Can't decode a simple ARM function prototype from a dissasembly?

I can't figure out the prototype for this simple function:

In stack:

Function call:

That's what I got so far, and it causes an error.

//No idea
void CameraDeviceCreate(int开发者_开发知识库 one,int two,int* three);

There are three registers used (R0,R1,R2) so there should be three arguments. Third one refers to a stack variable (I still don't get how that works). #0x28 (var_28) is only mentioned in the ADD call, not sure what it could be. Where did I make a mistake?

If I missed some info out tell me and I'll add it. This is from Camera.framework by the way.

Why do you think you have it wrong?

Note, there is no guarantee that the third parameter is 'int*' - you need to look at what is in R4 at that point - I would guess its actually some sort of structure being pointed at, rather than an int.