Hi Roman, Thanks for the reply.
I have not developed the device drivers myself. I just got a pre-built shared library from the vendor(MotionNode) of the orientation sensor. And that shared library too, runs in the user space. It just makes read/write system calls to access the device file /dev/ ttyUSB0, and the "usb-serial.c" device driver in the Linux kernel takes care of everything else, like creating the device file when the device is plugged in, and low-level communication with the device. Thanks, Puneet Jindal On Jul 7, 4:37 pm, Roman <roman.baumgaert...@t-mobile.com> wrote: > Hi Puneet, > > I noticed on my device that most of the device files have the > following permissions enabled > > crw-rw-rw- > > You might want to change your current driver code and set this > permissions correctly instead of changing it via script. > > The problem with changing the permissions via script is that you > execute the script only during bootup. You might have to add a daemon > process which acts on whether the device is available or not (how do > you handle cases where the driver is removed with a rmmod and is added > again) and then execute the script. Why not changing the driver right > away with the correct permissions? > > -- > Roman Baumgaertner > Sr. SW Engineer-OSDC > ·T· · ·Mobile· stick together > The views, opinions and statements in this email are those of the > author solely in their individual capacity, and do not necessarily > represent those of T-Mobile USA, Inc. > > On Jul 4, 2:49 pm, Puneet <puneetjindal.1...@gmail.com> wrote: > > > Hi everybody, > > > I am trying to run Android on my prototype phone. The phone has a > > sensor (a device that reports its orientation to the phone) attached > > to it through the USB interface. > > > I have developed a hardware module for that sensor, the name of the > > shared library for the module being "sensors.default.so". The module > > communicates with the sensor through the device file /dev/ttyUSB0. > > > The problem I am facing is that the device file /dev/ttyUSB0 has > > permissions as: > > crw------- root root 188, 0 > > 1980-01-10 18:47 ttyUSB0 > > > So, when I test the module's functionality by running a test android > > application, the application doesn't have enough privileges to read/ > > write from/to the device file. So, the results are negative. > > > And, if I test the same functionality by running a native test > > application (via the adb shell, so it runs as root), the results are > > positive. > > > I tried to solve this issue by modifying the startup scripts (these > > run as root) to change the device file permissions at startup, but it > > seems that the device file is created after the scripts have completed > > their execution. > > > Any suggestions on what should be done, to make the android > > application able to read/write from/to the device file ? > > How to change the device file permissions at the time of creation ? > > > Thanks, > > Puneet Jindal --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. To post to this group, send email to android-framework@googlegroups.com To unsubscribe from this group, send email to android-framework+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-framework?hl=en -~----------~----~----~----~------~----~------~--~---
