diff options
Diffstat (limited to 'Documentation/powerpc/dts-bindings/gpio')
| -rw-r--r-- | Documentation/powerpc/dts-bindings/gpio/gpio.txt | 50 | ||||
| -rw-r--r-- | Documentation/powerpc/dts-bindings/gpio/led.txt | 17 | ||||
| -rw-r--r-- | Documentation/powerpc/dts-bindings/gpio/mdio.txt | 19 |
3 files changed, 85 insertions, 1 deletions
diff --git a/Documentation/powerpc/dts-bindings/gpio/gpio.txt b/Documentation/powerpc/dts-bindings/gpio/gpio.txt new file mode 100644 index 0000000..edaa84d --- /dev/null +++ b/Documentation/powerpc/dts-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/powerpc/dts-bindings/gpio/led.txt b/Documentation/powerpc/dts-bindings/gpio/led.txt index 4fe14de..064db92 100644 --- a/Documentation/powerpc/dts-bindings/gpio/led.txt +++ b/Documentation/powerpc/dts-bindings/gpio/led.txt @@ -16,10 +16,17 @@ LED sub-node properties: 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 + "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: @@ -30,14 +37,22 @@ leds { 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"; }; } diff --git a/Documentation/powerpc/dts-bindings/gpio/mdio.txt b/Documentation/powerpc/dts-bindings/gpio/mdio.txt new file mode 100644 index 0000000..bc954952 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/gpio/mdio.txt @@ -0,0 +1,19 @@ +MDIO on GPIOs + +Currently defined compatibles: +- virtual,gpio-mdio + +MDC and MDIO lines connected to GPIO controllers are listed in the +gpios property as described in section VIII.1 in the following order: + +MDC, MDIO. + +Example: + +mdio { + compatible = "virtual,mdio-gpio"; + #address-cells = <1>; + #size-cells = <0>; + gpios = <&qe_pio_a 11 + &qe_pio_c 6>; +}; |
