blob: 972c6addde21b7338cb4183b9fcaf257fe85d77d [file] [log] [blame]
// 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 <scmi_agent.h>
#include <scmi_agent-uclass.h>
#include <dm/devres.h>
#include <dm/device_compat.h>
#include <dm/device-internal.h>
#include <linux/arm-smccc.h>
#include <linux/compat.h>
#include "smt.h"
#define SMCCC_RET_NOT_SUPPORTED ((unsigned long)-1)
/**
* struct scmi_smccc_channel - Description of an SCMI SMCCC transport
* @func_id: SMCCC function ID used by the SCMI transport
* @smt: Shared memory buffer
*/
struct scmi_smccc_channel {
ulong func_id;
struct scmi_smt smt;
};
/**
* struct scmi_channel - Channel instance referenced in SCMI drivers
* @ref: Reference to local channel instance
**/
struct scmi_channel {
struct scmi_smccc_channel ref;
};
static int scmi_smccc_process_msg(struct udevice *dev,
struct scmi_channel *channel,
struct scmi_msg *msg)
{
struct scmi_smccc_channel *chan = &channel->ref;
struct arm_smccc_res res;
int ret;
ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
if (ret)
return ret;
arm_smccc_smc(chan->func_id, 0, 0, 0, 0, 0, 0, 0, &res);
if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
ret = -ENXIO;
else
ret = scmi_read_resp_from_smt(dev, &chan->smt, msg);
scmi_clear_smt_channel(&chan->smt);
return ret;
}
static int setup_channel(struct udevice *dev, struct scmi_smccc_channel *chan)
{
u32 func_id;
int ret;
if (dev_read_u32(dev, "arm,smc-id", &func_id)) {
dev_err(dev, "Missing property func-id\n");
return -EINVAL;
}
chan->func_id = func_id;
ret = scmi_dt_get_smt_buffer(dev, &chan->smt);
if (ret)
dev_err(dev, "Failed to get smt resources: %d\n", ret);
return ret;
}
static int scmi_smccc_get_channel(struct udevice *dev,
struct udevice *protocol,
struct scmi_channel **channel)
{
struct scmi_smccc_channel *base_chan = dev_get_plat(dev);
struct scmi_smccc_channel *chan;
u32 func_id;
int ret;
if (dev_read_u32(protocol, "arm,smc-id", &func_id)) {
/* Uses agent base channel */
*channel = container_of(base_chan, struct scmi_channel, ref);
return 0;
}
/* Setup a dedicated channel */
chan = calloc(1, sizeof(*chan));
if (!chan)
return -ENOMEM;
ret = setup_channel(protocol, chan);
if (ret) {
free(chan);
return ret;
}
*channel = container_of(chan, struct scmi_channel, ref);
return 0;
}
static int scmi_smccc_of_to_plat(struct udevice *dev)
{
struct scmi_smccc_channel *chan = dev_get_plat(dev);
return setup_channel(dev, chan);
}
static const struct udevice_id scmi_smccc_ids[] = {
{ .compatible = "arm,scmi-smc" },
{ }
};
static const struct scmi_agent_ops scmi_smccc_ops = {
.of_get_channel = scmi_smccc_get_channel,
.process_msg = scmi_smccc_process_msg,
};
U_BOOT_DRIVER(scmi_smccc) = {
.name = "scmi-over-smccc",
.id = UCLASS_SCMI_AGENT,
.of_match = scmi_smccc_ids,
.plat_auto = sizeof(struct scmi_smccc_channel),
.of_to_plat = scmi_smccc_of_to_plat,
.ops = &scmi_smccc_ops,
};