:orphan:
.. raw:: html
.. dtcompatible:: worldsemi,ws2812-gpio
.. _dtbinding_worldsemi_ws2812_gpio:
worldsemi,ws2812-gpio
#####################
Vendor: :ref:`Worldsemi Co., Limited `
.. note::
An implementation of a driver matching this compatible is available in
:zephyr_file:`drivers/led_strip/ws2812_gpio.c`.
Description
***********
.. code-block:: none
Worldsemi WS2812 LED strip, GPIO binding
Driver bindings for bit-banging a WS2812 or compatible LED strip.
The CPU driver uses inline assembly, and isn't available for all
boards. The timing is automatically derived from the CPU clock frequency,
or can be provided by setting the delay-txx properties in the device
tree, or can be manually provided by the Kconfig settings DELAY_Txx.
The four delays provided (calculated based on the clock frequency,
provided by a dts, or Kconfig file) determine the delays as depicted
below. The exact timings of the LED strip data line might vary on the
type of LEDs used, consult the data-sheet for the precise timings.
0 code
+-------+ +---
| | |
| T0H | T0L |
| | |
---+ +-----------------+
1 code
+---------------+ +---
| | |
| T1H | T1L |
| | |
---+ +---------+
Example dts file:
/ {
cpus {
cpu@0 {
clock-frequency = <64000000>;
};
};
rgb_led: ws2812 {
compatible = "worldsemi,ws2812-gpio";
chain-length = <1>;
color-mapping = ;
gpios = <&gpio0 16 0>;
};
};
Example dts file:
/ {
chosen {
zephyr,led-strip = &rgb_led;
};
rgb_led: ws2812 {
compatible = "worldsemi,ws2812-gpio";
chain-length = <1>;
color-mapping = ;
reset-delay = <50>;
gpios = <&gpio0 16 0>;
delay-t1h = <48>;
delay-t1l = <32>;
delay-t0h = <16>;
delay-t0l = <32>;
};
};
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
* - ``delay-t1h``
- ``int``
- .. code-block:: none
Number of NOP assembly operations to create a delay for a 1 bit, high
voltage period (default 700 nsec)
* - ``delay-t1l``
- ``int``
- .. code-block:: none
Number of NOP assembly operations to create a delay for a 1 bit, low
voltage period (default 600 nsec)
* - ``delay-t0h``
- ``int``
- .. code-block:: none
Number of NOP assembly operations to create a delay for a 0 bit, high
voltage period (default 350 nsec)
* - ``delay-t0l``
- ``int``
- .. code-block:: none
Number of NOP assembly operations to create a delay for a 0 bit, low
voltage period (default 800 nsec)
* - ``gpios``
- ``phandle-array``
- .. code-block:: none
GPIO phandle and specifier for the pin connected to the
led-strip. Exactly one pin should be given.
This property is **required**.
* - ``reset-delay``
- ``int``
- .. code-block:: none
Minimum delay to wait (in microseconds) to make sure that the strip has
latched the signal. If omitted, a default value of 8 microseconds is used.
This default is good for the WS2812 controllers. Note that despite the
WS2812 datasheet states that a 50 microseconds delay is required, it seems
6 microseconds is enough. The default is set to 8 microseconds just to be
safe.
Default value: ``8``
* - ``chain-length``
- ``int``
- .. code-block:: none
The number of devices in the daisy-chain.
This property is **required**.
* - ``color-mapping``
- ``array``
- .. code-block:: none
Channel to color mapping (or pixel order).
For example a GRB channel to color mapping would be
color-mapping = ;
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 "worldsemi,ws2812-gpio" compatible.
.. list-table::
:widths: 1 1 4
:header-rows: 1
* - Name
- Type
- Details
* - ``status``
- ``string``
- .. code-block:: none
indicates the operational status of a device
Legal values: ``'ok'``, ``'okay'``, ``'disabled'``, ``'reserved'``, ``'fail'``, ``'fail-sss'``
See :ref:`zephyr:dt-important-props` for more information.
* - ``compatible``
- ``string-array``
- .. code-block:: none
compatible strings
This property is **required**.
See :ref:`zephyr:dt-important-props` for more information.
* - ``reg``
- ``array``
- .. code-block:: none
register space
See :ref:`zephyr:dt-important-props` for more information.
* - ``reg-names``
- ``string-array``
- .. code-block:: none
name of each register space
* - ``interrupts``
- ``array``
- .. code-block:: none
interrupts for device
See :ref:`zephyr:dt-important-props` for more information.
* - ``interrupts-extended``
- ``compound``
- .. code-block:: none
extended interrupt specifier for device
* - ``interrupt-names``
- ``string-array``
- .. code-block:: none
name of each interrupt
* - ``interrupt-parent``
- ``phandle``
- .. code-block:: none
phandle to interrupt controller node
* - ``label``
- ``string``
- .. code-block:: none
Human readable string describing the device (used as device_get_binding() argument)
See :ref:`zephyr:dt-important-props` for more information.
This property is **deprecated**.
* - ``clocks``
- ``phandle-array``
- .. code-block:: none
Clock gate information
* - ``clock-names``
- ``string-array``
- .. code-block:: none
name of each clock
* - ``#address-cells``
- ``int``
- .. code-block:: none
number of address cells in reg property
* - ``#size-cells``
- ``int``
- .. code-block:: none
number of size cells in reg property
* - ``dmas``
- ``phandle-array``
- .. code-block:: none
DMA channels specifiers
* - ``dma-names``
- ``string-array``
- .. code-block:: none
Provided names of DMA channel specifiers
* - ``io-channels``
- ``phandle-array``
- .. code-block:: none
IO channels specifiers
* - ``io-channel-names``
- ``string-array``
- .. code-block:: none
Provided names of IO channel specifiers
* - ``mboxes``
- ``phandle-array``
- .. code-block:: none
mailbox / IPM channels specifiers
* - ``mbox-names``
- ``string-array``
- .. code-block:: none
Provided names of mailbox / IPM channel specifiers
* - ``power-domains``
- ``phandle-array``
- .. code-block:: none
Power domain specifiers
* - ``power-domain-names``
- ``string-array``
- .. code-block:: none
Provided names of power domain specifiers
* - ``#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.