Re: [PATCH v2 3/3] dt/bindings: Add milivolt, milliamps, and nanohenry units

On Tue, 18 Oct 2016, Rob Herring wrote:

On Tue, Oct 18, 2016 at 12:43:48AM +0000, Handrigan, Paul wrote:

quoted

quoted

quoted

 Electricity
 ----------------------------------------
 -microamp      : micro amps
+-milliamp      : milli amps

Please explain why you need need this. Is 2^32 uA not enough range for
you? While we do have multiple units for some, that's because people
picked arbitrary units for their properties before this doc existed.
Ideally, we only have 1 unit to prevent that problem.

2^32 would be enough, however, microamps would not be a good
representation for
this particular entry. For example, if the current limit is 2.1A the
entry will have to be 2100000.  Micro amps will not be the best
representation for this value from a scientific notation perspective.
Since the scale is in miiliamps as it is defined in the data sheet of
this device, it will be best to stay consistent since an error in
conversion
could cause serious problems.

Also, I really don¹t see why adding milliamps and millivolts as being a
major
problems since both of them are commonly used.

As I explained, we want to have some uniformity in properties especially 
across different bindings. That's not something I want to check in every
review. Telling people to add units is enough.

I don't see how adding '000' is a problem.

Rob

Why is it such a big deal to not have a representation for all the common 
units of measurement? They are already defined so why not add them to your 
suffix file? I would think that if you are going to make us use this 
suffix devicetree thing, you would not restrict us to use only the units 
you think are appropriate.

I wouldn't think you would restrict us to saying it is a 5700ml Hemi V8 
would you?


Brian