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.. dtcompatible:: st,stm32-lptim
.. _dtbinding_st_stm32_lptim:

st,stm32-lptim
##############

Vendor: :ref:`STMicroelectronics N.V. <dt_vendor_st>`

.. note::

   An implementation of a driver matching this compatible is available in
   :zephyr_file:`drivers/timer/stm32_lptim_timer.c`.

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



.. code-block:: none

   STM32 low-power timer (LPTIM).

   The lptim node to be used for counting ticks during lowpower modes
   must be named stm32_lp_tick_source in the DTS, as follows:
   stm32_lp_tick_source: &lptim1 {
    status = "okay";
   }

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

         * - ``st,prescaler``
           - ``int``
           - .. code-block:: none

                Clock divider at the input of the lptimer clock, default reset value is 'not divided'.

                Prescaler allows to achieve higher LPTIM timeout (up to 256s when lptim clocked by LSE)
                and consequently higher core sleep durations, but impacts the tick precision.
                To be used with caution.
                CONFIG_SYS_CLOCK_TICKS_PER_SEC could be used to tune tick duration and gain precision,
                at kernel timing granularity cost.

                For example, when LPTIM is clocked by the LSE (32768Hz) and st,prescaler = <32>:
                LPTIM global timeout is 64 seconds with an increment of 0.97 ms.
                Using CONFIG_SYS_CLOCK_TICKS_PER_SEC = 4096, tick = 0.24 ms, LPTIM precision is 4 ticks.
                Using CONFIG_SYS_CLOCK_TICKS_PER_SEC = 1024, tick = 0.97 ms, LPTIM precision is 1 ticks.



             Default value: ``1``

             Legal values: ``1``, ``2``, ``4``, ``8``, ``16``, ``32``, ``64``, ``128``

         * - ``st,timeout``
           - ``int``
           - .. code-block:: none

                Gives the LPTIM an exact counting value (s) for timeout expiration.
                Valid range is [1, 256] and should be consistent with st,prescaler
                pre-defined setting. If not, an error is raised.



         * - ``reset-names``
           - ``string-array``
           - .. code-block:: none

                Name of each reset




   .. 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 "st,stm32-lptim" compatible.

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

         * - Name
           - Type
           - Details

         * - ``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.



             This property is **required**.

             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



             This property is **required**.

         * - ``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-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.

         * - ``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.