Rtwo/kernel/motorola/sm8550/drivers/iio/imu/st_asm330lhhx

Index

    * Introduction
    * Integration details
    * Self Test procedure
    * Copyright

Introduction

This repository contains STMEMS ASM330LHHX LDD.

The ASM330LHHX is a clone os ASM330LHH LDD with support to load MLC/FSM ucf file, parse it and configure new iio device of type mlc/fsm

MLC/FSM iio devices can be loaded and removed at anytime also when MLC/FSM IIO device are configured and running

Follow some features of MLC/FSM for ASM330LHHX driver:

• MLC/FSM devices can be loaded by using the load_mlc iio sysfs entry in MLC iio device. MLC firmware must be placed in /lib/firmware/ with name st_asm330lhhx_mlc.bin Please consider that ucf files can be loaded by using the SensorHAL Linux HAL with command --mlc which interprets the ucf file and generates the binary to be loaded with the driver
• MLC/FSM devices can be removed by using the mlc_flush iio sysfs entry in MLC iio device
• Added support to remove driver module unregistering all MLC dynamic IIO device

Tested on rapsberry pi zero-w with the kernel v5.4 (md HiKey960 kernel v4.19rpi-5.3.y_asm330lhhx_mlc) and v5.4 (rpi-5.4.y)

Integration details

In order to explain how to integrate ASM330LHHX sensor in raspberry kernel, please consider the following integration steps:

Source code integration

• Copy driver source code into the target directory (e.g. drivers/iio/imu)
• Edit related Kconfig (e.g. drivers/iio/imu/Kconfig) to include ASM330LHHX support:

    source "drivers/iio/imu/st_asm330lhhx/Kconfig"

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

    obj-y += st_asm330lhhx/

• Add custom events into include/uapi/linux/iio/types.h:

    @@ -89,6 +98,7 @@ enum iio_event_type {
            IIO_EV_TYPE_THRESH_ADAPTIVE,
            IIO_EV_TYPE_MAG_ADAPTIVE,
            IIO_EV_TYPE_CHANGE,
    +       IIO_EV_TYPE_FIFO_FLUSH,
    };

     @@ -96,6 +106,8 @@ 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 types include/uapi/linux/iio/types.h depending on the custom sensor implemented into driver:

     @@ -43,6 +43,14 @@ enum iio_chan_type {
             IIO_ELECTRICALCONDUCTIVITY,
             IIO_COUNT,
             IIO_INDEX,
     +       IIO_SIGN_MOTION,
     +       IIO_STEP_DETECTOR,
     +       IIO_STEP_COUNTER,
     +       IIO_TILT,
     +       IIO_TAP,
     +       IIO_TAP_TAP,
     +       IIO_WRIST_TILT_GESTURE,
     +       IIO_GESTURE,
             IIO_GRAVITY,
     };

Device Tree configuration

I2C example (based on Raspberry PI ZERO W):

  &i2c1 {
  	pinctrl-names = "default";
  	pinctrl-0 = <&i2c1_pins>;
  	clock-frequency = <400000>;
 +		asm330lhhx@6b {
 +			compatible = "st,asm330lhhx";
 +			reg = <0x6b>;
 +			interrupt-parent = <&gpio>;
 +			interrupts = <26 IRQ_TYPE_LEVEL_HIGH>;
 +			st,int-pin = <1>;
 +			status = "okay";
 +            };
  };

SPI example (based on Raspberry PI ZERO W):

          &spi0 {
                  status = "ok";
                  #address-cells = <0x1>;
                  #size-cells = <0x0>;
     +            asm330lhhx@0 {
     +                    spi-max-frequency = <1000000>;
     +                    compatible = "st,asm330lhhx";
     +                    reg = <0>;
     +                    interrupt-parent = <&gpio>;
     +                    interrupts = <26 IRQ_TYPE_LEVEL_HIGH>;
     +                    st,int-pin = <1>;
     +                    status = "okay";
     +            };
          };

Kernel configuration

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

          Device Drivers  --->
                  <M> Industrial I/O support  --->
                          Inertial measurement units  --->
  		<M> STMicroelectronics ASM330LHHX sensor
  		[*]   Enable machine learning core
  		[*]   Enable wake-up irq

Self Test procedure

Selftest procedure is embedded in the driver

For acc and gyro (iio device 0, 1) there are the following sysfs:

• selftest_available
• selftest

reading from selftest_available

$# > cat selftest_available positive-sign, negative-sign

for starting positive-sign self test:

echo positive-sign > selftest

for check result:

cat selftest

[results are pass or fail]

for starting negative-sign self test:

echo negative-sign > selftest

for check result:

cat selftest

[results are pass or fail]

Copyright Driver

Copyright (C) 2017 STMicroelectronics

This software is distributed under the GNU General Public License v2.0