linux驅動由淺入深系列：高通sensor架構實例分析之二(驅動代碼結構)

上一篇文章中我們瞭解了高通sensor的整體架構及對AP側的代碼進行了分析，這篇文章我們詳細分析一下aDSP側的代碼結構。

 

sensor數據流關鍵代碼概覽

下圖是sensor數據流程中的關鍵代碼部分:

 

實現sensor驅動最重要的一個結構體

結合上一篇的測試代碼，可以清楚的看到高通sensor的數據處理流程。圖中7位置指示了每個基於ADSP架構的傳感器需要實現的接口如下：

1. typedef struct

2. {

3. /**

4. * @brief Initializes the driver and sets up devices.

5. *

6. * Allocates a handle to a driver instance, opens a communication port to

7. * associated devices, configures the driver and devices, and places

8. * the devices in the default power state. Returns the instance handle along

9. * with a list of supported sensors. This function will be called at init

10. * time.

11. *

12. * @param[out] dd_handle_ptr Pointer that this function must malloc and

13. * populate. This is a handle to the driver

14. * instance that will be passed in to all other

15. * functions. NB: Do not use @a memhandler to

16. * allocate this memory.

17. * @param[in] smgr_handle Handle used to identify this driver when it

18. * calls into Sensors Manager functions.

19. * @param[in] nv_params NV parameters retrieved for the driver.

20. * @param[in] device_info Access info for physical devices controlled by

21. * this driver. Used to configure the bus

22. * and talk to the devices.

23. * @param[in] num_devices Number of elements in @a device_info.

24. * @param[in] memhandler Memory handler used to dynamically allocate

25. * output parameters, if applicable. NB: Do not

26. * use memhandler to allocate memory for

27. * @a dd_handle_ptr.

28. * @param[in/out] sensors List of supported sensors, allocated,

29. * populated, and returned by this function.

30. * @param[in/out] num_sensors Number of elements in @a sensors.

31. *

32. * @return Success if @a dd_handle_ptr was allocated and the driver was

33. * configured properly. Otherwise a specific error code is returned.

34. */

35. sns_ddf_status_e (*init)(

36. sns_ddf_handle_t* dd_handle_ptr,

37. sns_ddf_handle_t smgr_handle,

38. sns_ddf_nv_params_s* nv_params,

39. sns_ddf_device_access_s device_info[],

40. uint32_t num_devices,

41. sns_ddf_memhandler_s* memhandler,

42. sns_ddf_sensor_e** sensors,

43. uint32_t* num_sensors);

44.  

45. /**

46. * @brief Retrieves a single set of sensor data.

47. *

48. * Requests a single sample of sensor data from each of the specified

49. * sensors. Data is returned in one of two ways: (1) immediately after being

50. * read from the sensor, in which case data is populated in the same order

51. * it was requested, or (2) in cases where the sensor requires several steps

52. * to be read, this function will return with the status SNS_DDF_PENDING,

53. * and provide the data asynchronously via @a sns_ddf_smgr_data_notify()

54. * when it is ready. Note that @a sns_ddf_smgr_data_notify() must be called

55. * even in the event of an error in order to report a failed status. An

56. * asynchronous notification is also expected in the case of mixed data

57. * (i.e. synchronous and asynchronous).

58. *

59. * @note In the case where multiple sensors are requested, the driver must

60. * attempt to collect data from all requested sensors, meaning that

61. * the time it takes to execute this function will be determined by

62. * the number of sensors sampled, and their various delays. Drivers

63. * must never return partial responses. If a sensor has failed or

64. * isn't available, @a sns_ddf_sensor_data_s.status must be used to

65. * reflect this status.

66. *

67. * @param[in] dd_handle Handle to a driver instance.

68. * @param[in] sensors List of sensors for which data is requested.

69. * @param[in] num_sensors Number of elements in @a sensors.

70. * @param[in] memhandler Memory handler used to dynamically allocate

71. * output parameters, if applicable.

72. * @param[out] data Sampled sensor data. The number of elements must

73. * match @a num_sensors.

74. *

75. * @return SNS_DDF_SUCCESS if data was populated successfully. If any of the

76. * sensors queried are to be read asynchronously SNS_DDF_PENDING is

77. * returned and data is via @a sns_ddf_smgr_data_notify() when

78. * available. Otherwise a specific error code is returned.

