MFC r348153-r348155: gpioled: add a new hint for initial state

hint.gpioled.%d.state determines the initial state of the LED when the
driver takes control over it:
0 - the LED is off
1 - the LED is on
-1 - the LED is kept as it was

While here, add a module version declaration.

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

MFC r308428:

Refactor FDT part of gpioled driver

- Split driver in two parts: FDT and non-FDT
- Instead of reattach gpioled nodes to GPIO bus use
gpio_pin_get_by_ofw_idx and add ofwbus and simplebus as parrent buses

Reviewed by: loos
Differential Revision: https://reviews.freebsd.org/D8233

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

Get rid of two consumers of gpiobus acquire/release.

The GPIO hardware should not be owned by a single device, this defeats any
chance of use of the GPIO controller as an interrupt source.

ow(4) is now the only consumer of this 'feature' before we can remove it
for good.

Discussed with: ian, bsdimp

Fix probe routine to return BUS_PROBE_DEFAULT instead of BUS_PROBE_SPECIFIC.

While here fix a few style(9) issues.

Add OF_prop_free function as a counterpart for OF_*prop_alloc

- Introduce new OF API function OF_prop_free to free memory allocated by
OF_getprop_alloc and OF_getencprop_alloc. Current code just calls free(9)
with M_OFWPROP memory class which assumes knowledge about OF_*prop_alloc
functions' internals and leads to unneccessary code coupling

- Convert some of the free(..., M_OFWPROP) instances to OF_prop_free

Files affected by this commit are the ones I was able to test on real
hardware. The rest of free(..., M_OFWPROP) instances will be handled with
idividual maintainers

Reviewed by: andrew
Differential Revision: https://reviews.freebsd.org/D6315

Use DEVMETHOD_END instead of its value to indicate end of methods table

gpioled(4) depends on gpiobus.

This fixes the loading of gpioled as a module.

Sponsored by: Rubicon Communications (Netgate)

This implements default-state support as described in:

https://www.kernel.org/doc/Documentation/devicetree/bindings/leds/leds-gpio.txt

Without this booting the VSATV102 causes the blue "working" led to turn
off when the kernel starts up. With this the led (which is turned on by
the firmware) stays on since that's the default state specified in the FDT.

Expanded the meaning of the led_create_state state parameter in order
to implement support for "keep". The original values were:

== 0 Off
!= 0 On

The new values are:

== -1 don't change / keep current setting
== 0 Off
!= -1 && != 0 On

This should have no effect on acpi_asus_attach which only calls
led_create_state with state set to 1. Updated acpi_ibm_attach
in order to avoid surprises.

Differential Revision: https://reviews.freebsd.org/D2615
Submitted by: John Wehle
Reviewed by: gonzo, loos

Handle multiple "gpio-leds"-compatible nodes

There are cases when gpioled nodes in DTS come from different sources
(e.g. standard Beaglebone Black LEDs in main DTS + shield LEDs in
overlay DTS) so instead of handling only first compatible node go
through all child nodes

Add ofw_gpiobus_parse_gpios(), a new public function, to parse the gpios
property for devices that doesn't descend directly from gpiobus.

The parser supports multiple pins, different GPIO controllers and can use
arbitrary names for the property (to match the many linux variants:
cd-gpios, power-gpios, wp-gpios, etc.).

Pass the driver name on ofw_gpiobus_add_fdt_child(). Update gpioled to
match.

An usage example of ofw_gpiobus_parse_gpios() will follow soon.

Fix the build of non-FDT systems by moving the gpiobusvar.h header outside
the FDT #ifdef.

While here remove a few unused headers.

Fix the gpiobus locking by using a more sane model where it isn't necessary
hold the gpiobus lock between the gpio calls.

gpiobus_acquire_lock() now accepts a third parameter which tells gpiobus
what to do when the bus is already busy.

When GPIOBUS_WAIT wait is used, the calling thread will be put to sleep
until the bus became free.

With GPIOBUS_DONTWAIT the calling thread will receive EWOULDBLOCK right
away and then it can act upon.

This fixes the gpioiic(4) locking issues that arises when doing multiple
concurrent access on the bus.

Add OFW support to the in tree gpio compatible devices: gpioiic(4) and
gpioled(4).

Tested on RPi and BBB (using the hardware I2C controller and gpioiic(4) for
the I2C tests). It was also verified for regressions on RSPRO (MIPS/ar71xx)
used as reference for a non OFW-based system.

Update the gpioled(4) and gpioiic(4) man pages with some details and
examples about the FDT/OFW support.

Some compatibility details pointed out by imp@ will follow in subsequent
commits.

Approved by: adrian (mentor, implicit)

Move the GPIOBUS_SET_PINFLAGS(..., ..., pin, GPIO_PIN_OUTPUT) to led(4)
control callback function. This makes gpioled(4) works even if the pin
is accidentally set to an input.

Approved by: adrian (mentor)

Set the pin to output on attach, we can't assume it already is.

Reviewed by: gonzo

Fix legal staff in GPIO sources:
- license clause now contains "AUTHOR AND CONTRIBUTORS"
instead of just "AUTHOR"
- Add license/copyright to gpioc.c

Spotted by: Edward Tomasz Napierala, Andrew Turner

Initial GPIO bus support. Includes:
- GPIO bus controller interface
- GPIO bus interface
- Implementation of GPIO led(4) compatible device
- Implementation of iic(4) bus over GPIO (author: Luiz Otavio O Souza)

Tested by: Luiz Otavio O Souza, Alexandr Rybalko