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authorArnd Bergmann <arnd@arndb.de>2011-07-17 22:45:41 +0200
committerArnd Bergmann <arnd@arndb.de>2011-07-17 22:51:35 +0200
commit382bc10fbe827191218d4eecfaca0995b085dbfd (patch)
treefc335b59f754a5e4571937499c7296f06f27aba2 /Documentation
parentea3e643bbf03735f2109c2d18bee6263c2c71498 (diff)
parent752ad5e82dfd83851e44a2b9da8761994cd7e61c (diff)
Merge branch 'depends/gpio' into for-next
Conflicts: arch/arm/mach-imx/mm-imx1.c arch/arm/mach-imx/mm-imx21.c arch/arm/mach-imx/mm-imx25.c arch/arm/mach-imx/mm-imx27.c arch/arm/mach-imx/mm-imx31.c arch/arm/mach-imx/mm-imx35.c arch/arm/mach-mx5/mm.c
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt22
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio.txt46
-rw-r--r--Documentation/devicetree/bindings/gpio/gpio_nvidia.txt8
3 files changed, 67 insertions, 9 deletions
diff --git a/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt b/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt
new file mode 100644
index 00000000000..4363ae4b3c1
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/fsl-imx-gpio.txt
@@ -0,0 +1,22 @@
+* Freescale i.MX/MXC GPIO controller
+
+Required properties:
+- compatible : Should be "fsl,<soc>-gpio"
+- reg : Address and length of the register set for the device
+- interrupts : Should be the port interrupt shared by all 32 pins, if
+ one number. If two numbers, the first one is the interrupt shared
+ by low 16 pins and the second one is for high 16 pins.
+- gpio-controller : Marks the device node as a gpio controller.
+- #gpio-cells : Should be two. The first cell is the pin number and
+ the second cell is used to specify optional parameters (currently
+ unused).
+
+Example:
+
+gpio0: gpio@73f84000 {
+ compatible = "fsl,imx51-gpio", "fsl,imx31-gpio";
+ reg = <0x73f84000 0x4000>;
+ interrupts = <50 51>;
+ gpio-controller;
+ #gpio-cells = <2>;
+};
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt
index edaa84d288a..4e16ba4feab 100644
--- a/Documentation/devicetree/bindings/gpio/gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio.txt
@@ -4,17 +4,45 @@ 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
- ...>;
+Nodes that makes use of GPIOs should specify them using one or more
+properties, each containing a 'gpio-list':
-Note that gpio-specifier length is controller dependent.
+ gpio-list ::= <single-gpio> [gpio-list]
+ single-gpio ::= <gpio-phandle> <gpio-specifier>
+ gpio-phandle : phandle to gpio controller node
+ gpio-specifier : Array of #gpio-cells specifying specific gpio
+ (controller specific)
+
+GPIO properties should be named "[<name>-]gpios". Exact
+meaning of each gpios property must be documented in the device tree
+binding for each device.
+
+For example, the following could be used to describe gpios pins to use
+as chip select lines; with chip selects 0, 1 and 3 populated, and chip
+select 2 left empty:
+
+ gpio1: gpio1 {
+ gpio-controller
+ #gpio-cells = <2>;
+ };
+ gpio2: gpio2 {
+ gpio-controller
+ #gpio-cells = <1>;
+ };
+ [...]
+ chipsel-gpios = <&gpio1 12 0>,
+ <&gpio1 13 0>,
+ <0>, /* holes are permitted, means no GPIO 2 */
+ <&gpio2 2>;
+
+Note that gpio-specifier length is controller dependent. In the
+above example, &gpio1 uses 2 cells to specify a gpio, while &gpio2
+only uses one.
gpio-specifier may encode: bank, pin position inside the bank,
whether pin is open-drain and whether pin is logically inverted.
+Exact meaning of each specifier cell is controller specific, and must
+be documented in the device tree binding for the device.
Example of the node using GPIOs:
@@ -28,8 +56,8 @@ 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.
+Every GPIO controller node must both an empty "gpio-controller"
+property, and have #gpio-cells contain the size of the gpio-specifier.
Example of two SOC GPIO banks defined as gpio-controller nodes:
diff --git a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
new file mode 100644
index 00000000000..eb4b530d64e
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt
@@ -0,0 +1,8 @@
+NVIDIA Tegra 2 GPIO controller
+
+Required properties:
+- compatible : "nvidia,tegra20-gpio"
+- #gpio-cells : Should be two. The first cell is the pin number and the
+ second cell is used to specify optional parameters:
+ - bit 0 specifies polarity (0 for normal, 1 for inverted)
+- gpio-controller : Marks the device node as a GPIO controller.