st,lis2dw12 (on spi bus)
Vendor: STMicroelectronics N.V.
Note
An implementation of a driver matching this compatible is available in drivers/sensor/st/lis2dw12/lis2dw12.c.
Description
STMicroelectronics LIS2DW12 3-axis accelerometer accessed through SPI bus
Properties
Node specific properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
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Maximum clock frequency of device's SPI interface in Hz
This property is required. |
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Duplex mode, full or half. By default it's always full duplex thus 0
as this is, by far, the most common mode.
Use the macros not the actual enum value, here is the concordance
list (see dt-bindings/spi/spi.h)
0 SPI_FULL_DUPLEX
2048 SPI_HALF_DUPLEX
Legal values: |
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Motorola or TI frame format. By default it's always Motorola's,
thus 0 as this is, by far, the most common format.
Use the macros not the actual enum value, here is the concordance
list (see dt-bindings/spi/spi.h)
0 SPI_FRAME_FORMAT_MOTOROLA
32768 SPI_FRAME_FORMAT_TI
Legal values: |
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SPI clock polarity which indicates the clock idle state.
If it is used, the clock idle state is logic high; otherwise, low.
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SPI clock phase that indicates on which edge data is sampled.
If it is used, data is sampled on the second edge; otherwise, on the first edge.
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In some cases, it is necessary for the master to manage SPI chip select
under software control, so that multiple spi transactions can be performed
without releasing it. A typical use case is variable length SPI packets
where the first spi transaction reads the length and the second spi transaction
reads length bytes.
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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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DRDY pin
This pin defaults to active high 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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Select DRDY pin number (1 or 2).
1 # drdy is generated from INT1
2 # drdy is generated from INT2
This number represents which of the two interrupt pins
(INT1 or INT2) the drdy line is attached to. This property is not
mandatory and if not present it defaults to 1 which is the
configuration at power-up.
Default value: Legal values: |
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Range in g. Default is power-up configuration.
16 # 16g (1.952 mg/LSB)
8 # 8g (0.976 mg/LSB)
4 # 4g (0.488 mg/LSB)
2 # 2g (0.244 mg/LSB)
Default value: Legal values: |
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Output data rate in Hz. Default value is 12.5Hz if this is not set.
The output data rates which are represented with fractional
numbers are converted into their integer parts (1.65Hz -> 1, 12.5Hz -> 12).
If 0 selected as the odr, the accelerometer initializes into
power off state.
Legal values: |
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Digital filtering cutoff bandwidth. Default is power-up configuration.
- 0 # LIS2DW12_DT_FILTER_BW_ODR_DIV_2
- 1 # LIS2DW12_DT_FILTER_BW_ODR_DIV_4
- 2 # LIS2DW12_DT_FILTER_BW_ODR_DIV_10
- 3 # LIS2DW12_DT_FILTER_BW_ODR_DIV_20
Legal values: |
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Specify the sensor power mode. Default is power-up configuration.
- 0 # LIS2DW12_DT_LP_M1
- 1 # LIS2DW12_DT_LP_M2
- 2 # LIS2DW12_DT_LP_M3
- 3 # LIS2DW12_DT_LP_M4
- 4 # LIS2DW12_DT_HP_MODE
Legal values: |
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Tap mode. Default is power-up configuration.
- 0 # LIS2DW12_DT_SINGLE_TAP
- 1 # LIS2DW12_DT_SINGLE_DOUBLE_TAP
Legal values: |
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Tap X/Y/Z axes threshold. Default is power-up configuration.
(X/Y/Z values range from 0x00 to 0x1F)
Thresholds to start the tap-event detection procedure on the X/Y/Z axes.
Threshold values for each axis are unsigned 5-bit corresponding
to a 2g acceleration full-scale range. A threshold value equal to zero
corresponds to disable the tap detection on that axis.
For example, if you want to set the threshold for X to 12, for Z to 14
and want to disable tap detection on Y, you should specify in Device Tree
tap-threshold = <12>, <0>, <14>
which is equivalent to X = 12 * 2g/32 = 750mg and Z = 14 * 2g/32 = 875mg.
Default value: |
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Tap shock value. Default is power-up configuration.
