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.

2 files changed, 135 insertions, 3 deletions

diff --git a/share/man/man4/gpioiic.4 b/share/man/man4/gpioiic.4
index cbcaec9..e3f9814 100644
--- a/share/man/man4/gpioiic.4
+++ b/share/man/man4/gpioiic.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 5, 2013
+.Dd February 13, 2014
 .Dt GPIOIIC 4
 .Os
 .Sh NAME
@@ -65,7 +65,7 @@ This is a bitmask of the pins on the
 that are to be used for SCLOCK and SDATA from the GPIO IIC
 bit-banging bus.
 To configure pin 0 and 7, use the bitmask of
-10000001 and convert it to a hexadecimal value of 0x0081.
+0b10000001 and convert it to a hexadecimal value of 0x0081.
 Please note that this mask should only ever have two bits set
 (any others bits - i.e., pins - will be ignored).
 .It Va hint.gpioiic.%d.scl
@@ -73,13 +73,77 @@ Indicates which bit in the
 .Va hint.gpioiic.%d.pins
 should be used as the SCLOCK
 source.
+Optional, defaults to 0.
 .It Va hint.gpioiic.%d.sda
 Indicates which bit in the
 .Va hint.gpioiic.%d.pins
 should be used as the SDATA
 source.
+Optional, defaults to 1.
+.El
+.Pp
+On a
+.Xr FDT 4
+based system, like
+.Li ARM , the dts part for a
+.Nm gpioiic
+device usually looks like:
+.Bd -literal
+gpio: gpio {
+
+	gpio-controller;
+	...
+
+	gpioiic0 {
+		compatible = "gpioiic";
+		/*
+		 * Attach to GPIO pins 21 and 22.  Set them
+		 * initially as inputs.
+		 */
+		gpios = <&gpio 21 1 0
+			 &gpio 22 1 0>;
+		scl = <0>;		/* GPIO pin 21 - optional */
+		sda = <1>;		/* GPIO pin 22 - optional */
+
+		/* This is an example of a gpioiic child. */
+		gpioiic-child0 {
+			compatible = "lm75";
+			i2c-address = <0x4f>;
+		};
+	};
+};
+.Ed
+.Pp
+Where:
+.Bl -tag -width ".Va compatible"
+.It Va compatible
+Should always be set to "gpioiic".
+.It Va gpios
+The
+.Va gpios
+property indicates which GPIO pins should be used for SCLOCK and SDATA
+on the GPIO IIC bit-banging bus.
+For more details about the
+.Va gpios
+property, please consult
+.Pa /usr/src/sys/boot/fdt/dts/bindings-gpio.txt .
+.It Va scl
+The
+.Va scl
+option indicates which bit in the
+.Va gpios
+should be used as the SCLOCK source.
+Optional, defaults to 0.
+.It Va sda
+The
+.Va sda
+option indicates which bit in the
+.Va gpios
+should be used as the SDATA source.
+Optional, defaults to 1.
 .El
 .Sh SEE ALSO
+.Xr fdt 4 ,
 .Xr gpio 4 ,
 .Xr gpioled 4 ,
 .Xr iic 4 ,
diff --git a/share/man/man4/gpioled.4 b/share/man/man4/gpioled.4
index 76f59fa..74c28e6 100644
--- a/share/man/man4/gpioled.4
+++ b/share/man/man4/gpioled.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 5, 2013
+.Dd February 13, 2014
 .Dt GPIOLED 4
 .Os
 .Sh NAME
@@ -68,7 +68,75 @@ Which pin on the GPIO interface to map to this instance.
 Please note that this mask should only ever have one bit set
 (any others bits - i.e., pins - will be ignored).
 .El
+.Pp
+On a
+.Xr FDT 4
+based system, like
+.Li ARM , the dts part for a
+.Nm gpioled
+device usually looks like:
+.Bd -literal
+gpio: gpio {
+
+	gpio-controller;
+	...
+
+	led0 {
+		compatible = "gpioled";
+		gpios = <&gpio 16 2 0>;		/* GPIO pin 16. */
+		name = "ok";
+	};
+
+	led1 {
+		compatible = "gpioled";
+		gpios = <&gpio 17 2 0>;		/* GPIO pin 17. */
+		name = "user-led1";
+	};
+};
+.Ed
+.Pp
+And optionally, you can choose combine all the leds under a single
+.Dq gpio-leds
+compatible node:
+.Bd -literal
+simplebus0 {
+
+	...
+
+	leds {
+		compatible = "gpio-leds";
+
+		led0 {
+			gpios = <&gpio 16 2 0>;
+			name = "ok"
+		};
+
+		led1 {
+			gpios = <&gpio 17 2 0>;
+			name = "user-led1"
+		};
+	};
+};
+.Ed
+.Pp
+Both methods are equally supported and it is possible to have the leds
+defined with any sort of mix between the methods.
+The only restriction is that a GPIO pin cannot be mapped by two different
+(gpio)leds.
+.Pp
+For more details about the
+.Va gpios
+property, please consult
+.Pa /usr/src/sys/boot/fdt/dts/bindings-gpio.txt .
+.Pp
+The property
+.Va name
+is the arbitrary name of device in
+.Pa /dev/led/
+to create for
+.Xr led 4 .
 .Sh SEE ALSO
+.Xr fdt 4 ,
 .Xr gpio 4 ,
 .Xr led 4 ,
 .Xr gpioiic 4