nxp,pcf8574 (on i2c bus)

Description

PCF8574 8-bit I2C-based I/O expander

Properties

Top level properties

These property descriptions apply to “nxp,pcf8574” nodes themselves. This page also describes child node properties in the following sections.

Properties not inherited from the base binding file.

Name	Type	Details
`ngpios`	`int`	This property indicates the number of in-use slots of available slots for GPIOs. The typical example is something like this: the hardware register is 32 bits wide, but only 18 of the bits have a physical counterpart. The driver is generally written so that all 32 bits can be used, but the IP block is reused in a lot of designs, some using all 32 bits, some using 18 and some using 12. In this case, setting "ngpios = <18>;" informs the driver that only the first 18 GPIOs, at local offset 0 .. 17, are in use. For cases in which there might be holes in the slot range, this value should be the max slot number+1. This property is required. Default value: `32` Constant value: `8`
`int-gpios`	`phandle-array`	GPIO connected to the controller INT pin. This pin is active-low.
`#gpio-cells`	`int`	Number of items to expect in a GPIO specifier This property is required. Constant value: `2`
`supply-gpios`	`phandle-array`	GPIO specifier that controls power to the device. This property should be provided when the device has a dedicated switch that controls power to the device. The supply state is entirely the responsibility of the device driver. Contrast with vin-supply.
`vin-supply`	`phandle`	Reference to the regulator that controls power to the device. The referenced devicetree node must have a regulator compatible. This property should be provided when device power is supplied by a shared regulator. The supply state is dependent on the request status of all devices fed by the regulator. Contrast with supply-gpios. If both properties are provided then the regulator must be requested before the supply GPIOS is set to an active state, and the supply GPIOS must be set to an inactive state before releasing the regulator.
`gpio-controller`	`boolean`	Convey's this node is a GPIO controller This property is required.
`gpio-reserved-ranges`	`array`	If not all the GPIOs at offsets 0...N-1 are usable for ngpios = <N>, then this property contains an additional set of tuples which specify which GPIOs are unusable. This property indicates the start and size of the GPIOs that can't be used. For example, setting "gpio-reserved-ranges = <3 2>, <10 1>;" means that GPIO offsets 3, 4, and 10 are not usable, even if ngpios = <18>.
`gpio-line-names`	`string-array`	This is an array of strings defining the names of the GPIO lines going out of the GPIO controller

Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “nxp,pcf8574” compatible.

Name	Type	Details
`reg`	`array`	device address on i2c bus This property is required. See Important properties for more information.
`status`	`string`	indicates the operational status of a device Legal values: `'ok'`, `'okay'`, `'disabled'`, `'reserved'`, `'fail'`, `'fail-sss'` See Important properties for more information.
`compatible`	`string-array`	compatible strings This property is required. See Important properties for more information.
`reg-names`	`string-array`	name of each register space
`interrupts`	`array`	interrupts for device See Important properties for more information.
`interrupts-extended`	`compound`	extended interrupt specifier for device
`interrupt-names`	`string-array`	name of each interrupt
`interrupt-parent`	`phandle`	phandle to interrupt controller node
`label`	`string`	Human readable string describing the device (used as device_get_binding() argument) See Important properties for more information. This property is deprecated.
`clocks`	`phandle-array`	Clock gate information
`clock-names`	`string-array`	name of each clock
`#address-cells`	`int`	number of address cells in reg property
`#size-cells`	`int`	number of size cells in reg property
`dmas`	`phandle-array`	DMA channels specifiers
`dma-names`	`string-array`	Provided names of DMA channel specifiers
`io-channels`	`phandle-array`	IO channels specifiers
`io-channel-names`	`string-array`	Provided names of IO channel specifiers
`mboxes`	`phandle-array`	mailbox / IPM channels specifiers
`mbox-names`	`string-array`	Provided names of mailbox / IPM channel specifiers
`wakeup-source`	`boolean`	Property to identify that a device can be used as wake up source. When this property is provided a specific flag is set into the device that tells the system that the device is capable of wake up the system. Wake up capable devices are disabled (interruptions will not wake up the system) by default but they can be enabled at runtime if necessary.
`power-domain`	`phandle`	Power domain the device belongs to. The device will be notified when the power domain it belongs to is either suspended or resumed.
`zephyr,pm-device-runtime-auto`	`boolean`	Automatically configure the device for runtime power management after the init function runs.

Child node properties

Name	Type	Details
`gpio-hog`	`boolean`	Conveys this node is a GPIO hog. This property is required.
`gpios`	`array`	This is an array of GPIO specifiers (e.g. pin, flags) to be hogged. The number of array entries must be an integer multiple of the number of GPIO specifier cells for the parent GPIO controller. This property is required.
`input`	`boolean`	If this property is set, the GPIO is configured as an input. This property takes precedence over the output-low and output-high properties.
`output-low`	`boolean`	If this property is set, the GPIO is configured as an output set to logical low. This property takes precedence over the output-high property.
`output-high`	`boolean`	If this property is set, the GPIO is configured as an output set to logical high.
`line-name`	`string`	Optional GPIO line name.

Specifier cell names

gpio cells: pin, flags