nordic,nrf-twim
Vendor: Nordic Semiconductor
Description
These nodes are “i2c” bus nodes.
Nordic nRF family TWIM (TWI master with EasyDMA).
This binding can be used for nodes which can represent TWIM
peripherals. A single SoC peripheral ID is often associated with
multiple I2C peripherals, like a TWIM and a TWIS. You can choose
TWIM by setting the node's "compatible" to "nordic,nrf-twim"
and "status" to "okay", e.g. using an overlay file like this one:
/* This is for TWIM0 -- change to "i2c1" for TWIM1, etc. */
&i2c0 {
compatible = "nordic,nrf-twim";
status = "okay";
/* other property settings can go here */
};
This works on any supported SoC, for all TWIM instances.
Note: on nRF51 SoCs, use the "nordic,nrf-twi" binding instead.
Properties
Node specific properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
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Size of a concatenation buffer that the driver is to use for merging
multiple same direction I2C messages that have no RESTART or STOP
flag between them (see e.g. the i2c_burst_write() function) into one
transfer on the bus.
This property must be provided when interacting with devices like
the SSD1306 display that cannot tolerate a repeated start and
address appearing on the bus between message fragments. For many
devices a concatenation buffer is not necessary.
Default value: |
|
|
TWIM peripherals cannot perform write transactions from buffers
located in flash. If such buffers are expected to be used with
a given instance of the TWIM peripheral, this property must be
set to the maximum possible size of those buffers, so that the
driver can reserve enough space in RAM to copy there the contents
of particular buffers before requesting the actual transfers.
If this property is not set to a value adequate for a given
application, write transactions may fail for buffers that are
located in flash, what in turn may cause certain components,
like the DPS310 sensor driver, to not work.
It is recommended to use the same value for this property and for
the zephyr,concat-buf-size one, as both these buffering mechanisms
can utilize the same space in RAM.
Default value: |
|
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Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.
This property is required. |
|
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Names for the provided states. The number of names needs to match the
number of states.
This property is required. |
|
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Maximum number of bits available in the EasyDMA MAXCNT register. This
property must be set at SoC level DTS files.
This property is required. |
|
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Initial clock frequency in Hz
|
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Size of the submission queue for blocking requests
Default value: |
|
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Size of the completion queue for blocking requests
Default value: |
|
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Pin configuration/s for the second state. See pinctrl-0.
|
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Pin configuration/s for the third state. See pinctrl-0.
|
|
|
Pin configuration/s for the fourth state. See pinctrl-0.
|
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Pin configuration/s for the fifth state. See pinctrl-0.
|
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|
List of signals that require CLOCKPIN setting enablement.
|
|
|
List of memory region phandles
|
|
|
A list of names, one for each corresponding phandle in memory-region
|
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 “nordic,nrf-twim” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
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 Important properties for more information. |
|
|
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.
This property is required. See Important properties for more information. |
|
|
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.
This property is required. Constant value: |
|
|
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.
This property is required. |
|
|
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: See Important properties for more information. |
|
|
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. |
|
|
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"
|
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|
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.
|
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|
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.
|
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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.
|
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|
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. |
|
|
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
|
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Optional names given to each clock provider in the "clocks" property.
|
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DMA channel specifiers relevant to the device.
|
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Optional names given to the DMA channel specifiers in the "dmas" property.
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IO channel specifiers relevant to the device.
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Optional names given to the IO channel specifiers in the "io-channels" property.
|
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Mailbox / IPM channel specifiers relevant to the device.
|
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Optional names given to the mbox specifiers in the "mboxes" property.
|
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Power domain specifiers relevant to the device.
|
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Optional names given to the power domain specifiers in the "power-domains" property.
|
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Number of cells in power-domains property
|
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|
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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.
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Automatically configure the device for runtime power management after the
init function runs.
|
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List of power states that will disable this device power.
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