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.. dtcompatible:: st,stm32-fmc-nor-psram
.. _dtbinding_st_stm32_fmc_nor_psram:

st,stm32-fmc-nor-psram
######################

Vendor: :ref:`STMicroelectronics <dt_vendor_st>`

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



.. code-block:: none

   STM32 Flexible Memory Controller (NOR Flash/PSRAM/SRAM controller).

   The FMC generates the appropriate signal timings to drive the
   following types of memories:

   * Asynchronous SRAM and ROM
     - 8 bits
     - 16 bits
     - 32 bits
   * PSRAM (Cellular RAM)
     - Asynchronous mode
     - Burst mode for synchronous accesses with configurable option to split burst
       access when crossing boundary page for CRAM 1.5.
     - Multiplexed or non-multiplexed
   * NOR Flash memory
     - Asynchronous mode
     - Burst mode for synchronous accesses
     - Multiplexed or non-multiplexed

   A unique Chip Select signal (NE) is used per bank. All the other
   signals (addresses, data and control) are shared. A wide range of
   devices is supported through programmable timings.

   Refer to the reference manual for more details.

   The FMC NOR/PSRAM controller is defined below the FMC node and banks are
   defined as child nodes of the FMC NOR/PSRAM controller node.

   You can enable the controller in devicetree as follows:

   &fmc {
     status = "okay";
     pinctrl-0 = <&fmc_nwe_pd5 &fmc_noe_pd4 ...>;
     pinctrl-names = "default";

     sram {
       status = "okay";
       compatible = "st,stm32-fmc-nor-psram";

       #address-cells = <1>;
       #size-cells = <0>;

       sram2@2 {
         reg = <0x2>;
         st,control = <STM32_FMC_DATA_ADDRESS_MUX_DISABLE
                       STM32_FMC_MEMORY_TYPE_SRAM
                       STM32_FMC_NORSRAM_MEM_BUS_WIDTH_16
                       STM32_FMC_BURST_ACCESS_MODE_DISABLE
                       STM32_FMC_WAIT_SIGNAL_POLARITY_LOW
                       STM32_FMC_WAIT_TIMING_BEFORE_WS
                       STM32_FMC_WRITE_OPERATION_ENABLE
                       STM32_FMC_WAIT_SIGNAL_DISABLE
                       STM32_FMC_EXTENDED_MODE_DISABLE
                       STM32_FMC_ASYNCHRONOUS_WAIT_DISABLE
                       STM32_FMC_WRITE_BURST_DISABLE
                       STM32_FMC_CONTINUOUS_CLOCK_SYNC_ONLY
                       STM32_FMC_WRITE_FIFO_DISABLE
                       STM32_FMC_PAGE_SIZE_NONE>;
         st,timing = <4 2 3 0 16 17 STM32_FMC_ACCESS_MODE_A>;
       };
     };
   };

   Use constants defined in dt-bindings/memory-controller/stm32-fmc-nor-psram.h.

Properties
**********

Top level properties
====================


These property descriptions apply to "st,stm32-fmc-nor-psram"
nodes themselves. This page also describes child node
properties in the following sections.

.. tabs::

   .. group-tab:: Node specific properties

      Properties not inherited from the base binding file.

      (None)

   .. 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-fmc-nor-psram" compatible.

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

         * - Name
           - Type
           - Details

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

                number of address cells in reg property


             This property is **required**.

             Constant value: ``1``

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

                number of size cells in reg property


             This property is **required**.

         * - ``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.

         * - ``clocks``
           - ``phandle-array``
           - .. code-block:: none

                Clock gate information


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

                name of each clock


         * - ``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


         * - ``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.






Child node properties
=====================

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

   * - Name
     - Type
     - Details

   * - ``reg``
     - ``int``
     - This property is **required**.

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

   * - ``st,control``
     - ``array``
     - .. code-block:: none

          SRAM/NOR-Flash control register (FMC_BCRx).

          Contains control information of each memory bank,
          used for SRAMs, PSRAM and NOR Flash memories.

