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.. dtcompatible:: zephyr,gpio-emul-sdl
.. _dtbinding_zephyr_gpio_emul_sdl:
zephyr,gpio-emul-sdl
####################
Vendor: :ref:`Zephyr-specific binding <dt_vendor_zephyr>`
.. note::
An implementation of a driver matching this compatible is available in
:zephyr_file:`drivers/gpio/gpio_emul_sdl.c`.
Description
***********
.. code-block:: none
SDL keyboard GPIO input Emulator
Simulate GPIO state/interrupts using SDL keyboard events. This node has
to be a child of a `zephyr,gpio-emul` compatible.
Add a list of scancodes for the desired keys to be mapped.
This driver uses USB HID scancodes, they are different from linux key codes,
and thus do not match Zephyr code values as described in input-event-codes.h.
Refer to https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf
section Keyboard/Keypad (p53) for a list of scancode values.
The following example maps the first 3 numeric keys to GPIO pins:
- Scancode 30: "Keyboard 1 and !", mapped to gpio0 0
- Scancode 31: "Keyboard 2 and @", mapped to gpio0 1
- Scancode 32: "Keyboard 3 and \#", mapped to gpio0 2
The "typical position" column from HID table suggests to match them
with standard keycode values 2, 3 and 4, corresponding to
INPUT_KEY_1, INPUT_KEY_2 and INPUT_KEY_3 in input-event-codes.h.
/* gpio0 has to be a zephyr,gpio-emul device */
&gpio0 {
ngpios = <3>;
sdl_gpio {
compatible = "zephyr,gpio-emul-sdl";
scancodes = <30 31 32>;
};
};
keypad: keypad {
compatible = "gpio-keys";
key1: key1 {
gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
};
key2: key2 {
gpios = <&gpio0 1 GPIO_ACTIVE_HIGH>;
};
key3: key3 {
gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
};
};
The limitations of usage are:
- Only active high as we don't get events for keys that aren't pressed
- Pressing multiple keys is best effort, state will be kept but no events
are generated once the last key is released
Properties
**********
.. tabs::
.. group-tab:: Node specific properties
Properties not inherited from the base binding file.
.. list-table::
:widths: 1 1 4
:header-rows: 1
* - Name
- Type
- Details
* - ``scancodes``
- ``array``
- .. code-block:: none
An array of SDL scancodes mapped to its GPIO index
This property is **required**.
.. group-tab:: Deprecated node specific properties
Deprecated properties not inherited from the base binding file.
(None)
.. group-tab:: Base properties
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 "zephyr,gpio-emul-sdl" compatible.
.. list-table::
:widths: 1 1 4
:header-rows: 1
* - Name
- Type
- Details
* - ``status``
- ``string``
- .. code-block:: none
Indicates the operational status of the hardware or other
resource that the node represents. In particular:
- "okay" means the resource is operational and, for example,
can be used by device drivers
- "disabled" means the resource is not operational and the system
should treat it as if it is not present
For details, see "2.3.4 status" in Devicetree Specification v0.4.
Legal values: ``'ok'``, ``'okay'``, ``'disabled'``, ``'reserved'``, ``'fail'``, ``'fail-sss'``
See :ref:`zephyr:dt-important-props` for more information.
* - ``compatible``
- ``string-array``
- .. code-block:: none
This property is a list of strings that essentially define what
type of hardware or other resource this devicetree node
represents. Each device driver checks for specific compatible
property values to find the devicetree nodes that represent
resources that the driver should manage.
The recommended format is "vendor,device", The "vendor" part is
an abbreviated name of the vendor. The "device" is usually from
the datasheet.
The compatible property can have multiple values, ordered from
most- to least-specific. Having additional values is useful when the
device is a specific instance of a more general family, to allow the
system to match the most specific driver available.
For details, see "2.3.1 compatible" in Devicetree Specification v0.4.
This property is **required**.
See :ref:`zephyr:dt-important-props` for more information.
* - ``reg``
- ``array``
- .. code-block:: none
Information used to address the device. The value is specific to
the device (i.e. is different depending on the compatible
property).
The "reg" property is typically a sequence of (address, length) pairs.
Each pair is called a "register block". Values are
conventionally written in hex.
