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DISCONTINUED (October 2022): the maintenance for this repository has been discontinued.

Please refer to:

https://github.com/STMicroelectronics/st-mems-android-linux-drivers-iio

for the up-to-date drivers repository.

* Introduction* Integration details* More information* Copyright

This repository contains Linux kernel v4.4 with STMicroelectronics MEMS sensor support. STM sensor drivers are located under the directorydrivers/iio organized by sensor type:

LSM6DS3, LSM6DS3H, LSM6DSL, LSM6DSM, LSM9DS0, LSM9DS1, ISM330DLC, LSM6DSO, ASM330LHH, LSM6DSR, ISM330DHCX, LSM6DSO32,LSM6DSOX, LSM6DSRX, LSM6DSO32X, ASM330LHHX

LIS2DH, LIS2DH12, LIS3DH, LIS2DG, LSM303AH, LIS2DS12, LIS2HH12, LIS2DW12, LIS3LV02DL,LSM303DLH, LSM303DLHC, LSM330D, LSM330DL, LSM330DLC, LIS331DL, LIS331DLH, LSM303DL,LSM303DLM, LSM330, LSM303AGR, LIS3DHH, IIS2DH, ISM303DAC, IIS3DHHC, IIS2DLPC, AIS2IH

L3G4200D, LSM330D, LSM330DL, L3GD20, L3GD20H, L3G4IS, LSM330, LSM330DLC

LIS3MDL, LSM9DS1, LSM303AH, LSM303AGR, LSM303DLH, LSM303DLHC, LSM303DLM, LIS2MDL, IIS2MDC, ISM303DAC

HTS221

LPS22HB, LPS22HD, LPS25H, LPS331AP, LPS001WP, LPS33HW, LPS35HW, LPS22HH, LPS27HHW, LPS22DF

STTS22H

Data collected by STM sensors are pushed to userland through the kernel buffers of Linux IIO framework. User space applications can get sensor events by reading the related IIO devices created in the /dev directory (/dev/iio{x}). Please seeIIO for more information.

All STM MEMS sensors supportI2C/SPI digital interface. Please refer toI2C andSPI for detailed documentation.

In order to explain how to integrate STM sensors in a different kernel, please consider the followingLSM6DSM IMU example

• Copy driver source code into the target directory (e.g.drivers/iio/imu)
• Edit related Kconfig (e.g.drivers/iio/imu/Kconfig) to includeLSM6DSM support:

    source "drivers/iio/imu/st_lsm6dsm/Kconfig"

• Edit related Makefile (e.g.drivers/iio/imu/Makefile) adding the following line:

    obj-y += lsm6dsm/

• Add custom events intoinclude/uapi/linux/iio/types.h (follow a sample patch for kernel 4.4):

    @@ -85,6 +93,7 @@ enum iio_event_type {              IIO_EV_TYPE_THRESH_ADAPTIVE,              IIO_EV_TYPE_MAG_ADAPTIVE,              IIO_EV_TYPE_CHANGE,    +         IIO_EV_TYPE_FIFO_FLUSH,    };    @@ -92,6 +101,8 @@ enum iio_event_direction {              IIO_EV_DIR_RISING,              IIO_EV_DIR_FALLING,              IIO_EV_DIR_NONE,    +         IIO_EV_DIR_FIFO_EMPTY,    +         IIO_EV_DIR_FIFO_DATA,    };

• Add custom channel typesinclude/uapi/linux/iio/types.h depending on the custom sensor implemented into driver (follow a sample patch for kernel 4.4):

     @@ -37,6 +37,14 @@ enum iio_chan_type {              IIO_VELOCITY,              IIO_CONCENTRATION,              IIO_RESISTANCE,    +         IIO_SIGN_MOTION,    +         IIO_STEP_DETECTOR,    +         IIO_STEP_COUNTER,    +         IIO_TILT,    +         IIO_TAP,    +         IIO_TAP_TAP,    +         IIO_WRIST_TILT_GESTURE,    +         IIO_GESTURE,    +         IIO_WKUP,    +         IIO_FREE_FALL,    };

To enable driver probing, add the lsm6dsm node to the platform device tree as described below.

Required properties:

- compatible: "st,lsm6dsm"

- reg: the I2C address or SPI chip select the device will respond to

- interrupt-parent: phandle to the parent interrupt controller as documented ininterrupts

- interrupts: interrupt mapping for IRQ as documented ininterrupts

Recommended properties for SPI bus usage:

- spi-max-frequency: maximum SPI bus frequency as documented inSPI

Optional properties:

- st,drdy-int-pin: MEMS sensor interrupt line to use (default 1)

I2C example (based on Raspberry PI 3):

  &i2c0 {  status = "ok";  #address-cells = <0x1>;  #size-cells = <0x0>;  lsm6dsm@6b {  compatible = "st,lsm6dsm";  reg = <0x6b>;  interrupt-parent = <&gpio>;  interrupts = <26 IRQ_TYPE_LEVEL_HIGH>;  };

SPI example (based on Raspberry PI 3):

  &spi0 {  status = "ok";  #address-cells = <0x1>;  #size-cells = <0x0>;  lsm6dsm@0 {  spi-max-frequency = <500000>;  compatible = "st,lsm6dsm";  reg = <0>;  interrupt-parent = <&gpio>;  interrupts = <26 IRQ_TYPE_LEVEL_HIGH>;  };

Configure kernel withmake menuconfig (alternatively usemake xconfig ormake qconfig)

  Device Drivers  --->  <M> Industrial I/O support  --->  Inertial measurement units  --->  <M>   STMicroelectronics LSM6DSM/LSM6DSL sensor  --->

http://st.com

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/iio

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/i2c

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/spi

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bings/interrupt-controller/interrupts.txt

Copyright (C) 2019 STMicroelectronics

This software is distributed under the GNU General Public License - see the accompanying COPYING file for more details.