SCMI

Interfaces for ARM System Control and Management Interface (SCMI). More...

Topics
	Protocols
	Standard SCMI Protocol definitions.
	Transport
	SCMI Transport Layer abstraction and definitions.
	Utilities
	Helper macros and utilities for SCMI drivers.

Files
file	protocol.h
	Header file for the SCMI (System Control and Management Interface) driver API.

Data Structures
struct	scmi_protocol
	SCMI protocol structure. More...
struct	scmi_protocol_version
	SCMI protocol version. More...
struct	scmi_message
	SCMI message structure. More...

Macros
#define	SCMI_SHORT_NAME_MAX_SIZE   16
	Maximum size of strings to describe SCMI names, including NUL terminator.
#define	SCMI_MESSAGE_HDR_MAKE(id, type, proto, token)
	Build an SCMI message header.

Enumerations
enum	scmi_message_type { SCMI_COMMAND = 0x0 , SCMI_DELAYED_REPLY = 0x2 , SCMI_NOTIFICATION = 0x3 }
	SCMI message type. More...
enum	scmi_status_code {   SCMI_SUCCESS = 0 , SCMI_NOT_SUPPORTED = -1 , SCMI_INVALID_PARAMETERS = -2 , SCMI_DENIED = -3 ,   SCMI_NOT_FOUND = -4 , SCMI_OUT_OF_RANGE = -5 , SCMI_BUSY = -6 , SCMI_COMMS_ERROR = -7 ,   SCMI_GENERIC_ERROR = -8 , SCMI_HARDWARE_ERROR = -9 , SCMI_PROTOCOL_ERROR = -10 , SCMI_IN_USE = -11 }
	SCMI status codes. More...

Functions
int	scmi_status_to_errno (int scmi_status)
	Convert an SCMI status code to its Linux equivalent (if possible).
int	scmi_send_message (struct scmi_protocol *proto, struct scmi_message *msg, struct scmi_message *reply, bool use_polling)
	Send an SCMI message and wait for its reply.
int	scmi_protocol_get_version (struct scmi_protocol *proto, uint32_t *version)
	Get protocol version.
int	scmi_protocol_attributes_get (struct scmi_protocol *proto, uint32_t *attributes)
	Get protocol attributes.
int	scmi_protocol_message_attributes_get (struct scmi_protocol *proto, uint32_t message_id, uint32_t *attributes)
	Get protocol message attributes.
int	scmi_protocol_version_negotiate (struct scmi_protocol *proto, uint32_t version)
	Negotiate protocol version.

Detailed Description

Interfaces for ARM System Control and Management Interface (SCMI).

Macro Definition Documentation

SCMI_MESSAGE_HDR_MAKE

#define SCMI_MESSAGE_HDR_MAKE	(		id,
			type,
			proto,
			token )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Value:

(SCMI_FIELD_MAKE(id, GENMASK(7, 0), 0) | SCMI_FIELD_MAKE(type, GENMASK(1, 0), 8) |         \
 SCMI_FIELD_MAKE(proto, GENMASK(7, 0), 10) | SCMI_FIELD_MAKE(token, GENMASK(9, 0), 18))

Build an SCMI message header.

Builds an SCMI message header based on the fields that make it up. The resulting 32-bit header is laid out as follows:

• bits [7:0] message ID
• bits [9:8] message type (see scmi_message_type)
• bits [17:10] protocol ID
• bits [27:18] message token

Parameters

id	message ID
type	message type
proto	protocol ID
token	message token

SCMI_SHORT_NAME_MAX_SIZE

#define SCMI_SHORT_NAME_MAX_SIZE   16

#include <zephyr/drivers/firmware/scmi/protocol.h>

Maximum size of strings to describe SCMI names, including NUL terminator.

Enumeration Type Documentation

scmi_message_type

enum scmi_message_type

#include <zephyr/drivers/firmware/scmi/protocol.h>

SCMI message type.

Enumerator
SCMI_COMMAND	Command message.
SCMI_DELAYED_REPLY	Delayed reply message.
SCMI_NOTIFICATION	Notification message.

scmi_status_code

enum scmi_status_code

#include <zephyr/drivers/firmware/scmi/protocol.h>

SCMI status codes.

Enumerator
SCMI_SUCCESS	Successful completion.
SCMI_NOT_SUPPORTED	The command is not supported.
SCMI_INVALID_PARAMETERS	One or more parameters are invalid.
SCMI_DENIED	The caller is not permitted to perform the operation.
SCMI_NOT_FOUND	The entity referenced by the command was not found.
SCMI_OUT_OF_RANGE	A parameter or value is out of the supported range.
SCMI_BUSY	The platform is busy and cannot service the command.
SCMI_COMMS_ERROR	A communication error occurred.
SCMI_GENERIC_ERROR	An unspecified error occurred.
SCMI_HARDWARE_ERROR	A hardware error occurred.
SCMI_PROTOCOL_ERROR	A protocol error (e.g. malformed message) occurred
SCMI_IN_USE	The resource is already in use.

Function Documentation

scmi_protocol_attributes_get()

int scmi_protocol_attributes_get	(	struct scmi_protocol *	proto,
		uint32_t *	attributes )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Get protocol attributes.

Parameters

proto	Protocol instance
attributes	Pointer to store protocol attributes

Returns

0 on success, negative errno value on failure.

scmi_protocol_get_version()

int scmi_protocol_get_version	(	struct scmi_protocol *	proto,
		uint32_t *	version )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Get protocol version.

Parameters

proto	Protocol instance
version	Pointer to store protocol version

Returns

0 on success, negative errno value on failure.

scmi_protocol_message_attributes_get()

int scmi_protocol_message_attributes_get	(	struct scmi_protocol *	proto,
		uint32_t	message_id,
		uint32_t *	attributes )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Get protocol message attributes.

Parameters

proto	Protocol instance
message_id	Message ID to query
attributes	Pointer to store message attributes

Returns

0 on success, negative errno value on failure.

scmi_protocol_version_negotiate()

int scmi_protocol_version_negotiate	(	struct scmi_protocol *	proto,
		uint32_t	version )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Negotiate protocol version.

Parameters

proto	Protocol instance
version	Desired protocol version

Returns

0 on success, negative errno value on failure.

scmi_send_message()

int scmi_send_message	(	struct scmi_protocol *	proto,
		struct scmi_message *	msg,
		struct scmi_message *	reply,
		bool	use_polling )

#include <zephyr/drivers/firmware/scmi/protocol.h>

Send an SCMI message and wait for its reply.

Blocking function used to send an SCMI message over a given channel and wait for its reply

Parameters

proto	pointer to SCMI protocol
msg	pointer to SCMI message to send
reply	pointer to SCMI message in which the reply is to be written
use_polling	Specifies the communication mechanism used by the scmi platform to interact with agents.

• true: Polling mode — the platform actively checks the message status to determine if it has been processed
• false: Interrupt mode — the platform relies on SCMI interrupts to detect when a message has been handled.

Returns

0 on success, negative errno value on failure.

scmi_status_to_errno()

int scmi_status_to_errno

(

int

scmi_status

)

#include <zephyr/drivers/firmware/scmi/protocol.h>

Convert an SCMI status code to its Linux equivalent (if possible).

Parameters

scmi_status

SCMI status code as shown in enum scmi_status_code

Returns

Linux (errno) equivalent of the given SCMI status code