docs: driver-api: add a series of orphaned documents

There are lots of documents under Documentation/*.txt and a few other
orphan documents elsehwere that belong to the driver-API book.

Move them to their right place.

Reviewed-by: Cornelia Huck <cohuck@redhat.com> # vfio-related parts
Acked-by: Logan Gunthorpe <logang@deltatee.com> # switchtec
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 0 insertions, 132 deletions

diff --git a/Documentation/rfkill.txt b/Documentation/rfkill.txt
deleted file mode 100644
index 7d3684e81df6..000000000000
--- a/Documentation/rfkill.txt
+++ /dev/null
@@ -1,132 +0,0 @@
-===============================
-rfkill - RF kill switch support
-===============================
-
-
-.. contents::
-   :depth: 2
-
-Introduction
-============
-
-The rfkill subsystem provides a generic interface for disabling any radio
-transmitter in the system. When a transmitter is blocked, it shall not
-radiate any power.
-
-The subsystem also provides the ability to react on button presses and
-disable all transmitters of a certain type (or all). This is intended for
-situations where transmitters need to be turned off, for example on
-aircraft.
-
-The rfkill subsystem has a concept of "hard" and "soft" block, which
-differ little in their meaning (block == transmitters off) but rather in
-whether they can be changed or not:
-
- - hard block
-	read-only radio block that cannot be overridden by software
-
- - soft block
-	writable radio block (need not be readable) that is set by
-        the system software.
-
-The rfkill subsystem has two parameters, rfkill.default_state and
-rfkill.master_switch_mode, which are documented in
-admin-guide/kernel-parameters.rst.
-
-
-Implementation details
-======================
-
-The rfkill subsystem is composed of three main components:
-
- * the rfkill core,
- * the deprecated rfkill-input module (an input layer handler, being
-   replaced by userspace policy code) and
- * the rfkill drivers.
-
-The rfkill core provides API for kernel drivers to register their radio
-transmitter with the kernel, methods for turning it on and off, and letting
-the system know about hardware-disabled states that may be implemented on
-the device.
-
-The rfkill core code also notifies userspace of state changes, and provides
-ways for userspace to query the current states. See the "Userspace support"
-section below.
-
-When the device is hard-blocked (either by a call to rfkill_set_hw_state()
-or from query_hw_block), set_block() will be invoked for additional software
-block, but drivers can ignore the method call since they can use the return
-value of the function rfkill_set_hw_state() to sync the software state
-instead of keeping track of calls to set_block(). In fact, drivers should
-use the return value of rfkill_set_hw_state() unless the hardware actually
-keeps track of soft and hard block separately.
-
-
-Kernel API
-==========
-
-Drivers for radio transmitters normally implement an rfkill driver.
-
-Platform drivers might implement input devices if the rfkill button is just
-that, a button. If that button influences the hardware then you need to
-implement an rfkill driver instead. This also applies if the platform provides
-a way to turn on/off the transmitter(s).
-
-For some platforms, it is possible that the hardware state changes during
-suspend/hibernation, in which case it will be necessary to update the rfkill
-core with the current state at resume time.
-
-To create an rfkill driver, driver's Kconfig needs to have::
-
-	depends on RFKILL || !RFKILL
-
-to ensure the driver cannot be built-in when rfkill is modular. The !RFKILL
-case allows the driver to be built when rfkill is not configured, in which
-case all rfkill API can still be used but will be provided by static inlines
-which compile to almost nothing.
-
-Calling rfkill_set_hw_state() when a state change happens is required from
-rfkill drivers that control devices that can be hard-blocked unless they also
-assign the poll_hw_block() callback (then the rfkill core will poll the
-device). Don't do this unless you cannot get the event in any other way.
-
-rfkill provides per-switch LED triggers, which can be used to drive LEDs
-according to the switch state (LED_FULL when blocked, LED_OFF otherwise).
-
-
-Userspace support
-=================
-
-The recommended userspace interface to use is /dev/rfkill, which is a misc
-character device that allows userspace to obtain and set the state of rfkill
-devices and sets of devices. It also notifies userspace about device addition
-and removal. The API is a simple read/write API that is defined in
-linux/rfkill.h, with one ioctl that allows turning off the deprecated input
-handler in the kernel for the transition period.
-
-Except for the one ioctl, communication with the kernel is done via read()
-and write() of instances of 'struct rfkill_event'. In this structure, the
-soft and hard block are properly separated (unlike sysfs, see below) and
-userspace is able to get a consistent snapshot of all rfkill devices in the
-system. Also, it is possible to switch all rfkill drivers (or all drivers of
-a specified type) into a state which also updates the default state for
-hotplugged devices.
-
-After an application opens /dev/rfkill, it can read the current state of all
-devices. Changes can be obtained by either polling the descriptor for
-hotplug or state change events or by listening for uevents emitted by the
-rfkill core framework.
-
-Additionally, each rfkill device is registered in sysfs and emits uevents.
-
-rfkill devices issue uevents (with an action of "change"), with the following
-environment variables set::
-
-	RFKILL_NAME
-	RFKILL_STATE
-	RFKILL_TYPE
-
-The content of these variables corresponds to the "name", "state" and
-"type" sysfs files explained above.
-
-For further details consult Documentation/ABI/stable/sysfs-class-rfkill.