Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r265012, r265191, r265289, r265310

r265012:
Fix the gpio-specifier decoding by respecting the GPIO controller's
#gpio-cells property.

Add a new ofw_bus method (OFW_BUS_MAP_GPIOS()) that allows the GPIO
controller to implement its own mapping to deal with gpio-specifiers,
allowing the decoding of gpio-specifiers to be controller specific.

The default ofw_bus_map_gpios() decodes the linux standard (#gpio-cells =
<2>) and the FreeBSD standard (#gpio-cells = <3>).

It pass the gpio-specifier flag field to the children as an ivar variable so
they can act upon.

r265191:
Remove unnecessary headers. Sort out the headers. Add a missing header on
ofw_gpiobus.c (it was working because of sys/libkern.h).

r265289:
eally sort out the headers.

sys/systm.h must always come after sys/param.h.

Remove sys/types.h which should never be included together with sys/param.h.

Add sys/malloc.h for correctness even if it seems to don't be needed.

Remove more unused headers found by unusedinc (from bde@).

r265310:
Move gpiobus routines to dev/gpio. Avoid polluting ofw_bus with bus
specific parts.

MFC r258046, r258047, r258050, r259035, r259036, r259037, r261842, r261843,
r261844, r261845, r261846, r262194, r262522, r262559

r258046:
Fix a typo on a comment in ofw_bus_if.m, the default method will return -1
when a node doesn't exist.

r258047:
Move the KASSERT() check to the point before the increase of number of pins.

r258050:
Fix gpiobus to return BUS_PROBE_GENERIC insted of BUS_PROBE_SPECIFIC (0) so
it can be overriden by its OFW/FDT version.

Give a chance for GPIO devices that implement the device_identify method to
attach.

r259035:
Remove unnecessary includes and an unused softc variable. While here apply
two minor style(9) fixes.

r259036:
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.

r259037:
Fix the pin value reading on AM335x. Because of the inverted logic it was
always returning '0' for all the reads, even for the outputs. It is now
known to work with gpioiic(4) and gpioled(4).

r261842:
Add an OFW GPIO compatible bus. This allows the use of the DTS files to
describe GPIO bindings in the system.

Move the GPIOBUS lock macros to gpiobusvar.h as they are now shared between
the OFW and the non OFW versions of GPIO bus.

Export gpiobus_print_pins() so it can also be used on the OFW GPIO bus.

r261843:
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.

r261844:
Allow the use of OFW I2C bus together with iicbb(4) on OFW-based systems.

This change makes ofw_iicbus attach to iicbb(4) controllers in addition to
the already supported i2c host bridges (iichb).

On iicbb(4) allow the direct access of the OFW parent node by its children,
so they can be directly attached to iicbb(4) node on the DTS without the
need of describing the i2c bus.

r261845:
Allow the use of the OFW GPIO bus for ti_gpio and bcm2835_gpio. With this
change the gpio children can be described as directly connected to the GPIO
controller without the need of describing the OFW GPIO bus itself on the
DTS file.

With this commit the OFW GPIO bus is fully functional on BBB and RPi.

GPIO controllers which want to use the OFW GPIO bus will need similar
changes.

r261846:
Make the gpioled(4) work out of the box on BBB.

Add gpioled(4) to BEAGLEBONE kernel and add the description of the four
on-board leds of beaglebone-black to its DTS file.

r262194:
Remove an unnecessary header.

r262522:
Fix make depend for iicbus.

r262559:
Inspired by r262522, fix make depend. This fixes the build of gpio modules.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Minor printf nit to keep out clean

Properly free gpiobus ivars when gpiobus_parse_pins() fails and also on
gpiobus detachment.

Suggested by: imp
Approved by: adrian (mentor)

Style fixes

- Remove C++ - style comments
- Use proper device name in panic messages

Rename device_delete_all_children() into device_delete_children().

Suggested by: jhb @ and marius @
MFC after: 1 week

- There's no need to overwrite the default device method with the default
one. Interestingly, these are actually the default for quite some time
(bus_generic_driver_added(9) since r52045 and bus_generic_print_child(9)
since r52045) but even recently added device drivers do this unnecessarily.
Discussed with: jhb, marcel
- While at it, use DEVMETHOD_END.
Discussed with: jhb
- Also while at it, use __FBSDID.

Move the device_delete_all_children() function from usb_util.c
to kern/subr_bus.c. Simplify this function so that it no longer
depends on malloc() to execute. Identify a few other places where
it makes sense to use device_delete_all_children().

MFC after: 1 week

Add a GPIO driver for the Gateworks Cambria platform.

The external gpio pins are connected to a PLD on the i2c bus, unfortunatley
this device does not conform by failing to send an ack after each byte written.
The iicbb driver will abort the transfer when the address is not ack'd and it
would introduce a lot of churn to be able to pass a flag down to
iicbb_start/iicbb_write. Instead we do bad things by grabbing the iicbus but
then doing our own bit banging.

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