Subject: Re: [PATCH 2/6] PowerPC 440EPx: Sequoia DTS

From: Segher Boessenkool <[email-masked]>
Date: Mon, 6 Aug 2007 22:20:01 +0200

>>> +     - compatible : should contain the specific model of flash 
>>> chip(s) used
>>> +       followed by either "cfi-flash" or "jedec-flash"
>>
>>     This "compatible" prop (and the node in whole) doesn't say a
>> thing about how the flash is mapped into the CPU address space.  I
>> strongly disagree that this node provides enough info to select a
>> driver. :-/
>
> To be honest, I'm not sure that describing the mapping is really the
> job of the compatible property.  That the flash is mapped into the
> address space is kind of implicit in the way the reg interacts with
> the parents' ranges property.

Exactly.

> Can you describe some of the options for *not* direct mapped flash
> chips - I can't reasonably come up with a way of describing the
> distinction when I've never seen NOR flash other than direct mapped.

What, you've never seen SPI flash or IIC flash?  :-)

Not that these are handled by the MTD framework AFAIK.

Segher