Re: [PATCH 1/5 v2] Add the explanation and a sample of RapidIO DTS sector to the document of booting-without-of.txt file.

Segher Boessenkool
2007-06-29T09:49:55Z

>> No. The #address-cells is determined by the bus binding,
>> so that all RapidIO busses on the planet can be represented
>> in a similar way in the OF device tree. Take for example
>> the PCI binding, which gives you three address cells -- one
>> to distinguish between different address spaces (configuration
>> space, legacy I/O space, memory mapped space) and to contain
>> some flags (prefetchable vs. non-prefetchable, etc.); the
>> other two 32-bit cells contain a 64-bit address, although
>> config and legacy I/O never are more than 32 bit, and many
>> PCI devices can't do 64-bit addressing at all.
>>
>> Now, there is no OF binding for RapidIO yet of course, but
>> it would be good to start thinking about one while doing
>> the binding for your specific controller -- it will make
>> life easier down the line for everyone, including yourself.
>>
> How about I add more words here for more clear expression?
> Such as "<2> for 34 and 50 bit address, <3> for 66 bit address".

You should more explicitly define the address format, i.e.
what every bit means -- just saying it is 64 or 96 bits isn't
enough. While you're doing that, think of a way that can
represent _every possible_ RapidIO address, not just the ones
supported by this particular controller.

Segher