Re: [RFC v1 0/5] ARM: Initial support for Marvell Armada 1500

From: Sebastian Hesselbarth
Date: Tue Aug 27 2013 - 12:45:56 EST


On 08/27/13 16:19, Thomas Petazzoni wrote:
On Fri, 16 Aug 2013 21:41:33 +0200, Sebastian Hesselbarth wrote:
This is a RFC adding initial support for the Marvell Armada 1500
(88DE3100) found on various consumer devices (Chromecast, GoogleTV).

Actually, it is a two-fold RFC also raising discussions on mach-mvebu
cleanup roadmap to allow other SoCs to hop into it. While mach-mvebu
originally was created to add support for Armada 370/XP and merge
existing Marvell Orion familiy into it, I am not so sure about
Armada 1500 fits that well (the mbus has gone!).

After talking a bit with engineers within Marvell that work on this
SoC, I'm inclined to think that using mach-mvebu for this family of SoC
is not a good idea.

Thomas,

thanks for the info below. Reading a little bit through the GPL'ed
source, I also quickly came to the same conclusion. It is more likely
we can reuse some stuff from other SoCs than Orion or Armada 370/XP.

The reasons are:

* This family of SoC is architecturally completely different from the
family of Orion SoC: they use completely different hardware blocks
(i.e none of the plat-orion stuff would apply, and none of the
Orion device drivers would be useful), they don't use the MBus
mechanism, etc. They are really a different family of SoC, almost as
if they were coming from a different SoC company.

* The SMP and power management code, as well as all the "glue"
platform code that typically sits in mach-<foo> is going to be
substantially, if not completely different from the one in
mach-mvebu. I already believe doing all the "glue" platform code in
mach-mvebu for all of Kirkwood, Dove, 370/XP, Orion5x and MV78xx0 is
going to be a challenge, so I'd suggest to not add to this challenge
a completely separate family of SOCs.

The codename used for those Armada 1500 SOCs is "Berlin", so a name
like mach-berlin, or mach-mvberlin (if we want to keep 'mv' to identify
the founder) seems like a good name.

I have already moved it under mach-mv88de3xxx as for now, all SoCs
Marvell is providing as DE (Digital Entertainment) fit in that. I like
mach-codename style more than plain numbers, maybe I rename the folder
to mach-berlin before posting.

Speaking of "berlin", they found a 2WW bomb in my home town center today
and are evacuating apartments. Mine too, so it looks like I'll have
some time to prepare v2 tonight..

Also, to help us understand the organization of the family of SOCs, I
asked a few informations to Marvell, and here is what I could collect:

"""
BGxname CPU core codename L2 cache controller internal name
BG2 PJ4B Armada1500 Tauros3 MV88DE3100
BG2-CT Cortex-A9 N/A PL310 N/A
BG3 Cortex-A15 N/A CA15 integrated N/A
"""

As was told that the Armada X or MV88DEx names are not used during
development, and what Marvell is really using are the BGxx names.

Ok, I'll add that info to Marvell SoC documentation also.

Sebastian

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