Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

Pull HID updates from Jiri Kosina:
 - substantial cleanup of the generic and transport layers, in the
   direction of an ultimate goal of making struct hid_device completely
   transport independent, by Benjamin Tissoires
 - cp2112 driver from David Barksdale
 - a lot of fixes and new hardware support (Dualshock 4) to hid-sony
   driver, by Frank Praznik
 - support for Win 8.1 multitouch protocol by Andrew Duggan
 - other smaller fixes / device ID additions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (75 commits)
  HID: sony: fix force feedback mismerge
  HID: sony: Set the quriks flag for Bluetooth controllers
  HID: sony: Fix Sixaxis cable state detection
  HID: uhid: Add UHID_CREATE2 + UHID_INPUT2
  HID: hyperv: fix _raw_request() prototype
  HID: hyperv: Implement a stub raw_request() entry point
  HID: hid-sensor-hub: fix sleeping function called from invalid context
  HID: multitouch: add support for Win 8.1 multitouch touchpads
  HID: remove hid_output_raw_report transport implementations
  HID: sony: do not rely on hid_output_raw_report
  HID: cp2112: remove the last hid_output_raw_report() call
  HID: cp2112: remove various hid_out_raw_report calls
  HID: multitouch: add support of other generic collections in hid-mt
  HID: multitouch: remove pen special handling
  HID: multitouch: remove registered devices with default behavior
  HID: hidp: Add a comment that some devices depend on the current behavior of uniq
  HID: sony: Prevent duplicate controller connections.
  HID: sony: Perform a boundry check on the sixaxis battery level index.
  HID: sony: Fix work queue issues
  HID: sony: Fix multi-line comment styling
  ...

