Documentation/wimax/README.wimax

   1
   2    Linux kernel WiMAX stack
   3
   4    (C) 2008 Intel Corporation < linux-wimax@intel.com >
   5
   6    This provides a basic Linux kernel WiMAX stack to provide a common
   7    control API for WiMAX devices, usable from kernel and user space.
   8
   9 1. Design
  10
  11    The WiMAX stack is designed to provide for common WiMAX control
  12    services to current and future WiMAX devices from any vendor.
  13
  14    Because currently there is only one and we don't know what would be the
  15    common services, the APIs it currently provides are very minimal.
  16    However, it is done in such a way that it is easily extensible to
  17    accommodate future requirements.
  18
  19    The stack works by embedding a struct wimax_dev in your device's
  20    control structures. This provides a set of callbacks that the WiMAX
  21    stack will call in order to implement control operations requested by
  22    the user. As well, the stack provides API functions that the driver
  23    calls to notify about changes of state in the device.
  24
  25    The stack exports the API calls needed to control the device to user
  26    space using generic netlink as a marshalling mechanism. You can access
  27    them using your own code or use the wrappers provided for your
  28    convenience in libwimax (in the wimax-tools package).
  29
  30    For detailed information on the stack, please see
  31    include/linux/wimax.h.
  32
  33 2. Usage
  34
  35    For usage in a driver (registration, API, etc) please refer to the
  36    instructions in the header file include/linux/wimax.h.
  37
  38    When a device is registered with the WiMAX stack, a set of debugfs
  39    files will appear in /sys/kernel/debug/wimax:wmxX can tweak for
  40    control.
  41
  42 2.1. Obtaining debug information: debugfs entries
  43
  44    The WiMAX stack is compiled, by default, with debug messages that can
  45    be used to diagnose issues. By default, said messages are disabled.
  46
  47    The drivers will register debugfs entries that allow the user to tweak
  48    debug settings.
  49
  50    Each driver, when registering with the stack, will cause a debugfs
  51    directory named wimax:DEVICENAME to be created; optionally, it might
  52    create more subentries below it.
  53
  54 2.1.1. Increasing debug output
  55
  56    The files named *dl_* indicate knobs for controlling the debug output
  57    of different submodules of the WiMAX stack:
  58      *
  59 # find /sys/kernel/debug/wimax\:wmx0 -name \*dl_\*
  60 /sys/kernel/debug/wimax:wmx0/wimax_dl_stack
  61 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_rfkill
  62 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_reset
  63 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_msg
  64 /sys/kernel/debug/wimax:wmx0/wimax_dl_id_table
  65 /sys/kernel/debug/wimax:wmx0/wimax_dl_debugfs
  66 /sys/kernel/debug/wimax:wmx0/.... # other driver specific files
  67
  68        NOTE: Of course, if debugfs is mounted in a directory other than
  69        /sys/kernel/debug, those paths will change.
  70
  71    By reading the file you can obtain the current value of said debug
  72    level; by writing to it, you can set it.
  73
  74    To increase the debug level of, for example, the id-table submodule,
  75    just write:
  76
  77 $ echo 3 > /sys/kernel/debug/wimax:wmx0/wimax_dl_id_table
  78
  79    Increasing numbers yield increasing debug information; for details of
  80    what is printed and the available levels, check the source. The code
  81    uses 0 for disabled and increasing values until 8.