//*****************************************************************
/// <summary>
/// Initiates a USB control transfer with optional data sent to the USB device.
/// </summary>
/// <param name="bmRequestType">The USB <i>bmRequestType</i>field.</param>
/// <param name="bRequest">The USB <i>bRequest</i>field.</param>
/// <param name="wValue">The USB <i>wValue</i>field.</param>
/// <param name="wIndex">The USB <i>wIndex</i>field.</param>
/// <param name="buffer">An array of bytes with the data to write to the
/// USB device. May be <b>null</b>.</param>
/// <exception cref="IOException">The <see cref="UsbDevice"/> is not open,
/// or the transfer did not complete.</exception>
/// <exception cref="Win32Exception">An error was reported by
/// the operating system.</exception>
/// <remarks>
/// <para>
/// The first four arguments of this method correspond precisely with the
/// like-named fields of a USB Setup packet. See the USB specification
/// for the meaning and use of these parameters.</para>
/// <para>
/// The <i>wLength</i> field of the USB Setup packet is set to the
/// length of <paramref name="buffer"/>, or zero if <paramref name="buffer"/>
/// is <b>null</b>.
/// </para>
/// </remarks>
public void ControlWrite(byte bmRequestType, byte bRequest, ushort wValue, ushort wIndex, byte[] buffer)
{
bool retval;
uint cbWritten;
WinUsbApi.WINUSB_SETUP_PACKET packet;
packet.RequestType = (byte)(bmRequestType & WinUsbApi.PipeMask); // ensure OUT transfer
packet.Request = bRequest;
packet.Value = wValue;
packet.Index = wIndex;
if (buffer == null)
{
buffer = new byte[0];
}
packet.Length = (ushort)buffer.Length;
retval = WinUsbApi.WinUsb_ControlTransfer(
UsbHandle,
packet,
buffer,
(uint)buffer.Length,
out cbWritten,
IntPtr.Zero);
if (!retval)
{
throw new Win32Exception();
}
if (cbWritten != buffer.Length)
{
throw new IOException();
}
}
//*****************************************************************
/// <summary>
/// Initiates a USB control transfer that reads data from the USB device.
/// </summary>
/// <param name="bmRequestType">The USB <i>bmRequestType</i>field.</param>
/// <param name="bRequest">The USB <i>bRequest</i>field.</param>
/// <param name="wValue">The USB <i>wValue</i>field.</param>
/// <param name="wIndex">The USB <i>wIndex</i>field.</param>
/// <param name="wLength">The USB <i>wLength</i>field.</param>
/// <returns>
/// <para>A byte array containing the bytes read from the USB device.</para>
/// </returns>
/// <exception cref="IOException">The <see cref="UsbDevice"/> is not open.</exception>
/// <exception cref="Win32Exception">An error was reported by
/// the operating system.</exception>
/// <remarks>
/// <para>
/// The arguments of this method correspond precisely with the
/// like-named fields of a USB Setup packet. See the USB specification
/// for the meaning and use of these parameters.</para>
/// <para>
/// The <paramref name="wLength"/> parameter is the maximum number of
/// bytes to read from the USB device, and the USB device may send less.
/// The length of the returned byte array is the actual number of
/// bytes received.</para>
/// </remarks>
public byte[] ControlRead(byte bmRequestType, byte bRequest, ushort wValue, ushort wIndex, ushort wLength)
{
byte[] arbBuf;
byte[] arbData;
uint cbRead;
bool retval;
WinUsbApi.WINUSB_SETUP_PACKET packet;
packet.RequestType = (byte)(bmRequestType | WinUsbApi.ReadFlag); // ensure IN transfer
packet.Request = bRequest;
packet.Value = wValue;
packet.Index = wIndex;
packet.Length = wLength;
arbBuf = new byte[wLength];
retval = WinUsbApi.WinUsb_ControlTransfer(
UsbHandle,
packet,
arbBuf,
(uint)arbBuf.Length,
out cbRead,
IntPtr.Zero);
if (!retval)
{
throw new Win32Exception();
}
if (cbRead == arbBuf.Length)
{
return(arbBuf);
}
arbData = new byte[cbRead];
Array.Copy(arbBuf, arbData, cbRead);
return(arbData);
}