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IOUSBPipe |
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The object representing an open pipe for a device.
Abort |
public
virtual IOReturn Abort( void);
This method causes all outstanding I/O on a pipe to complete with return code kIOReturnAborted. It clears the halted bit but does NOT clear the toggle bit on the endpoint in the controller. If you wish to clear the toggle bit, see ClearPipeStall
ClearPipeStall |
public
virtual IOReturn ClearPipeStall( bool withDeviceRequest);
withDeviceRequestif true, a ClearFeature(ENDPOINT_HALT) is sent to the appropriate endpoint on the device after the transactions on the controllers endpoint are returned and the toggle bit on the controllers endpoint is cleared. if this parameter is false, then this is equivalent to the pre-1.9 API. This means that the endpoint on the controller is cleared, but no DeviceRequest is sent to the device's endpoint.
AVAILABLE ONLY IN VERSION 1.9 AND ABOVE This method causes all outstanding I/O on a pipe to complete with return code kIOUSBTransactionReturned. It also clears both the halted bit and the toggle bit on the endpoint in the controller. The driver may need to reset the data toggle within the device to avoid losing any data. If the device correctly handles the ClearFeature(ENDPOINT_HALT) device request, then this API will handle that by sending the correct request to the device.
ClearStall |
public
virtual IOReturn ClearStall( void);
This method is equivalent to ClearPipeStall(false). This method is available before version 1.9.
ControlRequest(IOUSBDevRequestDesc *, IOUSBCompletion *) |
public
virtual IOReturn ControlRequest( IOUSBDevRequestDesc *request, IOUSBCompletion *completion = 0);
requestparameter block for the control request
completiondescribes action to take when the request has been executed
Make a control request There are two versions of this method, one uses a simple void * to point to the data portion of the transfer, the other uses an IOMemoryDescriptor to point to the data.
ControlRequest(IOUSBDevRequestDesc *, UInt32, UInt32, IOUSBCompletion *) |
public
virtual IOReturn ControlRequest( IOUSBDevRequestDesc *request, UInt32 noDataTimeout, UInt32 completionTimeout, IOUSBCompletion *completion = 0);
requestparameter block for the control request
noDataTimeoutSpecifies an amount of time (in ms) after which the command will be aborted if no data has been transferred on the bus.
completionTimeoutSpecifies an amount of time (in ms) after which the command will be aborted if the entire command has not been completed.
completiondescribes action to take when the request has been executed
Make a control request. There are two versions of this method, one uses a simple void * to point to the data portion of the transfer, the other uses an IOMemoryDescriptor to point to the data.
GetDirection |
public
virtual UInt8 GetDirection();
returns the direction of the pipe:kUSBOut/kUSBIn for a bulk or interrupt pipe, kUSBAnyDirn for a control pipe.
GetEndpoint |
public
virtual const IOUSBController::Endpoint * GetEndpoint();
returns a pointer to the Endpoint structure for the pipe.
GetEndpointDescriptor |
public
virtual const IOUSBEndpointDescriptor * GetEndpointDescriptor();
returns the endpoint descriptor for the pipe.
GetEndpointNumber |
public
virtual UInt8 GetEndpointNumber();
returns the endpoint number in the device that the pipe is connected to.
GetPipeStatus |
public
virtual IOReturn GetPipeStatus( void);
Returns the status of the pipe (kIOUSBPipeStalled of the pipe is stalled, else kIOReturnSuccess)
GetStatus |
public
virtual UInt8 GetStatus( void);
This method does NOT work. Do not call it. See GetPipeStatus for the correct method. GetStatus will always return 0.
GetType |
public
virtual UInt8 GetType();
returns the pipe type: kUSBControl, kUSBBulk or kUSBInterrupt.
Read(IOMemoryDescriptor *, UInt32, UInt32, IOByteCount, IOUSBCompletion *, IOByteCount *) |
public
virtual IOReturn Read( IOMemoryDescriptor *buffer, UInt32 noDataTimeout, UInt32 completionTimeout, IOByteCount reqCount, IOUSBCompletion *completion = 0, IOByteCount *bytesRead = 0);
bufferplace to put the transferred data
noDataTimeoutnumber of milliseconds of no bus activity until transaction times out. Note that if a transaction times out the driver software may have to resynchronize the data toggle. See ClearPipeStall.
completionTimeoutnumber of milliseconds from the time the transaction is placed on the bus until it times out
reqCountrequested number of bytes to transfer. must be getLength()
completiondescribes action to take when buffer has been filled
bytesReadreturns total bytes read for synchronous reads
Read from an interrupt or bulk endpoint
Read(IOMemoryDescriptor *, UInt32, UInt32, IOByteCount, IOUSBCompletionWithTimeStamp *, IOByteCount *) |
public
virtual IOReturn Read( IOMemoryDescriptor *buffer, UInt32 noDataTimeout, UInt32 completionTimeout, IOByteCount reqCount, IOUSBCompletionWithTimeStamp *completion = 0, IOByteCount *bytesRead = 0);
bufferplace to put the transferred data
noDataTimeoutnumber of milliseconds of no bus activity until transaction times out. Note that if a transaction times out the driver software may have to resynchronize the data toggle. See ClearPipeStall.
