MFC r307943-r307944, r308698

r307943 by andrew:
Remove the need for the delay to be zero when MULTIDELAY is undefined,
it may be useful to only enable this in some configs.

Sponsored by: ABT Systems Ltd

r307944 by andrew:
Add MULTIDELAY support to the am335x dmtimer. This will be useful for
testing Cortex-A8 support in GENERIC.

Sponsored by: ABT Systems Ltd

r308698 by loos:
After r308533, the platform compatible string must be an exact match.

Use "ti,am33xx" instead of "ti,am335x", which gives an exact match in every
DTS we support.

This fixes the boot on TI SoCs after r308533.

Suggested by: gonzo
Sponsored by: Rubicon Communications, LLC (Netgate)

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove all dregs of the old PPS driver from this code, in preparation for
redoing it as a separate driver. Now that each hardware timer is handled by
a separate instance of the timer driver, it no longer makes sense to bundle
the pps driver with the regular timecounter code. (When all 8 timers were
handled by one driver there was no choice about this.)

Split the hardware register definitions out to their own file, so that the
new pps driver (coming in a separate commit later) can share them.

With the PPS driver gone, the question of which hardware timer to use for
what purpose becomes much easier (some instances can't do the PPS capture).
Now we can just hardcore timer2 for eventtimer and timer3 for timecounter.

This also now only instantiates devices for the 2 hardware timers actually
used to implement eventtimer and timecounter. This is required so that
other drivers can come along and attach to other hardware timers to provide
other functionality. (In addition to PPS, this hardware can also do PWM
stuff, general pulse width and frequency measurements, etc. Maybe some
day we'll have drivers for those things.)

Make this compile again when PPS_SYNC is defined. Also remove a couple
comment blocks and constants that no longer apply.

Switch TI platform support code from using FreeBSD's custom-baked DTS
files to vendor-provided ones. It should make easier to adopt platform
code to new revisions of hardware and to use DTS overlays for various
Beaglebone extensions (shields/capes).

Original dts filenames were not changed, they're now wrappers over dts
files provided by TI. So make sure you update .dtb files on your
devices as part of kernel update

GPIO addressing was changed: instead of one global /dev/gpioc0 there
are per-bank instances of /dev/gpiocX. Each bank has 32 pins so for
instance pin 121 on /dev/gpioc0 in old addressing scheme is now pin 25
on /dev/gpioc3

On Pandaboard serial console devices was changed from /dev/ttyu0 to
/dev/ttyu2 so you'll have to update /etc/ttys to get login prompt
on serial port in multiuser mode. Single user mode serial console
should work as-is

Differential Revision: https://reviews.freebsd.org/D2146
Reviewed by: rpaulo, ian, Michal Meloun, Svatopluk Kraus

Stop using machine/fdt.h in the arm kernel code when we don't need it.

Change the name of the dmtimer pps device from /dev/ppsN to /dev/dmtppsN.

ntpd is hard-coded to use /dev/ppsN, and typically when multiple PPS sources
are available the sysadmin will symlink the right one(s) to /dev/ppsN, so
it's best to not usurp those names directly.

Replace many pasted identical definitions of cpu_initclocks() with a common
implementation in arm/machdep.c. Most arm platforms either don't need to
do anything, or just need to call the standard eventtimer init routines.
A generic implementation that does that is now provided via weak linkage.
Any platform that needs to do something different can provide a its own
implementation to override the generic one.

Follow r261352 by updating all drivers which are children of simplebus
to check the status property in their probe routines.

Simplebus used to only instantiate its children whose status="okay"
but that was improper behavior, fixed in r261352. Now that it doesn't
check anymore and probes all its children; the children all have to
do the check because really only the children know how to properly
interpret their status property strings.

Right now all existing drivers only understand "okay" versus something-
that's-not-okay, so they all use the new ofw_bus_status_okay() helper.

Fix a typo that caused a loop to run beyond the end of the array it was
searching. If you didn't configure a timer capture pin you'd get a data
abort as it wandered into the weeds, now you get a nice warning message
about your config, as originally intended.

Add PPS support to the am335x timer driver. This uses the timer hardware's
capture mode together with the timecounter's PPS polling feature to get
very accurate PPS capture without any interrupt processing (or latency).

Hardware timers 4 through 7 have associated capture-trigger input pins.
When the PPS support is compiled in the code automatically chooses the
first timer it finds that has the capture-trigger pin set to input mode
(this is configured via the fdt data).

A variety of cleanups...
- Use named constants for register bits, instead of mystery numebrs
scattered around in the code.
- Use inline functions for bus space read/write, instead of macros
that rely on global variables.
- Move the timecounter struct into the softc instead of treating it
as a global variable. Backlink from it to the softc.
- This leaves a pointer to the softc as the only static/global variable
and it's now used only by DELAY().

Map out all the timer-related registers, and define named constants for
the bits within the registers.

Shorten the DMTIMER_ prefix used for register names to DMT_. This is in
preparation for adding more complete register defintions, some of which
have fairly long names.

Similar to r255816, fix the math for the DELAY() calculation. It was off
by a really small amount because of the higher timer resolution.

Approved by: adrian (mentor)
Verified on: BBB

Remove #include <machine/frame.h> from all the arm code that doesn't
really need it. That would be almost everywhere it was included. Add
it in a couple files that really do need it and were previously getting
it by accident via another header.

MFcalloutng:
Switch eventtimers(9) from using struct bintime to sbintime_t.
Even before this not a single driver really supported full dynamic range of
struct bintime even in theory, not speaking about practical inexpediency.
This change legitimates the status quo and cleans up the code.

Fix spelling.

remove duplicate semicolons where possible.

Approved by: cperciva
MFC after: 1 week

Merging of projects/armv6, part 10

- Support for Texas Instruments SoCs:
- AM335x
- OMAP4

- Kernel configs, DTS for Beaglebone and Pandaboard

Submitted by: Ben Gray, Damjan Marion