Re: [PATCH v2 mvebu-dt64 3/3] arm64: dts: marvell: add DTS for Turris Mox

[Andrew Lunn <andrew@lunn.ch>]

On Wed, Aug 28, 2019 at 05:12:43PM +0200, Marek Beh�n wrote:
> This adds support for the Turris Mox board from CZ.NIC.
> 
> Turris Mox is as modular router based on the Armada 3720 SOC (same as
> EspressoBin).
> 
> The basic board can be extended by different modules.
> If those are connected, U-Boot lets the kernel know via device-tree.
> 
> Since modules can be connected in different order and some modules can
> be connected multiple times (up to three modules containing 8-port
> ethernet switch in DSA configuration can be connected) we decided
> against using device-tree overlays, because it got complicated rather
> quickly. (For example the SFP module can be connected directly to the
> CPU, or after a switch module. There are four cases and all would need
> different SFP overlay. There are two types of switch modules (8-port
> with pass-through and 4-port with no pass-through). For those we would
> again need at least 6 more overlays.)
> 
> We therefore decided to put all the possibly connected devices in one
> device-tree and disable them by default. When U-Boot finds out which
> modules are connected, it fixes the loaded device-tree accordingly just
> before boot. By Rob Herring's suggestion we also made it so that U-Boot
> completely removes nodes which are disabled after this fixup.
> 
> Signed-off-by: Marek Beh�n <marek.behun@nic.cz>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Gregory CLEMENT <gregory.clement@bootlin.com>
> Cc: Andrew Lunn <andrew@lunn.ch>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew