9 files changed, 656 insertions, 46 deletions

diff --git a/Documentation/input/cma3000_d0x.txt b/Documentation/input/cma3000_d0x.txt
new file mode 100644
index 000000000000..29d088db4afd
--- /dev/null
+++ b/Documentation/input/cma3000_d0x.txt
@@ -0,0 +1,115 @@
+Kernel driver for CMA3000-D0x
+============================
+
+Supported chips:
+* VTI CMA3000-D0x
+Datasheet:
+  CMA3000-D0X Product Family Specification 8281000A.02.pdf
+  <http://www.vti.fi/en/>
+
+Author: Hemanth V <hemanthv@ti.com>
+
+
+Description
+-----------
+CMA3000 Tri-axis accelerometer supports Motion detect, Measurement and
+Free fall modes.
+
+Motion Detect Mode: Its the low power mode where interrupts are generated only
+when motion exceeds the defined thresholds.
+
+Measurement Mode: This mode is used to read the acceleration data on X,Y,Z
+axis and supports 400, 100, 40 Hz sample frequency.
+
+Free fall Mode: This mode is intended to save system resources.
+
+Threshold values: Chip supports defining threshold values for above modes
+which includes time and g value. Refer product specifications for more details.
+
+CMA3000 chip supports mutually exclusive I2C and SPI interfaces for
+communication, currently the driver supports I2C based communication only.
+Initial configuration for bus mode is set in non volatile memory and can later
+be modified through bus interface command.
+
+Driver reports acceleration data through input subsystem. It generates ABS_MISC
+event with value 1 when free fall is detected.
+
+Platform data need to be configured for initial default values.
+
+Platform Data
+-------------
+fuzz_x: Noise on X Axis
+
+fuzz_y: Noise on Y Axis
+
+fuzz_z: Noise on Z Axis
+
+g_range: G range in milli g i.e 2000 or 8000
+
+mode: Default Operating mode
+
+mdthr: Motion detect g range threshold value
+
+mdfftmr: Motion detect and free fall time threshold value
+
+ffthr: Free fall g range threshold value
+
+Input Interface
+--------------
+Input driver version is 1.0.0
+Input device ID: bus 0x18 vendor 0x0 product 0x0 version 0x0
+Input device name: "cma3000-accelerometer"
+Supported events:
+  Event type 0 (Sync)
+  Event type 3 (Absolute)
+    Event code 0 (X)
+      Value     47
+      Min    -8000
+      Max     8000
+      Fuzz     200
+    Event code 1 (Y)
+      Value    -28
+      Min    -8000
+      Max     8000
+      Fuzz     200
+    Event code 2 (Z)
+      Value    905
+      Min    -8000
+      Max     8000
+      Fuzz     200
+    Event code 40 (Misc)
+      Value      0
+      Min        0
+      Max        1
+  Event type 4 (Misc)
+
+
+Register/Platform parameters Description
+----------------------------------------
+
+mode:
+        0: power down mode
+        1: 100 Hz Measurement mode
+        2: 400 Hz Measurement mode
+        3: 40 Hz Measurement mode
+        4: Motion Detect mode (default)
+        5: 100 Hz Free fall mode
+        6: 40 Hz Free fall mode
+        7: Power off mode
+
+grange:
+        2000: 2000 mg or 2G Range
+        8000: 8000 mg or 8G Range
+
+mdthr:
+        X: X * 71mg (8G Range)
+        X: X * 18mg (2G Range)
+
+mdfftmr:
+        X: (X & 0x70) * 100 ms (MDTMR)
+           (X & 0x0F) * 2.5 ms (FFTMR 400 Hz)
+           (X & 0x0F) * 10 ms  (FFTMR 100 Hz)
+
+ffthr:
+       X: (X >> 2) * 18mg (2G Range)
+       X: (X & 0x0F) * 71 mg (8G Range)
diff --git a/Documentation/input/elantech.txt b/Documentation/input/elantech.txt
index 56941ae1f5db..db798af5ef98 100644
--- a/Documentation/input/elantech.txt
+++ b/Documentation/input/elantech.txt
@@ -34,7 +34,8 @@ Contents
 Currently the Linux Elantech touchpad driver is aware of two different
 hardware versions unimaginatively called version 1 and version 2. Version 1
 is found in "older" laptops and uses 4 bytes per packet. Version 2 seems to
-be introduced with the EeePC and uses 6 bytes per packet.
+be introduced with the EeePC and uses 6 bytes per packet, and provides
+additional features such as position of two fingers, and width of the touch.
 
 The driver tries to support both hardware versions and should be compatible
 with the Xorg Synaptics touchpad driver and its graphical configuration
@@ -94,18 +95,44 @@ Currently the Linux Elantech touchpad driver provides two extra knobs under
    can check these bits and reject any packet that appears corrupted. Using
    this knob you can bypass that check.
 