(values range from 0x0 to 0x3)
This register represents the maximum time of an over-threshold signal
detection to be recognized as a tap event. Where 0 equals 4*1/ODR and
1LSB = 8*1/ODR.
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Tap latency. Default is power-up configuration.
(values range from 0x0 to 0xF)
When double-tap recognition is enabled, this register expresses the
maximum time between two successive detected taps to determine a
double-tap event. Where 0 equals 16*1/ODR and 1LSB = 32*1/ODR.
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Expected quiet time after a tap detection. Default is power-up configuration.
(values range from 0x0 to 0x3)
This register represents the time after the first detected tap in which
there must not be any overthreshold event. Where 0 equals 2*1/ODR
and 1LSB = 4*1/ODR.
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Enables the LOW_NOISE flag in the CTRL6 register.
This influences the noise density and the current consumption.
See the datasheet for more information.
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Sets the Filtered Data Selection bit in the CTRL6 register.
When enabled, the high-pass filter path is selected.
When disabled, the low-pass filter path is selected.
Note that this influences the OUT_REG / FIFO values,
but not the Wakeup function.
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Enables the high-pass filter reference mode in the CTRL7 register.
When the high-pass filter is configured in reference mode,
the output data is calculated as the difference between the input
acceleration and the values captured when reference mode was enabled.
In this way only the difference is applied without any filtering
of the LIS2DW12.
Note that this influences both the OUT_REG / FIFO values,
as well as the Wakeup function.
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Selects the pulsed mode for data-ready interrupt when enabled,
and the latched mode when disabled.
Sets the corresponding DRDY_PULSED bit in the CTRL7 register.
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The freefall duration value represented in milliseconds.
If the accelerometer readings of the all axes are lower
than the freefall threshold value for the freefall duration long,
then a freefall trigger occurs. This value is 5 bits long in the
register and 1 LSB = 1 * 1/ODR. This value depends on the ODR.
if the data rate change in code with SENSOR ATTR SAMPLING FREQUENCY,
It must be set again with SENSOR_ATT_FF_DUR attribute. ST propose
100Hz ODR and 30ms ff-duration for recognize freefall detection
refer to ST DT0100 design tip document.
Default value: |
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The freefall threshold value represented in mg.
If the accelerometer readings of the all axes are lower
than the freefall threshold value for the freefall duration long,
then a freefall trigger occurs. This value is 3 bits long.
Default value chosen 3 (312 mg) refer to ST DT0100 design tip document.
- 0 # LIS2DW12_DT_FF_THRESHOLD_156_mg
- 1 # LIS2DW12_DT_FF_THRESHOLD_219_mg
- 2 # LIS2DW12_DT_FF_THRESHOLD_250_mg
- 3 # LIS2DW12_DT_FF_THRESHOLD_312_mg
- 4 # LIS2DW12_DT_FF_THRESHOLD_344_mg
- 5 # LIS2DW12_DT_FF_THRESHOLD_406_mg
- 6 # LIS2DW12_DT_FF_THRESHOLD_469_mg
- 7 # LIS2DW12_DT_FF_THRESHOLD_500_mg
Default value: Legal values: |
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The wakeup duration. Default value is the register reset value.
If the accelerometer readings of the all axes are higher
than the wakeup threshold value for the wakeup duration long,
then a wakeup trigger occurs. This value is 2 bits long in the
register and 1 LSB = 1 * 1/ODR.
- 0 # LIS2DW12_DT_WAKEUP_1_ODR
- 1 # LIS2DW12_DT_WAKEUP_2_ODR
- 2 # LIS2DW12_DT_WAKEUP_3_ODR
- 3 # LIS2DW12_DT_WAKEUP_4_ODR
Legal values: |
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The sleep duration. Default value is the register reset value (0000 -> 16*1/ODR).
If the accelerometer readings of the all axes are lower
than the wakeup threshold value for the sleep duration long,
then a sleep trigger occurs or the device goes in sleep mode. This value is 4 bits long in the
register and 1 LSB = 512 * 1/ODR.
Value goes from 0 to 15
- 0 # LIS2DW12_DT_SLEEP_0_ODR
...
- 15 # LIS2DW12_DT_SLEEP_15_ODR
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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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 “st,lis2dw12” compatible.
Name |
Type |
Details |
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register space
This property is required. See Important properties for more information. |
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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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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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