:orphan:
.. raw:: html
.. dtcompatible:: zephyr,fstab,littlefs
.. _dtbinding_zephyr_fstab_littlefs:
zephyr,fstab,littlefs
#####################
Vendor: :ref:`Zephyr-specific binding `
.. note::
An implementation of a driver matching this compatible is available in
:zephyr_file:`subsys/fs/littlefs_fs.c`.
Description
***********
.. code-block:: none
Description of pre-defined file systems.
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
* - ``read-size``
- ``int``
- .. code-block:: none
The size of file system read operations, in bytes.
All read operations will be a multiple of this value. A
reasonable default is 16.
This corresponds to CONFIG_FS_LITTLEFS_READ_SIZE.
This property is **required**.
* - ``prog-size``
- ``int``
- .. code-block:: none
The size of file system program (write) operations, in bytes.
All program operations will be a multiple of this value. A
reasonable default is 16.
This corresponds to CONFIG_FS_LITTLEFS_PROG_SIZE.
This property is **required**.
* - ``cache-size``
- ``int``
- .. code-block:: none
The size of block caches, in bytes.
Each cache buffers a portion of a block in RAM. The littlefs
needs a read cache, a program cache, and one additional cache per
file. Larger caches can improve performance by storing more data
and reducing the number of disk accesses. Must be a multiple of
the read and program sizes of the underlying flash device, and a
factor of the block size.
A reasonable default is 64.
This corresponds to CONFIG_FS_LITTLEFS_CACHE_SIZE.
This property is **required**.
* - ``lookahead-size``
- ``int``
- .. code-block:: none
The size of the lookahead buffer, in bytes.
A larger lookahead buffer increases the number of blocks found
during an allocation pass. The lookahead buffer is stored as a
compact bitmap, so each byte of RAM can track 8 blocks. Must be a
multiple of 8.
A reasonable default is 32.
This corresponds to CONFIG_FS_LITTLEFS_LOOKAHEAD_SIZE.
This property is **required**.
* - ``block-cycles``
- ``int``
- .. code-block:: none
The number of erase cycles before moving data to another block.
For dynamic wear leveling, the number of erase cycles before data
is moved to another block. Set to a non-positive value to disable
leveling.
This corresponds to CONFIG_FS_LITTLEFS_BLOCK_CYCLES.
This property is **required**.
* - ``disk-version``
- ``int``
- .. code-block:: none
The littlefs disk version.
To maintain backward compatibility with existing littlefs
with the same major disk version.
The default version is LFS_DISK_VERSION.
* - ``mount-point``
- ``string``
- .. code-block:: none
The absolute path used as the file system mount point.
This property is **required**.
* - ``partition``
- ``phandle``
- .. code-block:: none
A reference to the file system's partition.
This property is **required**.
* - ``automount``
- ``boolean``
- .. code-block:: none
Mount file system on boot if present.
During initialization the file system driver will attempt to mount
this partition.
* - ``read-only``
- ``boolean``
- .. code-block:: none
Mount file system read-only if present.
This adds the FS_MOUNT_FLAG_READ_ONLY option to be set in the
mount descriptor generated for the file system.
* - ``no-format``
- ``boolean``
- .. code-block:: none
Do not format file system if mount fails.
This causes the FS_MOUNT_FLAG_NO_FORMAT option to be set in the
mount descriptor generated for the file system.
* - ``disk-access``
- ``boolean``
- .. code-block:: none
Use disk-access for accessing storage media.
This causes the FS_MOUNT_FLAG_USE_DISK_ACCESS option to be set in
the mount descriptor generated for the file system.
.. 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 "zephyr,fstab,littlefs" compatible.
.. list-table::
:widths: 1 1 4
:header-rows: 1
* - Name
- Type
- Details
* - ``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``
- ``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.
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.
* - ``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
* - ``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 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 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.