-   It is not known yet whether hardware version 2 provides the same parity
-   bits. Hence checking is disabled by default. Currently even turning it on
-   will do nothing.
-
+   Hardware version 2 does not provide the same parity bits. Only some basic
+   data consistency checking can be done. For now checking is disabled by
+   default. Currently even turning it on will do nothing.
 
 /////////////////////////////////////////////////////////////////////////////
 
+3. Differentiating hardware versions
+   =================================
+
+To detect the hardware version, read the version number as param[0].param[1].param[2]
+
+ 4 bytes version: (after the arrow is the name given in the Dell-provided driver)
+ 02.00.22 => EF013
+ 02.06.00 => EF019
+In the wild, there appear to be more versions, such as 00.01.64, 01.00.21,
+02.00.00, 02.00.04, 02.00.06.
+
+ 6 bytes:
+ 02.00.30 => EF113
+ 02.08.00 => EF023
+ 02.08.XX => EF123
+ 02.0B.00 => EF215
+ 04.01.XX => Scroll_EF051
+ 04.02.XX => EF051
+In the wild, there appear to be more versions, such as 04.03.01, 04.04.11. There
+appears to be almost no difference, except for EF113, which does not report
+pressure/width and has different data consistency checks.
+
+Probably all the versions with param[0] <= 01 can be considered as
+4 bytes/firmware 1. The versions < 02.08.00, with the exception of 02.00.30, as
+4 bytes/firmware 2. Everything >= 02.08.00 can be considered as 6 bytes.
+
+/////////////////////////////////////////////////////////////////////////////
 
-3. Hardware version 1
+4. Hardware version 1
    ==================
 
-3.1 Registers
+4.1 Registers
     ~~~~~~~~~
 
 By echoing a hexadecimal value to a register it contents can be altered.
@@ -168,7 +195,7 @@ For example:
          smart edge activation area width?
 
 
-3.2 Native relative mode 4 byte packet format
+4.2 Native relative mode 4 byte packet format
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 byte 0:
@@ -226,9 +253,13 @@ byte 3:
                        positive = down
 
 
-3.3 Native absolute mode 4 byte packet format
+4.3 Native absolute mode 4 byte packet format
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+EF013 and EF019 have a special behaviour (due to a bug in the firmware?), and
+when 1 finger is touching, the first 2 position reports must be discarded.
+This counting is reset whenever a different number of fingers is reported.
+
 byte 0:
    firmware version 1.x:
 
@@ -279,11 +310,11 @@ byte 3:
 /////////////////////////////////////////////////////////////////////////////
 
 
-4. Hardware version 2
+5. Hardware version 2
    ==================
 
 
-4.1 Registers
+5.1 Registers
     ~~~~~~~~~
 
 By echoing a hexadecimal value to a register it contents can be altered.
@@ -316,16 +347,41 @@ For example:
                                    0x7f = never i.e. tap again to release)
 
 
-4.2 Native absolute mode 6 byte packet format
+5.2 Native absolute mode 6 byte packet format
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-4.2.1 One finger touch
+5.2.1 Parity checking and packet re-synchronization
+There is no parity checking, however some consistency checks can be performed.
+
+For instance for EF113:
+        SA1= packet[0];
+        A1 = packet[1];
+        B1 = packet[2];
+        SB1= packet[3];
+        C1 = packet[4];
+        D1 = packet[5];
+        if( (((SA1 & 0x3C) != 0x3C) && ((SA1 & 0xC0) != 0x80)) || // check Byte 1
+            (((SA1 & 0x0C) != 0x0C) && ((SA1 & 0xC0) == 0x80)) || // check Byte 1 (one finger pressed)
+            (((SA1 & 0xC0) != 0x80) && (( A1 & 0xF0) != 0x00)) || // check Byte 2
+            (((SB1 & 0x3E) != 0x38) && ((SA1 & 0xC0) != 0x80)) || // check Byte 4
+            (((SB1 & 0x0E) != 0x08) && ((SA1 & 0xC0) == 0x80)) || // check Byte 4 (one finger pressed)
+            (((SA1 & 0xC0) != 0x80) && (( C1 & 0xF0) != 0x00))  ) // check Byte 5
+                // error detected
+
+For all the other ones, there are just a few constant bits:
+        if( ((packet[0] & 0x0C) != 0x04) ||
+            ((packet[3] & 0x0f) != 0x02) )
+                // error detected
+
+
+In case an error is detected, all the packets are shifted by one (and packet[0] is discarded).
+
+5.2.1 One/Three finger touch
       ~~~~~~~~~~~~~~~~
 
 byte 0:
 
    bit   7   6   5   4   3   2   1   0
-        n1  n0   .   .   .   .   R   L
+         n1  n0  w3  w2   .   .   R   L
 
