22.4.3 SetControl() and GetControl() Implementation
GetControl() and SetControl() are used to view and modify respectively the
control bits on the serial device. All of the values listed in the following
table can be read back with GetControl(), but some cannot be modified with
SetControl(). If a non-modifiable bit is attempted to be set with
SetControl() then EFI_UNSUPPORTED must be returned.
The Mode pointer should be updated in this function when success has been
determined, but not modified if there is an error.
Table 35-Serial I/O protocol control bits
| Control Bit #define | Modifiable with SetControl() |
|---|---|
EFI_SERIAL_CLEAR_TO_SEND |
NO |
EFI_SERIAL_DATA_SET_READY |
NO |
EFI_SERIAL_RING_INDICATE |
NO |
EFI_SERIAL_CARRIER_DETECT |
NO |
EFI_SERIAL_REQUEST_TO_SEND |
YES |
EFI_SERIAL_DATA_TERMINAL_READY |
YES |
EFI_SERIAL_INPUT_BUFFER_EMPTY |
NO |
EFI_SERIAL_OUTPUT_BUFFER_EMPTY |
NO |
EFI_SERIAL_HARDWARE_LOOPBACK_ENABLE |
YES |
EFI_SERIAL_SOFTWARE_LOOPBACK_ENABLE |
YES |
EFI_SERIAL_HARDWARE_FLOW_CONTROL_ENABLE |
YES |