drivers/firmware/scmi/scmi_agent-uclass.c - platform/external/u-boot - Gitiles

 // 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 <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, },
 };

 /**
  * scmi_protocol_is_supported - check availability of protocol
  * @dev:	SCMI agent device
  * @proto_id:	Identifier of protocol
  *
  * check if the protocol, @proto_id, is provided by the SCMI agent,
  * @dev.
  *
  * Return:	0 on success, error code otherwise
  */
 static bool scmi_protocol_is_supported(struct udevice *dev,
 				       enum scmi_std_protocol proto_id)
 {
 	struct scmi_agent_priv *priv;
 	int i;

 	if (proto_id == SCMI_PROTOCOL_ID_BASE)
 		return true;

 	priv = dev_get_uclass_plat(dev);
 	if (!priv) {
 		dev_err(dev, "No priv data found\n");
 		return false;
 	}

 	for (i = 0; i < priv->num_protocols; i++)
 		if (priv->protocols[i] == proto_id)
 			return true;

 	return false;
 }

 struct udevice *scmi_get_protocol(struct udevice *dev,
 				  enum scmi_std_protocol id)
 {
 	struct scmi_agent_priv *priv;
 	struct udevice *proto;

 	priv = dev_get_uclass_plat(dev);
 	if (!priv) {
 		dev_err(dev, "No priv data found\n");
 		return NULL;
 	}

 	switch (id) {
 	case SCMI_PROTOCOL_ID_BASE:
 		proto = priv->base_dev;
 		break;
 	case SCMI_PROTOCOL_ID_CLOCK:
 		proto = priv->clock_dev;
 		break;
 	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
 		proto = priv->resetdom_dev;
 		break;
 	case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
 		proto = priv->voltagedom_dev;
 		break;
 	default:
 		dev_err(dev, "Protocol not supported\n");
 		proto = NULL;
 		break;
 	}
 	if (proto && device_probe(proto))
 		dev_err(dev, "Probe failed\n");

 	return proto;
 }

 /**
  * scmi_add_protocol - add protocol to agent
  * @dev:	SCMI agent device
  * @proto_id:	SCMI protocol ID
  * @proto:	SCMI protocol device
  *
  * Associate the protocol instance, @proto, to the agent, @dev,
  * for later use.
  *
  * Return:	0 on success, error code on failure
  */
 static int scmi_add_protocol(struct udevice *dev,
 			     enum scmi_std_protocol proto_id,
 			     struct udevice *proto)
 {
 	struct scmi_agent_priv *priv;

 	priv = dev_get_uclass_plat(dev);
 	if (!priv) {
 		dev_err(dev, "No priv data found\n");
 		return -ENODEV;
 	}

 	switch (proto_id) {
 	case SCMI_PROTOCOL_ID_BASE:
 		priv->base_dev = proto;
 		break;
 	case SCMI_PROTOCOL_ID_CLOCK:
 		priv->clock_dev = proto;
 		break;
 	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
 		priv->resetdom_dev = proto;
 		break;
 	case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
 		priv->voltagedom_dev = proto;
 		break;
 	default:
 		dev_err(dev, "Protocol not supported\n");
 		return -EPROTO;
 	}

 	return 0;
 }

 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;
 }

 static struct udevice *find_scmi_protocol_device(struct udevice *dev)
 {
 	struct udevice *parent = NULL, *protocol;

 	for (protocol = dev; protocol; protocol = parent) {
 		parent = dev_get_parent(protocol);
 		if (!parent ||
 		    device_get_uclass_id(parent) == UCLASS_SCMI_AGENT)
 			break;
 	}

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

 	return protocol;
 }

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

 /**
  * scmi_of_get_channel() - Get SCMI channel handle
  *
  * @dev:	SCMI agent device
  * @channel:	Output reference to the SCMI channel upon success
  *
  * On return, @channel will be set.
  * Return	0 on success and a negative errno on failure
  */
 static int scmi_of_get_channel(struct udevice *dev, struct udevice *protocol,
 			       struct scmi_channel **channel)
 {
 	const struct scmi_agent_ops *ops;

 	ops = transport_dev_ops(dev);
 	if (ops->of_get_channel)
 		return ops->of_get_channel(dev, protocol, channel);
 	else
 		return -EPROTONOSUPPORT;
 }

 int devm_scmi_of_get_channel(struct udevice *dev)
 {
 	struct udevice *protocol;
 	struct scmi_agent_proto_priv *priv;
 	int ret;

 	protocol = find_scmi_protocol_device(dev);
 	if (!protocol)
 		return -ENODEV;