          L, R = 1 when Left, Right mouse button pressed
          n1..n0 = numbers of fingers on touchpad
@@ -333,24 +389,40 @@ byte 0:
 byte 1:
 
    bit   7   6   5   4   3   2   1   0
-         .   .   .   .   .  x10 x9  x8
+         p7  p6  p5  p4  .  x10 x9  x8
 
 byte 2:
 
    bit   7   6   5   4   3   2   1   0
-        x7  x6  x5  x4  x4  x2  x1  x0
+         x7  x6  x5  x4  x3  x2  x1  x0
 
          x10..x0 = absolute x value (horizontal)
 
 byte 3:
 
    bit   7   6   5   4   3   2   1   0
-         .   .   .   .   .   .   .   .
+         n4  vf  w1  w0   .   .   .  b2
+
+         n4 = set if more than 3 fingers (only in 3 fingers mode)
+         vf = a kind of flag ? (only on EF123, 0 when finger is over one
+              of the buttons, 1 otherwise)
+         w3..w0 = width of the finger touch (not EF113)
+         b2 (on EF113 only, 0 otherwise), b2.R.L indicates one button pressed:
+                0 = none
+                1 = Left
+                2 = Right
+                3 = Middle (Left and Right)
+                4 = Forward
+                5 = Back
+                6 = Another one
+                7 = Another one
 
 byte 4:
 
    bit   7   6   5   4   3   2   1   0
-         .   .   .   .   .   .  y9  y8
+        p3  p1  p2  p0   .   .  y9  y8
+
+         p7..p0 = pressure (not EF113)
 
 byte 5:
 
@@ -363,6 +435,11 @@ byte 5:
 4.2.2 Two finger touch
       ~~~~~~~~~~~~~~~~
 
+Note that the two pairs of coordinates are not exactly the coordinates of the
+two fingers, but only the pair of the lower-left and upper-right coordinates.
+So the actual fingers might be situated on the other diagonal of the square
+defined by these two points.
+
 byte 0:
 
    bit   7   6   5   4   3   2   1   0
@@ -376,14 +453,14 @@ byte 1:
    bit   7   6   5   4   3   2   1   0
         ax7 ax6 ax5 ax4 ax3 ax2 ax1 ax0
 
-         ax8..ax0 = first finger absolute x value
+         ax8..ax0 = lower-left finger absolute x value
 
 byte 2:
 
    bit   7   6   5   4   3   2   1   0
         ay7 ay6 ay5 ay4 ay3 ay2 ay1 ay0
 
-         ay8..ay0 = first finger absolute y value
+         ay8..ay0 = lower-left finger absolute y value
 
 byte 3:
 
@@ -395,11 +472,11 @@ byte 4:
    bit   7   6   5   4   3   2   1   0
         bx7 bx6 bx5 bx4 bx3 bx2 bx1 bx0
 
-         bx8..bx0 = second finger absolute x value
+         bx8..bx0 = upper-right finger absolute x value
 
 byte 5:
 
