From 9a0d440427bfd1716410b13dea5feb6eb7cd7277 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Thu, 12 May 2016 00:07:48 +0200 Subject: 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 Signed-off-by: Rob Herring --- .../devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/ibm,ppc4xx-gpio.txt (limited to 'Documentation/devicetree') 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; +}; -- cgit v1.2.3