Dynamic Android Sensor HAL

Transcription

1 Dynamic Android Sensor HAL D*A*S*H Oskar Anderö Senior Software Architect

2 D*A*S*H 2 Just another sensor HAL implementation But... Easy to integrate Configurable Scalable

3 D*A*S*H DASH is open-source! 3 Github: Allows openness For mod hackers to enjoy 3rd party vendors Sensor HAL example for anyone

4 What we had 4 Messy code Lots of #ifdefs Many branches Different types of Linux drivers

5 What we wanted 5 What lead to the current situation? Different sensors on different products Different mounting on different products Different 3rd party sensor libraries for different sets of sensors What to do...? Solution: abstract the abstraction!

6 What we wanted 6 Scalable Configurable Common code should be common Ease integration of sensor fusion Avoid multiple branches

7 7

8 Code example 8 BMA250 Accelerometer from Bosch Linux interface is input device Polls events in kernel Polling frequency is set by sysfs Implemented in sensors/bma250_input.c

9 bma250_input.c 9

10 10

11 bma250_input.c...and in sensors_list.h: 11

12 12

13 bma250_input.c 13

14 bma250_input.c 14

15 bma250_input.c 15 Sensors.conf example:

16 16

17 bma250_input.c 17

18 18

19 bma250_input.c 19

20 20

21 bma250_input.c 21

22 Case study: integrate on Xperia S 22

23 Case study: integrate on Xperia S 23

24 Case study: integrate on Galaxy Nexus 24

25 Case study: integrate on Galaxy Nexus 25 Step 1: What kernel drivers do we have? Step 2: Write user-space drivers Step 3: Build it Step 4: Push it to target

26 What kernel drivers do we have? 26 Step 1: What kernel drivers do we have? Use some application adb shell dmesg adb shell getevent -i We are lucky: look in AOSP code! Result: Sharp GP2A proximity and light sensor Bosch BMP180 pressure sensor Invensense MPU3050 Gyroscope BMA250 Accelerometer YAS530 Compass

27 Writing user-space drivers have 27 Step 2: Writing user-space driver Create a BMP180 user-space driver Already included in DASH!..but the driver is not the same. Fix 1: input name is different Fix 2: sysfs attributes are different Add enable attribute Rename poll rate attribute

28 Writing user-space drivers have Create a Sharp GP2A proximity user-space driver 28 Again - there is already one! Fix 1: input name is different Fix 2: add handler for sysfs attribute enable

29 Writing user-space drivers have Create a Sharp GP2A light user-space driver Very similar to Sharp proximity 29 Uses enable sysfs and input device Fix 1: Copy-paste proximity user-space driver Fix 2: Use ABS_MISC instead of ABS_DISTANCE

30 Writing user-space drivers have Create MPU3050 user-space driver There is a user-space driver. Drivers and lib are incompatible with Sony solution! Fix 1: Port Galaxy invensens lib to DASH Fix 2: Add compass and accelerometer 30 Update the way DASH interfaces with the new lib SOMC version uses AKM and BMA250 through wrapper layer Fix 3: Make it polling

31 Building DASH 31 Step 3: Build it Make sure to enable sensors in makefile mm

32 Install DASH Step 4: Push it to target adb root adb remount 32 adb push $OUT/system/lib/hw/sensors.default.so \ /system/lib/hw/sensors.tuna.so adb shell stop adb shell start

33 All done! 33

34 Conclusion DASH is a... Generic Configurable Scalable Open-source!...framework for sensors 34

35 Questions? 35

36 SONY or make.believe is a registered trademark and/or trademark of Sony Corporation. Names of Sony products and services are the registered trademarks and/or trademarks of Sony Corporation or its Group companies. Other company names and product names are the registered trademarks and/or trademarks of the respective companies.