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/mdio.txt | 19 |
2 files changed, 69 insertions, 0 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/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>; +}; |