[U-Boot] [PATCH] serial: ns16550: Add register shift variable

[Felix Brack]

On 16.07.2018 14:42, Wolfgang Denk wrote:
> Dear Felix,
> 
> In message <1b0d33fa-adfb-9825-5ae8-8bded1678c0c at ltec.ch> you wrote:
>>
>>>> This needs to be rewritten.
>>>
>>> To try and help clarify, the property in question means "quantity to
>>> shift the register offsets by."  It should be clear in our Kconfig help
>>> entry as well that this is what we're looking for.
>>>
>> Thanks for this! The help text will be fixed in v2.
> 
> None of the places I could find in the Linux
> Documentation/devicetree/bindings directory actually explains what
> "shift the register offsets" means.   Only the code reveals that
> this means a LEFT shift of the register address (offset).
> 
> At least one place in Linux interprets <reg-shift> differently; here
> it operates on the _data_ (instead there they use <reg-spacing>):
> 
> "devicetree/bindings/ipmi/ipmi-smic.txt":
> 
> - reg-shift - The amount to shift the registers to the right to get the data
>         into bit zero.
> 
> (see ipmi_si_mem_io.c
> 
> 
> So can we please add an explanation what _exactly_ this means?
>
I will propose one with v2 post.

> Thanks.
> 
> 
> Wolfgang Denk
> 

regards, Felix