DMA Manager

Overview

DMA Manager provides a series of functions to manage the DMAMUX instances and channels.

Function groups

DMAMGR Initialization and De-initialization

This function group initializes and deinitializes the DMA Manager.

DMAMGR Operation

This function group requests/releases the DMAMUX channel and configures the channel request source.

Typical use case

DMAMGR static channel allocattion

uint8_t channel;
dmamanager_handle_t dmamanager_handle;

/* Initialize DMAMGR */
DMAMGR_Init(&dmamanager_handle, EXAMPLE_DMA_BASEADDR, DMA_CHANNEL_NUMBER, startChannel);
/* Request a DMAMUX channel by static allocate mechanism */
channel = kDMAMGR_STATIC_ALLOCATE;
DMAMGR_RequestChannel(&dmamanager_handle, kDmaRequestMux0AlwaysOn63, channel, &handle);

DMAMGR dynamic channel allocation

uint8_t channel;
dmamanager_handle_t dmamanager_handle;

/* Initialize DMAMGR */
DMAMGR_Init(&dmamanager_handle, EXAMPLE_DMA_BASEADDR, DMA_CHANNEL_NUMBER, startChannel);
/* Request a DMAMUX channel by Dynamic allocate mechanism */
channel = DMAMGR_DYNAMIC_ALLOCATE;
DMAMGR_RequestChannel(&dmamanager_handle, kDmaRequestMux0AlwaysOn63, channel, &handle);

Data Structures
struct	dmamanager_handle_t
	dmamanager handle typedef. More...

Macros
#define	DMAMGR_DYNAMIC_ALLOCATE   0xFFU
	Dynamic channel allocation mechanism. More...

Enumerations
enum	_dma_manager_status {   kStatus_DMAMGR_ChannelOccupied = MAKE_STATUS(kStatusGroup_DMAMGR, 0),   kStatus_DMAMGR_ChannelNotUsed = MAKE_STATUS(kStatusGroup_DMAMGR, 1),   kStatus_DMAMGR_NoFreeChannel = MAKE_STATUS(kStatusGroup_DMAMGR, 2) }
	DMA manager status. More...

DMAMGR Initialization and De-initialization
void	DMAMGR_Init (dmamanager_handle_t *dmamanager_handle, DMA_Type *dma_base, uint32_t channelNum, uint32_t startChannel)
	Initializes the DMA manager. More...
void	DMAMGR_Deinit (dmamanager_handle_t *dmamanager_handle)
	Deinitializes the DMA manager. More...

DMAMGR Operation
status_t	DMAMGR_RequestChannel (dmamanager_handle_t *dmamanager_handle, uint32_t requestSource, uint32_t channel, void *handle)
	Requests a DMA channel. More...
status_t	DMAMGR_ReleaseChannel (dmamanager_handle_t *dmamanager_handle, void *handle)
	Releases a DMA channel. More...
bool	DMAMGR_IsChannelOccupied (dmamanager_handle_t *dmamanager_handle, uint32_t channel)
	Get a DMA channel status. More...

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Data Structure Documentation

struct dmamanager_handle_t

Note

The contents of this structure are private and subject to change.

This dma manager handle structure is used to store the parameters transfered by users.And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.

Data Fields
void *	dma_base
	Peripheral DMA instance. More...
uint32_t	channelNum
	Channel numbers for the DMA instance which need to be managed by dma manager. More...
uint32_t	startChannel
	The start channel that can be managed by dma manager,users need to transfer it with a certain number or NULL. More...
bool	s_DMAMGR_Channels [64]
	The s_DMAMGR_Channels is used to store dma manager state. More...
uint32_t	DmamuxInstanceStart
	The DmamuxInstance is used to calculate the DMAMUX Instance according to the DMA Instance. More...
uint32_t	multiple
	The multiple is used to calculate the multiple between DMAMUX count and DMA count. More...

