[PATCH v3 1/8] ARM: Samsung: Add register definitions for Samsung S5P SoC camera interface

[Russell King - ARM Linux]

On Mon, Aug 02, 2010 at 02:08:42PM +0200, Pawel Osciak wrote:
> >Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:
> >On Mon, Aug 02, 2010 at 12:32:20PM +0200, Pawel Osciak wrote:
> >> Well, some of them are indeed unused, but it's not an uncommon practice in
> >> kernel and might help future developers.
> >
> >On the other hand, arch/arm is getting soo big that we need to do
> >something about this - and one solution is to avoid unnecessary
> >definitions that we're not using.
> >
> >Another good idea is to put definitions along side the drivers which
> >they're relevant to - maybe in a local driver-name.h file which
> >driver-name.c includes, or maybe even within driver-name.c if they're
> >not excessive.  This has the advantage of distributing the "bloat" to
> >where its actually used, and means that the driver isn't dependent so
> >much on arch/arm or even the SoC itself.
> >
> >Take a look at arch/arm/mach-vexpress/include/mach/ct-ca9x4.h and
> >arch/arm/mach-vexpress/include/mach/motherboard.h - these are the only
> >two files which contain platform definitions which are actually used
> >for Versatile Express.  Compare that with
> >arch/arm/mach-realview/include/mach/platform.h which contains lots
> >more...
> 
> So basically, what you and Mauro are recommending is that we move the *.h
> file with register definitions to drivers/media?

What I'm suggesting is what's been pretty standard in Linux for a long
time.  Take a look at: drivers/net/3c503.[ch], or for a more recent
driver, drivers/net/e1000/*.[ch].  Or drivers/mmc/host/mmci.[ch]

Putting definitions which are only used by one driver in arch/arm/*/include
is silly.