    bit   7   6   5   4   3   2   1   0
         by7 by8 by5 by4 by3 by2 by1 by0
 
-         by8..by0 = second finger absolute y value
+         by8..by0 = upper-right finger absolute y value
diff --git a/Documentation/input/event-codes.txt b/Documentation/input/event-codes.txt
new file mode 100644
index 000000000000..23fcb05175be
--- /dev/null
+++ b/Documentation/input/event-codes.txt
@@ -0,0 +1,262 @@
+The input protocol uses a map of types and codes to express input device values
+to userspace. This document describes the types and codes and how and when they
+may be used.
+
+A single hardware event generates multiple input events. Each input event
+contains the new value of a single data item. A special event type, EV_SYN, is
+used to separate input events into packets of input data changes occurring at
+the same moment in time. In the following, the term "event" refers to a single
+input event encompassing a type, code, and value.
+
+The input protocol is a stateful protocol. Events are emitted only when values
+of event codes have changed. However, the state is maintained within the Linux
+input subsystem; drivers do not need to maintain the state and may attempt to
+emit unchanged values without harm. Userspace may obtain the current state of
+event code values using the EVIOCG* ioctls defined in linux/input.h. The event
+reports supported by a device are also provided by sysfs in
+class/input/event*/device/capabilities/, and the properties of a device are
+provided in class/input/event*/device/properties.
+
+Types:
+==========
+Types are groupings of codes under a logical input construct. Each type has a
+set of applicable codes to be used in generating events. See the Codes section
+for details on valid codes for each type.
+
+* EV_SYN:
+  - Used as markers to separate events. Events may be separated in time or in
+    space, such as with the multitouch protocol.
+
+* EV_KEY:
+  - Used to describe state changes of keyboards, buttons, or other key-like
+    devices.
+
+* EV_REL:
+  - Used to describe relative axis value changes, e.g. moving the mouse 5 units
+    to the left.
+
+* EV_ABS:
+  - Used to describe absolute axis value changes, e.g. describing the
+    coordinates of a touch on a touchscreen.
+
+* EV_MSC:
+  - Used to describe miscellaneous input data that do not fit into other types.
+
+* EV_SW:
+  - Used to describe binary state input switches.
+
+* EV_LED:
+  - Used to turn LEDs on devices on and off.
+
+* EV_SND:
+  - Used to output sound to devices.
+
+* EV_REP:
+  - Used for autorepeating devices.
+
+* EV_FF:
+  - Used to send force feedback commands to an input device.
+
+* EV_PWR:
+  - A special type for power button and switch input.
+
+* EV_FF_STATUS:
+  - Used to receive force feedback device status.
+
+Codes:
+==========
+Codes define the precise type of event.
+
+EV_SYN:
+----------
+EV_SYN event values are undefined. Their usage is defined only by when they are
+sent in the evdev event stream.
+
+* SYN_REPORT:
+  - Used to synchronize and separate events into packets of input data changes
+    occurring at the same moment in time. For example, motion of a mouse may set
+    the REL_X and REL_Y values for one motion, then emit a SYN_REPORT. The next
+    motion will emit more REL_X and REL_Y values and send another SYN_REPORT.
+
+* SYN_CONFIG:
+  - TBD
+
+* SYN_MT_REPORT:
+  - Used to synchronize and separate touch events. See the
+    multi-touch-protocol.txt document for more information.
+
+* SYN_DROPPED:
+  - Used to indicate buffer overrun in the evdev client's event queue.
+    Client should ignore all events up to and including next SYN_REPORT
+    event and query the device (using EVIOCG* ioctls) to obtain its
+    current state.
+
+EV_KEY:
+----------
+EV_KEY events take the form KEY_<name> or BTN_<name>. For example, KEY_A is used
+to represent the 'A' key on a keyboard. When a key is depressed, an event with
+the key's code is emitted with value 1. When the key is released, an event is
+emitted with value 0. Some hardware send events when a key is repeated. These
+events have a value of 2. In general, KEY_<name> is used for keyboard keys, and
+BTN_<name> is used for other types of momentary switch events.
+
+A few EV_KEY codes have special meanings:
+
+* BTN_TOOL_<name>:
+  - These codes are used in conjunction with input trackpads, tablets, and
+    touchscreens. These devices may be used with fingers, pens, or other tools.
+    When an event occurs and a tool is used, the corresponding BTN_TOOL_<name>
+    code should be set to a value of 1. When the tool is no longer interacting
+    with the input device, the BTN_TOOL_<name> code should be reset to 0. All
+    trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name>
+    code when events are generated.
+
+* BTN_TOUCH:
+    BTN_TOUCH is used for touch contact. While an input tool is determined to be
+    within meaningful physical contact, the value of this property must be set
+    to 1. Meaningful physical contact may mean any contact, or it may mean
+    contact conditioned by an implementation defined property. For example, a
+    touchpad may set the value to 1 only when the touch pressure rises above a
+    certain value. BTN_TOUCH may be combined with BTN_TOOL_<name> codes. For
+    example, a pen tablet may set BTN_TOOL_PEN to 1 and BTN_TOUCH to 0 while the
+    pen is hovering over but not touching the tablet surface.
+
+Note: For appropriate function of the legacy mousedev emulation driver,
+BTN_TOUCH must be the first evdev code emitted in a synchronization frame.
+
+Note: Historically a touch device with BTN_TOOL_FINGER and BTN_TOUCH was
+interpreted as a touchpad by userspace, while a similar device without
+BTN_TOOL_FINGER was interpreted as a touchscreen. For backwards compatibility
