[PATCH v3 1/3] mfd: mc13xxx: add device tree probe support

On Wed, Dec 21, 2011 at 09:25:21AM +0800, Shawn Guo wrote:

On Tue, Dec 20, 2011 at 11:25:27PM +0000, Mark Brown wrote:

quoted

It's unique but I feel the disadvantages in terms of legibility of the
resulting device trees are substantial - we want humans to be able to
read and write device trees, preferrably without having to dig out the
datasheet for the part.

Eh, device tree is all about describing hardware.  I do not understand
what is wrong with looking at hardware manual when writing dts.

For the same reason we define constants for register names and values
when writing drivers - so humans can make sense of what's in front of
them and to reduce the chance of errors when things are being written.

quoted

So long as the names are reasonably sensible
and can be understood in the case of any lack of clarity we should be
OK.

The problem is even if we have the name defined that way, it has to be
matched to the name used in mc13892 driver somehow, if we want to use
name as the key to find the regulator defined in mc13892 driver as
array mc13892_regulators[].

This doesn't seem like a problem - the most obvious thing would just be
to adjust the strings in the code to correspond to what the device tree
binding says.

quoted

This is the whole reason why I'm saying that you need to define the
names used in the binding - if the names are a defined part of the
binding then there's nothing driver specific about them.

Can you please help me understand how this can be achieved with an
example?  Taking 'mc13892__sw1' as the example, if I read your comment
before correctly, 'sw1' is the name that you are suggesting.  How this
name can be nothing driver specific?  After all, we need to find
regulator MC13892_SW1 defined in mc13892_regulators[] by matching name
'sw1' defined by binding and name 'MC13892_SW1' defined by driver
somehow, if we want to use name to bind the regulator.

Your binding document would say something like "the regulators are bound
using their names as listed below with their enable bits:

  sw1 - SW1 regulator (register X bit Y)

" so in the binding document it would say what strings map onto which
regulators.  Then any driver implementing that binding would pick the
same strings.