Unit DMA
From Ultibo.org
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Description
To be documented
Constants
To be documented
Type definitions
To be documented
Public variables
To be documented
Function declarations
Initialization functions
procedure DMAInit;
Description: To be documented
| Note | To be documented |
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DMA host functions
function DMAHostStart(DMA:PDMAHost):LongWord;
Description: To be documented
| Note | To be documented |
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function DMAHostStop(DMA:PDMAHost):LongWord;
Description: To be documented
| Note | To be documented |
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function DMAHostReset(DMA:PDMAHost):LongWord;
Description: To be documented
| Note | To be documented |
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function DMAHostProperties(DMA:PDMAHost; Properties:PDMAProperties):LongWord;
Description: To be documented
| Note | To be documented |
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function DMAHostCreate:PDMAHost;
Description: Create a new DMA entry
| Return | Pointer to new DMA entry or nil if DMA could not be created |
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function DMAHostCreateEx(Size:LongWord):PDMAHost;
Description: Create a new DMA entry
| Size | Size in bytes to allocate for new DMA (Including the DMA entry") |
|---|---|
| Return | Pointer to new DMA entry or nil if DMA could not be created |
function DMAHostDestroy(DMA:PDMAHost):LongWord;
Description: Destroy an existing DMA entry
| Note | To be documented |
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function DMAHostRegister(DMA:PDMAHost):LongWord;
Description: Register a new DMA in the DMA host table
| Note | To be documented |
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function DMAHostDeregister(DMA:PDMAHost):LongWord;
Description: Deregister a DMA from the DMA host table
| Note | To be documented |
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function DMAHostFind(DMAId:LongWord):PDMAHost;
Description: To be documented
| Note | To be documented |
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function DMAHostEnumerate(Callback:TDMAEnumerate; Data:Pointer):LongWord;
Description: To be documented
| Note | To be documented |
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function DMAHostNotification(DMA:PDMAHost; Callback:TDMANotification; Data:Pointer; Notification,Flags:LongWord):LongWord;
Description: To be documented
| Note | To be documented |
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DMA data functions
function DMADataCount(Data:PDMAData):LongWord;
Description: Return the total number of data blocks in the linked list
| Note | To be documented |
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function DMADataFlags(Data:PDMAData):LongWord;
Description: Return the combined flags of the data blocks in the linked list
| Note | To be documented |
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function DMADataMaximum(Data:PDMAData):LongWord;
Description: Return the size of the largest data block in the linked list
| Note | To be documented |
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DMA buffer functions
function DMABufferAllocate(DMA:PDMAHost; Size:LongWord):Pointer; inline;
Description: Allocate a data buffer for a DMA request
| DMA | The DMA host that the request will be sent to |
|---|---|
| Size | The size of the data buffer to allocate |
| Return | The newly allocated buffer or nil on failure |
function DMABufferAllocateEx(DMA:PDMAHost; var Size:LongWord):Pointer;
Description: Allocate a data buffer for a DMA request
| DMA | The DMA host that the request will be sent to |
|---|---|
| Size | The size of the data buffer to allocate (Updated on return to actual size) |
| Return | The newly allocated buffer or nil on failure |
| Note | This differs from DMABufferAllocate in that it updates the size value to reflect the actual size of the buffer allocated which may be required for some uses |
function DMABufferValidate(DMA:PDMAHost; Buffer:Pointer; Size:LongWord):LongWord;
Description: Validate a data buffer for a DMA request against the DMA host requirements
| DMA | The DMA host that the request will be sent to |
|---|---|
| Buffer | The data buffer to validate |
| Size | The size of the data buffer |
| Return | ERROR_SUCCESS on success or another error code on failure (ERROR_NOT_COMPATIBLE if not compatible with host) |
| Note | Does not check for cache coherency requirements (Shared, Non Cached) only alignment and size. Buffers used as the source of a DMA request do not neccessarily need to meet alignment and size requirements, however buffers used as a destintation must meet these requirements or the caller must take appropriate actions to prevent undesiraable side effects from cache invalidation. |
function DMABufferRelease(Buffer:Pointer):LongWord;
Description: Release a data buffer from a DMA request
| Data | The buffer to be released |
|---|---|
| Return | ERROR_SUCCESS on success or another error code on failure |
DMA request functions
function DMARequestAllocate(DMA:PDMAHost; Data:PDMAData; Callback:TDMARequestCompleted; DriverData:Pointer; Direction,Peripheral,Flags:LongWord):PDMARequest;
Description: Allocate a new DMA request
| DMA | The DMA host this request will be sent to |
|---|---|
| Data | A linked list of DMA data blocks for the transfer (Optional) |
| Callback | The callback function to be called on completion of the request |
| DriverData | Driver private data for the callback (Optional) |
| Direction | The direction of the DMA request (eg DMA_DIR_MEM_TO_MEM) |
| Peripheral | The peripheral ID for data request gating (eg DMA_DREQ_ID_NONE) |
| Flags | Additional flags for this request (eg DMA_REQUEST_FLAG_CYCLIC) |
| Return | The newly allocated request or nil on failure |
function DMARequestRelease(Request:PDMARequest):LongWord;
Description: Release and destroy a DMA request
| Request | The request to be released |
|---|---|
| Return | ERROR_SUCCESS on success or another error code on failure |
function DMARequestSubmit(Request:PDMARequest):LongWord;
Description: Submit a DMA request to a DMA host
| Request | The request to be submitted |
|---|---|
| Return | ERROR_SUCCESS if completed or another error code on failure |
| Note | The request will be completed asynchronously by the DMA host and the completion callback will be called when the request has either succeeded or failed |
function DMARequestCancel(Request:PDMARequest):LongWord;
Description: Cancel a DMA request previously submitted to a DMA host
| Request | The request to be cancelled |
|---|---|
| Return | ERROR_SUCCESS if completed or another error code on failure |
procedure DMARequestComplete(Request:PDMARequest);
Description: Called by a DMA host when a DMA request completes
| Request | The DMA request which has completed |
|---|---|
| Note | DMA host drivers may call this on a worker thread |
DMA transfer functions
function DMATransferRequest(DMA:PDMAHost; Data:PDMAData; Direction,Peripheral,Flags,Timeout:LongWord):LongWord;
Description: Perform a DMA transfer request with the supplied data blocks on the supplied host
| DMA | The DMA host to execute the request on |
|---|---|
| Data | A linked list of DMA data blocks for the transfer |
| Direction | The direction of the DMA request (eg DMA_DIR_MEM_TO_MEM) |
| Peripheral | The peripheral ID for data request gating (eg DMA_DREQ_ID_NONE) |
| Flags | Additional flags for this transfer request (eg DMA_REQUEST_FLAG_CYCLIC) |
| Timeout | Milliseconds to wait for request to complete (INFINITE to wait forever) |
| Note | An internal callback will be specified and the function will wait for the transfer to complete |
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