PWM-driven external clock binding

:orphan:

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.. dtcompatible:: pwm-clock
.. _dtbinding_pwm_clock:

pwm-clock
#########

Vendor: :ref:`Generic or vendor-independent <dt_no_vendor>`

Description
***********



.. code-block:: none

   An external clock signal driven by a PWM pin.

   The devicetree must define a clock node:

   pwmclock: pwmclock {
       status = "okay";
       compatible = "pwm-clock";
       #clock-cells = <1>;
       pwms = <&pwm_ccu40 2 PWM_HZ(1000000) PWM_POLARITY_NORMAL>;
   };

   This will create a device node with a clock-controller
   API. Internally the device node will use PWM API to start the
   clock signals at 1MHz. Note that the PWM_HZ() macro converts the
   frequency to time (nanoseconds units). This may result in rounding
   errors if the clock frequency is not an integer number of nanoseconds.
   The clock frequency can be explicitly set using the clock-frequency
   property.

   The PWM node may need to be properly configured to generate
   the target period (i.e. using prescaler options). See the documentation
   for the target PWM driver.

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

         * - ``#clock-cells``
           - ``int``
           - .. code-block:: none

                Number of items to expect in a Clock specifier


             This property is **required**.

             Constant value: ``1``

         * - ``pwms``
           - ``phandle-array``
           - This property is **required**.

         * - ``clock-frequency``
           - ``int``
           - .. code-block:: none

                Exact output frequency, in case the PWM period is not exact
                but was rounded to nanoseconds. This property is optional.



         * - ``pwm-on-delay``
           - ``int``
           - .. code-block:: none

                Optional blocking delay in micro seconds to make sure that the PWM clock has started after returning from clock_control_on().




   .. 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 "pwm-clock" compatible.

      .. list-table::
         :widths: 1 1 4
         :header-rows: 1

         * - Name
           - Type
           - Details

         * - ``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.



         * - ``power-domain``
           - ``phandle``
           - .. code-block:: none


                Power domain the device belongs to.

                The device will be notified when the power domain it belongs to is either
                suspended or resumed.



         * - ``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.



         * - ``status``
           - ``string``
           - .. code-block:: none

                indicates the operational status of a device


             Legal values: ``'ok'``, ``'okay'``, ``'disabled'``, ``'reserved'``, ``'fail'``, ``'fail-sss'``

             See :ref:`dt-important-props` for more information.

         * - ``compatible``
           - ``string-array``
           - .. code-block:: none

                compatible strings


             This property is **required**.

             See :ref:`dt-important-props` for more information.

         * - ``reg``
           - ``array``
           - .. code-block:: none

                register space


             See :ref:`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:`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:`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


         * - ``zephyr,deferred-init``
           - ``boolean``
           - .. code-block:: none

                Do not initialize device automatically on boot. Device should be manually
                initialized using device_init().






Specifier cell names
********************

- clock cells: id