SMBus and I2C in USER mode

Discussion in 'Windows Vista Drivers' started by Andrea, Jul 28, 2006.

  1. Andrea

    Andrea Guest

    Hi all,
    I need to access I2C bus (a portion of SBBus) from my USER (ring 3) app, I
    noticed pci.sys implemented the functionality 'Intel 82801FB/FBM SBBus
    Controller' but I do not know its device interface and its IOCTL. Can you
    help me?
    In the I2C some diagnostic chips are present in order to read CPU
    temperature, fan speed and so on...
    Thanks in advance.
    Regards,
    Andrea
     
    Andrea, Jul 28, 2006
    #1
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  2. You will need to know the IOCTL's that the I2C device driver(s) define. You
    cannot access IO space from the user application.
     
    Gary G. Little, Jul 28, 2006
    #2
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  3. Andrea

    Andrea Guest

    Do you know how to get the IOCTL and Device interface? The driver does exist
    I only need to access the bus and send frames on it (i2c is a very
    straigthforward bus architecture).
    Kind regards,
    Andrea
     
    Andrea, Jul 29, 2006
    #3
  4. Sure. You open the documentation for the device driver and read. If it is
    not there then you look for documentation that documents any exported
    interfaces and IOCTLs. Google and MSN search are two good places to start.
    If that docuementation does not exist then you may have to go all the way
    back to the OEM/author to acquire it. You can spend time in WinDbg and
    looking at the IOCTL calls that ferret themslves into the Dispatch function
    of the driver, but that takes quite a bit of time, and you may not get all
    of them.

    Again ... you CANNOT do IO from a user application.
     
    Gary G. Little, Jul 31, 2006
    #4
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