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Device-Tree bindings for gpio i2c driver
A simple parameterized no-irq of_driven i2c->gpio expander,
cut down from gpio-pcf857x.c to be totally device-tree driven.
Suitable for any "memory-like" device, where a 1-byte i2c read yields data
which can safely be written back, possibly with a bit changed, with the
effect of changing only the output level of that bit's GPIO pin.
Required properties:
- compatible = "gpio-i2c"
- reg = i2c-address
- gpio-controller
- #gpio-cells = <1>;
- ngpios = number of pins modeled
Example nodes:
&i2c_bus {
gpio1: cpld@6c {
compatible = "gpio-i2c";
gpio-controller;
reg = <0x6c>;
#gpio-cells = <1>;
ngpios = <160>; // 8bits for each reg 0..0x13
};
};
_some_device_ {
// pin controlled by bitmask 0x2 of byte 0x4 of gpio1
enable-gpios = <&gpio1 33>;
}
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