Wiktionary
cash in one's chips
vb. 1 (context idiomatic English) To discontinue an activity, accepting whatever gains or losses one has incurred; to give up. 2 (context idiomatic English) To die.
WordNet
cash in one's chips
v. die; "The old man finally kicked the bucket" [syn: kick the bucket, buy the farm, conk, give-up the ghost, drop dead, pop off, choke, croak, snuff it]