29 files changed, 3022 insertions, 658 deletions

diff --git a/Documentation/hid/hid-transport.txt b/Documentation/hid/hid-transport.txt
new file mode 100644
index 000000000000..3dcba9fd4a3a
--- /dev/null
+++ b/Documentation/hid/hid-transport.txt
@@ -0,0 +1,317 @@
+                          HID I/O Transport Drivers
+                         ===========================
+
+The HID subsystem is independent of the underlying transport driver. Initially,
+only USB was supported, but other specifications adopted the HID design and
+provided new transport drivers. The kernel includes at least support for USB,
+Bluetooth, I2C and user-space I/O drivers.
+
+1) HID Bus
+==========
+
+The HID subsystem is designed as a bus. Any I/O subsystem may provide HID
+devices and register them with the HID bus. HID core then loads generic device
+drivers on top of it. The transport drivers are responsible of raw data
+transport and device setup/management. HID core is responsible of
+report-parsing, report interpretation and the user-space API. Device specifics
+and quirks are handled by all layers depending on the quirk.
+
+ +-----------+  +-----------+            +-----------+  +-----------+
+ | Device #1 |  | Device #i |            | Device #j |  | Device #k |
+ +-----------+  +-----------+            +-----------+  +-----------+
+          \\      //                              \\      //
+        +------------+                          +------------+
+        | I/O Driver |                          | I/O Driver |
+        +------------+                          +------------+
+              ||                                      ||
+     +------------------+                    +------------------+
+     | Transport Driver |                    | Transport Driver |
+     +------------------+                    +------------------+
+                       \___                ___/
+                           \              /
+                          +----------------+
+                          |    HID Core    |
+                          +----------------+
+                           /  |        |  \
+                          /   |        |   \
+             ____________/    |        |    \_________________
+            /                 |        |                      \
+           /                  |        |                       \
+ +----------------+  +-----------+  +------------------+  +------------------+
+ | Generic Driver |  | MT Driver |  | Custom Driver #1 |  | Custom Driver #2 |
+ +----------------+  +-----------+  +------------------+  +------------------+
+
+Example Drivers:
+  I/O: USB, I2C, Bluetooth-l2cap
+  Transport: USB-HID, I2C-HID, BT-HIDP
+
+Everything below "HID Core" is simplified in this graph as it is only of
+interest to HID device drivers. Transport drivers do not need to know the
+specifics.
+
+1.1) Device Setup
+-----------------
+
+I/O drivers normally provide hotplug detection or device enumeration APIs to the
+transport drivers. Transport drivers use this to find any suitable HID device.
+They allocate HID device objects and register them with HID core. Transport
+drivers are not required to register themselves with HID core. HID core is never
+aware of which transport drivers are available and is not interested in it. It
+is only interested in devices.
+
+Transport drivers attach a constant "struct hid_ll_driver" object with each
+device. Once a device is registered with HID core, the callbacks provided via
+this struct are used by HID core to communicate with the device.
+
+Transport drivers are responsible of detecting device failures and unplugging.
+HID core will operate a device as long as it is registered regardless of any
+device failures. Once transport drivers detect unplug or failure events, they
+must unregister the device from HID core and HID core will stop using the
+provided callbacks.
+
+1.2) Transport Driver Requirements
+----------------------------------
+
+The terms "asynchronous" and "synchronous" in this document describe the
+transmission behavior regarding acknowledgements. An asynchronous channel must
+not perform any synchronous operations like waiting for acknowledgements or
+verifications. Generally, HID calls operating on asynchronous channels must be
+running in atomic-context just fine.
+On the other hand, synchronous channels can be implemented by the transport
+driver in whatever way they like. They might just be the same as asynchronous
+channels, but they can also provide acknowledgement reports, automatic
+retransmission on failure, etc. in a blocking manner. If such functionality is
+required on asynchronous channels, a transport-driver must implement that via
+its own worker threads.
+
+HID core requires transport drivers to follow a given design. A Transport
+driver must provide two bi-directional I/O channels to each HID device. These
+channels must not necessarily be bi-directional in the hardware itself. A
+transport driver might just provide 4 uni-directional channels. Or it might
+multiplex all four on a single physical channel. However, in this document we
+will describe them as two bi-directional channels as they have several
+properties in common.
+
+ - Interrupt Channel (intr): The intr channel is used for asynchronous data
+   reports. No management commands or data acknowledgements are sent on this
+   channel. Any unrequested incoming or outgoing data report must be sent on
+   this channel and is never acknowledged by the remote side. Devices usually
+   send their input events on this channel. Outgoing events are normally
+   not send via intr, except if high throughput is required.
+ - Control Channel (ctrl): The ctrl channel is used for synchronous requests and
+   device management. Unrequested data input events must not be sent on this
+   channel and are normally ignored. Instead, devices only send management
+   events or answers to host requests on this channel.
+   The control-channel is used for direct blocking queries to the device
+   independent of any events on the intr-channel.
+   Outgoing reports are usually sent on the ctrl channel via synchronous
+   SET_REPORT requests.
+
+Communication between devices and HID core is mostly done via HID reports. A
+report can be of one of three types:
+
+ - INPUT Report: Input reports provide data from device to host. This
+   data may include button events, axis events, battery status or more. This
+   data is generated by the device and sent to the host with or without
+   requiring explicit requests. Devices can choose to send data continuously or
+   only on change.
+ - OUTPUT Report: Output reports change device states. They are sent from host
+   to device and may include LED requests, rumble requests or more. Output
+   reports are never sent from device to host, but a host can retrieve their
+   current state.
+   Hosts may choose to send output reports either continuously or only on
+   change.
+ - FEATURE Report: Feature reports are used for specific static device features
+   and never reported spontaneously. A host can read and/or write them to access
+   data like battery-state or device-settings.
+   Feature reports are never sent without requests. A host must explicitly set
+   or retrieve a feature report. This also means, feature reports are never sent
+   on the intr channel as this channel is asynchronous.
+
+INPUT and OUTPUT reports can be sent as pure data reports on the intr channel.