[U-Boot] litesom.c: Board stuff in SOC ?

[Stefano Babic]

Hi Tom,

On 19/05/2017 15:39, Tom Rini wrote:
> On Fri, May 19, 2017 at 12:51:18PM +0200, Stefano Babic wrote:
>> Hi Marcin,
>>
>> On 19/05/2017 12:41, Marcin Niestroj wrote:
>>> Hi Stefano,
>>>
>>> I've added Tom to the discussion.
>>
>> Of course !
>>
>>> So if we make some changes to SOM
>>> code position in u-boot tree, let's make sure we do it for all
>>> architectures the same 
>>
>> We have already not done in this way. We have all boards / SOM code
>> inside bords/, the only exceptions are yours. If there is a decision to
>> add an abstraction for SOM, we have to put coherently all SOMs that are
>> now stored in the boards directory.
>>
>> What you mention are just exception - that I would like to clean up.
> 
> So, we do have a problem with the layout today.

Indeed, true. There is not an abstraction for SOM today.

>  The point of SOMs is
> that yes, you can drop them into a carrier from the same vendor (and
> this is true for both "3rd party" ones like
> litesom/chilisom/solidrun/etc and vendor ones like more recent NXP eval
> boards) or company X buys the SOMs and puts them in their own custom
> carrier (which hell, we have customers that do).

Right, this is the common case.

>  In the latter case, it
> doesn't make sense for company X to put their board in
> boards/SOM-vendor/.

The question is how they reference to the common / SOM code. I am quite
sure that the object should be part of the board library, that is at the
end part of board/<vendor>/<board name>/lib.a.

> 
> In my mind, arch/arm/mach-omap2/am33xx/chilisom.c is the right solution
> and the big problem with i.MX right now is that arch/arm/imx-common and
> arch/arm/cpu/armv7/mx* need to get some re-organization under
> arch/arm/mach-imx/.

Sure the SOM code should be not under cpu/....mx6. This is wrong.

imx-common was created (as far as I can still remember) as solution to
put code shared between all i.MX processors, from imx.2x up to i.MX6 or
i.MX7. Code that does not belong to a single SOC.

As far as I see, there is not a single solution for SOM in u-boot. In
some cases (what you mention) are in mach-*, in some other cases they
are under board/<vendor>. Just check the number of "common" directories
under boards. In most cases they are SOM, and I am sure I am still
missing a lot of them.


>  And I'm not going to claim that arch/arm/mach-omap2
> is best organized here, I largely moved the old omap-common to
> mach-omap2 and everything else into subdirs of that.

Nevertheless, this is a much more sustainable solution. If imx-common is
changed into mach-imx, and it contains subdirectories for the specific
type, we could simplify imx-common/Makefile, that is become messy with
two many filters in a way as in mach-omap2.
And then, moving litesom.c in a place as arch/arm/mach-imx/som/mx6 seems
much more appropriate.

>  I can certainly
> see an argument for arch/arm/mach-$X/som/ (or mach-$X/$soc/som/) instead
> of just putting them in arch/arm/mach-$X/ (or again, mach-$X/$soc/).

mach-$X/$soc/som/ is  my preferred choice if we vote.. :-)

Best regards,
Stefano

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