diff options
author | Christian Lamparter <chunkeey@googlemail.com> | 2016-05-12 01:07:48 +0300 |
---|---|---|
committer | Rob Herring <robh@kernel.org> | 2016-05-19 17:16:36 +0300 |
commit | 9a0d440427bfd1716410b13dea5feb6eb7cd7277 (patch) | |
tree | d3de705ca77471f2e99e4be4ce77413e713c9d0d /Documentation | |
parent | 27f4ec1443fb71127ed6fc8b43d6195d9473b049 (diff) | |
download | linux-9a0d440427bfd1716410b13dea5feb6eb7cd7277.tar.xz |
gpio: dt-bindings: add ibm,ppc4xx-gpio binding
This patch adds binding information for IBM/AMCC/APM GPIO
Controllers of the PowerPC 4XX series and compatible SoCs.
The "PowerPC 405EP Embedded Processor Data Sheet" has the
following to say about the GPIO controllers: "
- Controller functions and GPIO registers are programmed
and accessed via memory-mapped OPB bus master accesses
- All GPIOs are pin-shared with other functions. DCRs control
whether a particular pin that has GPIO capabilities acts
as a GPIO or is used for another purpose.
- Each GPIO outputs is separately programmable to emulate
an open-drain driver (i.e. drives to zero, threestated if
output bit is 1)
"
The ppc4xx_gpio.c driver is part of the platform/sysdev drivers
in arch/powerpc/sysdev.
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt b/Documentation/devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt new file mode 100644 index 000000000000..d58b3958f3ea --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt @@ -0,0 +1,24 @@ +* IBM/AMCC/APM GPIO Controller for PowerPC 4XX series and compatible SoCs + +All GPIOs are pin-shared with other functions. DCRs control whether a +particular pin that has GPIO capabilities acts as a GPIO or is used for +another purpose. GPIO outputs are separately programmable to emulate +an open-drain driver. + +Required properties: + - compatible: must be "ibm,ppc4xx-gpio" + - reg: address and length of the register set for the device + - #gpio-cells: must be set to 2. The first cell is the pin number + and the second cell is used to specify the gpio polarity: + 0 = active high + 1 = active low + - gpio-controller: marks the device node as a gpio controller. + +Example: + +GPIO0: gpio@ef600b00 { + compatible = "ibm,ppc4xx-gpio"; + reg = <0xef600b00 0x00000048>; + #gpio-cells = <2>; + gpio-controller; +}; |