Index

* Introduction
* Integration details
* More information
* Copyright

Introduction

This repository contains Linux kernel (v3.10, v3.4) with STMicroelectronics MEMS sensor support. STM sensor drivers are located under the directory drivers/input/misc/st organized by sensor type:

Inertial Module Unit (IMU):

asm330lxh, lsm330, lsm330dlc, lsm6dl0, lsm6ds0, lsm6ds3, lsm6dsl, lsm6dsm, lsm9ds0, lsm9ds1

eCompass:

lsm303agr, lsm303ah, lsm303c, lsm303d, lsm303dlhc

Accelerometer:

ais328dq, ais3624dq, h3lis100dl, h3lis331dl, lis2de, lis2dh, lis2ds12, lis2hh12, lis331dlh, lis331hh, lis3de, lis3dh, lis3dsh, n2dm, lis2dw12

Gyroscope:

a3g4250d, l3g4200d, l3gd20, l3gd20h

Magnetometer:

lis3mdl, lis2mdl

Humidity:

hts221

Pressure:

lps22hb, lps25h

Ultraviolet:

uvis25

Data collected by STM sensors are pushed to userland through the Linux kernel Input framework using EV_MSC events. User space applications can get sensor events by reading the related input device created in the /dev directory. Please see Input for more information.

All STM MEMS sensors support I2C/SPI digital interface. Please refer to I2C and SPI for detailed documentation.

Integration details

In order to explain how to integrate STM sensors in a different kernel, please consider the following LSM6DSM IMU example

Source code integration

• Copy driver source code (XXX link) into the target directory (e.g. drivers/input/misc)
• Edit related Kconfig (e.g. drivers/input/misc/Kconfig) to include LSM6DSM support:

    source "drivers/input/misc/lsm6dsm/Kconfig"

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

    obj-y += lsm6dsm/

Device Tree configuration

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 in interrupts - interrupts: interrupt mapping for IRQ as documented in interrupts

Recommended properties for SPI bus usage: - spi-max-frequency: maximum SPI bus frequency as documented in SPI

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_EDGE_RISING>;

  };

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_EDGE_RISING>;

  	};

Kernel configuration

Configure kernel with make menuconfig (alternatively use make xconfig or make qconfig)

  Device Drivers  --->

  	Input device support  --->

  	[*]   Miscellaneous devices  --->

  		<*>   STM MEMs Device Drivers  --->

  			<M>   Inertial motion unit  --->

  				<M>   STMicroelectronics LSM6DSM sensor

More Information

http://st.com

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

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

Copyright (C) 2016 STMicroelectronics

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