Field Documentation

void* dmamanager_handle_t::dma_base

uint32_t dmamanager_handle_t::channelNum

uint32_t dmamanager_handle_t::startChannel

bool dmamanager_handle_t::s_DMAMGR_Channels[64]

uint32_t dmamanager_handle_t::DmamuxInstanceStart

uint32_t dmamanager_handle_t::multiple

Macro Definition Documentation

#define DMAMGR_DYNAMIC_ALLOCATE   0xFFU

Enumeration Type Documentation

enum _dma_manager_status

Enumerator
kStatus_DMAMGR_ChannelOccupied	Channel has been occupied.
kStatus_DMAMGR_ChannelNotUsed	Channel has not been used.
kStatus_DMAMGR_NoFreeChannel	All channels have been occupied.

Function Documentation

void DMAMGR_Init	(	dmamanager_handle_t *	dmamanager_handle,
		DMA_Type *	dma_base,
		uint32_t	channelNum,
		uint32_t	startChannel
	)

This function initializes the DMA manager, ungates the DMAMUX clocks, and initializes the eDMA or DMA peripherals.

Parameters

dmamanager_handle	DMA manager handle pointer, this structure is maintained by dma manager internal,users only need to transfer the structure to the function. And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.
dma_base	Peripheral DMA instance base pointer.
dmamux_base	Peripheral DMAMUX instance base pointer.
channelNum	Channel numbers for the DMA instance which need to be managed by dma manager.
startChannel	The start channel that can be managed by dma manager.

void DMAMGR_Deinit

(

dmamanager_handle_t *

dmamanager_handle

)

This function deinitializes the DMA manager, disables the DMAMUX channels, gates the DMAMUX clocks, and deinitializes the eDMA or DMA peripherals.

Parameters

dmamanager_handle

DMA manager handle pointer, this structure is maintained by dma manager internal,users only need to transfer the structure to the function. And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.

status_t DMAMGR_RequestChannel	(	dmamanager_handle_t *	dmamanager_handle,
		uint32_t	requestSource,
		uint32_t	channel,
		void *	handle
	)

This function requests a DMA channel which is not occupied. The two channels to allocate the mechanism are dynamic and static channels. For the dynamic allocation mechanism (channe = DMAMGR_DYNAMIC_ALLOCATE), DMAMGR allocates a DMA channel according to the given request source and startChannel and then configures it. For static allocation mechanism, DMAMGR configures the given channel according to the given request source and channel number.

Parameters

dmamanager_handle	DMA manager handle pointer, this structure is maintained by dma manager internal,users only need to transfer the structure to the function. And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.
requestSource	DMA channel request source number. See the soc.h, see the enum dma_request_source_t
channel	The channel number users want to occupy. If using the dynamic channel allocate mechanism, set the channel equal to DMAMGR_DYNAMIC_ALLOCATE.
handle	DMA or eDMA handle pointer.

Return values

kStatus_Success	In a dynamic/static channel allocation mechanism, allocate the DMAMUX channel successfully.
kStatus_DMAMGR_NoFreeChannel	In a dynamic channel allocation mechanism, all DMAMUX channels are occupied.
kStatus_DMAMGR_ChannelOccupied	In a static channel allocation mechanism, the given channel is occupied.

status_t DMAMGR_ReleaseChannel	(	dmamanager_handle_t *	dmamanager_handle,
		void *	handle
	)

This function releases an occupied DMA channel.

Parameters

dmamanager_handle	DMA manager handle pointer, this structure is maintained by dma manager internal,users only need to transfer the structure to the function. And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.
handle	DMA or eDMA handle pointer.

Return values

kStatus_Success	Releases the given channel successfully.
kStatus_DMAMGR_ChannelNotUsed	The given channel to be released had not been used before.

bool DMAMGR_IsChannelOccupied	(	dmamanager_handle_t *	dmamanager_handle,
		uint32_t	channel
	)

This function get a DMA channel status. Return 0 indicates the channel has not been used, return 1 indicates the channel has been occupied.

Parameters

dmamanager_handle	DMA manager handle pointer, this structure is maintained by dma manager internal,users only need to transfer the structure to the function. And users shall not free the memory before calling DMAMGR_Deinit, also shall not modify the contents of the memory.
channel	The channel number that users want get its status.