linux驱动由浅入深系列：高通sensor架构实例分析之二(驱动代码结构)

本系列导航：

linux驱动由浅入深系列：高通sensor架构实例分析之一(整体概览+AP侧代码分析)


linux驱动由浅入深系列：高通sensor架构实例分析之二(adsp驱动代码结构)
[b]Linux驱动由浅入深系列：高通sensor架构实例分析之三(adsp上报数据详解、校准流程详解)[/b]


上一篇文章中我们了解了高通sensor的整体架构及对AP侧的代码进行了分析，这篇文章我们详细分析一下aDSP侧的代码结构。

 

sensor数据流关键代码概览

下图是sensor数据流程中的关键代码部分:





实现sensor驱动最重要的一个结构体

结合上一篇的测试代码，可以清楚的看到高通sensor的数据处理流程。图中7位置指示了每个基于ADSP架构的传感器需要实现的接口如下：

typedef struct
{
/**
* @brief Initializes the driver and sets up devices.
*
* Allocates a handle to a driver instance, opens a communication port to
* associated devices, configures the driver and devices, and places
* the devices in the default power state. Returns the instance handle along
* with a list of supported sensors. This function will be called at init
* time.
*
* @param[out] dd_handle_ptr  Pointer that this function must malloc and
*                            populate. This is a handle to the driver
*                            instance that will be passed in to all other
*                            functions. NB: Do not use @a memhandler to
*                            allocate this memory.
* @param[in]  smgr_handle    Handle used to identify this driver when it
*                            calls into Sensors Manager functions.
* @param[in]  nv_params      NV parameters retrieved for the driver.
* @param[in]  device_info    Access info for physical devices controlled by
*                            this driver. Used to configure the bus
*                            and talk to the devices.
* @param[in]  num_devices    Number of elements in @a device_info.
* @param[in]  memhandler     Memory handler used to dynamically allocate
*                            output parameters, if applicable. NB: Do not
*                            use memhandler to allocate memory for
*                            @a dd_handle_ptr.
* @param[in/out] sensors     List of supported sensors, allocated,
*                            populated, and returned by this function.
* @param[in/out] num_sensors Number of elements in @a sensors.
*
* @return Success if @a dd_handle_ptr was allocated and the driver was
*         configured properly. Otherwise a specific error code is returned.
*/
sns_ddf_status_e (*init)(
sns_ddf_handle_t*        dd_handle_ptr,
sns_ddf_handle_t         smgr_handle,
sns_ddf_nv_params_s*     nv_params,
sns_ddf_device_access_s  device_info[],
uint32_t                 num_devices,
sns_ddf_memhandler_s*    memhandler,
sns_ddf_sensor_e**       sensors,
uint32_t*                num_sensors);

/**
* @brief Retrieves a single set of sensor data.
*
* Requests a single sample of sensor data from each of the specified
* sensors. Data is returned in one of two ways: (1) immediately after being
* read from the sensor, in which case data is populated in the same order
* it was requested, or (2) in cases where the sensor requires several steps
* to be read, this function will return with the status SNS_DDF_PENDING,
* and provide the data asynchronously via @a sns_ddf_smgr_data_notify()
* when it is ready. Note that @a sns_ddf_smgr_data_notify() must be called
* even in the event of an error in order to report a failed status. An
* asynchronous notification is also expected in the case of mixed data
* (i.e. synchronous and asynchronous).
*
* @note In the case where multiple sensors are requested, the driver must
*       attempt to collect data from all requested sensors, meaning that
*       the time it takes to execute this function will be determined by
*       the number of sensors sampled, and their various delays. Drivers
*       must never return partial responses. If a sensor has failed or
*       isn't available, @a sns_ddf_sensor_data_s.status must be used to
*       reflect this status.
*
* @param[in]  dd_handle    Handle to a driver instance.
* @param[in]  sensors      List of sensors for which data is requested.
* @param[in]  num_sensors  Number of elements in @a sensors.
* @param[in]  memhandler   Memory handler used to dynamically allocate
*                          output parameters, if applicable.
* @param[out] data         Sampled sensor data. The number of elements must
*                          match @a num_sensors.
*
* @return SNS_DDF_SUCCESS if data was populated successfully. If any of the
*         sensors queried are to
4000
be read asynchronously SNS_DDF_PENDING is
*         returned and data is via @a sns_ddf_smgr_data_notify() when
*         available. Otherwise a specific error code is returned.
*
* @see sns_ddf_data_notify()
*/
sns_ddf_status_e (*get_data)(
sns_ddf_handle_t         dd_handle,
sns_ddf_sensor_e         sensors[],
uint32_t                 num_sensors,
sns_ddf_memhandler_s*    memhandler,
sns_ddf_sensor_data_s**  data);