79. *

80. * @see sns_ddf_data_notify()

81. */

82. sns_ddf_status_e (*get_data)(

83. sns_ddf_handle_t dd_handle,

84. sns_ddf_sensor_e sensors[],

85. uint32_t num_sensors,

86. sns_ddf_memhandler_s* memhandler,

87. sns_ddf_sensor_data_s** data);

88.  

89. /**

90. * @brief Sets a sensor attribute to a specific value.

91. *

92. * @param[in] dd_handle Handle to a driver instance.

93. * @param[in] sensor Sensor for which this attribute is to be set. When

94. * addressing an attribute that refers to the driver

95. * this value is set to SNS_DDF_SENSOR__ALL.

96. * @param[in] attrib Attribute to be set.

97. * @param[in] value Value to set this attribute.

98. *

99. * @return Success if the value of the attribute was set properly. Otherwise

100. * a specific error code is returned.

101. */

102. sns_ddf_status_e (*set_attrib)(

103. sns_ddf_handle_t dd_handle,

104. sns_ddf_sensor_e sensor,

105. sns_ddf_attribute_e attrib,

106. void* value);

107.  

108. /**

109. * @brief Retrieves the value of an attribute for a sensor.

110. *

111. * @param[in] dd_handle Handle to a driver instance.

112. * @param[in] sensor Sensor whose attribute is to be retrieved. When

113. * addressing an attribute that refers to the driver

114. * this value is set to SNS_DDF_SENSOR__ALL.

115. * @param[in] attrib Attribute to be retrieved.

116. * @param[in] memhandler Memory handler used to dynamically allocate

117. * output parameters, if applicable.

118. * @param[out] value Pointer that this function will allocate or set

119. * to the attribute's value.

120. * @param[out] num_elems Number of elements in @a value.

121. *

122. * @return Success if the attribute was retrieved and the buffer was

123. * populated. Otherwise a specific error code is returned.

124. */

125. sns_ddf_status_e (*get_attrib)(

126. sns_ddf_handle_t dd_handle,

127. sns_ddf_sensor_e sensor,

128. sns_ddf_attribute_e attrib,

129. sns_ddf_memhandler_s* memhandler,

130. void** value,

131. uint32_t* num_elems);

132.  

133. /**

134. * @brief Called when the timer set by this driver has expired. This must be

135. * the callback function submitted when initializing a timer.

136. *

137. * @note This will be called within the context of the Sensors Manager task.

138. *

139. * @param[in] dd_handle Handle to a driver instance.

140. * @param[in] arg The argument submitted when the timer was set.

141. *

142. * @see sns_ddf_set_timer()

143. */

144. void (*handle_timer)(sns_ddf_handle_t dd_handle, void* arg);

145.  

146. /**

147. * @brief Called in response to an interrupt for this driver.

148. *

149. * @note This function will be called within the context of the SMGR task,

150. * *not* the ISR.

151. *

152. * @param[in] dd_handle Handle to a driver instance.

153. * @param[in] gpio_num GPIO number that triggered this interrupt.

154. * @param[in] timestamp Time at which interrupt happened.

155. */

156. void (*handle_irq)(

157. sns_ddf_handle_t dd_handle,

158. uint32_t gpio_num,

159. sns_ddf_time_t timestamp);

160.  

161. /**

162. * @brief Resets the driver and device so they return to the state they were

163. * in after init() was called.

164. *

165. * @param[in] dd_handle Handle to a driver instance.

166. *

167. * @return Success if the driver was able to reset its state and the device.

168. * Otherwise a specific error code is returned.

169. */

170. sns_ddf_status_e (*reset)(sns_ddf_handle_t dd_handle);

171.  

172. /**

173. * @brief Runs a factory test case.

174. *

175. * Tests may include embedded hardware tests in cases where the sensor

176. * supports it, as well as driver based sensor tests. This is generally run

177. * in a factory setting and must not be called while a device is streaming

178. * data.

179. *

180. * @param[in] dd_handle Handle to a driver instance.

181. * @param[in] sensor Sensor on which to run the test.

182. * @param[in] test Test case to run.

183. * @param[out] err Optional driver-specific error code.

