# st-mems-android-linux-drivers-iio

**Repository Path**: danny99111/st-mems-android-linux-drivers-iio

## Basic Information

- **Project Name**: st-mems-android-linux-drivers-iio
- **Description**: No description available
- **Primary Language**: C
- **License**: GPL-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-06-23
- **Last Updated**: 2025-06-23

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Introduction
This repository contains STMicroelectronics MEMS IIO drivers for the following LTS Linux/Android kernels:
 - 4.9 (EOL)
 - 4.14
 - 4.19
 - 5.4
 - 5.10
 - 5.15
 - 6.1
 - 6.6
 - 6.12

For EOL kernel the maintenance has been discontinued and is strongly discouraged from using it for new developments.

## Source code integration
From your kernel source code directory add the git remote (i.e. stmems_iio_github) for this repository:
```bash
git remote add stmems_iio_github \
               https://github.com/STMicroelectronics/st-mems-android-linux-drivers-iio.git
```

Fetch the just added remote:
```bash
git fetch stmems_iio_github
```

There are now two ways to integrate the drivers code into the kernel target branch:
* merge (**suggested strategy**)
* rebase

### merge
Merge the stmems_iio_github/master with your target kernel source branch (i.e branch linux-5.4.y):

```bash
git merge --allow-unrelated-histories \
          linux-5.4.y \
          stmems_iio_github/master
```

### rebase
Rebase the stmems_iio_github/master on top of your target kernel source branch (i.e branch linux-5.4.y):

```bash
git rebase --no-fork-point \
           linux-5.4.y \
           stmems_iio_github/master
```

Note: older git versions (i.e.: 2.7.4) would require to use sligthly different options:

```bash
git merge --no-fork-point \
          linux-5.4.y \
          stmems_iio_github/master
```

```bash
git rebase -Xno-renames \
           --no-fork-point \
           linux-5.4.y \
           stmems_iio_github/master
```

## Apply patches
Now that drivers code has been added to the target kernel branch, few patches needs to be added in order to:
* add STM drivers into Kconfig & Makefile systems
* patch IIO framework with custom events with custom events, channels and devices

Apply the patches available in the just added repository (i.e branch linux-5.4.y):

```bash
git am stm_iio_patches/5.4.y/*-stm-*.patch
```

## Configuration
A folder named stm_iio_configs should now be available with the default configs for the supported drivers.

### Modify target defconfig
Sensors defconfig can be appended to the board defconfig (i.e. if your current configuration file is arch/arm/configs/stm32_defconfig):

```bash
cat stm_iio_configs/lsm6dsm_defconfig >> arch/arm/configs/stm32_defconfig
```

Alternatively, it can be done at build time without altering the board config file, as follow.

### Merge configuration
Driver config can be merged into current target pre-configured kernel using a script available in the kernel itself:

```bash
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnu-
scripts/kconfig/merge_config.sh -n .config stm_iio_configs/lsm6dsm_defconfig
```

## Build Modules
This repo include Makefile for building in tree and out of tree modules

### In Kernel Tree build
Set CROSS_COMPILE and ARCH accordingly to your target board. Follow an example for a RPI 4 target board (32 bits):
```bash
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnu-
make KCFLAGS=-Werror -j $(nproc)
```
### Out of Kernel Tree build
The drivers in this project can also be build as external module. Follow an example for RPI 4 target board (32 bits):
```bash
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnu-
export KDIR=<the directory where Linux kernel is build>

# Specifying INSTALL_MOD_PATH the modules installation path will be:
# /INSTALL_MOD_PATH/lib/modules/$(KERNELRELEASE)/kernel/
# instead of /lib/modules/$(KERNELRELEASE)/extra/
export INSTALL_MOD_PATH=<modules installation path>

# Specifying INSTALL_MOD_DIR to set analternative name to "extra" path:
# /lib/modules/$(KERNELRELEASE)/INSTALL_MOD_DIR/ instead of standard
# /lib/modules/$(KERNELRELEASE)/extra/
export INSTALL_MOD_DIR=<modules alternate dir>

# Add flags "-Werror" for stop build on warning, then build the driver modules project:
make KCFLAGS=-Werror -C drivers/iio/stm/ $1 -j$(nproc)

# Install modules
make -C drivers/iio/stm/ modules_install
```

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