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Diffstat (limited to 'Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt deleted file mode 100644 index a482455a205b..000000000000 --- a/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt +++ /dev/null @@ -1,69 +0,0 @@ -* 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 - - - 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 <dt-bindings/gpio/gpio.h>. 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 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. - - 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>; - }; |