Prison, literature, truth

Prison and literature. In order to the huge literary production in centuries (high, good and mediocre literature; memoirs, fictions, essays, etc), can prison be considered just a where or better a reason why? Since literature in and from prison is not a genre itself, is it possible to trace out coordinates_(formal and conceptual ones) at least for some part of such literature? The present paper details these coordinates, for autobiographical prison literature, with the express willingness to tell the truth', that can be at most considered as an opposition between 'telling stories' (literature) and 'the urge to tell' (speech of truth).