zephyr,gpio-emul-sdl
Vendor: Zephyr-specific binding
Description
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
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
|
An array of SDL scancodes mapped to its GPIO index
This property is required. |
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 “zephyr,gpio-emul-sdl” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
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 the device belongs to.
The device will be notified when the power domain it belongs to is either
suspended or resumed.
|
|
|
Automatically configure the device for runtime power management after the
init function runs.
|
|
|
List of power states that will disable this device power.
|
|
|
indicates the operational status of a device
Legal values: See Important properties for more information. |
|
|
compatible strings
This property is required. See Important properties for more information. |
|
|
register space
See Important properties for more information. |
|
|
name of each register space
|
|
|
interrupts for device
See Important properties for more information. |
|
|
extended interrupt specifier for device
|
|
|
name of each interrupt
|
|
|
phandle to interrupt controller node
|
|
|
Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
|
|
Clock gate information
|
|
|
name of each clock
|
|
|
number of address cells in reg property
|
|
|
number of size cells in reg property
|
|
|
DMA channels specifiers
|
|
|
Provided names of DMA channel specifiers
|
|
|
IO channels specifiers
|
|
|
Provided names of IO channel specifiers
|
|
|
mailbox / IPM channels specifiers
|
|
|
Provided names of mailbox / IPM channel specifiers
|
|
|
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|