silabs,vdac
Vendor: Silicon Laboratories
Note
An implementation of a driver matching this compatible is available in drivers/dac/dac_silabs_vdac.c.
Description
Silicon Labs Series 2 VDAC (Voltage Digital-to-Analog Converter)
The VDAC has two channels, a resolution of 12-bit and a configurable output
range from 0V to 2.5V.
The minimal default configuration for the Silabs VDAC node is as follows:
#include <zephyr/dt-bindings/dac/silabs-vdac.h>
&vdac0 {
status = "okay";
voltage-reference = "2.5V";
channel@0 {
reg = <0>;
main-output;
};
};
Using the main output is the preferred way for any DAC output. Defines like
`VDAC0_CH0_MAIN_OUT_PIN` exists in em_device.h to get the dedicated pin for
your device.
It is also possible to use the auxiliary output to route the output to other
peripherals like the IADC or the ACMP, or to the analog bus to output on any GPIO.
Note that the analog bus multiplexer adds significant impedance, and this option
may not be suitable for certain loads or dynamic conditions.
To connect the analog bus to a GPIO, the `pinctrl` driver must be configured to
allocate an analog bus corresponding to the port and pin of each GPIO input selected.
The following is an example of how that can be configured:
#include <zephyr/dt-bindings/pinctrl/silabs/xg24-pinctrl.h>
#include <zephyr/dt-bindings/dac/silabs-vdac.h>
&pinctrl {
vdac0_default: vdac0_default {
group0 {
silabs,analog-bus = <ABUS_CDODD0_VDAC0CH0>;
};
group1 {
silabs,analog-bus = <ABUS_CDEVEN1_VDAC0CH1>;
};
};
&vdac0 {
pinctrl-0 = <&vdac0_default>;
pinctrl-names = "default";
status = "okay";
voltage-reference = "1.25V";
channel@0 {
reg = <0>;
aux-output = <VDAC_OUTPUT_PC1>;
};
channel@1 {
reg = <1>;
aux-output = <VDAC_OUTPUT_PC2>;
};
};
In the above example, note that the device specific bindings for pinctrl
were included. This header defines the set of analog bus allocations possible
for xg24 parts, and similar headers exist for other parts.
Properties
Top level properties
These property descriptions apply to “silabs,vdac” nodes themselves. This page also describes child node properties in the following sections.
Node specific properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
|
|
Reference voltage to use.
The default corresponds to the reset value of the register field.
Default value: Legal values: |
|
|
Number of prescaled CLK_VDAC + 1 for the DAC to warmup.
This determines how many clock cycles are needed for the DAC to stabilize
before it can be used for conversions.
The default corresponds to the reset value of the register field.
|
|
|
Channel refresh period configuration.
Determines how often the DAC channels are refreshed to maintain accuracy.
The default corresponds to the reset value of the register field.
Default value: Legal values: |
|
|
This property is required. Constant value: |
|
|
Pin configuration/s for the first state. Content is specific to the
selected pin controller driver implementation.
|
|
|
Pin configuration/s for the second state. See pinctrl-0.
|
|
|
Pin configuration/s for the third state. See pinctrl-0.
|
|
|
Pin configuration/s for the fourth state. See pinctrl-0.
|
|
|
Pin configuration/s for the fifth state. See pinctrl-0.
|
|
|
Names for the provided states. The number of names needs to match the
number of states.
|
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 “silabs,vdac” compatible.
Name |
Type |
Details |
|---|---|---|
|
|
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.
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.
|
|
|
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. |
|
|
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. |
|
|
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"
|
|
|
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. |
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Optional names given to the mbox specifiers in the "mboxes" property.
|
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|
Power domain specifiers relevant to the device.
|
|
|
Optional names given to the power domain specifiers in the "power-domains" property.
|
|
|
Number of cells in power-domains property
|
|
|
Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
|
|
|
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.
|
Child node properties
Name |
Type |
Details |
|---|---|---|
|
|
Channel identifier.
This property is required. Legal values: See Important properties for more information. |
|
|
Connects the channel to the dedicated output pin.
|
|
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Connects the low-power channel to the auxiliary outputs.
Connects the channel to the specified output pin on the analog bus.
|
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Short-circuits the main and auxiliary outputs.
Set to use high-power mode with auxiliary outputs.
|
|
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Sets the power mode of the main output to low instead of high.
|
|
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Enables high-capacitance load mode for the DAC channel.
Only usable without low-power-mode.
|
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Enables sample-off mode for the DAC channel.
If enabled, the output is only driven for a limited time per conversion.
|
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|
Time in DAC clock cycles that the output is held for the DAC channel.
Only usable with sample-off-mode.
The default corresponds to the reset value of the register field.
|
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Enables the refresh timer.
|
Specifier cell names
io-channel cells: output