agent_ops scmi_mbox_ops = {
.of_get_channel = scmi_mbox_get_channel,
.process_msg = scmi_mbox_process_msg,
};
U_BOOT_DRIVER(scmi_mbox) = {
.name = "scmi-over-mailbox",
.id = UCLASS_SCMI_AGENT,
.of_match = scmi_mbox_ids,
.plat_auto = sizeof(struct scmi_mbox_channel),
.of_to_plat = scmi_mbox_of_to_plat,
.ops = &scmi_mbox_ops,
};