zephyr,fstab,littlefs

Vendor: Zephyr-specific binding

Note

An implementation of a driver matching this compatible is available in subsys/fs/littlefs_fs.c.

Description

Description of pre-defined file systems.

Properties

Node specific properties

Properties not inherited from the base binding file.

Name

Type

Details

read-size

int

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

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

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

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

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

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

The absolute path used as the file system mount point.

This property is required.

partition

phandle

A reference to the file system's partition.

This property is required.

automount

boolean

Mount file system on boot if present.

During initialization the file system driver will attempt to mount
this partition.

read-only

boolean

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

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

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.

Deprecated node specific properties

Deprecated properties not inherited from the base binding file.

(None)

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.

Name

Type

Details

status

string

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 Important properties for more information.

compatible

string-array

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 Important properties for more information.

reg

array

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 Important properties for more information.

reg-names

string-array

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

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 Important properties for more information.

interrupts-extended

compound

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

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

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

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 Important properties for more information.

clocks

phandle-array

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

Optional names given to each clock provider in the "clocks" property.

#address-cells

int

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

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

DMA channel specifiers relevant to the device.

dma-names

string-array

Optional names given to the DMA channel specifiers in the "dmas" property.

io-channels

phandle-array

IO channel specifiers relevant to the device.

io-channel-names

string-array

Optional names given to the IO channel specifiers in the "io-channels" property.

mboxes

phandle-array

Mailbox / IPM channel specifiers relevant to the device.

mbox-names

string-array

Optional names given to the mbox specifiers in the "mboxes" property.

power-domains

phandle-array

Power domain specifiers relevant to the device.

power-domain-names

string-array

Optional names given to the power domain specifiers in the "power-domains" property.

#power-domain-cells

int

Number of cells in power-domains property

zephyr,deferred-init

boolean

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

wakeup-source

boolean

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

Automatically configure the device for runtime power management after the
init function runs.

zephyr,disabling-power-states

phandles

List of power states that will disable this device power.