Luwian is a language of the Anatolian branch of the Indo-European language family. It is attested either as Cuneiform Luwian or Hieroglyphic Luwian. Cuneiform Luwian is attested in Hittite manuscripts, which are dated from the sixteenth to the thirteenth century BC. First Hieroglyphic Luwian texts are attested from the fourteenth century BC, although most date from the tenth to the seventh century BC.
Cuneiform Luwian texts are found on Hittite cuneiform tablets and contain mainly rituals (Starke 1985). Hieroglyphic texts are mainly monumental inscriptions on stone. They refer to activities of local rulers and contain dedicatory and historical passages. Whether Cuneiform Luwian and Hieroglyphic Luwian represent the same language or two distinct dialects is still a matter of debate (Melchert 2004:577). As neither the time not the genres of both languages match and as the understanding of Hieroglyphic Luwian is limited, our present knowledge does not permit us to decide the matter as yet.
Adjective valence is not frequent in Luwian.

Although Luwian regularly uses adpositions (with dative-locative, mainly attested as postpositions), there is no attested example of adjective valence with postpositions.

They are annan “under”, parran “before”, sarri “over”, tawiyan “towards, facing”, CUM-ni “with, for”, *366-na-na “among” (Melchert 2003:203). 

Melchert, H. Craig (ed). 2003. The Luwians. Boston: Brill Academic Publishers.
Melchert, H. Craig. 1994. Anatolian Historical Phonology. Amsterdam: Rodopi.
Melchert, H. Craig. 1993. Cuneiform Luvian Lexicon. Chapel Hill: self-published.
Starke, Frank. 1985. Die keilschrift-luwischen Texte in Umschrift. StBoT 30.