Perform a synchronous control transfer (endpoint 0).

int32_t UsbControlXfer( 
    int32_t udev, 
    uint8_t request, 
    uint8_t requesttype, 
    uint16_t value, 
    uint16_t index, 
    void *data, 
    uint16_t len, 
    uint16_t * act_len, 
    uint32_t flags, 
    uint32_t timeout 
);

Parameters

udev

Device handle from UsbOpenDevice.

request 

Control request. One of:

USB_REQ_GET_STATUS
USB_REQ_CLEAR_FEATURE
USB_REQ_SET_FEATURE
USB_REQ_SET_ADDRESS
USB_REQ_GET_DESCRIPTOR
USB_REQ_SET_DESCRIPTOR
USB_REQ_GET_CONFIGURATION
USB_REQ_SET_CONFIGURATION
USB_REQ_GET_INTERFACE
USB_REQ_SET_INTERFACE
USB_REQ_SYNCH_FRAME

requesttype 

Control request type. One of:
USB_RT_WRITE
USB_RT_READ
USB_RT_STANDARD
USB_RT_CLASS
USB_RT_VENDOR
USB_RT_DEVICE
USB_RT_INTERFACE
USB_RT_ENDPOINT
USB_RT_OTHER

value

Request specific data. See USB specification for details.

index

Identifies a particular target. 

data 

Pointer to user buffer.

len 

Length of expected data transfer.

act_len

Pointer to a variable to receive the actual length of the transfer.

flags

Transfer flags. One of the following:
USB_FORCE_SHORT_XFER - force a short transmit last
USB_SHORT_XFER_OK - allow short reads
USB_DELAY_STATUS_STAGE - insert delay before STATUS
USB_MULTI_SHORT_OK - allow multiple short frames  

timeout 

Millisecond timeout for the operation.

Return Values

USB_ERR_NORMAL_COMPLETION	Success. The operation was completed.
USB_ERR_NO_STACK	The USB stack is not ready.
USB_ERR_MEMORY	Memory could not be allocated for the operation.
USB_ERR_TIMEOUT	The device did not respond.

Requirements