linux-imx

ARM: dts: omap4: Add l4 interconnect hierarchy and ti-sysc data

Let's add proper interconnect hierarchy for l4 interconnect
instances with the related ti-sysc interconnect module data as
documented in Documentation/devicetree/bindings/bus/ti-sysc.txt.

Using ti-sysc driver binding allows us to start dropping
legacy platform data in arch/arm/mach-omap2/omap*hwmod*data.c
files later on in favor of ti-sysc dts data.

For setting up a proper hierarchy for the interconnect and
ti-sysc data, there are multiple reasons:

1. We can use dts ranges to protect registers from being
   ioremapped from other devices and prevent hard to track
   issues with failed flush of posted write between modules

2. Some of the ranges may not be accessible to operating systems
   at all if configured so on high-security devices

3. The interconnect hierarchy provides proper clockdomain
   hierarchy that can be used for genpd later on

4. We can avoid almost all deferred probe related issues simply
   by probing the resource providing interconnect instance first
   for l4 wkup instance

5. With deferred probe issues gone, we can probe everything
   later at module_init time except for system timer and interrupt
   controller and their clocks.

This data is generated based on platform data from a booted system
and the interconnect acces protection registers for ranges. To avoid
regressions, we initially validate the device tree provided data
against the existing platform data on boot.

Each interconnect instance is typically divided into segments
to avoid powering up the whole interconnect. And each segment
has one or more ranges TI specific interconnect target modules
connected to it. Some devices can also have a separate data
access port directly to the parent L3 interconnect for DMA that
can be set up as a separate range.

Note that we cannot yet include this file from omap4.dtsi
until child devices are moved to their proper locations in
the interconnect hierarchy in the following patch. Otherwise
we would have the each module probed twice.

Also note that this does not yet add l4 abe instance, that will
be added separately later on.

Signed-off-by: Tony Lindgren <tony@atomide.com>