Re: [PATCH 0/4] Series to add device tree naming to i2c

Olof Johansson wrote:

On Mon, Dec 03, 2007 at 04:20:32PM -0500, Jon Smirl wrote:

quoted

The following series implements standard linux module aliasing for i2c modules
It then converts the mpc i2c driver from being a platform driver to an open
firmware one. I2C device names are picked up from the device tree. Module
aliasing is used to translate from device tree names into to linux kernel
names. Several i2c drivers are updated to use the new aliasing. 

May I ask why you want to modify the i2c layer instead of keeping the
OF->i2c driver mapping in PPC code?

Because it doesn't belong there -- at the least, it should be in 
drivers/of.  But putting it in the driver is better, IMHO.

It seems simpler to keep it in the
PPC-specific code, since otherwise you might end up with confused i2c
driver writers that make up their own OF names without knowing for sure
that's what will be used. No?

How is this different from drivers that have of_platform bindings?

That said, there should probably be some sort of tag to indicate the 
namespace being matched against (OF, Linux, etc), to avoid matching an 
OF device with a non-OF name (or vice versa).

I recently posted (and asked Paulus to pull) a patch where I consolidate
the fsl_soc mapping code so I can also use that on pasemi, and modified
the pasemi platform code to setup the board_info from the device tree
accordingly.

Having just one bit i2c glue code for arch/powerpc is certainly an 
improvement over the current situation, but it's not really powerpc 
specific.  Just because other architectures don't use it now doesn't 
mean they won't in the future -- and I don't like the "we'll move it 
when they do" argument because I want to make it easy for other 
architectures to decide to use it. :-)

-Scott