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

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

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...