ios - how to only allow uiscrollview when on a 3.5 inch Iphone -

i'm working on ios app simple view (some text + photo). looks fine on iphone 5 end screen size. on iphone 4s 3.5 inch screen need more spacing, want use uiscrollview this. other screen sizes wouldn't make sense.

how use allow user scroll when app installed on iphone 4s.

i've found of answer i'm developing swift couldn't figure out.

thanks!

if set contentsize of scroll view 4 inch screen size (320 x 568, minus pixels navigation & status bar), not allow scrolling on iphone 5 , higher, will scroll smaller screens.