From mboxrd@z Thu Jan 1 00:00:00 1970 From: david.goodenough@btconnect.com (David Goodenough) Date: Fri, 30 Jan 2015 13:32:47 +0000 Subject: [PATCH] ARM: dts: mvebu: add ethernet to the cm-a510 board In-Reply-To: <54CB822B.8080809@gmail.com> References: <1507191.iMZ4oC8rrr@stargate> <54CB822B.8080809@gmail.com> Message-ID: <3064359.D6vvF0Rimq@stargate> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Friday 30 January 2015 14:07:55 Sebastian Hesselbarth wrote: > [Re-adding the most obvious People to Cc] > > On 30.01.2015 13:44, David Goodenough wrote: > > On Friday 30 January 2015 13:03:59 Sebastian Hesselbarth wrote: > >> On 30.01.2015 12:41, Jean-Francois Moine wrote: > >>> On Fri, 30 Jan 2015 12:00:16 +0100 > >> > >>> Sebastian Hesselbarth wrote: > >> That what dtsi's are made for with one exception: the dtsi cannot "run" > >> on its own but needs at least one baseboard.dts that includes it. We > >> could create a "bare"-baseboard that represents what is (easily) > >> accessible on the SoM itself. Given the fact that even UART0 needs a > >> baseboard that grabs it from the SoM connector, I see no value in that. > >> > >>> In any case, any real cm-a510 board should work with the > >>> generic/full .dts even if some hardware modules are lacking. No? > >> > >> Nope. The cm-a510 is just an add-on for a baseboard, it does not make > >> a working board. Just think of it as a feature-improved SoC. > > > > This sounds like capes on the BeagleBoard. Are these extension boards > > self-identifying? If so then the approach used with the capes might work > > here too. > > David, > > IMHO capes are a different thing. The BB can run just fine without any > cape installed, the cm-a510 cannot run without a baseboard. Also, once > you have your SoM installed it cannot change over runtime, there is no > need for any dynamic overlays and such. > > You can build some 5 or 10 different configurations given the SoM and > a specific baseboard but not hundreds of possible combinations. > Besides, Gabriel is the first in almost 2 years that actually has an > cm-a510 - so, I doubt we'll have to mainline dozens of baseboards > using the cm-a510 in the near future. > > Regarding the self-identification, it would be great if the actual SoM > configuration would be stored in the (always available) SPI flash, but > from my experience with the boards I have seen so far, I have a bad > feeling about it ;) A quick look at the sb-a510 (the compulab baseboard > for cm-a510) suggests that there is more configuration available but > by jumpers that (hopefully) can be read out by GPIOs at least. > > The best similar board available in mainline I can remember is the > SolidRun Hummingboard, i.e. one baseboard that can be equipped with > 3-4 different SoMs. Ah this sounds like history repeating itself. I have some old PC-104 Compulab boards which had pluggable CPUs. They were x86 based, so DTS was not a question. I guess that the only approach is to start with the plugin, and then add the baseboard as a standard include. David > > Sebastian > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel