Reducing number of Espressobin DTS files

[Pali Rohár]

Hello!

For Espressobin A3720 board there are currently 4 DTS files:

https://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu.git/tree/arch/arm64/boot/dts/marvell/armada-3720-espressobin.dts?h=for-next
https://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu.git/tree/arch/arm64/boot/dts/marvell/armada-3720-espressobin-emmc.dts?h=for-next
https://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu.git/tree/arch/arm64/boot/dts/marvell/armada-3720-espressobin-v7-emmc.dts?h=for-next
https://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu.git/tree/arch/arm64/boot/dts/marvell/armada-3720-espressobin-v7.dts?h=for-next

There are two board revisions (V5 and V7) and each has variant with and
without eMMC.

V5 and V7 DTS files differs order of ethernet switch ports and presence
of led2 (not in next branch yet).

I would like to ask, do we need two DTS files for eMMC and non-eMMC
variants? Is there any issue if we enable sdhci0 globally for all
Espressobin board and therefore reduce number of DTS variants?

For example, Turris MOX board which is also A3720 based has optional
SDIO module which can be plugged / unplugged, standard variant is sold
without it and in DTS file is this node always enabled:

https://git.kernel.org/pub/scm/linux/kernel/git/gclement/mvebu.git/tree/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts?h=for-next#n178

Could not we enable by default this node also on Espressobin? It is a
problem if node for eMMC is enabled also on board without eMMC? As it
would simplify configuration, compilation and setup of system for
Espressobin boards.