59e4c5aed0
- Updated basic samples READMEs to use the new zephyr:code-sample:: directive. Dropped "-sample" suffix that's not required anymore now that samples have their own namespace. - Updated all references to the samples to use the :zephyr:code-sample: role. Checked and updated the wording of said references to account for the fact that samples should not have "... sample" in their name anymore. Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
57 lines
1.9 KiB
ReStructuredText
57 lines
1.9 KiB
ReStructuredText
.. zephyr:code-sample:: gpio-custom-dts-binding
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:name: GPIO with custom Devicetree binding
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:relevant-api: gpio_interface devicetree-generic-id devicetree-generic-exist
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Use custom Devicetree binding to control a GPIO.
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Overview
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********
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In Zephyr, all hardware-specific configuration is described in the devicetree.
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Consequently, also GPIO pins are configured in the devicetree and assigned to a specific purpose
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using a compatible.
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This is in contrast to other embedded environments like Arduino, where e.g. the direction (input /
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output) of a GPIO pin is configured in the application firmware.
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For typical use cases like LEDs or buttons, the existing :dtcompatible:`gpio-leds` or
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:dtcompatible:`gpio-keys` compatibles can be used.
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This sample demonstrates how to use a GPIO pin for other purposes with a custom devicetree binding.
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We assume that a load with high current demands should be switched on or off via a MOSFET. The
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custom devicetree binding for the power output controlled via a GPIO pin is specified in the file
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:zephyr_file:`samples/basic/custom_dts_binding/dts/bindings/power-switch.yaml`. The gate driver for
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the MOSFET would be connected to the pin as specified in the ``.overlay`` file in the boards
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folder.
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Building and Running
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********************
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For each board that should be supported, a ``.overlay`` file has to be defined
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in the ``boards`` subfolder.
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Afterwards, the sample can be built and executed for the ``<board>`` as follows:
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.. zephyr-app-commands::
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:zephyr-app: samples/basic/custom_dts_binding
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:board: <board>
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:goals: build flash
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:compact:
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For demonstration purposes, some boards use the GPIO pin of the built-in LED.
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Sample output
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=============
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The GPIO pin should be switched to active level after one second.
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The following output is printed:
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.. code-block:: console
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Initializing pin with inactive level.
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Waiting one second.
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Setting pin to active level.
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