LIRC_SET_TRANSMITTER_MASK - Enables send codes on a given set of transmitters
Some IR TX devices have multiple output channels, in such case, LIRC_CAN_SET_TRANSMITTER_MASK is returned via ioctl LIRC_GET_FEATURES and this ioctl sets what channels will send IR codes.
This ioctl enables the given set of transmitters. The first transmitter is encoded by the least significant bit and so on.
When an invalid bit mask is given, i.e. a bit is set, even though the device does not have so many transitters, then this ioctl returns the number of available transitters and does nothing otherwise.
On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the Generic Error Codes chapter.