184. *

185. * @return One of the following error codes:

186. * SNS_DDF_SUCCESS - Test passed.

187. * SNS_DDF_PENDING - Test result will be sent as an event.

188. * SNS_DDF_EDEVICE_BUSY - Device is busy streaming, cannot run test.

189. * SNS_DDF_EINVALID_TEST - Test is not defined for this sensor.

190. * SNS_DDF_EINVALID_PARAM - One of the parameters is invalid.

191. * SNS_DDF_EFAIL - Unknown error occurred.

192. */

193. sns_ddf_status_e (*run_test)(

194. sns_ddf_handle_t dd_handle,

195. sns_ddf_sensor_e sensor,

196. sns_ddf_test_e test,

197. uint32_t* err);

198.  

199. /**

200. * @brief Begins device-scheduled sampling and enables notification via Data

201. * Ready Interrupts (DRI).

202. *

203. * The driver commands the device to begin sampling at the configured

204. * ODR (@a SNS_DDF_ATTRIB_ODR) and enables DRI. When data is ready, the

205. * driver's handle_irq() function is called and the driver notifies

206. * SMGR of the event via @a sns_ddf_smgr_notify_event() and @a

207. * SNS_DDF_EVENT_DATAREADY.

208. *

209. * @param[in] handle Handle to the driver's instance.

210. * @param[in] sensor Sensor to be sampled.

211. * @param[in] enable True to enable or false to disable data stream.

212. *

213. * @return SNS_DDF_SUCCESS if sensor was successfully configured and

214. * internal sampling has commenced or ceased. Otherwise an

215. * appropriate error code.

216. */

217. sns_ddf_status_e (*enable_sched_data)(

218. sns_ddf_handle_t handle,

219. sns_ddf_sensor_e sensor,

220. bool enable);

221.  

222. /**

223. * @brief Probes for the device with a given configuration.

224. *

225. * This commands the driver to look for the device with the specified

226. * configuration (ie, I2C address/bus defined in the sns_ddf_device_access_s

227. * struct.

228. *

229. * @param[in] dev_info Access info for physical devices controlled by

230. * this driver. Used to determine if the device is

231. * physically present.

232. * @param[in] memhandler Memory handler used to dynamically allocate

233. * output parameters, if applicable.

234. * @param[out] num_sensors Number of sensors supported. 0 if none.

235. * @param[out] sensor_type Array of sensor types supported, with num_sensor

236. * elements. Allocated by this function.

237. *

238. * @return SNS_DDF_SUCCESS if the part was probed function completed, even

239. * if no device was found (in which case num_sensors will be set to

240. * 0).

241. */

242. sns_ddf_status_e(*probe)(

243. sns_ddf_device_access_s* device_info,

244. sns_ddf_memhandler_s* memhandler,

245. uint32_t* num_sensors,

246. sns_ddf_sensor_e** sensors );

247.  
248.  

249. /**

250. * @brief Retrieves a set of sensor data. Asynchronous API

251. *

252. * Requests sample of sensor data from the specified sensor.

253. *

254. * @note If a sensor has failed or

255. * isn't available, @a sns_ddf_sensor_data_s.status must be used to

256. * reflect this status.

257. *

258. * @param[in] dd_handle Handle to a driver instance.

259. * @param[in] sensor sensor for which data is requested.

260. *

261. * @param[in] num_samples number of samples to retrieve as available. Drain the FIFO if value is set to Zero.

262. * @param[in] trigger now trigger notify fifo data now or

263. * later when trigger_now is set to true.

264. *

265. *

266. * @return SNS_DDF_SUCCESS if data was populated successfully.

267. * via sns_ddf_smgr_data_notify() or if trigger_now is

268. * set to false; Otherwise a specific error code is

269. * returned.

270. *

271. * @see sns_ddf_data_notify_data() as this will be used to report the data.

272. */

273. sns_ddf_status_e (*trigger_fifo_data)(

274. sns_ddf_handle_t dd_handle,

275. sns_ddf_sensor_e sensor,

276. uint16_t num_samples,

277. bool trigger_now);

278.  
279.  

280. /**

281. * @brief Delivers a Driver Access Framework message to the driver.

282. * Asynchronous/Synchronous API.