 	priv = dev_get_parent_priv(protocol);
 	ret = scmi_of_get_channel(protocol->parent, protocol, &priv->channel);
 	if (ret == -EPROTONOSUPPORT) {
 		/* Drivers without a get_channel operator don't need a channel ref */
 		priv->channel = NULL;

 		return 0;
 	}

 	return ret;
 }

 /**
  * scmi_process_msg() - Send and process an SCMI message
  *
  * Send a message to an SCMI server.
  * Caller sets scmi_msg::out_msg_sz to the output message buffer size.
  *
  * @dev:	SCMI agent device
  * @channel:	Communication channel for the device
  * @msg:	Message structure reference
  *
  * On return, scmi_msg::out_msg_sz stores the response payload size.
  * Return:	0 on success and a negative errno on failure
  */
 static int scmi_process_msg(struct udevice *dev, struct scmi_channel *channel,
 			    struct scmi_msg *msg)
 {
 	const struct scmi_agent_ops *ops;

 	ops = transport_dev_ops(dev);
 	if (ops->process_msg)
 		return ops->process_msg(dev, channel, msg);
 	else
 		return -EPROTONOSUPPORT;
 }

 int devm_scmi_process_msg(struct udevice *dev, struct scmi_msg *msg)
 {
 	struct udevice *protocol;
 	struct scmi_agent_proto_priv *priv;

 	protocol = find_scmi_protocol_device(dev);
 	if (!protocol)
 		return -ENODEV;

 	priv = dev_get_parent_priv(protocol);

 	return scmi_process_msg(protocol->parent, priv->channel, msg);
 }

 /**
  * scmi_fill_base_info - get base information about SCMI server
  * @agent:	SCMI agent device
  * @dev:	SCMI protocol device
  *
  * By using Base protocol commands, collect the base information
  * about SCMI server.
  *
  * Return: 0 on success, error code on failure
  */
 static int scmi_fill_base_info(struct udevice *agent, struct udevice *dev)
 {
 	struct scmi_agent_priv *priv = dev_get_uclass_plat(agent);
 	int ret;

 	ret = scmi_base_protocol_version(dev, &priv->version);
 	if (ret) {
 		dev_err(dev, "protocol_version() failed (%d)\n", ret);
 		return ret;
 	}
 	/* check for required version */
 	if (priv->version < SCMI_BASE_PROTOCOL_VERSION) {
 		dev_err(dev, "base protocol version (%d) lower than expected\n",
 			priv->version);
 		return -EPROTO;
 	}

 	ret = scmi_base_protocol_attrs(dev, &priv->num_agents,
 				       &priv->num_protocols);
 	if (ret) {
 		dev_err(dev, "protocol_attrs() failed (%d)\n", ret);
 		return ret;
 	}
 	ret = scmi_base_discover_vendor(dev, &priv->vendor);
 	if (ret) {
 		dev_err(dev, "base_discover_vendor() failed (%d)\n", ret);
 		return ret;
 	}
 	ret = scmi_base_discover_sub_vendor(dev, &priv->sub_vendor);
 	if (ret) {
 		if (ret != -EOPNOTSUPP) {
 			dev_err(dev, "base_discover_sub_vendor() failed (%d)\n",
 				ret);
 			return ret;
 		}
 		priv->sub_vendor = "NA";
 	}
 	ret = scmi_base_discover_impl_version(dev, &priv->impl_version);
 	if (ret) {
 		dev_err(dev, "base_discover_impl_version() failed (%d)\n",
 			ret);
 		return ret;
 	}

 	ret = scmi_base_discover_agent(dev, 0xffffffff,
 				       &priv->agent_id, &priv->agent_name);
 	if (ret) {
 		if (ret != -EOPNOTSUPP) {
 			dev_err(dev,
 				"base_discover_agent() failed for myself (%d)\n",
 				ret);
 			return ret;
 		}
 		priv->agent_id = 0xffffffff;
 		priv->agent_name = "NA";
 	}

 	ret = scmi_base_discover_list_protocols(dev, &priv->protocols);
 	if (ret != priv->num_protocols) {
 		dev_err(dev, "base_discover_list_protocols() failed (%d)\n",
 			ret);
 		return -EPROTO;
 	}

 	return 0;
 }

 /*
  * SCMI agent devices binds devices of various uclasses depending 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;
 	struct driver *drv;
 	struct udevice *agent, *proto;

 	if (!uclass_get_device(UCLASS_SCMI_AGENT, 1, &agent)) {
 		/* This is a second SCMI agent */
 		dev_err(dev, "Cannot have more than one SCMI agent\n");
 		return -EEXIST;
 	}

 	/* initialize the device from device tree */
 	drv = DM_DRIVER_GET(scmi_base_drv);
 	name = "scmi-base.0";
 	ret = device_bind(dev, drv, name, NULL, ofnode_null(), &proto);
 	if (ret) {
 		dev_err(dev, "failed to bind base protocol\n");
 		return ret;
 	}
 	ret = scmi_add_protocol(dev, SCMI_PROTOCOL_ID_BASE, proto);
 	if (ret) {
 		dev_err(dev, "failed to add protocol: %s, ret: %d\n",
 			proto->name, ret);
 		return ret;
 	}

 	ret = device_probe(proto);
 	if (ret) {
 		dev_err(dev, "failed to probe base protocol\n");
 		return ret;
 	}

 	ret = scmi_fill_base_info(dev, proto);
 	if (ret) {
 		dev_err(dev, "failed to get base information\n");
 		return ret;
 	}

 	dev_for_each_subnode(node, dev) {
 		u32 protocol_id;

 		if (!ofnode_is_enabled(node))
 			continue;

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

 		drv = NULL;
 		name = ofnode_get_name(node);
 		switch (protocol_id) {
 		case SCMI_PROTOCOL_ID_CLOCK:
 			if (CONFIG_IS_ENABLED(CLK_SCMI) &&
 			    scmi_protocol_is_supported(dev, protocol_id))
 				drv = DM_DRIVER_GET(scmi_clock);
 			break;
 		case SCMI_PROTOCOL_ID_RESET_DOMAIN:
 			if (IS_ENABLED(CONFIG_RESET_SCMI) &&
 			    scmi_protocol_is_supported(dev, protocol_id))
 				drv = DM_DRIVER_GET(scmi_reset_domain);
 			break;
 		case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
 			if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI) &&
 			    scmi_protocol_is_supported(dev, protocol_id)) {
 				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, &proto);
 		if (ret) {
 			dev_err(dev, "failed to bind %s protocol\n", drv->name);
 			break;
 		}
 		ret = scmi_add_protocol(dev, protocol_id, proto);
 		if (ret) {
 			dev_err(dev, "failed to add protocol: %s, ret: %d\n",
 				proto->name, ret);
 			break;
 		}
 	}

 	return ret;
 }

 UCLASS_DRIVER(scmi_agent) = {
 	.id		= UCLASS_SCMI_AGENT,
 	.name		= "scmi_agent",
 	.post_bind	= scmi_bind_protocols,
 	.per_device_plat_auto = sizeof(struct scmi_agent_priv),
 	.per_child_auto	= sizeof(struct scmi_agent_proto_priv),
 };
	// 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 <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, },
	};

	/**
	* scmi_protocol_is_supported - check availability of protocol
	* @dev: SCMI agent device
	* @proto_id: Identifier of protocol
	*
	* check if the protocol, @proto_id, is provided by the SCMI agent,
	* @dev.
	*
	* Return: 0 on success, error code otherwise
	*/
	static bool scmi_protocol_is_supported(struct udevice *dev,
	enum scmi_std_protocol proto_id)
	{
	struct scmi_agent_priv *priv;
	int i;

	if (proto_id == SCMI_PROTOCOL_ID_BASE)
	return true;

	priv = dev_get_uclass_plat(dev);
	if (!priv) {
	dev_err(dev, "No priv data found\n");
	return false;
	}

	for (i = 0; i < priv->num_protocols; i++)
	if (priv->protocols[i] == proto_id)
	return true;

	return false;
	}

	struct udevice scmi_get_protocol(struct udevice dev,
	enum scmi_std_protocol id)
	{
	struct scmi_agent_priv *priv;
	struct udevice *proto;

	priv = dev_get_uclass_plat(dev);
	if (!priv) {
	dev_err(dev, "No priv data found\n");
	return NULL;
	}

	switch (id) {
	case SCMI_PROTOCOL_ID_BASE:
	proto = priv->base_dev;
	break;
	case SCMI_PROTOCOL_ID_CLOCK:
	proto = priv->clock_dev;
	break;
	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
	proto = priv->resetdom_dev;
	break;
	case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
	proto = priv->voltagedom_dev;
	break;
	default:
	dev_err(dev, "Protocol not supported\n");
	proto = NULL;
	break;
	}
	if (proto && device_probe(proto))
	dev_err(dev, "Probe failed\n");

	return proto;
	}

	/**
	* scmi_add_protocol - add protocol to agent
	* @dev: SCMI agent device
	* @proto_id: SCMI protocol ID
	* @proto: SCMI protocol device
	*
	* Associate the protocol instance, @proto, to the agent, @dev,
	* for later use.
	*
	* Return: 0 on success, error code on failure
	*/
	static int scmi_add_protocol(struct udevice *dev,
	enum scmi_std_protocol proto_id,
	struct udevice *proto)
	{
	struct scmi_agent_priv *priv;

	priv = dev_get_uclass_plat(dev);
	if (!priv) {
	dev_err(dev, "No priv data found\n");
	return -ENODEV;
	}

	switch (proto_id) {
	case SCMI_PROTOCOL_ID_BASE:
	priv->base_dev = proto;
	break;
	case SCMI_PROTOCOL_ID_CLOCK:
	priv->clock_dev = proto;
	break;
	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
	priv->resetdom_dev = proto;
	break;
	case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
	priv->voltagedom_dev = proto;
	break;
	default:
	dev_err(dev, "Protocol not supported\n");
	return -EPROTO;
	}

	return 0;
	}

	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;
	}

	static struct udevice find_scmi_protocol_device(struct udevice dev)
	{
	struct udevice parent = NULL, protocol;

	for (protocol = dev; protocol; protocol = parent) {
	parent = dev_get_parent(protocol);
	if (!parent \|\|
	device_get_uclass_id(parent) == UCLASS_SCMI_AGENT)
	break;
	}

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

	return protocol;
	}

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

	/**
	* scmi_of_get_channel() - Get SCMI channel handle
	*
	* @dev: SCMI agent device
	* @channel: Output reference to the SCMI channel upon success
	*
	* On return, @channel will be set.
	* Return 0 on success and a negative errno on failure
	*/
	static int scmi_of_get_channel(struct udevice dev, struct udevice protocol,
	struct scmi_channel **channel)
	{
	const struct scmi_agent_ops *ops;

	ops = transport_dev_ops(dev);
	if (ops->of_get_channel)
	return ops->of_get_channel(dev, protocol, channel);
	else
	return -EPROTONOSUPPORT;
	}

	int devm_scmi_of_get_channel(struct udevice *dev)
	{
	struct udevice *protocol;
	struct scmi_agent_proto_priv *priv;
	int ret;

	protocol = find_scmi_protocol_device(dev);
	if (!protocol)
	return -ENODEV;

	priv = dev_get_parent_priv(protocol);
	ret = scmi_of_get_channel(protocol->parent, protocol, &priv->channel);
	if (ret == -EPROTONOSUPPORT) {
	/* Drivers without a get_channel operator don't need a channel ref */
	priv->channel = NULL;

	return 0;
	}

	return ret;
	}

	/**
	* scmi_process_msg() - Send and process an SCMI message
	*
	* Send a message to an SCMI server.
	* Caller sets scmi_msg::out_msg_sz to the output message buffer size.
	*
	* @dev: SCMI agent device
	* @channel: Communication channel for the device
	* @msg: Message structure reference
	*
	* On return, scmi_msg::out_msg_sz stores the response payload size.
	* Return: 0 on success and a negative errno on failure
	*/
	static int scmi_process_msg(struct udevice dev, struct scmi_channel channel,
	struct scmi_msg *msg)
	{
	const struct scmi_agent_ops *ops;

	ops = transport_dev_ops(dev);
	if (ops->process_msg)
	return ops->process_msg(dev, channel, msg);
	else
	return -EPROTONOSUPPORT;
	}

	int devm_scmi_process_msg(struct udevice dev, struct scmi_msg msg)
	{
	struct udevice *protocol;
	struct scmi_agent_proto_priv *priv;

	protocol = find_scmi_protocol_device(dev);
	if (!protocol)
	return -ENODEV;

	priv = dev_get_parent_priv(protocol);

	return scmi_process_msg(protocol->parent, priv->channel, msg);
	}

	/**
	* scmi_fill_base_info - get base information about SCMI server
	* @agent: SCMI agent device
	* @dev: SCMI protocol device
	*
	* By using Base protocol commands, collect the base information
	* about SCMI server.
	*
	* Return: 0 on success, error code on failure
	*/
	static int scmi_fill_base_info(struct udevice agent, struct udevice dev)
	{
	struct scmi_agent_priv *priv = dev_get_uclass_plat(agent);
	int ret;

	ret = scmi_base_protocol_version(dev, &priv->version);
	if (ret) {
	dev_err(dev, "protocol_version() failed (%d)\n", ret);
	return ret;
	}
	/* check for required version */
	if (priv->version < SCMI_BASE_PROTOCOL_VERSION) {
	dev_err(dev, "base protocol version (%d) lower than expected\n",
	priv->version);
	return -EPROTO;
	}

	ret = scmi_base_protocol_attrs(dev, &priv->num_agents,
	&priv->num_protocols);
	if (ret) {
	dev_err(dev, "protocol_attrs() failed (%d)\n", ret);
	return ret;
	}
	ret = scmi_base_discover_vendor(dev, &priv->vendor);
	if (ret) {
	dev_err(dev, "base_discover_vendor() failed (%d)\n", ret);
	return ret;
	}
	ret = scmi_base_discover_sub_vendor(dev, &priv->sub_vendor);
	if (ret) {
	if (ret != -EOPNOTSUPP) {
	dev_err(dev, "base_discover_sub_vendor() failed (%d)\n",
	ret);
	return ret;
	}
	priv->sub_vendor = "NA";
	}
	ret = scmi_base_discover_impl_version(dev, &priv->impl_version);
	if (ret) {
	dev_err(dev, "base_discover_impl_version() failed (%d)\n",
	ret);
	return ret;
	}

	ret = scmi_base_discover_agent(dev, 0xffffffff,
	&priv->agent_id, &priv->agent_name);
	if (ret) {
	if (ret != -EOPNOTSUPP) {
	dev_err(dev,
	"base_discover_agent() failed for myself (%d)\n",
	ret);
	return ret;
	}
	priv->agent_id = 0xffffffff;
	priv->agent_name = "NA";
	}

	ret = scmi_base_discover_list_protocols(dev, &priv->protocols);
	if (ret != priv->num_protocols) {
	dev_err(dev, "base_discover_list_protocols() failed (%d)\n",
	ret);
	return -EPROTO;
	}

	return 0;
	}

	/*
	* SCMI agent devices binds devices of various uclasses depending 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;
	struct driver *drv;
	struct udevice agent, proto;

	if (!uclass_get_device(UCLASS_SCMI_AGENT, 1, &agent)) {
	/* This is a second SCMI agent */
	dev_err(dev, "Cannot have more than one SCMI agent\n");
	return -EEXIST;
	}

	/* initialize the device from device tree */
	drv = DM_DRIVER_GET(scmi_base_drv);
	name = "scmi-base.0";
	ret = device_bind(dev, drv, name, NULL, ofnode_null(), &proto);
	if (ret) {
	dev_err(dev, "failed to bind base protocol\n");
	return ret;
	}
	ret = scmi_add_protocol(dev, SCMI_PROTOCOL_ID_BASE, proto);
	if (ret) {
	dev_err(dev, "failed to add protocol: %s, ret: %d\n",
	proto->name, ret);
	return ret;
	}

	ret = device_probe(proto);
	if (ret) {
	dev_err(dev, "failed to probe base protocol\n");
	return ret;
	}

	ret = scmi_fill_base_info(dev, proto);
	if (ret) {
	dev_err(dev, "failed to get base information\n");
	return ret;
	}

	dev_for_each_subnode(node, dev) {
	u32 protocol_id;

	if (!ofnode_is_enabled(node))
	continue;

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

	drv = NULL;
	name = ofnode_get_name(node);
	switch (protocol_id) {
	case SCMI_PROTOCOL_ID_CLOCK:
	if (CONFIG_IS_ENABLED(CLK_SCMI) &&
	scmi_protocol_is_supported(dev, protocol_id))
	drv = DM_DRIVER_GET(scmi_clock);
	break;
	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
	if (IS_ENABLED(CONFIG_RESET_SCMI) &&
	scmi_protocol_is_supported(dev, protocol_id))
	drv = DM_DRIVER_GET(scmi_reset_domain);
	break;
	case SCMI_PROTOCOL_ID_VOLTAGE_DOMAIN:
	if (IS_ENABLED(CONFIG_DM_REGULATOR_SCMI) &&
	scmi_protocol_is_supported(dev, protocol_id)) {
	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, &proto);
	if (ret) {
	dev_err(dev, "failed to bind %s protocol\n", drv->name);
	break;
	}
	ret = scmi_add_protocol(dev, protocol_id, proto);
	if (ret) {
	dev_err(dev, "failed to add protocol: %s, ret: %d\n",
	proto->name, ret);
	break;
	}
	}

	return ret;
	}

	UCLASS_DRIVER(scmi_agent) = {
	.id = UCLASS_SCMI_AGENT,
	.name = "scmi_agent",
	.post_bind = scmi_bind_protocols,
	.per_device_plat_auto = sizeof(struct scmi_agent_priv),
	.per_child_auto = sizeof(struct scmi_agent_proto_priv),
	};