Re: Strange location and name for platform devices when device-tree is used.

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Fri, 2013-11-01 at 14:59 +1100, NeilBrown wrote:
> and I wonder how relevant it still is in this context.  As platform devices
> are all in the root of the device-tree and hence are siblings, they must have
> unique names in the device-tree and  so the platform devices created from
> them will also have unique names -- won't they?

I agree about /sys/devices -> /sys/devices/platform, that makes more
sense

The problem with names is that we don't *know* that your devices are
at the root and unique. They don't have to be. I have platforms that
have several "chips" each containing all the same devices. They need to
be de-duped.

Maybe the right approach is to build the de-duplication in sysfs
itself ?

Cheers,
Ben.

> Any help understanding and/or fixing this discrepancy greatly appreciated.
> 
> The change of name is particularly annoying to me because one of my platform
> devices is a pwm_bl.c backlight.  With a boardfile I
> get /sys/class/pwm_backlight.  With devicetree the best I can get
> is /sys/class/pwm_backlight.23 (or similar).  It would be really nice to have
> a more stable and sensible name here.