+with current userspace it is recommended to follow this distinction. In the
+future, this distinction will be deprecated and the device properties ioctl
+EVIOCGPROP, defined in linux/input.h, will be used to convey the device type.
+
+* BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP, BTN_TOOL_TRIPLETAP, BTN_TOOL_QUADTAP:
+  - These codes denote one, two, three, and four finger interaction on a
+    trackpad or touchscreen. For example, if the user uses two fingers and moves
+    them on the touchpad in an effort to scroll content on screen,
+    BTN_TOOL_DOUBLETAP should be set to value 1 for the duration of the motion.
+    Note that all BTN_TOOL_<name> codes and the BTN_TOUCH code are orthogonal in
+    purpose. A trackpad event generated by finger touches should generate events
+    for one code from each group. At most only one of these BTN_TOOL_<name>
+    codes should have a value of 1 during any synchronization frame.
+
+Note: Historically some drivers emitted multiple of the finger count codes with
+a value of 1 in the same synchronization frame. This usage is deprecated.
+
+Note: In multitouch drivers, the input_mt_report_finger_count() function should
+be used to emit these codes. Please see multi-touch-protocol.txt for details.
+
+EV_REL:
+----------
+EV_REL events describe relative changes in a property. For example, a mouse may
+move to the left by a certain number of units, but its absolute position in
+space is unknown. If the absolute position is known, EV_ABS codes should be used
+instead of EV_REL codes.
+
+A few EV_REL codes have special meanings:
+
+* REL_WHEEL, REL_HWHEEL:
+  - These codes are used for vertical and horizontal scroll wheels,
+    respectively.
+
+EV_ABS:
+----------
+EV_ABS events describe absolute changes in a property. For example, a touchpad
+may emit coordinates for a touch location.
+
+A few EV_ABS codes have special meanings:
+
+* ABS_DISTANCE:
+  - Used to describe the distance of a tool from an interaction surface. This
+    event should only be emitted while the tool is hovering, meaning in close
+    proximity of the device and while the value of the BTN_TOUCH code is 0. If
+    the input device may be used freely in three dimensions, consider ABS_Z
+    instead.
+
+* ABS_MT_<name>:
+  - Used to describe multitouch input events. Please see
+    multi-touch-protocol.txt for details.
+
+EV_SW:
+----------
+EV_SW events describe stateful binary switches. For example, the SW_LID code is
+used to denote when a laptop lid is closed.
+
+Upon binding to a device or resuming from suspend, a driver must report
+the current switch state. This ensures that the device, kernel, and userspace
+state is in sync.
+
+Upon resume, if the switch state is the same as before suspend, then the input
+subsystem will filter out the duplicate switch state reports. The driver does
+not need to keep the state of the switch at any time.
+
+EV_MSC:
+----------
+EV_MSC events are used for input and output events that do not fall under other
+categories.
+
+EV_LED:
+----------
+EV_LED events are used for input and output to set and query the state of
+various LEDs on devices.
+
+EV_REP:
+----------
+EV_REP events are used for specifying autorepeating events.
+
+EV_SND:
+----------
+EV_SND events are used for sending sound commands to simple sound output
+devices.
+
+EV_FF:
+----------
+EV_FF events are used to initialize a force feedback capable device and to cause
+such device to feedback.
+
+EV_PWR:
+----------
+EV_PWR events are a special type of event used specifically for power
+mangement. Its usage is not well defined. To be addressed later.
+
+Guidelines:
+==========
+The guidelines below ensure proper single-touch and multi-finger functionality.
+For multi-touch functionality, see the multi-touch-protocol.txt document for
+more information.
+
+Mice:
+----------
+REL_{X,Y} must be reported when the mouse moves. BTN_LEFT must be used to report
+the primary button press. BTN_{MIDDLE,RIGHT,4,5,etc.} should be used to report
+further buttons of the device. REL_WHEEL and REL_HWHEEL should be used to report
+scroll wheel events where available.
+
+Touchscreens:
+----------
+ABS_{X,Y} must be reported with the location of the touch. BTN_TOUCH must be
+used to report when a touch is active on the screen.
+BTN_{MOUSE,LEFT,MIDDLE,RIGHT} must not be reported as the result of touch
+contact. BTN_TOOL_<name> events should be reported where possible.
+
+Trackpads:
+----------
+Legacy trackpads that only provide relative position information must report
+events like mice described above.
+
+Trackpads that provide absolute touch position must report ABS_{X,Y} for the
+location of the touch. BTN_TOUCH should be used to report when a touch is active
+on the trackpad. Where multi-finger support is available, BTN_TOOL_<name> should
+be used to report the number of touches active on the trackpad.
+
+Tablets:
+----------
+BTN_TOOL_<name> events must be reported when a stylus or other tool is active on
+the tablet. ABS_{X,Y} must be reported with the location of the tool. BTN_TOUCH
+should be used to report when the tool is in contact with the tablet.
+BTN_{STYLUS,STYLUS2} should be used to report buttons on the tool itself. Any
+button may be used for buttons on the tablet except BTN_{MOUSE,LEFT}.
+BTN_{0,1,2,etc} are good generic codes for unlabeled buttons. Do not use
+meaningful buttons, like BTN_FORWARD, unless the button is labeled for that
+purpose on the device.
diff --git a/Documentation/input/ff.txt b/Documentation/input/ff.txt
index ded4d5f53109..b3867bf49f8f 100644
--- a/Documentation/input/ff.txt
+++ b/Documentation/input/ff.txt
@@ -49,7 +49,9 @@ This information is subject to change.
 #include <linux/input.h>
 #include <sys/ioctl.h>
 
-unsigned long features[1 + FF_MAX/sizeof(unsigned long)];
+#define BITS_TO_LONGS(x) \
+        (((x) + 8 * sizeof (unsigned long) - 1) / (8 * sizeof (unsigned long)))
+unsigned long features[BITS_TO_LONGS(FF_CNT)];
 int ioctl(int file_descriptor, int request, unsigned long *features);
 
 "request" must be EVIOCGBIT(EV_FF, size of features array in bytes )
diff --git a/Documentation/input/joystick-parport.txt b/Documentation/input/joystick-parport.txt
index 1c856f32ff2c..56870c70a796 100644
--- a/Documentation/input/joystick-parport.txt
+++ b/Documentation/input/joystick-parport.txt
@@ -272,7 +272,7 @@ if you want to use gamecon.c.
 
   Also, the connection is a bit more complex. You'll need a bunch of diodes,
 and one pullup resistor. First, you connect the Directions and the button
-the same as for db9, however with the diodes inbetween.
+the same as for db9, however with the diodes between.
 
             Diodes
 (pin 2) -----|<|----> Up
diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
index bdcba154b83e..71536e78406f 100644
--- a/Documentation/input/multi-touch-protocol.txt
+++ b/Documentation/input/multi-touch-protocol.txt
@@ -1,6 +1,6 @@
 Multi-touch (MT) Protocol
 -------------------------
-        Copyright (C) 2009      Henrik Rydberg <rydberg@euromail.se>
+        Copyright (C) 2009-2010 Henrik Rydberg <rydberg@euromail.se>
 
 
 Introduction
@@ -161,19 +161,24 @@ against the glass. The inner region will increase, and in general, the
 ratio ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR, which is always smaller than
 unity, is related to the contact pressure. For pressure-based devices,
 ABS_MT_PRESSURE may be used to provide the pressure on the contact area
-instead.
+instead. Devices capable of contact hovering can use ABS_MT_DISTANCE to
+indicate the distance between the contact and the surface.
 
 In addition to the MAJOR parameters, the oval shape of the contact can be
 described by adding the MINOR parameters, such that MAJOR and MINOR are the
 major and minor axis of an ellipse. Finally, the orientation of the oval
 shape can be describe with the ORIENTATION parameter.
 
+For type A devices, further specification of the touch shape is possible
+via ABS_MT_BLOB_ID.
+
 The ABS_MT_TOOL_TYPE may be used to specify whether the touching tool is a
-contact or a pen or something else.  Devices with more granular information
-may specify general shapes as blobs, i.e., as a sequence of rectangular
-shapes grouped together by an ABS_MT_BLOB_ID. Finally, for the few devices
-that currently support it, the ABS_MT_TRACKING_ID event may be used to
-report contact tracking from hardware [5].
+finger or a pen or something else. Finally, the ABS_MT_TRACKING_ID event
+may be used to track identified contacts over time [5].
+
+In the type B protocol, ABS_MT_TOOL_TYPE and ABS_MT_TRACKING_ID are
+implicitly handled by input core; drivers should instead call
+input_mt_report_slot_state().
 
 
 Event Semantics
@@ -213,6 +218,12 @@ The pressure, in arbitrary units, on the contact area. May be used instead
 of TOUCH and WIDTH for pressure-based devices or any device with a spatial
 signal intensity distribution.
 
+ABS_MT_DISTANCE
+
+The distance, in surface units, between the contact and the surface. Zero
+distance means the contact is touching the surface. A positive number means
+the contact is hovering above the surface.
+
 ABS_MT_ORIENTATION
 
 The orientation of the ellipse. The value should describe a signed quarter
@@ -240,21 +251,24 @@ ABS_MT_TOOL_TYPE
 The type of approaching tool. A lot of kernel drivers cannot distinguish
 between different tool types, such as a finger or a pen. In such cases, the
 event should be omitted. The protocol currently supports MT_TOOL_FINGER and
-MT_TOOL_PEN [2].
+MT_TOOL_PEN [2]. For type B devices, this event is handled by input core;
+drivers should instead use input_mt_report_slot_state().
 
 ABS_MT_BLOB_ID
 
 The BLOB_ID groups several packets together into one arbitrarily shaped
-contact. This is a low-level anonymous grouping for type A devices, and
+contact. The sequence of points forms a polygon which defines the shape of
+the contact. This is a low-level anonymous grouping for type A devices, and
 should not be confused with the high-level trackingID [5]. Most type A
 devices do not have blob capability, so drivers can safely omit this event.
 
