wimax: move out to staging

There are no known users of this driver as of October 2020, and it will
be removed unless someone turns out to still need it in future releases.

According to https://en.wikipedia.org/wiki/List_of_WiMAX_networks, there
have been many public wimax networks, but it appears that many of these
have migrated to LTE or discontinued their service altogether.
As most PCs and phones lack WiMAX hardware support, the remaining
networks tend to use standalone routers. These almost certainly
run Linux, but not a modern kernel or the mainline wimax driver stack.

NetworkManager appears to have dropped userspace support in 2015
https://bugzilla.gnome.org/show_bug.cgi?id=747846, the
www.linuxwimax.org
site had already shut down earlier.

WiMax is apparently still being deployed on airport campus networks
("AeroMACS"), but in a frequency band that was not supported by the old
Intel 2400m (used in Sandy Bridge laptops and earlier), which is the
only driver using the kernel's wimax stack.

Move all files into drivers/staging/wimax, including the uapi header
files and documentation, to make it easier to remove it when it gets
to that. Only minimal changes are made to the source files, in order
to make it possible to port patches across the move.

Also remove the MAINTAINERS entry that refers to a broken mailing
list and website.

Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-By: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Suggested-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 89 insertions, 0 deletions

diff --git a/drivers/staging/wimax/Documentation/wimax.rst b/drivers/staging/wimax/Documentation/wimax.rst
new file mode 100644
index 000000000000..817ee8ba2732
--- /dev/null
+++ b/drivers/staging/wimax/Documentation/wimax.rst
@@ -0,0 +1,89 @@
+.. include:: <isonum.txt>
+
+========================
+Linux kernel WiMAX stack
+========================
+
+:Copyright: |copy| 2008 Intel Corporation < linux-wimax@intel.com >
+
+   This provides a basic Linux kernel WiMAX stack to provide a common
+   control API for WiMAX devices, usable from kernel and user space.
+
+1. Design
+=========
+
+   The WiMAX stack is designed to provide for common WiMAX control
+   services to current and future WiMAX devices from any vendor.
+
+   Because currently there is only one and we don't know what would be the
+   common services, the APIs it currently provides are very minimal.
+   However, it is done in such a way that it is easily extensible to
+   accommodate future requirements.
+
+   The stack works by embedding a struct wimax_dev in your device's
+   control structures. This provides a set of callbacks that the WiMAX
+   stack will call in order to implement control operations requested by
+   the user. As well, the stack provides API functions that the driver
+   calls to notify about changes of state in the device.
+
+   The stack exports the API calls needed to control the device to user
+   space using generic netlink as a marshalling mechanism. You can access
+   them using your own code or use the wrappers provided for your
+   convenience in libwimax (in the wimax-tools package).
+
+   For detailed information on the stack, please see
+   include/linux/wimax.h.
+
+2. Usage
+========
+
+   For usage in a driver (registration, API, etc) please refer to the
+   instructions in the header file include/linux/wimax.h.
+
+   When a device is registered with the WiMAX stack, a set of debugfs
+   files will appear in /sys/kernel/debug/wimax:wmxX can tweak for
+   control.
+
+2.1. Obtaining debug information: debugfs entries
+-------------------------------------------------
+
+   The WiMAX stack is compiled, by default, with debug messages that can
+   be used to diagnose issues. By default, said messages are disabled.
+
+   The drivers will register debugfs entries that allow the user to tweak
+   debug settings.
+
+   Each driver, when registering with the stack, will cause a debugfs
+   directory named wimax:DEVICENAME to be created; optionally, it might
+   create more subentries below it.
+
+2.1.1. Increasing debug output
+------------------------------
+
+   The files named *dl_* indicate knobs for controlling the debug output
+   of different submodules of the WiMAX stack::
+
+	# find /sys/kernel/debug/wimax\:wmx0 -name \*dl_\*
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_stack
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_op_rfkill
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_op_reset
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_op_msg
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_id_table
+	/sys/kernel/debug/wimax:wmx0/wimax_dl_debugfs
+	/sys/kernel/debug/wimax:wmx0/.... # other driver specific files
+
+   NOTE:
+       Of course, if debugfs is mounted in a directory other than
+       /sys/kernel/debug, those paths will change.
+
+   By reading the file you can obtain the current value of said debug
+   level; by writing to it, you can set it.
+
+   To increase the debug level of, for example, the id-table submodule,
+   just write:
+
+	$ echo 3 > /sys/kernel/debug/wimax:wmx0/wimax_dl_id_table
+
+   Increasing numbers yield increasing debug information; for details of
+   what is printed and the available levels, check the source. The code
+   uses 0 for disabled and increasing values until 8.