/**
* @brief Sets a sensor attribute to a specific value.
*
* @param[in] dd_handle  Handle to a driver instance.
* @param[in] sensor     Sensor for which this attribute is to be set. When
*                       addressing an attribute that refers to the driver
*                       this value is set to SNS_DDF_SENSOR__ALL.
* @param[in] attrib     Attribute to be set.
* @param[in] value      Value to set this attribute.
*
* @return Success if the value of the attribute was set properly. Otherwise
*         a specific error code is returned.
*/
sns_ddf_status_e (*set_attrib)(
sns_ddf_handle_t     dd_handle,
sns_ddf_sensor_e     sensor,
sns_ddf_attribute_e  attrib,
void*                value);

/**
* @brief Retrieves the value of an attribute for a sensor.
*
* @param[in]  dd_handle   Handle to a driver instance.
* @param[in]  sensor      Sensor whose attribute is to be retrieved. When
*                         addressing an attribute that refers to the driver
*                         this value is set to SNS_DDF_SENSOR__ALL.
* @param[in]  attrib      Attribute to be retrieved.
* @param[in]  memhandler  Memory handler used to dynamically allocate
*                         output parameters, if applicable.
* @param[out] value       Pointer that this function will allocate or set
*                         to the attribute's value.
* @param[out] num_elems   Number of elements in @a value.
*
* @return Success if the attribute was retrieved and the buffer was
*         populated. Otherwise a specific error code is returned.
*/
sns_ddf_status_e (*get_attrib)(
sns_ddf_handle_t       dd_handle,
sns_ddf_sensor_e       sensor,
sns_ddf_attribute_e    attrib,
sns_ddf_memhandler_s*  memhandler,
void**                 value,
uint32_t*              num_elems);

/**
* @brief Called when the timer set by this driver has expired. This must be
*        the callback function submitted when initializing a timer.
*
* @note This will be called within the context of the Sensors Manager task.
*
* @param[in] dd_handle  Handle to a driver instance.
* @param[in] arg        The argument submitted when the timer was set.
*
* @see sns_ddf_set_timer()
*/
void (*handle_timer)(sns_ddf_handle_t dd_handle, void* arg);

/**
* @brief Called in response to an interrupt for this driver.
*
* @note This function will be called within the context of the SMGR task,
*       *not* the ISR.
*
* @param[in] dd_handle  Handle to a driver instance.
* @param[in] gpio_num   GPIO number that triggered this interrupt.
* @param[in] timestamp  Time at which interrupt happened.
*/
void (*handle_irq)(
sns_ddf_handle_t  dd_handle,
uint32_t          gpio_num,
sns_ddf_time_t    timestamp);

/**
* @brief Resets the driver and device so they return to the state they were
*        in after init() was called.
*
* @param[in] dd_handle  Handle to a driver instance.
*
* @return Success if the driver was able to reset its state and the device.
*         Otherwise a specific error code is returned.
*/
sns_ddf_status_e (*reset)(sns_ddf_handle_t dd_handle);

