drivers/firmware/scmi/scmi_agent-uclass.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 <scmi_agent-uclass.h>
#include <scmi_protocols.h>
#include <dm/device_compat.h>
#include <dm/device-internal.h>
#include <linux/compat.h>

/**
 * struct error_code - Helper structure for SCMI error code conversion
 * @scmi:	SCMI error code
 * @errno:	Related standard error number
 */
struct error_code {
	int scmi;
	int errno;
};

static const struct error_code scmi_linux_errmap[] = {
	{ .scmi = SCMI_NOT_SUPPORTED, .errno = -EOPNOTSUPP, },
	{ .scmi = SCMI_INVALID_PARAMETERS, .errno = -EINVAL, },
	{ .scmi = SCMI_DENIED, .errno = -EACCES, },
	{ .scmi = SCMI_NOT_FOUND, .errno = -ENOENT, },
	{ .scmi = SCMI_OUT_OF_RANGE, .errno = -ERANGE, },
	{ .scmi = SCMI_BUSY, .errno = -EBUSY, },
	{ .scmi = SCMI_COMMS_ERROR, .errno = -ECOMM, },
	{ .scmi = SCMI_GENERIC_ERROR, .errno = -EIO, },
	{ .scmi = SCMI_HARDWARE_ERROR, .errno = -EREMOTEIO, },
	{ .scmi = SCMI_PROTOCOL_ERROR, .errno = -EPROTO, },
};

int scmi_to_linux_errno(s32 scmi_code)
{
	int n;

	if (!scmi_code)
		return 0;

	for (n = 0; n < ARRAY_SIZE(scmi_linux_errmap); n++)
		if (scmi_code == scmi_linux_errmap[n].scmi)
			return scmi_linux_errmap[n].errno;

	return -EPROTO;
}

/*
 * SCMI agent devices binds devices of various uclasses depeding on
 * the FDT description. scmi_bind_protocol() is a generic bind sequence
 * called by the uclass at bind stage, that is uclass post_bind.
 */
static int scmi_bind_protocols(struct udevice *dev)
{
	int ret = 0;
	ofnode node;
	const char *name;

	dev_for_each_subnode(node, dev) {
		struct driver *drv = NULL;
		u32 protocol_id;

		if (!ofnode_is_enabled(node))
			continue;

		if (ofnode_read_u32(node, "reg", &protocol_id))
			continue;

		name = ofnode_get_name(node);
		switch (protocol_id) {
		case SCMI_PROTOCOL_ID_CLOCK:
			if (CONFIG_IS_ENABLED(CLK_SCMI))
				drv = DM_DRIVER_GET(scmi_clock);
			break;
		case SCMI_PROTOCOL_ID_RESET_DOMAIN:
			if (IS_ENABLED(CONFIG_RESET_SCMI))
				drv = DM_DRIVER_GET(scmi_reset_domain);
			break;
		case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
			if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI)) {
				node = ofnode_find_subnode(node, "regulators");
				if (!ofnode_valid(node)) {
					dev_err(dev, "no regulators node\n");
					return -ENXIO;
				}
				drv = DM_DRIVER_GET(scmi_voltage_domain);
			}
			break;
		default:
			break;
		}

		if (!drv) {
			dev_dbg(dev, "Ignore unsupported SCMI protocol %#x\n",
				protocol_id);
			continue;
		}

		ret = device_bind(dev, drv, name, NULL, node, NULL);
		if (ret)
			break;
	}

	return ret;
}

static struct udevice *find_scmi_transport_device(struct udevice *dev)
{
	struct udevice *parent = dev;

	do {
		parent = dev_get_parent(parent);
	} while (parent && device_get_uclass_id(parent) != UCLASS_SCMI_AGENT);

	if (!parent)
		dev_err(dev, "Invalid SCMI device, agent not found\n");

	return parent;
}

static const struct scmi_agent_ops *transport_dev_ops(struct udevice *dev)
{
	return (const struct scmi_agent_ops *)dev->driver->ops;
}

int devm_scmi_of_get_channel(struct udevice *dev, struct scmi_channel **channel)
{
	struct udevice *parent;

	parent = find_scmi_transport_device(dev);
	if (!parent)
		return -ENODEV;

	if (transport_dev_ops(parent)->of_get_channel)
		return transport_dev_ops(parent)->of_get_channel(parent, channel);

	/* Drivers without a get_channel operator don't need a channel ref */
	*channel = NULL;

	return 0;
}

int devm_scmi_process_msg(struct udevice *dev, struct scmi_channel *channel,
			  struct scmi_msg *msg)
{
	const struct scmi_agent_ops *ops;
	struct udevice *parent;

	parent = find_scmi_transport_device(dev);
	if (!parent)
		return -ENODEV;

	ops = transport_dev_ops(parent);

	if (ops->process_msg)
		return ops->process_msg(parent, channel, msg);

	return -EPROTONOSUPPORT;
}

UCLASS_DRIVER(scmi_agent) = {
	.id		= UCLASS_SCMI_AGENT,
	.name		= "scmi_agent",
	.post_bind	= scmi_bind_protocols,
};