 ABS_MT_TRACKING_ID
 
 The TRACKING_ID identifies an initiated contact throughout its life cycle
-[5]. This event is mandatory for type B devices. The value range of the
-TRACKING_ID should be large enough to ensure unique identification of a
-contact maintained over an extended period of time.
+[5]. The value range of the TRACKING_ID should be large enough to ensure
+unique identification of a contact maintained over an extended period of
+time. For type B devices, this event is handled by input core; drivers
+should instead use input_mt_report_slot_state().
 
 
 Event Computation
@@ -301,18 +315,19 @@ and with ORIENTATION, one can detect twisting of fingers.
 Notes
 -----
 
-In order to stay compatible with existing applications, the data
-reported in a finger packet must not be recognized as single-touch
-events. In addition, all finger data must bypass input filtering,
-since subsequent events of the same type refer to different fingers.
+In order to stay compatible with existing applications, the data reported
+in a finger packet must not be recognized as single-touch events.
+
+For type A devices, all finger data bypasses input filtering, since
+subsequent events of the same type refer to different fingers.
 
-The first kernel driver to utilize the MT protocol is the bcm5974 driver,
-where examples can be found.
+For example usage of the type A protocol, see the bcm5974 driver. For
+example usage of the type B protocol, see the hid-egalax driver.
 
 [1] With the extension ABS_MT_APPROACH_X and ABS_MT_APPROACH_Y, the
 difference between the contact position and the approaching tool position
 could be used to derive tilt.
 [2] The list can of course be extended.
-[3] Multitouch X driver project: http://bitmath.org/code/multitouch/.
+[3] The mtdev project: http://bitmath.org/code/mtdev/.
 [4] See the section on event computation.
 [5] See the section on finger tracking.
diff --git a/Documentation/input/ntrig.txt b/Documentation/input/ntrig.txt
new file mode 100644
index 000000000000..be1fd981f73f
--- /dev/null
+++ b/Documentation/input/ntrig.txt
@@ -0,0 +1,126 @@
+N-Trig touchscreen Driver
+-------------------------
+        Copyright (c) 2008-2010 Rafi Rubin <rafi@seas.upenn.edu>
+        Copyright (c) 2009-2010 Stephane Chatty
+
+This driver provides support for N-Trig pen and multi-touch sensors.  Single
+and multi-touch events are translated to the appropriate protocols for
+the hid and input systems.  Pen events are sufficiently hid compliant and
+are left to the hid core.  The driver also provides additional filtering
+and utility functions accessible with sysfs and module parameters.
+
+This driver has been reported to work properly with multiple N-Trig devices
+attached.
+
+
+Parameters
+----------
+
+Note: values set at load time are global and will apply to all applicable
+devices.  Adjusting parameters with sysfs will override the load time values,
+but only for that one device.
+
+The following parameters are used to configure filters to reduce noise:
+
+activate_slack          number of fingers to ignore before processing events
+
+activation_height       size threshold to activate immediately
+activation_width
+
+min_height              size threshold bellow which fingers are ignored
+min_width               both to decide activation and during activity
+
+deactivate_slack        the number of "no contact" frames to ignore before
+                        propagating the end of activity events
+
+When the last finger is removed from the device, it sends a number of empty
+frames.  By holding off on deactivation for a few frames we can tolerate false
+erroneous disconnects, where the sensor may mistakenly not detect a finger that
+is still present.  Thus deactivate_slack addresses problems where a users might
+see breaks in lines during drawing, or drop an object during a long drag.
+
+
+Additional sysfs items
+----------------------
+
+These nodes just provide easy access to the ranges reported by the device.
+sensor_logical_height   the range for positions reported during activity
+sensor_logical_width
+
+sensor_physical_height  internal ranges not used for normal events but
+sensor_physical_width   useful for tuning
+
+All N-Trig devices with product id of 1 report events in the ranges of
+X: 0-9600
+Y: 0-7200
+However not all of these devices have the same physical dimensions.  Most
+seem to be 12" sensors (Dell Latitude XT and XT2 and the HP TX2), and
+at least one model (Dell Studio 17) has a 17" sensor.  The ratio of physical
+to logical sizes is used to adjust the size based filter parameters.
+
+
+Filtering
+---------
+
+With the release of the early multi-touch firmwares it became increasingly
+obvious that these sensors were prone to erroneous events.  Users reported
+seeing both inappropriately dropped contact and ghosts, contacts reported
+where no finger was actually touching the screen.
+
+Deactivation slack helps prevent dropped contact for single touch use, but does
+not address the problem of dropping one of more contacts while other contacts
+are still active.  Drops in the multi-touch context require additional
+processing and should be handled in tandem with tacking.
+
+As observed ghost contacts are similar to actual use of the sensor, but they
+seem to have different profiles.  Ghost activity typically shows up as small
+short lived touches.  As such, I assume that the longer the continuous stream
+of events the more likely those events are from a real contact, and that the
+larger the size of each contact the more likely it is real.  Balancing the
+goals of preventing ghosts and accepting real events quickly (to minimize
+user observable latency), the filter accumulates confidence for incoming
+events until it hits thresholds and begins propagating.  In the interest in
+minimizing stored state as well as the cost of operations to make a decision,
+I've kept that decision simple.
+
+Time is measured in terms of the number of fingers reported, not frames since
+the probability of multiple simultaneous ghosts is expected to drop off
+dramatically with increasing numbers.  Rather than accumulate weight as a
+function of size, I just use it as a binary threshold.  A sufficiently large
+contact immediately overrides the waiting period and leads to activation.
+
+Setting the activation size thresholds to large values will result in deciding
+primarily on activation slack.  If you see longer lived ghosts, turning up the
+activation slack while reducing the size thresholds may suffice to eliminate
+the ghosts while keeping the screen quite responsive to firm taps.
+
+Contacts continue to be filtered with min_height and min_width even after
+the initial activation filter is satisfied.  The intent is to provide
+a mechanism for filtering out ghosts in the form of an extra finger while
+you actually are using the screen.  In practice this sort of ghost has
+been far less problematic or relatively rare and I've left the defaults
+set to 0 for both parameters, effectively turning off that filter.
+
+I don't know what the optimal values are for these filters.  If the defaults
+don't work for you, please play with the parameters.  If you do find other
+values more comfortable, I would appreciate feedback.
+
+The calibration of these devices does drift over time.  If ghosts or contact
+dropping worsen and interfere with the normal usage of your device, try
+recalibrating it.
+
+
+Calibration
+-----------
+
+The N-Trig windows tools provide calibration and testing routines.  Also an
+unofficial unsupported set of user space tools including a calibrator is
+available at:
+http://code.launchpad.net/~rafi-seas/+junk/ntrig_calib
+
+
+Tracking
+--------
+
+As of yet, all tested N-Trig firmwares do not track fingers.  When multiple
+contacts are active they seem to be sorted primarily by Y position.
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt
index 8b4129de1d2d..92e68bce13a4 100644
--- a/Documentation/input/rotary-encoder.txt
+++ b/Documentation/input/rotary-encoder.txt
@@ -9,6 +9,9 @@ peripherals with two wires. The outputs are phase-shifted by 90 degrees
 and by triggering on falling and rising edges, the turn direction can
 be determined.
 