/**
* @brief Runs a factory test case.
*
* Tests may include embedded hardware tests in cases where the sensor
* supports it, as well as driver based sensor tests. This is generally run
* in a factory setting and must not be called while a device is streaming
* data.
*
* @param[in]  dd_handle  Handle to a driver instance.
* @param[in]  sensor     Sensor on which to run the test.
* @param[in]  test       Test case to run.
* @param[out] err        Optional driver-specific error code.
*
* @return One of the following error codes:
*     SNS_DDF_SUCCESS        - Test passed.
*     SNS_DDF_PENDING        - Test result will be sent as an event.
*     SNS_DDF_EDEVICE_BUSY   - Device is busy streaming, cannot run test.
*     SNS_DDF_EINVALID_TEST  - Test is not defined for this sensor.
*     SNS_DDF_EINVALID_PARAM - One of the parameters is invalid.
*     SNS_DDF_EFAIL          - Unknown error occurred.
*/
sns_ddf_status_e (*run_test)(
sns_ddf_handle_t  dd_handle,
sns_ddf_sensor_e  sensor,
sns_ddf_test_e    test,
uint32_t*         err);

/**
* @brief Begins device-scheduled sampling and enables notification via Data
*        Ready Interrupts (DRI).
*
* The driver commands the device to begin sampling at the configured
* ODR (@a SNS_DDF_ATTRIB_ODR) and enables DRI. When data is ready, the
* driver's handle_irq() function is called and the driver notifies
* SMGR of the event via @a sns_ddf_smgr_notify_event() and @a
* SNS_DDF_EVENT_DATAREADY.
*
* @param[in] handle  Handle to the driver's instance.
* @param[in] sensor  Sensor to be sampled.
* @param[in] enable  True to enable or false to disable data stream.
*
* @return SNS_DDF_SUCCESS if sensor was successfully configured and
*         internal sampling has commenced or ceased. Otherwise an
*         appropriate error code.
*/
sns_ddf_status_e (*enable_sched_data)(
sns_ddf_handle_t  handle,
sns_ddf_sensor_e  sensor,
bool              enable);

/**
* @brief Probes for the device with a given configuration.
*
* This commands the driver to look for the device with the specified
* configuration (ie, I2C address/bus defined in the sns_ddf_device_access_s
* struct.
*
* @param[in]  dev_info    Access info for physical devices controlled by
*                         this driver. Used to determine if the device is
*                         physically present.
* @param[in]  memhandler  Memory handler used to dynamically allocate
*                         output parameters, if applicable.
* @param[out] num_sensors Number of sensors supported. 0 if none.
* @param[out] sensor_type Array of sensor types supported, with num_sensor
*                         elements. Allocated by this function.
*
* @return SNS_DDF_SUCCESS if the part was probed function completed, even
*         if no device was found (in which case num_sensors will be set to
*         0).
*/
sns_ddf_status_e(*probe)(
sns_ddf_device_access_s* device_info,
sns_ddf_memhandler_s*    memhandler,
uint32_t*                num_sensors,
sns_ddf_sensor_e**       sensors );

/**
* @brief Retrieves a set of sensor data. Asynchronous API
*
* Requests sample of sensor data from the specified sensor.
*
* @note If a sensor has failed or
*       isn't available, @a sns_ddf_sensor_data_s.status must be used to
*       reflect this status.
*
* @param[in]  dd_handle    	Handle to a driver instance.
* @param[in]  sensor      	sensor for which data is requested.
*
* @param[in]  num_samples  	number of samples to retrieve as available. Drain the FIFO if value is set to Zero.
* @param[in]  trigger now  	trigger notify fifo data now or
*       later when trigger_now is set to true.
*
*
* @return SNS_DDF_SUCCESS 	if data was populated successfully.
*         via sns_ddf_smgr_data_notify() or if trigger_now is
*         set to false; Otherwise a specific error code is
*         returned.
*
* @see sns_ddf_data_notify_data() as this will be used to report the data.
*/
sns_ddf_status_e (*trigger_fifo_data)(
sns_ddf_handle_t         dd_handle,
sns_ddf_sensor_e         sensor,
uint16_t                 num_samples,
bool                     trigger_now);

