IOCTL_SERIAL_SET_BAUD_RATE control code
The IOCTL_SERIAL_SET_BAUD_RATE request sets the baud rate on a serial controller device. The serial controller driver verifies the specified baud rate.
To obtain the baud rate, a client can use an IOCTL_SERIAL_GET_BAUD_RATE request.
The AssociatedIrp.SystemBuffer member points to a SERIAL_BAUD_RATE structure that a client allocates and sets to input the baud rate.
The Parameters.DeviceIoControl.InputBufferLength member is set to the size, in bytes, of a SERIAL_BAUD_RATE structure.
The Information member is set to zero.
The Status member is set to one of the Generic Status Values for Serial Device Control Requests.