A cop cant drive away with your phone when he already looked thorugh it can he?

i gave the officer concent to look through my phone since he said he would get a warent if i didnt let him. so i did then he said he had to take it to the station for pictures????? this is ****** up. not only that this all happend cuz i was walkin accros the crosswalk and decided to curve off a little to get to the otherside faster. he held my hands behind my back and told me if i kept moving he would put handcuffs on. i was not moving at all he just wanted an excuse to search me cuz he had no right! is this ****** up? i mean yeah he found hella weed but still he can't just do that!!!!!!!!!!!