# Re: dcr stuff.

- From: Josh Boyer \<hidden\>
- Date: 2008-03-22 01:18:40 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2008/03/9437105
- Thread: https://ratatoskr.run/linuxppc-dev/2008/03/9437089/t.md

```text
On Fri, 21 Mar 2008 12:05:40 -0700
"Stephen Neuendorffer" [ref] wrote:

> 
> Is anybody working on the dcr infrastructure?
> 
> In particular, there seems to be inconsistency between what the kernel
> does and what ePAPR thinks it should.  The code in the kernel selects
> mmio or native access based on a Kconfig parameter and uses some device
> tree parameters to correctly configure the mmio access, whereas ePAPR
> doesn't seem to document all the device tree attributes (in particular,
> dcr-mmio-stride and dcr-mmio-range) and provides a dynamic binding for
> dcr-access-method...

Code can be fixed if needs be.  Keep in mind that ePAPR isn't publicly
available yet.

> Is there a plan here?  (In particular, in FPGA designs, its possible to
> have crazy things like multiple independent dcr busses, some using
> native access, some using mmio.  Or even if there is one bus, many of
> the existing non-linux drivers we have assume native or mmio access.
> I'd like to clean this up, obviously.. :)

Clean it up how?  I'd hate to add bloat to boards with native DCR
access just because a few require oddities.

If it ain't broke, don't fix it.

josh
```