dt: Move device tree documentation out of powerpc directory

The device tree is used by more than just PowerPC.  Make the documentation
directory available to all.

v2: reorganized files while moving to create arch and driver specific
    directories.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

3 files changed, 168 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt
new file mode 100644
index 000000000000..b0019eb5330e
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt
@@ -0,0 +1,60 @@
+GPIO controllers on MPC8xxx SoCs
+
+This is for the non-QE/CPM/GUTs GPIO controllers as found on
+8349, 8572, 8610 and compatible.
+
+Every GPIO controller node must have #gpio-cells property defined,
+this information will be used to translate gpio-specifiers.
+
+Required properties:
+- compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for
+  83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx.
+- #gpio-cells : Should be two. The first cell is the pin number and the
+  second cell is used to specify optional parameters (currently unused).
+ - interrupts : Interrupt mapping for GPIO IRQ.
+ - interrupt-parent : Phandle for the interrupt controller that
+   services interrupts for this device.
+- gpio-controller : Marks the port as GPIO controller.
+
+Example of gpio-controller nodes for a MPC8347 SoC:
+
+        gpio1: gpio-controller@c00 {
+                #gpio-cells = <2>;
+                compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
+                reg = <0xc00 0x100>;
+                interrupts = <74 0x8>;
+                interrupt-parent = <&ipic>;
+                gpio-controller;
+        };
+
+        gpio2: gpio-controller@d00 {
+                #gpio-cells = <2>;
+                compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio";
+                reg = <0xd00 0x100>;
+                interrupts = <75 0x8>;
+                interrupt-parent = <&ipic>;
+                gpio-controller;
+        };
+
+See booting-without-of.txt for details of how to specify GPIO
+information for devices.
+
+To use GPIO pins as interrupt sources for peripherals, specify the
+GPIO controller as the interrupt parent and define GPIO number +
+trigger mode using the interrupts property, which is defined like
+this:
+
+interrupts = <number trigger>, where:
+ - number: GPIO pin (0..31)
+ - trigger: trigger mode:
+        2 = trigger on falling edge
+        3 = trigger on both edges
+
+Example of device using this is:
+
+        funkyfpga@0 {
+                compatible = "funky-fpga";
+                ...
+                interrupts = <4 3>;
+                interrupt-parent = <&gpio1>;
+        };
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
new file mode 100644
index 000000000000..edaa84d288a1
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -0,0 +1,50 @@
+Specifying GPIO information for devices
+============================================
+
+1) gpios property
+-----------------
+
+Nodes that makes use of GPIOs should define them using `gpios' property,
+format of which is: <&gpio-controller1-phandle gpio1-specifier
+                     &gpio-controller2-phandle gpio2-specifier
+                     0 /* holes are permitted, means no GPIO 3 */
+                     &gpio-controller4-phandle gpio4-specifier
+                     ...>;
+
+Note that gpio-specifier length is controller dependent.
+
+gpio-specifier may encode: bank, pin position inside the bank,
+whether pin is open-drain and whether pin is logically inverted.
+
+Example of the node using GPIOs:
+
+        node {
+                gpios = <&qe_pio_e 18 0>;
+        };
+
+In this example gpio-specifier is "18 0" and encodes GPIO pin number,
+and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller.
+
+2) gpio-controller nodes
+------------------------
+
+Every GPIO controller node must have #gpio-cells property defined,
+this information will be used to translate gpio-specifiers.
+
+Example of two SOC GPIO banks defined as gpio-controller nodes:
+
+        qe_pio_a: gpio-controller@1400 {
+                #gpio-cells = <2>;
+                compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
+                reg = <0x1400 0x18>;
+                gpio-controller;
+        };
+
+        qe_pio_e: gpio-controller@1460 {
+                #gpio-cells = <2>;
+                compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
+                reg = <0x1460 0x18>;
+                gpio-controller;
+        };
+
+
diff --git a/Documentation/devicetree/bindings/gpio/led.txt b/Documentation/devicetree/bindings/gpio/led.txt
new file mode 100644
index 000000000000..064db928c3c1
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/led.txt
@@ -0,0 +1,58 @@
+LEDs connected to GPIO lines
+
+Required properties:
+- compatible : should be "gpio-leds".
+
+Each LED is represented as a sub-node of the gpio-leds device.  Each
+node's name represents the name of the corresponding LED.
+
+LED sub-node properties:
+- gpios :  Should specify the LED's GPIO, see "Specifying GPIO information
+  for devices" in Documentation/powerpc/booting-without-of.txt.  Active
+  low LEDs should be indicated using flags in the GPIO specifier.
+- label :  (optional) The label for this LED.  If omitted, the label is
+  taken from the node name (excluding the unit address).
+- linux,default-trigger :  (optional) This parameter, if present, is a
+  string defining the trigger assigned to the LED.  Current triggers are:
+    "backlight" - LED will act as a back-light, controlled by the framebuffer
+                  system
+    "default-on" - LED will turn on, but see "default-state" below
+    "heartbeat" - LED "double" flashes at a load average based rate
+    "ide-disk" - LED indicates disk activity
+    "timer" - LED flashes at a fixed, configurable rate
+- default-state:  (optional) The initial state of the LED.  Valid
+  values are "on", "off", and "keep".  If the LED is already on or off
+  and the default-state property is set the to same value, then no
+  glitch should be produced where the LED momentarily turns off (or
+  on).  The "keep" setting will keep the LED at whatever its current
+  state is, without producing a glitch.  The default is off if this
+  property is not present.
+
+Examples:
+
+leds {
+        compatible = "gpio-leds";
+        hdd {
+                label = "IDE Activity";
+                gpios = <&mcu_pio 0 1>; /* Active low */
+                linux,default-trigger = "ide-disk";
+        };
+
+        fault {
+                gpios = <&mcu_pio 1 0>;
+                /* Keep LED on if BIOS detected hardware fault */
+                default-state = "keep";
+        };
+};
+
+run-control {
+        compatible = "gpio-leds";
+        red {
+                gpios = <&mpc8572 6 0>;
+                default-state = "off";
+        };
+        green {
+                gpios = <&mpc8572 7 0>;
+                default-state = "on";
+        };
+}