MHU Interface (for secure and non secure channels)

Detailed Description

Interface for Message Handling Unit.

Summary

The Message Handling Unit interface provides a common API for MHU HAL drivers. The Message Handling Unit interface supports:

• Message communication between Cortex-A55 and Cortex-M33.
• 32-bit data can be communicated between CPUs via shared memory.

Implemented by:

• Message Handling Unit for secure channels (r_mhu_s)
• Message Handling Unit for non secure channels (r_mhu_ns)

Data Structures
struct	mhu_callback_args_t
struct	mhu_cfg_t
struct	mhu_api_t
struct	mhu_instance_t

Typedefs
typedef void	mhu_ctrl_t

Enumerations
enum	mhu_send_type_t

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Data Structure Documentation

mhu_callback_args_t

struct mhu_callback_args_t

MHU callback parameter definition

Data Fields
void const *	p_context	Placeholder for user data. Set in mhu_api_t::open function in mhu_cfg_t.
uint32_t	channel	Channel where the receive interrupt occurred.
uint32_t	msg	32-bit received data.

mhu_cfg_t

struct mhu_cfg_t

MHU configuration block

Data Fields
uint32_t	channel
	Identifier recognizable by implementation. More...
uint8_t	rx_ipl
	Receive interrupt priority.
IRQn_Type	rx_irq
	Receive interrupt ID.
void(*	p_callback )(mhu_callback_args_t *p_args)
	Pointer to callback function. More...
void const *	p_shared_memory
	Pointer to 64-bit send/receive data buffer.
void const *	p_context

Field Documentation

channel

uint32_t mhu_cfg_t::channel

Identifier recognizable by implementation.

Generic configuration

p_callback

void(* mhu_cfg_t::p_callback) (mhu_callback_args_t *p_args)

Pointer to callback function.

Parameters to control software behavior

p_context

void const* mhu_cfg_t::p_context

Placeholder for user data. Passed to the user callback in mhu_callback_args_t.

mhu_api_t

struct mhu_api_t

Interface definition for MHU

Data Fields
fsp_err_t(*	open )(mhu_ctrl_t *const p_ctrl, mhu_cfg_t const *const p_cfg)
fsp_err_t(*	msgSend )(mhu_ctrl_t *const p_ctrl, uint32_t const msg)
fsp_err_t(*	callbackSet )(mhu_ctrl_t *const p_api_ctrl, void(*p_callback)(mhu_callback_args_t *), void const *const p_context, mhu_callback_args_t *const p_callback_memory)
fsp_err_t(*	close )(mhu_ctrl_t *const p_ctrl)

Field Documentation

open

fsp_err_t(* mhu_api_t::open) (mhu_ctrl_t *const p_ctrl, mhu_cfg_t const *const p_cfg)

Opens the MHU driver and initializes the hardware.

Implemented as

• R_MHU_S_Open()
• R_MHU_NS_Open()

Parameters

[in]	p_ctrl	Pointer to control block. Must be declared by user. Elements are set here.
[in]	p_cfg	Pointer to configuration structure.

msgSend

fsp_err_t(* mhu_api_t::msgSend) (mhu_ctrl_t *const p_ctrl, uint32_t const msg)

Performs a send operation on an MHU device.

Implemented as

• R_MHU_S_MsgSend()
• R_MHU_NS_MsgSend()

Parameters

[in]	p_ctrl	Pointer to control block set in mhu_api_t::open call.
[in]	msg	32bit send data.

callbackSet

fsp_err_t(* mhu_api_t::callbackSet) (mhu_ctrl_t *const p_api_ctrl, void(*p_callback)(mhu_callback_args_t *), void const *const p_context, mhu_callback_args_t *const p_callback_memory)

Specify callback function and optional context pointer and working memory pointer.

Implemented as

• R_MHU_S_CallbackSet()
• R_MHU_NS_CallbackSet()

Parameters

[in]	p_ctrl	Control block set in mhu_api_t::open call for this channel.
[in]	p_callback	Callback function to register
[in]	p_context	Pointer to send to callback function
[in]	p_callback_memory	Pointer to volatile memory where callback structure can be allocated. Callback arguments allocated here are only valid during the callback.

close

fsp_err_t(* mhu_api_t::close) (mhu_ctrl_t *const p_ctrl)

Closes the driver and releases the MHU device.

Implemented as

• R_MHU_S_Close()
• R_MHU_NS_Close()

Parameters

[in]

p_ctrl

Pointer to control block set in mhu_api_t::open call.

mhu_instance_t

struct mhu_instance_t

This structure encompasses everything that is needed to use an instance of this interface.

Data Fields
mhu_ctrl_t *	p_ctrl	Pointer to the control structure for this instance.
mhu_cfg_t const *	p_cfg	Pointer to the configuration structure for this instance.
mhu_api_t const *	p_api	Pointer to the API structure for this instance.

Typedef Documentation

mhu_ctrl_t

typedef void mhu_ctrl_t

MHU control block. Allocate an instance specific control block to pass into the MHU API calls.

Implemented as

• mhu_instance_ctrl_t

Enumeration Type Documentation

mhu_send_type_t

enum mhu_send_type_t

Enumerator
MHU_SEND_TYPE_MSG	Channel for sending "message" and receiving "response".
MHU_SEND_TYPE_RSP	Channel for sending "response" and receiving "message".