diff options
author | Ingo Molnar <mingo@elte.hu> | 2011-02-16 13:33:35 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2011-02-16 13:33:41 +0100 |
commit | a3ec4a603faf4244e275bf11b467aad092dfbd8a (patch) | |
tree | 1c15009716b37629070ea221a00eb9fe2303a317 /Documentation/devicetree/bindings/gpio/gpio.txt | |
parent | 51563cd53c4b1c1790fccd2e0af0e2b756589af9 (diff) | |
parent | 85e2efbb1db9a18d218006706d6e4fbeb0216213 (diff) | |
download | kernel_samsung_tuna-a3ec4a603faf4244e275bf11b467aad092dfbd8a.zip kernel_samsung_tuna-a3ec4a603faf4244e275bf11b467aad092dfbd8a.tar.gz kernel_samsung_tuna-a3ec4a603faf4244e275bf11b467aad092dfbd8a.tar.bz2 |
Merge commit 'v2.6.38-rc5' into core/locking
Merge reason: pick up upstream fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/devicetree/bindings/gpio/gpio.txt')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio.txt | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt b/Documentation/devicetree/bindings/gpio/gpio.txt new file mode 100644 index 0000000..edaa84d --- /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; + }; + + |