CyUSB.sys的说明文档CyUSB.chm-IOCTL接口范例-IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER

DeviceIoControl()可以利用Io Control (aka IOCTL) code操作USB设备驱动，这些IOCTL码由谁定义由谁解释呢？（CyAPI.lib? CyUSB.dll? CyUSB.sys?）

答案：cyioctl.h
例如：
#define IOCTL_ADAPT_GET_DRIVER_VERSION         CTL_CODE(FILE_DEVICE_UNKNOWN, IOCTL_ADAPT_INDEX, METHOD_BUFFERED, FILE_ANY_ACCESS)

..

#define IOCTL_ADAPT_GET_ALT_INTERFACE_SETTING CTL_CODE(FILE_DEVICE_UNKNOWN, IOCTL_ADAPT_INDEX+2, METHOD_BUFFERED, FILE_ANY_ACCESS)

至于“FILE_DEVICE_UNKNOWN, IOCTL_ADAPT_INDEX, METHOD_BUFFERED, FILE_ANY_ACCESS”这些东西的定义，应该是在Windows相关头文件or库里面吧。

这是IOCTL Interface的IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER的使用范例：

Description

This command sends a control request to the default Control endpoint, endpoint zero.

DeviceIoControl( ) is passed a pointer to a two-part structure as both the lpInBuffer and lpOutBuffer parameters. This two-part structure contains a SINGLE_TRANSFER structure followed by a data buffer.

The SINGLE_TRANSFER structure contains all the parameters for the control request.

The buffer contains the transfer data.

pXmitBuf
　　SINGLE_TRANFER
　　　　bmRequest
　　　　Request
　　　　.
　　　　.
　　buff

　

union  {

struct   {

UCHAR Recipient:5; //接收方: Device,Interface,Endpoint,Other
UCHAR  Type:2;  //Type: Standard,Class,Vendor
UCHAR Direction:1; //数据传输方向: Host2Device,Device2Host
} bmRequest;
 UCHAR bmReq;   //请求类型
};

bmRequest.Recipient = 0; //  Device
bmRequest.Type      = 2; //  Vendor
bmRequest.Direction = 1; // IN command (from  Device to Host)

 
int iXmitBufSize = sizeof(SINGLE_TRANSFER) + bufLen; //  The size of the two-part structure. XmitBuf is the two-part structure.

UCHAR *pXmitBuf = new UCHAR[iXmitBufSize];           //  Allocate the memory 创建iXmitBufSize大小的UCHAR变量

ZeroMemory(pXmitBuf, iXmitBufSize);     // 指定存储空(UCHAR)间清零

PSINGLE_TRANSFER pTransfer = (PSINGLE_TRANSFER)pXmitBuf; //  The SINGLE_TRANSFER comes first 下面首先定义SINGLE_TRANSFER Structure的值

pTransfer->SetupPacket.bmRequest = bmReq;　　　　//Birmap Characteristics of request
pTransfer->SetupPacket.bRequest = ReqCode;　　　　//Specific request
pTransfer->SetupPacket.wValue = Value;　　　　　　　
pTransfer->SetupPacket.wIndex = Index;
pTransfer->SetupPacket.wLength = bufLen;　　　　　　//Number of bytes to transfer if there is a Data stage
pTransfer->SetupPacket.ulTimeOut = TimeOut / 1000;
pTransfer->Reserved = 0;
pTransfer->ucEndpointAddress = 0x00;     //  Control pipe
pTransfer->IsoPacketLength = 0;
pTransfer->BufferOffset = sizeof (SINGLE_TRANSFER);
pTransfer->BufferLength = bufLen;
DWORD dwReturnBytes;
 
DeviceIoControl (hDevice, IOCTL_ADAPT_SEND_EP0_CONTROL_TRANSFER,
             pXmitBuf,  iXmitBufSize,
             pXmitBuf,  iXmitBufSize,
             &dwReturnBytes,  NULL);
 
// Copy data into  buf
UCHAR *ptr = pXmitBuf + sizeof (SINGLE_TRANSFER);
memcpy(buf, ptr, dwReturnBytes);