completionTimeoutnumber of milliseconds from the time the transaction is placed on the bus until it times out
reqCountrequested number of bytes to transfer. must be getLength()
completiondescribes action to take when buffer has been filled
bytesReadreturns total bytes read for synchronous reads
Read from an interrupt or bulk endpoint
Read(IOMemoryDescriptor *, UInt64, UInt32, IOUSBIsocFrame *, IOUSBIsocCompletion *) |
public
virtual IOReturn Read( IOMemoryDescriptor *buffer, UInt64 frameStart, UInt32 numFrames, IOUSBIsocFrame *frameList, IOUSBIsocCompletion *completion = 0);
bufferplace to put the transferred data
frameStartUSB frame number of the frame to start transfer
numFramesNumber of frames to transfer
frameListBytes to transfer and result for each frame
completiondescribes action to take when buffer has been filled
Read from an isochronous endpoint
Read(IOMemoryDescriptor *, UInt64, UInt32, IOUSBLowLatencyIsocFrame *, IOUSBLowLatencyIsocCompletion *, UInt32) |
public
virtual IOReturn Read( IOMemoryDescriptor *buffer, UInt64 frameStart, UInt32 numFrames, IOUSBLowLatencyIsocFrame *frameList, IOUSBLowLatencyIsocCompletion *completion = 0, UInt32 updateFrequency = 0);
bufferplace to put the transferred data
frameStartUSB frame number of the frame to start transfer
numFramesNumber of frames to transfer
frameListBytes to transfer, result, and time stamp for each frame
completiondescribes action to take when buffer has been filled
updateFrequencydescribes how often (in milliseconds) should the frame list be processed
AVAILABLE ONLY IN VERSION 1.9.2 AND ABOVE Read from an isochronous endpoint and process the IOUSBLowLatencyIsocFrame fields at hardware interrupt time
Reset |
public
virtual IOReturn Reset( void);
This method is identical to ClearPipeStall(false). The use of that API is preferred.
SetPipePolicy |
public
virtual IOReturn SetPipePolicy( UInt16 maxPacketSize, UInt8 maxInterval);
maxPacketSizespecifies the maximum number of bytes to be used in any one millisecond frame by this pipe. The value must be less than or equal to the maxPacketSize specified in the endpoint descriptor.
maxIntervalnot currently used. reserved for future expansion
AVAILABLE ONLY IN VERSION 1.9 AND ABOVE This method allows a driver to change the maxPacketSize of an Isochronous pipe, or the polling interval for an interrupt pipe. There is a limited amount of bandwidth on any single bus, and isochronous pipes tend to use much of this bandwidth. The driver may know, however, that there will never be as much bandwidth used as is specified in the pipe's endpoint descriptor. Therefore, the driver may return some of this bandwidth to the system by using this method. Additionally, if on an open of an IOUSBInterface any of the Isochronous pipes is unable to be opened because of a lack of bandwidth, the pipe will be created with a bandwidth of zero, and the driver may get some of the limited bandwidth remaining by using this call. This method returns kIOReturnBadArgument if the pipe is a bulk on control pipe, or if the maxPacketSize parameter is larger than the amount specified in the endpoint descriptor. It returns kIOReturnNoBandwidth if the bandwidth requested cannot be allocated. Otherwise it returns kIOReturnSuccess.
Write |
public
virtual IOReturn Write( IOMemoryDescriptor *buffer, UInt64 frameStart, UInt32 numFrames, IOUSBLowLatencyIsocFrame *frameList, IOUSBLowLatencyIsocCompletion *completion = 0, UInt32 updateFrequency = 0);
bufferplace to get the data to transfer
frameStartUSB frame number of the frame to start transfer
numFramesNumber of frames to transfer
frameListPointer to list of frames indicating bytes to transfer and result for each frame
completiondescribes action to take when buffer has been emptied
updateFrequencydescribes how often (in milliseconds) the frame list should be processed
AVAILABLE ONLY IN VERSION 1.9.2 AND ABOVE Write to an isochronous endpoint
Write(IOMemoryDescriptor *, UInt32, UInt32, IOByteCount, IOUSBCompletion *) |
public
virtual IOReturn Write( IOMemoryDescriptor *buffer, UInt32 noDataTimeout, UInt32 completionTimeout, IOByteCount reqCount, IOUSBCompletion *completion = 0);
bufferplace to get the transferred data
noDataTimeoutnumber of milliseconds of no bus activity until transaction times out. Note that if a transaction times out the driver software may have to resynchronize the data toggle. See ClearPipeStall.
completionTimeoutnumber of milliseconds from the time the transaction is placed on the bus until it times out
reqCountrequested number of bytes to transfer. must be getLength()
completiondescribes action to take when buffer has been emptied
Write to an interrupt or bulk endpoint
Write(IOMemoryDescriptor *, UInt64, UInt32, IOUSBIsocFrame *, IOUSBIsocCompletion *) |
public
virtual IOReturn Write( IOMemoryDescriptor *buffer, UInt64 frameStart, UInt32 numFrames, IOUSBIsocFrame *frameList, IOUSBIsocCompletion *completion = 0);
bufferplace to get the transferred data
frameStartUSB frame number of the frame to start transfer
numFramesNumber of frames to transfer
frameListBytes to transfer and result for each frame
completiondescribes action to take when buffer has been emptied
Write to an isochronous endpoint
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Last Updated: 2008-12-19