Add Custom sensor in AOSP - linux-kernel

Question

I want to add the LSM6DS3 sensor driver in my AOSP source code. I am using SC600T device.
I have already add lsm6ds3 to the location
/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9/drivers/iio/imu/st_lsm6ds3, with Makefile and Kconfig files.
Added below line to /../../iio/imu/Kconfig file:
source "drivers/iio/imu/st_lsm6ds3/Kconfig"
Added below line to /../../iio/imu/Makefile.
obj-y += st_lsm6ds3/
Content of /SC600T/../../iio/imu/st_lsm6ds3/Makefile:
# SPDX-License-Identifier: GPL-2.0-only
st_lsm6dsx-y := st_lsm6dsx_core.o st_lsm6dsx_buffer.o \
st_lsm6dsx_shub.o
obj-$(CONFIG_IIO_ST_LSM6DSX) += st_lsm6dsx.o
obj-$(CONFIG_IIO_ST_LSM6DSX_I2C) += st_lsm6dsx_i2c.o
obj-$(CONFIG_IIO_ST_LSM6DSX_SPI) += st_lsm6dsx_spi.o
obj-$(CONFIG_IIO_ST_LSM6DSX_I3C) += st_lsm6dsx_i3c.o
I have also added lsm6ds3 node in the device tree file:
&i2c_2 {
status = "ok";
#address-cells = <0x1>;
#size-cells = <0x0>;
lsm6ds3#6b {
compatible = "st,lsm6ds3";
reg = <0x6b>;
interrupt-parent = <&tlmm>;
interrupt-gpios = <&tlmm 45 0x2008>;
interrupts = <45 0x02>;
};
I have connected LSM6DS3 accelerometer Sensor on SENSOR_I2C_SCL (Pin number 131) and SENSOR_I2C_SDA (Pin number 132).
After that I have compiled the source code and flash boot and dtbo on target device(SC600T) successfully.
When I am trying to check sensor data using adb shell >> /sys/bus/devices/i2C/devices node is available and
lsm6ds3 address node which is 6b is also available.
But lsm6ds3 sensor is not probed.
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enter image description here
Then after I will add below lines in msm8953_defconfig file.
Added below lines in msm8953_defconfig fie:
CONFIG_IIO_ST_LSM6DSX=y
CONFIG_IIO_ST_LSM6DSX_I2C=y
CONFIG_IIO_ST_LSM6DSX_SPI=y
CONFIG_IIO_ST_LSM6DSX_I3C=y
after adding this file when i compiling the source code getting below errors:
[ 2% 309/12824] Building kernel...
FAILED: out/target/product/msm8953_64/obj/kernel/msm-4.9/arch/arm64/boot/Image.gz-dtb
/bin/bash -c "(rm -rf out/target/product/msm8953_64/obj/kernel/msm-4.9/arch/arm64/boot/dts ) && (make -j3 -C kernel/msm-4.9 O=../../out/target/product/msm8953_64/obj/kernel/msm-4.9 DTC_EXT=dtc CONFIG_BUILD_ARM64_DT_OVERLAY=y ARCH=arm64 CROSS_COMPILE=aarch64-linux-android- KCFLAGS=-mno-android ) && (make -j3 -C kernel/msm-4.9 O=../../out/target/product/msm8953_64/obj/kernel/msm-4.9 DTC_EXT=dtc CONFIG_BUILD_ARM64_DT_OVERLAY=y ARCH=arm64 CROSS_COMPILE=aarch64-linux-android- KCFLAGS=-mno-android modules ) && (make -j3 -C kernel/msm-4.9 O=../../out/target/product/msm8953_64/obj/kernel/msm-4.9 INSTALL_MOD_PATH=../../../dlkm INSTALL_MOD_STRIP=1 DTC_EXT=dtc CONFIG_BUILD_ARM64_DT_OVERLAY=y ARCH=arm64 CROSS_COMPILE=aarch64-linux-android- modules_install ) && (mdpath=\`find out/target/product/msm8953_64/dlkm/lib/modules -type f -name modules.dep\`; if [ \"\$mdpath\" != \"\" ];then mpath=\`dirname \$mdpath\`; ko=\`find \$mpath/kernel -type f -name *.ko\`; for i in \$ko; do mv \$i out/target/product/msm8953_64/dlkm/lib/modules/; done; fi ) && (mdpath=\`find out/target/product/msm8953_64/dlkm/lib/modules -type f -name modules.dep\`; if [ \"\$mdpath\" != \"\" ];then mpath=\`dirname \$mdpath\`; rm -rf \$mpath; fi )"
make: Entering directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9'
make[1]: Entering directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/out/target/product/msm8953_64/obj/kernel/msm-4.9'
GEN ./Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
make[2]: Leaving directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/out/target/product/msm8953_64/obj/kernel/msm-4.9'
make[1]: Entering directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/out/target/product/msm8953_64/obj/kernel/msm-4.9'
CHK include/config/kernel.release
GEN ./Makefile
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
Using /media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9 as source for kernel
/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9 is not clean, please run 'make mrproper'
in the '/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9' directory.
make[2]: *** [prepare3] Error 1
make[2]: *** Waiting for unfinished jobs....
make[2]: Leaving directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/out/target/product/msm8953_64/obj/kernel/msm-4.9'
make: *** [sub-make] Error 2
make: Leaving directory `/media/ubuntu/Vezo_360/SC600T/SC60_SC600_Android9.0.0_kernel4.9_r029/kernel/msm-4.9'
[ 2% 312/12824] target C: libdsutils <= vendor/qcom/proprietary/data/dsutils/src/ds_util.c
vendor/qcom/proprietary/data/dsutils/src/ds_util.c:719:7: warning: unused variable 'adb_lvl' [-Wunused-variable]
int adb_lvl = 0;
^
vendor/qcom/proprietary/data/dsutils/src/ds_util.c:2357:5: warning: unused function 'ds_can_exec' [-Wunused-function]
int ds_can_exec
^
2 warnings generated.
[ 2% 314/12824] target C++: KmInstallKeybox <= ven...ecuremsm/keymaster_install_toolbox/InstallKeybox.cpp
ninja: build stopped: subcommand failed.
20:36:27 ninja failed with: exit status 1
#### failed to build some targets (42 seconds) ####
Adding any custom sensor in the AOSP, are this all steps mandatory or not?
Why lsm6ds3 sensor is not probed? Do I need to check anything from the hardware side?

Answer 1

Sensors on Quectel SC600 devices go through something called ADSP, that is closed source. Under this system, sensors are configured through the vendor/qcom/proprietary/sensors/dsps/reg_defaults/sensor_def_qcomdev.conf file.
There is a list of compatible sensors that can work with the ADSP. You have to ask it to your Quectel representative. Otherwise you have to ask them to integrate the sensor you want, and this is, of course, too much to ask, so consider it impossible (unless Qualcomm hands you the ADSP source code, which I don't think it is going to happen).