diff options
Diffstat (limited to 'Documentation/devicetree/bindings/gpio')
6 files changed, 114 insertions, 10 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 0000000..4363ae4 --- /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 edaa84d..4e16ba4 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_keys.txt b/Documentation/devicetree/bindings/gpio/gpio_keys.txt new file mode 100644 index 0000000..5c2c021 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio_keys.txt @@ -0,0 +1,36 @@ +Device-Tree bindings for input/gpio_keys.c keyboard driver + +Required properties: + - compatible = "gpio-keys"; + +Optional properties: + - autorepeat: Boolean, Enable auto repeat feature of Linux input + subsystem. + +Each button (key) is represented as a sub-node of "gpio-keys": +Subnode properties: + + - gpios: OF device-tree gpio specification. + - label: Descriptive name of the key. + - linux,code: Keycode to emit. + +Optional subnode-properties: + - linux,input-type: Specify event type this button/key generates. + If not specified defaults to <1> == EV_KEY. + - debounce-interval: Debouncing interval time in milliseconds. + If not specified defaults to 5. + - gpio-key,wakeup: Boolean, button can wake-up the system. + +Example nodes: + + gpio_keys { + compatible = "gpio-keys"; + #address-cells = <1>; + #size-cells = <0>; + autorepeat; + button@21 { + label = "GPIO Key UP"; + linux,code = <103>; + gpios = <&gpio1 0 1>; + }; + ... diff --git a/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt b/Documentation/devicetree/bindings/gpio/gpio_nvidia.txt new file mode 100644 index 0000000..eb4b530 --- /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. diff --git a/Documentation/devicetree/bindings/gpio/led.txt b/Documentation/devicetree/bindings/gpio/led.txt index 064db92..141087c 100644 --- a/Documentation/devicetree/bindings/gpio/led.txt +++ b/Documentation/devicetree/bindings/gpio/led.txt @@ -8,7 +8,7 @@ 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 + for devices" in Documentation/devicetree/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). diff --git a/Documentation/devicetree/bindings/gpio/pl061-gpio.txt b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt new file mode 100644 index 0000000..a2c416b --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/pl061-gpio.txt @@ -0,0 +1,10 @@ +ARM PL061 GPIO controller + +Required properties: +- compatible : "arm,pl061", "arm,primecell" +- #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. +- interrupts : Interrupt mapping for GPIO IRQ. + |