• All "* devh" should be "*devh"
• The function prototypes are not aligned, they have varying numbers of space to the left of the function identifier.

Maybe a checkin with only white-space changes is in order.

• In the function prototypes the asterisks for pointers should all be consistent without a space next to the identifier. All "* ctx" should be "*ctx".
• There is no need to cast the argument of free(), since it takes a ptr-to-void and they are assignment compatible to any pointer.