STM32 BDMA binding

:orphan:

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.. dtcompatible:: st,stm32-bdma
.. _dtbinding_st_stm32_bdma:

st,stm32-bdma
#############

Vendor: :ref:`STMicroelectronics <dt_vendor_st>`

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

These nodes are "dma" bus nodes.

.. code-block:: none

   STM32 BDMA controller

   The STM32 BDMA is a general-purpose direct memory access controller
   capable of supporting 5 or 6 or 7 or 8 independent BDMA channels.
   Each channel can have up to 8 requests.
   BDMA clients connected to the STM32 BDMA controller must use the format
   described in the dma.txt file, using a four-cell specifier for each
   channel: a phandle to the BDMA controller plus the following four integer cells:
     1. channel: the bdma stream from 0 to <bdma-requests>
     2. slot: bdma request
     3. channel-config: A 32bit mask specifying the BDMA channel configuration
     which is device dependent:
         -bit 6-7 : Direction  (see dma.h)
                0x0: MEM to MEM
                0x1: MEM to PERIPH
                0x2: PERIPH to MEM
                0x3: reserved for PERIPH to PERIPH
         -bit 9 : Peripheral Increment Address
                0x0: no address increment between transfers
                0x1: increment address between transfers
         -bit 10 : Memory Increment Address
                0x0: no address increment between transfers
                0x1: increment address between transfers
         -bit 11-12 : Peripheral data size
                0x0: Byte (8 bits)
                0x1: Half-word (16 bits)
                0x2: Word (32 bits)
                0x3: reserved
         -bit 13-14 : Memory data size
                0x0: Byte (8 bits)
                0x1: Half-word (16 bits)
                0x2: Word (32 bits)
                0x3: reserved
         -bit 15: Peripheral Increment Offset Size
                0x0: offset size is linked to the peripheral bus width
                0x1: offset size is fixed to 4 (32-bit alignment)
         -bit 16-17 : Priority level
                0x0: low
                0x1: medium
                0x2: high
                0x3: very high

     examples for stm32h7
      bdma1: dma-controller@58025400 {
          compatible = "st,stm32-bdma";
          ...
          st,mem2mem;
          dma-requests = <7>;
          status = "disabled";
         };

   For the client part, example for STM32H743 on BDMA1 instance
   using dmamux2

     &adc3 {
        dmas = < &dmamux2 0 17 0x2C80 >;
        dma-names = "dmamux";
     };

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

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

                Number of items to expect in a DMA specifier


             This property is **required**.

             Constant value: ``4``

         * - ``dma-channel-mask``
           - ``int``
           - .. code-block:: none

                Bitmask of available DMA channels in ascending order that are
                not reserved by firmware and are available to the
                kernel. i.e. first channel corresponds to LSB.



         * - ``dma-channels``
           - ``int``
           - .. code-block:: none

                Number of DMA channels supported by the controller


         * - ``dma-requests``
           - ``int``
           - .. code-block:: none

                Number of DMA request signals supported by the controller.


         * - ``dma-buf-addr-alignment``
           - ``int``
           - .. code-block:: none

                Memory address alignment requirement for DMA buffers used by the controller.


         * - ``dma-buf-size-alignment``
           - ``int``
           - .. code-block:: none

                Memory size alignment requirement for DMA buffers used by the controller.


         * - ``dma-copy-alignment``
           - ``int``
           - .. code-block:: none

                Minimal chunk of data possible to be copied by the controller.


         * - ``st,mem2mem``
           - ``boolean``
           - .. code-block:: none

                If the BDMA controller supports memory to memory transfer


         * - ``dma-offset``
           - ``int``
           - .. code-block:: none

                offset in the table of channels when mapping to a DMAMUX for 1st dma instance, offset is 0, for 2nd dma instance, offset is the nb of dma channels of the 1st dma, for 3rd dma instance, offset is the nb of dma channels of the 2nd dma plus the nb of dma channels of the 1st dma instance, etc.





   .. 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-bdma" 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


             This property is **required**.

             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


             This property is **required**.

             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
********************

- dma cells: channel, slot, channel-config