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

[Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>]

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