本文將介紹基于Android11 系統下i.MX8MQ設備添加光強傳感器驅動調試介紹：

• cpu: i.mx8mq
• OS：Android 11
• Kernel version：kernel 5.4
• Sensor ：opt3001
  儲備相關知識：
  linux IIO 子系統

1. Linux 部分

opt3001驅動文件

./drivers/iio/light/opt3001.c

在掛載I2C節點下添加設備樹

opt3001: opt3001@44 {
                compatible = "ti,opt3001";
                reg = < 0x44 >;
                pinctrl-0 = < &pinctrl_i2c1_dsi_ts_int >;
                interrupt-parent = < &gpio3 >;
                interrupts = < 10 IRQ_TYPE_EDGE_RISING >;
                status = "okay";
        };

別忘記在iomux下添加IO初始化，在節點&iomuxc

pinctrl_i2c1_dsi_ts_int: dsi_ts_int {
                fsl,pins = < 
                        MX8MQ_IOMUXC_NAND_DATA04_GPIO3_IO10             0x19
                  ?>;
        };

添加內核配置

CONFIG_OPT3001=y

調試相關 ：

可以用i2cdetect 工具進行檢測opt3001是否存在

圖中0x44已經發現是存在的。

Linux 加載成功后，可以看到在iio子系統下看到一個新的設備：

evk_8mq:/ # ls /sys/bus/iio/devices/iio:device0/
current_timestamp_clock  in_illuminance_input             name     subsystem
dev                      in_illuminance_integration_time  of_node  uevent
events                   integration_time_available       power

2. Android 修改部分

device/nxp/imx8m/evk_8mq/evk_8mq.mk中新增內容

USE_SENSOR_MULTI_HAL := true
BOARD_USE_SENSOR_FUSION := true
TARGET_SUPPORT_DIRECT_REPORT := true
# Enable sensor Version V_2
USE_SENSOR_HAL_VER := 2.0


PRODUCT_PACKAGES += 
    android.hardware.sensors@2.0-nxp-IIO-Subhal 
    android.hardware.sensors@2.0-service.multihal 
    android.hardware.sensors@2.0-service.multihal.rc 




PRODUCT_COPY_FILES += 
    frameworks/native/data/etc/android.hardware.sensor.accelerometer.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.accelerometer.xml 
frameworks/native/data/etc/android.hardware.sensor.assist.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.assist.xml 
frameworks/native/data/etc/android.hardware.sensor.compass.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.compass.xml 
frameworks/native/data/etc/android.hardware.sensor.gyroscope.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.gyroscope.xml 
frameworks/native/data/etc/android.hardware.sensor.light.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.light.xml 
frameworks/native/data/etc/android.hardware.sensor.proximity.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.proximity.xml 
frameworks/native/data/etc/android.hardware.sensor.barometer.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.barometer.xml 
frameworks/native/data/etc/android.hardware.sensor.stepcounter.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.stepcounter.xml 
frameworks/native/data/etc/android.hardware.sensor.stepdetector.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.stepdetector.xml 
frameworks/native/data/etc/android.hardware.sensor.hifi_sensors.xml:$(TARGET_COPY_OUT_VENDOR)/etc/permissions/android.hardware.sensor.hifi_sensors.xml
 
PRODUCT_COPY_FILES += 
    $(IMX_PATH)/imx/iio_sensor/hals.conf:vendor/etc/sensors/hals.conf 
$(IMX_PATH)/imx/iio_sensor/config/sensor_hal_configuration.xml:$(TARGET_COPY_OUT_VENDOR)/etc/sensors/sensor_hal_configuration.xml 
$(IMX_PATH)/imx/iio_sensor/config/sensor_hal_configuration.xsd:$(TARGET_COPY_OUT_VENDOR)/etc/sensors/sensor_hal_configuration.xsd
PRODUCT_COPY_FILES += 
$(IMX_PATH)/imx/iio_sensor/config/sensor_hal_configuration.xml:$(TARGET_COPY_OUT_VENDOR)/odm/etc/sensors/sensor_hal_configuration.xml
PRODUCT_COPY_FILES += 
$(IMX_DEVICE_PATH)/thermal_info_config_imx8mq.json:$(TARGET_COPY_OUT_VENDOR)/etc/configs/thermal_info_config_imx8mq.json

