- Put all clock and control unit driver in BUS_PASS_RESOURCE except
for the DE2 CCU as it needs the main CCU to be available.
- Use BUS_PASS_CPU for a20_cpu_cfg as it makes more sense.
- For aw_syscon use SCHEDULER pass as we need it early for drivers
that attach in BUS_PASS_SUPPORTDEV
- For the rest we can use BUS_PASS_SUPPORTDEV
Allwinner H3 and H5 share many internal components, that's why they can
use the same drivers.
This patch adds the compatible strings to enable clock drivers
probing on Allwinner NanoPI NEO2 device.
Tested on: NanoPi NEO2 (by submitter), OrangePi PC2 (by manu)
Submitted by: Manuel Stühn (freebsdnewbie@freenet.de)
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D20069
Since 5.0 DTS the syscon controller have a new compatible as it
exports new subnodes, we currently only use it as a syscon provider
so just add the new compatible.
Tested On: H3
MFC after: 1 month
Recent DTS use the syscon for the emac controller.
We support this but since U-Boot is still using old DTS it was never
needed for us to add this support, but this is a problem when using upstream
recent DTS and will be when U-Boot will catch up.
While here add a new compatible to the aw_syscon driver as Linux changed it ...
It would have been on an actual named pass before, but none were really
appropriate in name. Move it to the recently created SUPPORTDEV pass, which
perfectly describes it and keeps it in the right order.
Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more
difficult for specific syscon drivers to attach to the syscon node and to
get ordering right. Further discussion yielded the following set of
decisions:
- Move syscon_generic to BUS_PASS_DEFAULT
- If a platform needs a syscon with different attach order or probe
behavior, it should subclass syscon_generic and match on the SoC specific
compat string
- When we come across a need for a syscon that attaches earlier but only
specifies compatible = "syscon", we should create a syscon_exclusive driver
that provides generic access but probes earlier and only matches if "syscon"
is the only compatible. Such fdt nodes do exist in the wild right now, but
we don't really use them at the moment.
Additionally:
- Any syscon provider that has needs any more complex than a spinlock solely
for syscon access and a single memory resource should subclass syscon
directly rather than attempting to subclass syscon_generic or add complexity
to it. syscon_generic's attach/detach methods may be made public should the
need arise to subclass it with additional attach/detach behavior.
We introduce aw_syscon(4) that just subclasses syscon_generic but probes
earlier to meet our requirements for if_awg and implements #2 above for this
specific situation. It currently only matches a64/a83t/h3 since these are
the only platforms that really need it at the time being.
Discussed with: ian
Reviewed by: manu, andrew, bcr (manpages, content unchanged since review)
Differential Revision: https://reviews.freebsd.org/D13793
