microchip,mcp23017 (on i2c bus)
Vendor: Microchip Technology Inc.
Note
An implementation of a driver matching this compatible is available in drivers/gpio/gpio_mcp230xx.c.
Description
This is a representation of the Microchip MCP23017 I2C GPIO Expander.
Properties
Top level properties
These property descriptions apply to “microchip,mcp23017” nodes themselves. This page also describes child node properties in the following sections.
Properties not inherited from the base binding file.
Name |
Type |
Details |
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Number of items to expect in a GPIO specifier
This property is required. Constant value: |
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GPIO connected to the controller INT pin. This pin is active-low.
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GPIO connected to the controller RESET pin. This pin is active-low.
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Convey's this node is a GPIO controller
This property is required. |
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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.
Default value: |
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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>.
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This is an array of strings defining the names of the GPIO lines
going out of the GPIO controller
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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.
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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.
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Deprecated properties not inherited from the base binding file.
(None)
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 “microchip,mcp23017” compatible.
Name |
Type |
Details |
|---|---|---|
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device address on i2c bus
This property is required. See Important properties for more information. |
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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name of each register space
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interrupts for device
See Important properties for more information. |
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extended interrupt specifier for device
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name of each interrupt
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phandle to interrupt controller node
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Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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Clock gate information
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name of each clock
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number of address cells in reg property
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number of size cells in reg property
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
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Provided names of IO channel specifiers
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mailbox / IPM channels specifiers
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Provided names of mailbox / IPM channel specifiers
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Power domain specifiers
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Provided names of power domain specifiers
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Number of cells in power-domains property
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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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.
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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Child node properties
Name |
Type |
Details |
|---|---|---|
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Conveys this node is a GPIO hog.
This property is required. |
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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. |
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If this property is set, the GPIO is configured as an input. This property takes
precedence over the output-low and output-high properties.
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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.
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If this property is set, the GPIO is configured as an output set to logical high.
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Optional GPIO line name.
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Specifier cell names
gpio cells: pin, flags