For details, see "2.3.6 reg" in Devicetree Specification v0.4.
See :ref:`zephyr:dt-important-props` for more information.
* - ``reg-names``
- ``string-array``
- .. code-block:: none
Optional names given to each register block in the "reg" property.
For example:
/ {
soc {
#address-cells = <1>;
#size-cells = <1>;
uart@1000 {
reg = <0x1000 0x2000>, <0x3000 0x4000>;
reg-names = "foo", "bar";
};
};
};
The uart@1000 node has two register blocks:
- one with base address 0x1000, size 0x2000, and name "foo"
- another with base address 0x3000, size 0x4000, and name "bar"
* - ``interrupts``
- ``array``
- .. code-block:: none
Information about interrupts generated by the device, encoded as an array
of one or more interrupt specifiers. The format of the data in this property
varies by where the device appears in the interrupt tree. Devices with the same
"interrupt-parent" will use the same format in their interrupts properties.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
See :ref:`zephyr:dt-important-props` for more information.
* - ``interrupts-extended``
- ``compound``
- .. code-block:: none
Extended interrupt specifier for device, used as an alternative to
the "interrupts" property.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
* - ``interrupt-names``
- ``string-array``
- .. code-block:: none
Optional names given to each interrupt generated by a device.
The interrupts themselves are defined in either "interrupts" or
"interrupts-extended" properties.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
* - ``interrupt-parent``
- ``phandle``
- .. code-block:: none
If present, this refers to the node which handles interrupts generated
by this device.
For details, see "2.4 Interrupts and Interrupt Mapping" in
Devicetree Specification v0.4.
* - ``label``
- ``string``
- .. code-block:: none
Human readable string describing the device. Use of this property is
deprecated except as needed on a case-by-case basis.
For details, see "4.1.2 Miscellaneous Properties" in Devicetree
Specification v0.4.
See :ref:`zephyr:dt-important-props` for more information.
* - ``clocks``
- ``phandle-array``
- .. code-block:: none
Information about the device's clock providers. In general, this property
should follow conventions established in the dt-schema binding:
https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/clock/clock.yaml
* - ``clock-names``
- ``string-array``
- .. code-block:: none
Optional names given to each clock provider in the "clocks" property.
* - ``#address-cells``
- ``int``
- .. code-block:: none
This property encodes the number of <u32> cells used by address fields
in "reg" properties in this node's children.
For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.
* - ``#size-cells``
- ``int``
- .. code-block:: none
This property encodes the number of <u32> cells used by size fields in
"reg" properties in this node's children.
For details, see "2.3.5 #address-cells and #size-cells" in Devicetree
Specification v0.4.
* - ``dmas``
- ``phandle-array``
- .. code-block:: none
DMA channel specifiers relevant to the device.
* - ``dma-names``
- ``string-array``
- .. code-block:: none
Optional names given to the DMA channel specifiers in the "dmas" property.
* - ``io-channels``
- ``phandle-array``
- .. code-block:: none
IO channel specifiers relevant to the device.
* - ``io-channel-names``
- ``string-array``
- .. code-block:: none
Optional names given to the IO channel specifiers in the "io-channels" property.
* - ``mboxes``
- ``phandle-array``
- .. code-block:: none
Mailbox / IPM channel specifiers relevant to the device.
* - ``mbox-names``
- ``string-array``
- .. code-block:: none
Optional names given to the mbox specifiers in the "mboxes" property.
* - ``power-domains``
- ``phandle-array``
- .. code-block:: none
Power domain specifiers relevant to the device.
* - ``power-domain-names``
- ``string-array``
- .. code-block:: none
Optional names given to the power domain specifiers in the "power-domains" property.
* - ``#power-domain-cells``
- ``int``
- .. code-block:: none
Number of cells in power-domains property
* - ``zephyr,deferred-init``
- ``boolean``
- .. code-block:: none
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
* - ``wakeup-source``
- ``boolean``
- .. code-block:: none
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.
* - ``zephyr,pm-device-runtime-auto``
- ``boolean``
- .. code-block:: none
Automatically configure the device for runtime power management after the
init function runs.
* - ``zephyr,disabling-power-states``
- ``phandles``
- .. code-block:: none
List of power states that will disable this device power.