+Some encoders have both outputs low in stable states, whereas others also have
+a stable state with both outputs high (half-period mode).
+
 The phase diagram of these two outputs look like this:
 
                   _____       _____       _____
@@ -26,6 +29,8 @@ The phase diagram of these two outputs look like this:
                 |<-------->|
                   one step
 
+                |<-->|
+                  one step (half-period mode)
 
 For more information, please see
         http://en.wikipedia.org/wiki/Rotary_encoder
@@ -34,6 +39,13 @@ For more information, please see
 1. Events / state machine
 -------------------------
 
+In half-period mode, state a) and c) above are used to determine the
+rotational direction based on the last stable state. Events are reported in
+states b) and d) given that the new stable state is different from the last
+(i.e. the rotation was not reversed half-way).
+
+Otherwise, the following apply:
+
 a) Rising edge on channel A, channel B in low state
         This state is used to recognize a clockwise turn
 
@@ -46,7 +58,7 @@ c) Falling edge on channel A, channel B in high state
 
 d) Falling edge on channel B, channel A in low state
         Parking position. If the encoder enters this state, a full transition
-        should have happend, unless it flipped back on half the way. The
+        should have happened, unless it flipped back on half the way. The
         'armed' state tells us about that.
 
 2. Platform requirements
@@ -96,6 +108,7 @@ static struct rotary_encoder_platform_data my_rotary_encoder_info = {
         .gpio_b         = GPIO_ROTARY_B,
         .inverted_a     = 0,
         .inverted_b     = 0,
+        .half_period    = false,
 };
 
 static struct platform_device rotary_encoder_device = {
diff --git a/Documentation/input/walkera0701.txt b/Documentation/input/walkera0701.txt
index 8f4289efc5c4..561385d38482 100644
--- a/Documentation/input/walkera0701.txt
+++ b/Documentation/input/walkera0701.txt
@@ -77,7 +77,7 @@ pulse length:
 
 24 bin+oct values + 1 bin value = 24*4+1 bits  = 97 bits
 
-(Warning, pulses on ACK ar inverted by transistor, irq is rised up on sync
+(Warning, pulses on ACK are inverted by transistor, irq is raised up on sync
 to bin change or octal value to bin change).
 
 Binary data representations: