firmware: scmi: implement SCMI base protocol

SCMI base protocol is mandatory according to the SCMI specification.

With this patch, SCMI base protocol can be accessed via SCMI transport
layers. All the commands, except SCMI_BASE_NOTIFY_ERRORS, are supported.
This is because U-Boot doesn't support interrupts and the current transport
layers are not able to handle asynchronous messages properly.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>

2 files changed, 657 insertions, 0 deletions

diff --git a/drivers/firmware/scmi/Makefile b/drivers/firmware/scmi/Makefile
index b2ff483..1a23d49 100644
--- a/drivers/firmware/scmi/Makefile
+++ b/drivers/firmware/scmi/Makefile
@@ -1,4 +1,5 @@
 obj-y	+= scmi_agent-uclass.o
+obj-y	+= base.o
 obj-y	+= smt.o
 obj-$(CONFIG_SCMI_AGENT_SMCCC)		+= smccc_agent.o
 obj-$(CONFIG_SCMI_AGENT_MAILBOX)	+= mailbox_agent.o
diff --git a/drivers/firmware/scmi/base.c b/drivers/firmware/scmi/base.c
new file mode 100644
index 0000000..ee84e26
--- /dev/null
+++ b/drivers/firmware/scmi/base.c
@@ -0,0 +1,656 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * SCMI Base protocol as U-Boot device
+ *
+ * Copyright (C) 2023 Linaro Limited
+ *		author: AKASHI Takahiro <takahiro.akashi@linaro.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <scmi_agent.h>
+#include <scmi_protocols.h>
+#include <stdlib.h>
+#include <string.h>
+#include <asm/types.h>
+#include <dm/device_compat.h>
+#include <linux/kernel.h>
+
+/**
+ * scmi_generic_protocol_version - get protocol version
+ * @dev:	SCMI device
+ * @id:		SCMI protocol ID
+ * @version:	Pointer to SCMI protocol version
+ *
+ * Obtain the protocol version number in @version.
+ *
+ * Return: 0 on success, error code on failure
+ */
+int scmi_generic_protocol_version(struct udevice *dev,
+				  enum scmi_std_protocol id, u32 *version)
+{
+	struct scmi_protocol_version_out out;
+	struct scmi_msg msg = {
+		.protocol_id = id,
+		.message_id = SCMI_PROTOCOL_VERSION,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*version = out.version;
+
+	return 0;
+}
+
+/**
+ * scmi_base_protocol_version_int - get Base protocol version
+ * @dev:	SCMI device
+ * @version:	Pointer to SCMI protocol version
+ *
+ * Obtain the protocol version number in @version for Base protocol.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_protocol_version_int(struct udevice *dev, u32 *version)
+{
+	return scmi_generic_protocol_version(dev, SCMI_PROTOCOL_ID_BASE,
+					     version);
+}
+
+/**
+ * scmi_protocol_attrs_int - get protocol attributes
+ * @dev:		SCMI device
+ * @num_agents:		Number of SCMI agents
+ * @num_protocols:	Number of SCMI protocols
+ *
+ * Obtain the protocol attributes, the number of agents and the number
+ * of protocols, in @num_agents and @num_protocols respectively, that
+ * the device provides.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_protocol_attrs_int(struct udevice *dev, u32 *num_agents,
+				   u32 *num_protocols)
+{
+	struct scmi_protocol_attrs_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_PROTOCOL_ATTRIBUTES,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*num_agents = SCMI_PROTOCOL_ATTRS_NUM_AGENTS(out.attributes);
+	*num_protocols = SCMI_PROTOCOL_ATTRS_NUM_PROTOCOLS(out.attributes);
+
+	return 0;
+}
+
+/**
+ * scmi_protocol_message_attrs_int - get message-specific attributes
+ * @dev:		SCMI device
+ * @message_id:		SCMI message ID
+ * @attributes:		Message-specific attributes
+ *
+ * Obtain the message-specific attributes in @attributes.
+ * This command succeeds if the message is implemented and available.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_protocol_message_attrs_int(struct udevice *dev, u32 message_id,
+					   u32 *attributes)
+{
+	struct scmi_protocol_msg_attrs_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_PROTOCOL_MESSAGE_ATTRIBUTES,
+		.in_msg = (u8 *)&message_id,
+		.in_msg_sz = sizeof(message_id),
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*attributes = out.attributes;
+
+	return 0;
+}
+
+/**
+ * scmi_base_discover_vendor_int - get vendor name
+ * @dev:	SCMI device
+ * @vendor:	Pointer to vendor name
+ *
+ * Obtain the vendor's name in @vendor.
+ * It is a caller's responsibility to free @vendor.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_discover_vendor_int(struct udevice *dev, u8 **vendor)
+{
+	struct scmi_base_discover_vendor_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_DISCOVER_VENDOR,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	if (!vendor)
+		return -EINVAL;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*vendor = strdup(out.vendor_identifier);
+	if (!*vendor)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * scmi_base_discover_sub_vendor_int - get sub-vendor name
+ * @dev:	SCMI device
+ * @sub_vendor:	Pointer to sub-vendor name
+ *
+ * Obtain the sub-vendor's name in @sub_vendor.
+ * It is a caller's responsibility to free @sub_vendor.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_discover_sub_vendor_int(struct udevice *dev,
+					     u8 **sub_vendor)
+{
+	struct scmi_base_discover_vendor_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_DISCOVER_SUB_VENDOR,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	if (!sub_vendor)
+		return -EINVAL;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*sub_vendor = strdup(out.vendor_identifier);
+	if (!*sub_vendor)
+		return -ENOMEM;
+
+	return 0;
+}
+
+/**
+ * scmi_base_discover_impl_version_int - get implementation version
+ * @dev:		SCMI device
+ * @impl_version:	Pointer to implementation version
+ *
+ * Obtain the implementation version number in @impl_version.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_discover_impl_version_int(struct udevice *dev,
+					       u32 *impl_version)
+{
+	struct scmi_base_discover_impl_version_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_DISCOVER_IMPL_VERSION,
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	*impl_version = out.impl_version;
+
+	return 0;
+}
+
+/**
+ * scmi_base_discover_list_protocols_int - get list of protocols
+ * @dev:	SCMI device
+ * @protocols:	Pointer to array of SCMI protocols
+ *
+ * Obtain the list of protocols provided in @protocols.
+ * The number of elements in @protocols always match to the number of
+ * protocols returned by smci_protocol_attrs() when this function succeeds.
+ * It is a caller's responsibility to free @protocols.
+ *
+ * Return: the number of protocols in @protocols on success, error code on
+ * failure
+ */
+static int scmi_base_discover_list_protocols_int(struct udevice *dev,
+						 u8 **protocols)
+{
+	struct scmi_base_discover_list_protocols_out out;
+	int cur;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_DISCOVER_LIST_PROTOCOLS,
+		.in_msg = (u8 *)&cur,
+		.in_msg_sz = sizeof(cur),
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	u32 num_agents, num_protocols;
+	u8 *buf;
+	int i, ret;
+
+	ret = scmi_base_protocol_attrs(dev, &num_agents, &num_protocols);
+	if (ret)
+		return ret;
+
+	buf = calloc(sizeof(u8), num_protocols);
+	if (!buf)
+		return -ENOMEM;
+
+	cur = 0;
+	do {
+		ret = devm_scmi_process_msg(dev, &msg);
+		if (ret)
+			goto err;
+		if (out.status) {
+			ret = scmi_to_linux_errno(out.status);
+			goto err;
+		}
+
+		for (i = 0; i < out.num_protocols; i++, cur++)
+			buf[cur] = out.protocols[i / 4] >> ((i % 4) * 8);
+	} while (cur < num_protocols);
+
+	*protocols = buf;
+
+	return num_protocols;
+err:
+	free(buf);
+
+	return ret;
+}
+
+/**
+ * scmi_base_discover_agent_int - identify agent
+ * @dev:		SCMI device
+ * @agent_id:		SCMI agent ID
+ * @ret_agent_id:	Pointer to SCMI agent ID
+ * @name:		Pointer to SCMI agent name
+ *
+ * Obtain the agent's name in @name. If @agent_id is equal to 0xffffffff,
+ * this function returns the caller's agent id in @ret_agent_id.
+ * It is a caller's responsibility to free @name.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_discover_agent_int(struct udevice *dev, u32 agent_id,
+					u32 *ret_agent_id, u8 **name)
+{
+	struct scmi_base_discover_agent_out out;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_DISCOVER_AGENT,
+		.in_msg = (u8 *)&agent_id,
+		.in_msg_sz = sizeof(agent_id),
+		.out_msg = (u8 *)&out,
+		.out_msg_sz = sizeof(out),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (out.status)
+		return scmi_to_linux_errno(out.status);
+
+	if (ret_agent_id)
+		*ret_agent_id = out.agent_id;
+	if (name) {
+		*name = strdup(out.name);
+		if (!*name)
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/**
+ * scmi_base_set_device_permissions_int - configure access permission to device
+ * @dev:	SCMI device
+ * @agent_id:	SCMI agent ID
+ * @device_id:	ID of device to access
+ * @flags:	A set of flags
+ *
+ * Ask for allowing or denying access permission to the device, @device_id.
+ * The meaning of @flags is defined in SCMI specification.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_set_device_permissions_int(struct udevice *dev, u32 agent_id,
+						u32 device_id, u32 flags)
+{
+	struct scmi_base_set_device_permissions_in in = {
+		.agent_id = agent_id,
+		.device_id = device_id,
+		.flags = flags,
+	};
+	s32 status;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_SET_DEVICE_PERMISSIONS,
+		.in_msg = (u8 *)&in,
+		.in_msg_sz = sizeof(in),
+		.out_msg = (u8 *)&status,
+		.out_msg_sz = sizeof(status),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (status)
+		return scmi_to_linux_errno(status);
+
+	return 0;
+}
+
+/**
+ * scmi_base_set_protocol_permissions_int - configure access permission to
+ *					    protocol on device
+ * @dev:	SCMI device
+ * @agent_id:	SCMI agent ID
+ * @device_id:	ID of device to access
+ * @command_id:	SCMI command ID
+ * @flags:	A set of flags
+ *
+ * Ask for allowing or denying access permission to the protocol, @command_id,
+ * on the device, @device_id.
+ * The meaning of @flags is defined in SCMI specification.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_set_protocol_permissions_int(struct udevice *dev,
+						  u32 agent_id, u32 device_id,
+						  u32 command_id, u32 flags)
+{
+	struct scmi_base_set_protocol_permissions_in in = {
+		.agent_id = agent_id,
+		.device_id = device_id,
+		.command_id = command_id,
+		.flags = flags,
+	};
+	s32 status;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_SET_PROTOCOL_PERMISSIONS,
+		.in_msg = (u8 *)&in,
+		.in_msg_sz = sizeof(in),
+		.out_msg = (u8 *)&status,
+		.out_msg_sz = sizeof(status),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (status)
+		return scmi_to_linux_errno(status);
+
+	return 0;
+}
+
+/**
+ * scmi_base_reset_agent_configuration_int - reset resource settings
+ * @dev:	SCMI device
+ * @agent_id:	SCMI agent ID
+ * @flags:	A set of flags
+ *
+ * Reset all the resource settings against @agent_id.
+ * The meaning of @flags is defined in SCMI specification.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_reset_agent_configuration_int(struct udevice *dev,
+						   u32 agent_id, u32 flags)
+{
+	struct scmi_base_reset_agent_configuration_in in = {
+		.agent_id = agent_id,
+		.flags = flags,
+	};
+	s32 status;
+	struct scmi_msg msg = {
+		.protocol_id = SCMI_PROTOCOL_ID_BASE,
+		.message_id = SCMI_BASE_RESET_AGENT_CONFIGURATION,
+		.in_msg = (u8 *)&in,
+		.in_msg_sz = sizeof(in),
+		.out_msg = (u8 *)&status,
+		.out_msg_sz = sizeof(status),
+	};
+	int ret;
+
+	ret = devm_scmi_process_msg(dev, &msg);
+	if (ret)
+		return ret;
+	if (status)
+		return scmi_to_linux_errno(status);
+
+	return 0;
+}
+
+/**
+ * scmi_base_probe - probe base protocol device
+ * @dev:	SCMI device
+ *
+ * Probe the device for SCMI base protocol and initialize the private data.
+ *
+ * Return: 0 on success, error code on failure
+ */
+static int scmi_base_probe(struct udevice *dev)
+{
+	int ret;
+
+	ret = devm_scmi_of_get_channel(dev);
+	if (ret) {
+		dev_err(dev, "get_channel failed\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static struct scmi_base_ops scmi_base_ops = {
+	/* Commands */
+	.protocol_version = scmi_base_protocol_version_int,
+	.protocol_attrs = scmi_protocol_attrs_int,
+	.protocol_message_attrs = scmi_protocol_message_attrs_int,
+	.base_discover_vendor = scmi_base_discover_vendor_int,
+	.base_discover_sub_vendor = scmi_base_discover_sub_vendor_int,
+	.base_discover_impl_version = scmi_base_discover_impl_version_int,
+	.base_discover_list_protocols = scmi_base_discover_list_protocols_int,
+	.base_discover_agent = scmi_base_discover_agent_int,
+	.base_notify_errors = NULL,
+	.base_set_device_permissions = scmi_base_set_device_permissions_int,
+	.base_set_protocol_permissions = scmi_base_set_protocol_permissions_int,
+	.base_reset_agent_configuration =
+			scmi_base_reset_agent_configuration_int,
+};
+
+int scmi_base_protocol_version(struct udevice *dev, u32 *version)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->protocol_version)
+		return (*ops->protocol_version)(dev, version);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_protocol_attrs(struct udevice *dev, u32 *num_agents,
+			     u32 *num_protocols)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->protocol_attrs)
+		return (*ops->protocol_attrs)(dev, num_agents, num_protocols);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_protocol_message_attrs(struct udevice *dev, u32 message_id,
+				     u32 *attributes)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->protocol_message_attrs)
+		return (*ops->protocol_message_attrs)(dev, message_id,
+						      attributes);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_discover_vendor(struct udevice *dev, u8 **vendor)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_discover_vendor)
+		return (*ops->base_discover_vendor)(dev, vendor);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_discover_sub_vendor(struct udevice *dev, u8 **sub_vendor)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_discover_sub_vendor)
+		return (*ops->base_discover_sub_vendor)(dev, sub_vendor);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_discover_impl_version(struct udevice *dev, u32 *impl_version)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_discover_impl_version)
+		return (*ops->base_discover_impl_version)(dev, impl_version);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_discover_list_protocols(struct udevice *dev, u8 **protocols)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_discover_list_protocols)
+		return (*ops->base_discover_list_protocols)(dev, protocols);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_discover_agent(struct udevice *dev, u32 agent_id,
+			     u32 *ret_agent_id, u8 **name)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_discover_agent)
+		return (*ops->base_discover_agent)(dev, agent_id, ret_agent_id,
+						   name);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_notify_errors(struct udevice *dev, u32 enable)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_notify_errors)
+		return (*ops->base_notify_errors)(dev, enable);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_set_device_permissions(struct udevice *dev, u32 agent_id,
+				     u32 device_id, u32 flags)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_set_device_permissions)
+		return (*ops->base_set_device_permissions)(dev, agent_id,
+							   device_id, flags);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_set_protocol_permissions(struct udevice *dev,
+				       u32 agent_id, u32 device_id,
+				       u32 command_id, u32 flags)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_set_protocol_permissions)
+		return (*ops->base_set_protocol_permissions)(dev, agent_id,
+							     device_id,
+							     command_id,
+							     flags);
+
+	return -EOPNOTSUPP;
+}
+
+int scmi_base_reset_agent_configuration(struct udevice *dev, u32 agent_id,
+					u32 flags)
+{
+	const struct scmi_base_ops *ops = device_get_ops(dev);
+
+	if (ops->base_reset_agent_configuration)
+		return (*ops->base_reset_agent_configuration)(dev, agent_id,
+							      flags);
+
+	return -EOPNOTSUPP;
+}
+
+U_BOOT_DRIVER(scmi_base_drv) = {
+	.id = UCLASS_SCMI_BASE,
+	.name = "scmi_base_drv",
+	.ops = &scmi_base_ops,
+	.probe = scmi_base_probe,
+};
+
+UCLASS_DRIVER(scmi_base) = {
+	.id		= UCLASS_SCMI_BASE,
+	.name		= "scmi_base",
+};