其實在device/nxp/imx8m/evk_8mq/evk_8mq.mk主要是將sensor 這個服務進行加入編譯，選定版本，再把一些文件進行拷貝。

修改./vendor/nxp-opensource/imx/iio_sensor/SensorsSubHal.cpp

將opt3001傳感器加入到列表中

static const std::vector< sensors_supported_hal > sensors_supported = {
        SENSOR_SUPPORTED("fxas21002c", SensorType::GYROSCOPE),
        SENSOR_SUPPORTED("mpl3115", SensorType::PRESSURE),
        SENSOR_SUPPORTED("mpl3115", SensorType::TEMPERATURE),
        SENSOR_SUPPORTED("fxos8700", SensorType::ACCELEROMETER),
        SENSOR_SUPPORTED("fxos8700", SensorType::MAGNETIC_FIELD),
        SENSOR_SUPPORTED("opt3001", SensorType::LIGHT), //add LIGHT SENSOR
};

但是添加完畢后發現還是存在問題，進一步發現中間層代碼存在問題

./vendor/nxp-opensource/imx/iio_sensor/LightSensor.cpp

LightSensor::LightSensor(int32_t sensorHandle, ISensorsEventCallback* callback,
               struct iio_device_data& iio_data,
                           const std::optional< std::vector< Configuration > >& config)
        : HWSensorBase(sensorHandle, callback, iio_data, config)  {
    // no power_microwatts sys node, so mSensorInfo.power fake the default one.
    mSensorInfo.power = 0.001f;
    mSensorInfo.flags |= V1_0::SensorFlagBits::DATA_INJECTION | V1_0::SensorFlagBits::ON_CHANGE_MODE;


    std::string time_file;
    //time_file = iio_data.sysfspath + "/in_illuminance_integration_time_available";
    time_file = iio_data.sysfspath + "/integration_time_available"; //opt3001


    get_sampling_time_available(time_file, &iio_data.sampling_time_avl);
    
    //...... 省略代碼
}

./vendor/nxp-opensource/imx/iio_sensor/iio_utils.cpp

//static const char* IIO_LIGHT_INPUT = "in_illuminance0_input";
static const char* IIO_LIGHT_INPUT = "in_illuminance_input";

根據xml文件提示android.hardware.sernsors支持1.0與2.0-1版本，這里將選用1.0即可。

./hardware/interfaces/compatibility_matrices/compatibility_matrix.5.xml【無需添加】

< hal format="hidl" optional="true" >
        < name >android.hardware.sensors< /name >
        < version >1.0< /version >
        < version >2.0-1< /version >
        < interface >
            < name >ISensors< /name >
            < instance >default< /instance >
        < /interface >
    < /hal >

./device/nxp/imx8m/evk_8mq/manifest.xml【需要添加】

添加sensors

< hal format="hidl" >
        < name >android.hardware.sensors< /name >
        < transport >hwbinder< /transport >
        < version >1.0< /version >
        < interface >
            < name >ISensors< /name >
            < instance >default< /instance >
        < /interface >
        < fqname >@1.0::ISensors/default< /fqname >
    < /hal >

安卓部分添加完畢，直接編譯既可；

燒寫系統可以查看相關信息，

命令：dumpsys sensorservice

3. 問題：

發現通過光強傳感器自動調整屏幕亮度非常低鈍，可以修改以下文件解決：

frameworks/base/core/res/res/values/config.xml

< integer name="config_autoBrightnessBrighteningLightDebounce" >1500< /integer >
    < integer name="config_autoBrightnessDarkeningLightDebounce" >1500< /integer >