Subject: Re: [PATCH] cpm: Describe multi-user ram in its own device node.

From: Vitaly Bordug <[email-masked]>
Date: Sat, 29 Sep 2007 00:30:05 +0400

Kumar,

Realizing this may suffer a bit from cleanest-dts flame war, but anyway I pretty much see a lot of
sense in getting this in during next merge window. Is this possible?

On Fri, 28 Sep 2007 14:06:16 -0500
Scott Wood wrote:

> The way the current CPM binding describes available multi-user (a.k.a.
> dual-ported) RAM doesn't work well when there are multiple free regions,
> and it doesn't work at all if the region doesn't begin at the start of
> the muram area (as the hardware needs to be programmed with offsets into
> this area).  The latter situation can happen with SMC UARTs on CPM2, as its
> parameter RAM is relocatable, u-boot puts it at zero, and the kernel doesn't
> support moving it.
> 
> It is now described with a muram node, similar to QE.  The current CPM
> binding is sufficiently recent (i.e. never appeared in an official release)
> that compatibility with existing device trees is not an issue.
> 
> The code supporting the new binding is shared between cpm1 and cpm2, rather
> than remain separated.  QE should be able to use this code as well, once
> minor fixes are made to its device trees.
> 
> Signed-off-by: Scott Wood <[email-masked]>
Acked-by: Vitaly Bordug <[email-masked]>

> ---
>  Documentation/powerpc/booting-without-of.txt |   40 ++++++-
>  arch/powerpc/Kconfig.debug                   |    6 +-
>  arch/powerpc/boot/cpm-serial.c               |   44 +++++--
>  arch/powerpc/boot/dts/ep88xc.dts             |   13 ++-
>  arch/powerpc/boot/dts/mpc8272ads.dts         |   11 ++
>  arch/powerpc/boot/dts/mpc885ads.dts          |   13 ++-
>  arch/powerpc/boot/dts/pq2fads.dts            |   13 ++-
>  arch/powerpc/sysdev/commproc.c               |   11 ++-
>  arch/powerpc/sysdev/cpm2_common.c            |   36 ++----
>  arch/powerpc/sysdev/cpm_common.c             |  159 ++++++++++++++++++++++++++
>  drivers/serial/cpm_uart/cpm_uart_cpm2.c      |    4 +-
>  include/asm-powerpc/commproc.h               |   12 ++
>  include/asm-powerpc/cpm.h                    |   14 +++
>  include/asm-powerpc/cpm2.h                   |   10 ++
>  14 files changed, 338 insertions(+), 48 deletions(-)

-- 
Sincerely, Vitaly