1.. include:: <isonum.txt> 2 3======================== 4Linux kernel WiMAX stack 5======================== 6 7:Copyright: |copy| 2008 Intel Corporation < linux-wimax@intel.com > 8 9 This provides a basic Linux kernel WiMAX stack to provide a common 10 control API for WiMAX devices, usable from kernel and user space. 11 121. Design 13========= 14 15 The WiMAX stack is designed to provide for common WiMAX control 16 services to current and future WiMAX devices from any vendor. 17 18 Because currently there is only one and we don't know what would be the 19 common services, the APIs it currently provides are very minimal. 20 However, it is done in such a way that it is easily extensible to 21 accommodate future requirements. 22 23 The stack works by embedding a struct wimax_dev in your device's 24 control structures. This provides a set of callbacks that the WiMAX 25 stack will call in order to implement control operations requested by 26 the user. As well, the stack provides API functions that the driver 27 calls to notify about changes of state in the device. 28 29 The stack exports the API calls needed to control the device to user 30 space using generic netlink as a marshalling mechanism. You can access 31 them using your own code or use the wrappers provided for your 32 convenience in libwimax (in the wimax-tools package). 33 34 For detailed information on the stack, please see 35 include/linux/wimax.h. 36 372. Usage 38======== 39 40 For usage in a driver (registration, API, etc) please refer to the 41 instructions in the header file include/linux/wimax.h. 42 43 When a device is registered with the WiMAX stack, a set of debugfs 44 files will appear in /sys/kernel/debug/wimax:wmxX can tweak for 45 control. 46 472.1. Obtaining debug information: debugfs entries 48------------------------------------------------- 49 50 The WiMAX stack is compiled, by default, with debug messages that can 51 be used to diagnose issues. By default, said messages are disabled. 52 53 The drivers will register debugfs entries that allow the user to tweak 54 debug settings. 55 56 Each driver, when registering with the stack, will cause a debugfs 57 directory named wimax:DEVICENAME to be created; optionally, it might 58 create more subentries below it. 59 602.1.1. Increasing debug output 61------------------------------ 62 63 The files named *dl_* indicate knobs for controlling the debug output 64 of different submodules of the WiMAX stack:: 65 66 # find /sys/kernel/debug/wimax\:wmx0 -name \*dl_\* 67 /sys/kernel/debug/wimax:wmx0/wimax_dl_stack 68 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_rfkill 69 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_reset 70 /sys/kernel/debug/wimax:wmx0/wimax_dl_op_msg 71 /sys/kernel/debug/wimax:wmx0/wimax_dl_id_table 72 /sys/kernel/debug/wimax:wmx0/wimax_dl_debugfs 73 /sys/kernel/debug/wimax:wmx0/.... # other driver specific files 74 75 NOTE: 76 Of course, if debugfs is mounted in a directory other than 77 /sys/kernel/debug, those paths will change. 78 79 By reading the file you can obtain the current value of said debug 80 level; by writing to it, you can set it. 81 82 To increase the debug level of, for example, the id-table submodule, 83 just write: 84 85 $ echo 3 > /sys/kernel/debug/wimax:wmx0/wimax_dl_id_table 86 87 Increasing numbers yield increasing debug information; for details of 88 what is printed and the available levels, check the source. The code 89 uses 0 for disabled and increasing values until 8. 90