ti,fdc2x1x (on i2c bus)
Vendor: Texas Instruments
Note
An implementation of a driver matching this compatible is available in drivers/sensor/ti/fdc2x1x/fdc2x1x.c.
Description
Texas Instruments FDC2X1X capacitive sensor
Properties
Top level properties
These property descriptions apply to “ti,fdc2x1x” nodes themselves. This page also describes child node properties in the following sections.
Properties not inherited from the base binding file.
Name |
Type |
Details |
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The SD pin defaults to active high when consumed by the sensor.
The property value should ensure the flags properly describe
the signal that is presented to the driver.
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The INTB pin defaults to active low when produced by the sensor.
The property value should ensure the flags properly describe
the signal that is presented to the driver.
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Set to identify the sensor as FDC2114 or FDC2214 (4-channel version)
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Set the Auto-Scan Mode.
false = Continuous conversion on the single channel selected by
"active-channel" (single channel mode).
true = Auto-Scan conversions as selected by "rr-sequence"
(multichannel mode).
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Reference frequency of the used clock source in KHz.
The internal clock oscillates at around 43360 KHz (43.36 MHz)
at 20 degrees Celsius.
Recommended external clock source frequency is 40000 KHz (40 MHz).
This property is required. |
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Auto-Scan Sequence Configuration.
The FDC will perform a single conversion on each channel
in the sequence selected, and then restart the sequence continuously.
The sensor performs conversion on Channel 0 to 1 by default after
power-on-reset. This setting only applies if autoscan=true
(multichannel mode).
0 = Ch0, Ch1
1 = Ch0, Ch1, Ch2 (FDC2114, FDC2214 only)
2 = Ch0, Ch1, Ch2, Ch3 (FDC2114, FDC2214 only)
Legal values: |
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Selects channel for continuous conversions.
The sensor performs continuous conversion on Channel 0 by default after
power-on-reset. This setting only applies if autoscan=false
(single channel mode).
0 = Perform continuous conversions on Channel 0
1 = Perform continuous conversions on Channel 1
2 = Perform continuous conversions on Channel 2 (FDC2114, FDC2214 only)
3 = Perform continuous conversions on Channel 3 (FDC2114, FDC2214 only)
Legal values: |
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Input deglitch filter bandwidth. Select the lowest setting that exceeds
the oscillation tank oscillation frequency.
1 = 1MHz
4 = 3.3MHz
5 = 10MHz
7 = 33MHz
This property is required. Legal values: |
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Sensor Activation Mode Selection.
The sensor uses low-power activation mode by default after
power-on-reset.
full-current = the FDC will drive maximum
sensor current for a shorter sensor activation time.
low-power = the FDC uses the value programmed by "idrive" during
sensor activation to minimize power consumption.
Default value: Legal values: |
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Select Reference Frequency Source.
The sensor uses the internal clock by default after power-on-reset.
internal = Use Internal oscillator as reference frequency
external = Reference frequency is provided from CLKIN pin.
Default value: Legal values: |
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Select Current Sensor Drive.
The sensor uses normal current drive by default after power-on-reset.
High current drive is not supported if autoscan=false and will default
to normal.
normal = The FDC will drive all channels with normal sensor current
(1.5mA max).
high = The FDC will drive channel 0 with current >1.5mA.
Default value: Legal values: |
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Output gain control (FDC2112, FDC2114 only)
The default output gain is 0 after power-on-reset.
0 = Gain = 1 | Effective Resolution 12 bits | 100% full scale
1 = Gain = 4 | Effective Resolution 14 bits | 25% full scale
2 = Gain = 8 | Effective Resolution 15 bits | 12.5% full scale
3 = Gain = 16 | Effective Resolution 16 bits | 6.25% full scale
Legal values: |
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Human readable string describing the sensor. It can be used to
distinguish multiple instances of the same model (e.g., lid accelerometer
vs. base accelerometer in a laptop) to a host operating system.
This property is defined in the Generic Sensor Property Usages of the HID
Usage Tables specification
(https://usb.org/sites/default/files/hut1_3_0.pdf, section 22.5).
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GPIO specifier that controls power to the device.
This property should be provided when the device has a dedicated
switch that controls power to the device. The supply state is
entirely the responsibility of the device driver.
Contrast with vin-supply.
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Reference to the regulator that controls power to the device.
The referenced devicetree node must have a regulator compatible.
This property should be provided when device power is supplied
by a shared regulator. The supply state is dependent on the
request status of all devices fed by the regulator.
Contrast with supply-gpios. If both properties are provided
then the regulator must be requested before the supply GPIOS is
set to an active state, and the supply GPIOS must be set to an
inactive state before releasing the regulator.
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Deprecated properties not inherited from the base binding file.
(None)
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 “ti,fdc2x1x” compatible.
Name |
Type |
Details |
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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register space
This property is required. See Important properties for more information. |
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name of each register space
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interrupts for device
See Important properties for more information. |
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extended interrupt specifier for device
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name of each interrupt
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phandle to interrupt controller node
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Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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Clock gate information
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name of each clock
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number of address cells in reg property
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number of size cells in reg property
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
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Provided names of IO channel specifiers
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mailbox / IPM channels specifiers
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Provided names of mailbox / IPM channel specifiers
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Power domain specifiers
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Provided names of power domain specifiers
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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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Child node properties
Name |
Type |
Details |
|---|---|---|
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Channel X Reference Count Conversion Interval Time.
Valid range: 256 - 65535
This property is required. |
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Channel X Conversion Offset (FDC2112 and FDC2212 only).
The default offset value after power-on-reset is 0.
Valid range: 0 - 65535
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Channel X Conversion Settling.
The FDC will use this settling time to allow the LC sensor to
stabilize before initiation of a conversion on Channel X.
Valid range: 0 - 65535
This property is required. |
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Channel X Reference Divider.
Sets the divider for Channel X reference.
Use this to scale the maximum conversion frequency.
Valid range: 1 - 1023
This property is required. |
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Channel X Sensor drive current.
This field defines the Drive Current used during the settling +
conversion time of Channel X sensor clock.
Valid range: 0 - 31
This property is required. |
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Channel X Sensor frequency select.
For differential sensor configuration:
1 = divide by 1. Choose for sensor frequencies between
0.01MHz and 8.75MHz
2 = divide by 2. Choose for sensor frequencies between 5MHz
and 10MHz
For single-ended sensor configuration:
2 = divide by 2. Choose for sensor frequencies between
0.01MHz and 10MHz
This property is required. Legal values: |
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Inductor value used on the PCB for the sensing network of the
specific channel, which is usually 18uH.
This property is required. |