__AD7991_CHANNEL
__AD7991_CHANNEL(_si, _channel1, _channel2, _address, _bits, \
__AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \
__AD7991_CHANNEL(_si, _channel, _channel, _address, _bits, \
__AD7991_CHANNEL(_si, _channel, -1, _address, _bits, \