283. *

284. * @detail

285. *

286. * @param[in] dd_handle Handle to a driver instance.

287. * @param[in] req_id Request identifier.

288. * @param[in] req_msg Request message in the opaque payload. If no

289. * payload is supplied, then this pointer will be

290. * null.

291. * @param[in] req_size Number of bytes in @req_msg. If req_msg is empty,

292. * this value must be 0.

293. * @param[in] memhandler Memory handler used to dynamically allocate

294. * output parameters, if applicable.

295. * @param[out] resp_msg Pointer to the output message pointer. The output

296. * message must be allocated first using @memhandler.

297. * @param[out] resp_size Pointer to number of bytes in @resp_msg. If there

298. * is no DAF response message for the request, then

299. * this must be 0 to show that the DAF response is

300. * not present. Response messages are limited in

301. * size to @SNS_SMGR_MAX_DAF_MESSAGE_SIZE_V01 bytes.

302. * Any response message larger than

303. * @SNS_SMGR_MAX_DAF_MESSAGE_SIZE_V01 bytes will be

304. * truncated.

305. * @param[in] trans_id_ptr Pointer to the optional transaction identifier.

306. This will be null if a transaction ID was not

307. provided.

308. * @param[in] conn_handle The connection handle for the request message.

309. * This value must be saved if the particular request

310. * is expected to generate indications. Upon

311. * notifying the SMGR of an indication, this value

312. * must be provided to the SMGR.

313. *

314. * @return Success if the message was retrieved and the buffer was correctly

315. * populated. Otherwise a specific error code is returned.

316. */

317. sns_ddf_status_e (*process_daf_req)(

318. sns_ddf_handle_t dd_handle,

319. uint32_t req_id,

320. const void* req_msg,

321. uint32_t req_size,

322. sns_ddf_memhandler_s* memhandler,

323. void** resp_msg,

324. uint32_t* resp_size,

325. const uint8_t* trans_id_ptr,

326. void* conn_handle);

327.  
328.  

329. /**

330. * @brief Cancels all of the driver's current Driver Access Framework

331. * asynchronous transactions for the provided connection handle.

332. *

333. * @note This does not have to cancel a response message in the process of

334. * being created.

335. * This function does not have to be implemented for drivers that do

336. * not support or implement any asynchronous messages (these messages

337. * require the usage of sns_ddf_smgr_notify_daf_ind).

338. *

339. * @param[in] dd_handle Handle to a driver instance.

340. * @param[in] conn_handle The connection handle for the client that is

341. * cancelling the Driver Access Framework

342. * transaction.

343. */

344. void (*cancel_daf_trans)(

345. sns_ddf_handle_t dd_handle,

346. void* conn_handle);

347.  

348. } sns_ddf_driver_if_s;

 

 

aDSP初始化流程

 

aDSP的初始化工作從[Sns_init_dsps.c]文件中的  sns_init()函數開始，其中調用  ->    sns_init_once(); -> SNS_INIT_FUNCTIONS存在一個各個模塊的初始化函數指針列表，依次調用各個模塊的初始化函數init_ptrs[i]()          -> 其中我們關注傳感器相關的[sns_smgr_main_uimg.c]sns_smgr_init() ->        創建了 [sns_smgr_main.c]sns_smgr_task() 進程 ->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() -> 通過drv_fn_ptr->probe()指針，調用相應傳感器實現的probe函數。如果某傳感器沒有實現probe函數，則調用sns_smgr_populate_cfg_from_devinfo()。

 

aDSP上報傳感器數據

 

 

Sensor上報數據的三種方式：

1，  （Polling）0x00調用一次get_data後啓動timer，等到timer到時間後調用sns_ddf_driver_if_s中指定的handle_timer()函數上報一組傳感器數據

2，  （DRI）0x80調用enable_sched_data()啓用DRI（Data ReadyInterrupt，數據完成中斷），按照set_cycle_time指定的ODR（Output Data Rate，數據輸出速率）進行數據採集，採集完成後調用sns_ddf_driver_if_s中指定的handle_irq()函數上報傳感器數據。

3，  （FIFO）0xD0調用trigger_fifo_data()函數啓動FIFO模式，當數據量到達指定的閾值，觸發sns_ddf_smgr_data_notify()函數上報一批數據。