From 00ce25c6dcdae5582ae4be37147ab33678adc995 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Fri, 25 Apr 2014 11:22:32 +0200 Subject: Add devicetree source files as of Linux-3.15-rc2 This adds the Linux dts files to barebox. The dts files are generated from Ian Campbells device-tree-rebasing.git: git://xenbits.xen.org/people/ianc/device-tree-rebasing.git The dts are found in dts/ in the barebox repository and will be updated from upstream regularly, probably for each upstream -rc. To keep the synchronization with upstream easy no changes to the original files are allowed under dts/. Instead changes to upstream dts files will be done using overlays in arch/$ARCH/dts/. Signed-off-by: Sascha Hauer --- dts/Bindings/gpio/gpio-pcf857x.txt | 71 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 dts/Bindings/gpio/gpio-pcf857x.txt (limited to 'dts/Bindings/gpio/gpio-pcf857x.txt') diff --git a/dts/Bindings/gpio/gpio-pcf857x.txt b/dts/Bindings/gpio/gpio-pcf857x.txt new file mode 100644 index 0000000000..d63194a2c8 --- /dev/null +++ b/dts/Bindings/gpio/gpio-pcf857x.txt @@ -0,0 +1,71 @@ +* PCF857x-compatible I/O expanders + +The PCF857x-compatible chips have "quasi-bidirectional" I/O lines that can be +driven high by a pull-up current source or driven low to ground. This combines +the direction and output level into a single bit per line, which can't be read +back. We can't actually know at initialization time whether a line is configured +(a) as output and driving the signal low/high, or (b) as input and reporting a +low/high value, without knowing the last value written since the chip came out +of reset (if any). The only reliable solution for setting up line direction is +thus to do it explicitly. + +Required Properties: + + - compatible: should be one of the following. + - "maxim,max7328": For the Maxim MAX7378 + - "maxim,max7329": For the Maxim MAX7329 + - "nxp,pca8574": For the NXP PCA8574 + - "nxp,pca8575": For the NXP PCA8575 + - "nxp,pca9670": For the NXP PCA9670 + - "nxp,pca9671": For the NXP PCA9671 + - "nxp,pca9672": For the NXP PCA9672 + - "nxp,pca9673": For the NXP PCA9673 + - "nxp,pca9674": For the NXP PCA9674 + - "nxp,pca9675": For the NXP PCA9675 + - "nxp,pcf8574": For the NXP PCF8574 + - "nxp,pcf8574a": For the NXP PCF8574A + - "nxp,pcf8575": For the NXP PCF8575 + - "ti,tca9554": For the TI TCA9554 + + - reg: I2C slave address. + + - gpio-controller: Marks the device node as a gpio controller. + - #gpio-cells: Should be 2. The first cell is the GPIO number and the second + cell specifies GPIO flags, as defined in . Only the + GPIO_ACTIVE_HIGH and GPIO_ACTIVE_LOW flags are supported. + +Optional Properties: + + - lines-initial-states: Bitmask that specifies the initial state of each + line. When a bit is set to zero, the corresponding line will be initialized to + the input (pulled-up) state. When the bit is set to one, the line will be + initialized the the low-level output state. If the property is not specified + all lines will be initialized to the input state. + + The I/O expander can detect input state changes, and thus optionally act as + an interrupt controller. When the expander interrupt line is connected all the + following properties must be set. For more information please see the + interrupt controller device tree bindings documentation available at + Documentation/devicetree/bindings/interrupt-controller/interrupts.txt. + + - interrupt-controller: Identifies the node as an interrupt controller. + - #interrupt-cells: Number of cells to encode an interrupt source, shall be 2. + - interrupt-parent: phandle of the parent interrupt controller. + - interrupts: Interrupt specifier for the controllers interrupt. + + +Please refer to gpio.txt in this directory for details of the common GPIO +bindings used by client devices. + +Example: PCF8575 I/O expander node + + pcf8575: gpio@20 { + compatible = "nxp,pcf8575"; + reg = <0x20>; + interrupt-parent = <&irqpin2>; + interrupts = <3 0>; + gpio-controller; + #gpio-cells = <2>; + interrupt-controller; + #interrupt-cells = <2>; + }; -- cgit v1.2.3