          Expected fields, in order:

          * MUXEN - Address/data multiplexing enable bit.
          * MTYP  - Memory type.
          * MWID  - Memory data bus width.
          * FACCEN - Flash access enable.
          * BURSTEN - Burst enable bit.
          * WAITPOL - Wait signal polarity bit.
          * WAITCFG - Wait timing configuration.
          * WREN - Write enable bit.
          * WAITEN - Wait enable bit.
          * EXTMOD - Extended mode enable.
                     If set, then 'st,timing-ext' shall be provided.
          * ASYNCWAIT -  Wait signal during asynchronous transfers.
          * CPSIZE - Cellular RAM (CRAM) 1.5 Page Size.
          * CBURSTRW - Write burst enable.
          * CCLKEN - Continuous Clock Enable.
          * WFDIS - Write FIFO Disable.
          * BMAP - FMC bank mapping.



       This property is **required**.

   * - ``st,timing``
     - ``array``
     - .. code-block:: none

          SRAM/NOR-Flash (read) timing register (FMC_BTRx).

          If the EXTMOD is set (see control register FMC_BCRx), then
          FMC_BTRx register is partitioned for write and read access.
          That means, use this property to configure read accesses and
          'st,timing-ext' to configure write accesses.

          Expected fields, in order:

          * ADDSET  - Address setup phase duration.
                      Number of HCLK cycles to configure the duration of
                      the address setup time. This parameter can be a value
                      between Min_Data = 0 and Max_Data = 15.
                      Note: Not used with synchronous NOR Flash memories.
          * ADDHLD  - Address-hold phase duration.
                      Number of HCLK cycles to configure the duration of
                      the address hold time. This parameter can be a value
                      between Min_Data = 1 and Max_Data = 15.
                      Note: Not used with synchronous NOR Flash memories.
          * DATAST  - Data-phase duration.
                      Number of HCLK cycles to configure the duration of
                      the data setup time. This parameter can be a value
                      between Min_Data = 1 and Max_Data = 255.
                      Note: Used for SRAMs, ROMs and asynchronous multiplexed
                      NOR Flash memories.
          * BUSTURN - Bus turnaround phase duration.
                      Number of HCLK cycles to configure the duration of
                      the bus turnaround. This parameter can be a value
                      between Min_Data = 0 and Max_Data = 15.
                      Note: Only used for multiplexed NOR Flash memories.
          * CLKDIV  - Clock divide ratio (for FMC_CLK signal).
                      Period of CLK clock output signal, expressed in number of
                      HCLK cycles. This parameter can be a value
                      between Min_Data = 2 and Max_Data = 16.
                      Note: Not used for asynchronous NOR Flash, SRAM or ROM
                      accesses.
          * DATLAT  - Data latency for synchronous memory.
                      Number of memory clock cycles to issue to the memory
                      before getting the first data.
                      The value depends on the memory type as shown below:
                      - It must be set to 0 in case of a CRAM
                      - It is don't care in asynchronous NOR, SRAM or ROM accesses
                      - It may assume a value between Min_Data = 2 and Max_Data = 17
                        in NOR Flash memories with synchronous burst mode enable
          * ACCMOD  - Access mode.
                      See access mode defines
                      in dt-bindings/memory-controller/stm32-fmc-nor-psram.h.



       This property is **required**.

   * - ``st,timing-ext``
     - ``array``
     - .. code-block:: none

          SRAM/NOR-Flash (write) timing register (FMC_BWTRx).

          Expected fields, in order:

          * ADDSET  - Address setup phase duration.
                      Reset state: 15 (0xF).
          * ADDHLD  - Address-hold phase duration.
                      Reset state: 15 (0xF).
          * DATAST  - Data-phase duration.
                      Reset state: 255 (0xFF).
          * BUSTURN - Bus turnaround phase duration.
                      Reset state: 15 (0xF).
          * ACCMOD  - Access mode.
                      Reset state: 0 (0x0).

          Refer to 'st,timing' for detailed field descriptions.

          This property is applied only when EXTMOD is set
          (see control register FMC_BCRx).

          If absent, then reset state values are used.



       Default value: ``[15, 15, 255, 15, 0]``