st,lis2dw12 (on spi bus)

Vendor: STMicroelectronics

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

Properties not inherited from the base binding file.

Name

Type

Details

spi-max-frequency

int

 
Maximum clock frequency of device's SPI interface in Hz

This property is required.

duplex

int

 
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: 0, 2048

frame-format

int

 
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: 0, 32768

spi-cpol

boolean

 
SPI clock polarity which indicates the clock idle state.
If it is used, the clock idle state is logic high; otherwise, low.

spi-cpha

boolean

 
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.

spi-hold-cs

boolean

 
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.

supply-gpios

phandle-array

 
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.

vin-supply

phandle

 
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.

irq-gpios

phandle-array

 
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.

int-pin

int

 
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: 1

Legal values: 1, 2

range

int

 
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: 2

Legal values: 16, 8, 4, 2

odr

int

 
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: 0, 1, 12, 25, 50, 100, 200, 400, 800, 1600

bw-filt

int

 
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: 0, 1, 2, 3

power-mode

int

 
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: 0, 1, 2, 3, 4

tap-mode

int

 
Tap mode. Default is power-up configuration.

- 0 # LIS2DW12_DT_SINGLE_TAP
- 1 # LIS2DW12_DT_SINGLE_DOUBLE_TAP

Legal values: 0, 1

tap-threshold

array

 
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: [0, 0, 0]

tap-shock

int

 
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.

tap-latency

int

 
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.

tap-quiet

int

 
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.

low-noise

boolean

 
Enables the LOW_NOISE flag in the CTRL6 register.
This influences the noise density and the current consumption.
See the datasheet for more information.

hp-filter-path

boolean

 
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.

hp-ref-mode

boolean

 
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.

drdy-pulsed

boolean

 
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.

ff-duration

int

 
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: 30

ff-threshold

int

 
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: 3

Legal values: 0, 1, 2, 3, 4, 5, 6, 7

wakeup-duration

int

 
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: 0, 1, 2, 3

sleep-duration

int

 
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: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15

friendly-name

string

 
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).