Android Qcom Sensor架构学习
Android Sensor Brief Flow
Android Sensor Specific Flow
ADSP SSC
ADSP.VT.5.4.1/adsp_proc/ssc_api/pb/
ADSP.VT.5.4.1/adsp_proc/ssc/sensors
ADSP.VT.5.4.1/adsp_proc/ssc/frameworks
ADSP Framework初始化的时候首先通过load image并初始化的静态加载方式register_static_sensors
ssc_static_lib_builder.py 会编译出静态加载的sensor列表 framework/build/sensor_img/…/sns_static_sensors.c
sensor的入口是register_function 定义在具体sensor的目录下的scons中 ssc/sensor/xxx/build/xxx.scons island_mode 支持低功耗
if 'USES_SSC_STATIC_LIB_BUILDER' in env: env.AddSSCSU(inspect.getfile(inspect.currentframe()),register_func_name =
如果是动态加载的话，则是ssc/framework/dl/src/sns_dynamic_sensors.c，没具体研究
registry用于存放sensor信息的，放置在perisist分区，可通过registry sensor获取
通过/vendor/etc/sensors/config/
mnt/vendor/persist/sensors/registry/
registry
sensor_list.txt
sensors_settings
在sensor_api::notify_event的过程中一般都会去处理registry,physical sensor包含很多硬件配置
if(SNS_REGISTRY_MSGID_SNS_REGISTRY_READ_EVENT == event->message_id){sns_registry_read_event read_event = sns_registry_read_event_init_default;pb_buffer_arg group_name = {0,0};read_event.name.arg = &group_name;read_event.name.funcs.decode = pb_decode_string_cb;if(!pb_decode(&stream, sns_registry_read_event_fields, &read_event)){SNS_PRINTF(ERROR, this, "Error decoding registry event");}else{...sns_registry_phy_sensor_pf_cfg phy_sensor_pf_cfg;memset(&phy_sensor_pf_cfg, 0, sizeof(phy_sensor_pf_cfg));sns_registry_decode_arg arg = {.item_group_name = &group_name,.parse_info_len = 1,.parse_info[0] = {.group_name = "config",.parse_func = sns_registry_parse_phy_sensor_pf_cfg,.parsed_buffer = &phy_sensor_pf_cfg}};read_event.data.items.funcs.decode = &sns_registry_item_decode_cb;read_event.data.items.arg = &arg;rv = pb_decode(&stream, sns_registry_read_event_fields, &read_event);...
}
json中具体的配置，与解析后的应用后续再研究
sns_sensor::init -> publish_attibutes (physical sensor -> platform define name)
ltrx1303_publish_attributes -> "ambient_light"
icm4x6xx_accel_publish_attributes -> "accel"
sns_publish_attribute(this, SNS_STD_SENSOR_ATTRID_TYPE, &value, 1, false);
HAL SSC
https://source.android.google.cn/devices/sensors/sensors-multihal?skip_cache=true&hl=zh-cn
/hardware/interfaces/sensors/common/default/2.X/multihal/HalProxy.cpp
/vendor/qcom/proprietary/sensors-see/ssc/sns_std_sensor.proto -> sns_std_sensor.pb.h
/vendor/qcom/proprietary/sensors-see/sensors-hal-2.0/framework/
/vendor/qcom/proprietary/sensors-see/sensors-hal-2.0/sensors/
vendor/qcom/proprietary/sensors-see/registry/config
SENSOR_MODULE_INIT初始化会注册两个unordered_map: callbacks and datatypes
sensor_factory::register_sensor sensorType define in sensors_qti.h
sensor_factory::request_datatype dataType "accel" get_available_sensors(callbacks)push_back(make_uniquesuid, SENSOR_WAKEUP)) //construct sensor push_back(make_unique suid, SENSOR_NO_WAKEUP)) //construct sensorset_type //QTI_SENSOR_TYPEset_string_type //QTI_SENSOR_STRING_TYPEset_nowk_msgid //SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_PHYSICAL_CONFIG_EVENTset_sensor_typename //"Accelerometer" "SAR Sensor"
无论时HAL与ADSP通信，还是ADSP内各sensor的通信，必须通过send_request, 通信的过程必须遵从protocol-buffers
其中最重要的两点需要suid和msg_id，suid时指定sensor(platform sensor:suid sensor，physical sensor:accel，virtual sensor:amd)
sensors_hal::activate ssc_sensor::activate
suid_lookup lookupconst sensor_uid LOOKUP_SUID = { //与suid sensor通信12370169555311111083ull,12370169555311111083ull};
pb_req_msg.set_msg_id(SNS_SUID_MSGID_SNS_SUID_REQ); //请求具体sensor的suid lookup.request_suid //通过stringtype获取具体sensor的suid
send_sensor_config_requestcreate_sensor_config_request()pb_req_msg.mutable_suid()->set_suid_high(_suid.high); //request通信携带具体sensor的suidpb_req_msg.mutable_suid()->set_suid_low(_suid.low);_ssc_conn->send_request if (stream_type == SNS_STD_SENSOR_STREAM_TYPE_STREAMING) //attributes中的SNS_STD_SENSOR_ATTRID_STREAM_TYPEpb_req_msg.set_msg_id(SNS_STD_SENSOR_MSGID_SNS_STD_SENSOR_CONFIG);//elsepb_req_msg.set_msg_id(SNS_STD_SENSOR_MSGID_SNS_STD_ON_CHANGE_CONFIG)
APP and Framework
/frameworks/base/core/java/android/hardware/SensorManager.java
/frameworks/base/core/java/android/hardware/SystemSensorManager.java
Typical Sensor Type
* Sensor.TYPE_LIGHT：光传感器
* Sensor.TYPE_GRAVITY：重力传感器
* Sensor.TYPE_PRESSURE：压力传感器
* Sensor.TYPE_ALL: 所有支持的传感器
* Sensor.TYPE_ORIENTATION：方向传感器
* Sensor.TYPE_GYROSCOPE：陀螺仪传感器
* Sensor.TYPE_MAGNETIC_FIELD：磁场传感器
* Sensor.TYPE_AMBIENT_TEMPERATURE：温度传感器
* Sensor.TYPE_LINEAR_ACCELERATION：线性加速度传感器
如果是非典型的sensor类型，或者是客制化的，则需要从所有传感器类型中通过getStringType进行过滤,
注册并激活所需要的sensor,创建SensorEventQueue用于数据分发调用回调 onAccuracyChanged onSensorChanged
在注册时需要注意isWakeUpSensor判断，因为在HAL初始化的时候我们知道同一类型sensor又会细分为两种类型
SENSOR_WAKEUP和SENSOR_NO_WAKEUP，SENSOR_WAKEUP在系统休眠时也可以上报事件，可以用作抬腕唤醒等功能