Function SoapySDRDevice_setFrontendMapping 

pub unsafe extern "C" fn SoapySDRDevice_setFrontendMapping(
    device: *mut SoapySDRDevice,
    direction: c_int,
    mapping: *const c_char,
) -> c_int

Set the frontend mapping of available DSP units to RF frontends.

This mapping controls channel mapping and channel availability. \param device a pointer to a device instance \param direction the channel direction RX or TX \param mapping a vendor-specific mapping string \return an error code or 0 for success