to do something with heart, voluntarily, or freely (see Molina)
Alonso de Molina:
teyollocopa. lo mesmo es que teyolloca copa. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 95r. col. 1. Thanks to Joe Campbell for providing the transcription.