/**
* @brief Delivers a Driver Access Framework message to the driver.
*        Asynchronous/Synchronous API.
*
* @detail
*
* @param[in]  dd_handle     Handle to a driver instance.
* @param[in]  req_id        Request identifier.
* @param[in]  req_msg       Request message in the opaque payload. If no
*                           payload is supplied, then this pointer will be
*                           null.
* @param[in]  req_size      Number of bytes in @req_msg. If req_msg is empty,
*                           this value must be 0.
* @param[in]  memhandler    Memory handler used to dynamically allocate
*                           output parameters, if applicable.
* @param[out] resp_msg      Pointer to the output message pointer. The output
*                           message must be allocated first using @memhandler.
* @param[out] resp_size     Pointer to number of bytes in @resp_msg. If there
*                           is no DAF response message for the request, then
*                           this must be 0 to show that the DAF response is
*                           not present. Response messages are limited in
*                           size to @SNS_SMGR_MAX_DAF_MESSAGE_SIZE_V01 bytes.
*                           Any response message larger than
*                           @SNS_SMGR_MAX_DAF_MESSAGE_SIZE_V01 bytes will be
*                           truncated.
* @param[in]  trans_id_ptr  Pointer to the optional transaction identifier.
This will be null if a transaction ID was not
provided.
* @param[in]  conn_handle   The connection handle for the request message.
*                           This value must be saved if the particular request
*                           is expected to generate indications. Upon
*                           notifying the SMGR of an indication, this value
*                           must be provided to the SMGR.
*
* @return Success if the message was retrieved and the buffer was correctly
*         populated. Otherwise a specific error code is returned.
*/
sns_ddf_status_e (*process_daf_req)(
sns_ddf_handle_t       dd_handle,
uint32_t               req_id,
const void*            req_msg,
uint32_t               req_size,
sns_ddf_memhandler_s*  memhandler,
void**                 resp_msg,
uint32_t*              resp_size,
const uint8_t*         trans_id_ptr,
void*                  conn_handle);

/**
* @brief Cancels all of the driver's current Driver Access Framework
*        asynchronous transactions for the provided connection handle.
*
* @note This does not have to cancel a response message in the process of
*       being created.
*       This function does not have to be implemented for drivers that do
*       not support or implement any asynchronous messages (these messages
*       require the usage of sns_ddf_smgr_notify_daf_ind).
*
* @param[in]  dd_handle     Handle to a driver instance.
* @param[in]  conn_handle   The connection handle for the client that is
*                           cancelling the Driver Access Framework
*                           transaction.
*/
void (*cancel_daf_trans)(
sns_ddf_handle_t       dd_handle,
void*                  conn_handle);

} sns_ddf_driver_if_s;

aDSP初始化流程



aDSP的初始化工作从[Sns_init_dsps.c]文件中的 
sns_init()函数开始，其中调用  ->   
sns_init_once(); -> SNS_INIT_FUNCTIONS存在一个各个模块的初始化函数指针列表，依次调用各个模块的初始化函数init_ptrs[i]()          -> 其中我们关注传感器相关的[sns_smgr_main_uimg.c]sns_smgr_init()
->        创建了 [sns_smgr_main.c]sns_smgr_task() 进程 ->sns_smgr_hw_init(); ->sns_smgr_process_msg();
->sns_smgr_process_reg_resp_msg();         ->sns_smgr_process_reg_data() ->sns_smgr_process_reg_devinfo()
->sns_smgr_parse_reg_devinfo_resp() -> 通过drv_fn_ptr->probe()指针，调用相应传感器实现的probe函数。如果某传感器没有实现probe函数，则调用sns_smgr_populate_cfg_from_devinfo()。

 

aDSP上报传感器数据





Sensor上报数据的三种方式：

1，  （Polling）0x00调用一次get_data后启动timer，等到timer到时间后调用sns_ddf_driver_if_s中指定的handle_timer()函数上报一组传感器数据

2，  （DRI）0x80调用enable_sched_data()启用DRI（Data ReadyInterrupt，数据完成中断），按照set_cycle_time指定的ODR（Output Data Rate，数据输出速率）进行数据采集，采集完成后调用sns_ddf_driver_if_s中指定的handle_irq()函数上报传感器数据。

3，  （FIFO）0xD0调用trigger_fifo_data()函数启动FIFO模式，当数据量到达指定的阈值，触发sns_ddf_smgr_data_notify()函数上报一批数据。

关于数据上报流程更详细的见下一篇博客：Linux驱动由浅入深系列：高通sensor架构实例分析之三(adsp上报数据详解)

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