linux/Documentation/input/sentelic.txt

Copyright (C) 2002-2011 Sentelic Corporation.
Last update: Dec-07-2011

==============================================================================
* Finger Sensing Pad Intellimouse Mode(scrolling wheel, 4th and 5th buttons)
==============================================================================
A) MSID 4: Scrolling wheel mode plus Forward page(4th button) and Backward
   page (5th button)
@1. Set sample rate to 200;
@2. Set sample rate to 200;
@3. Set sample rate to 80;
@4. Issuing the "Get device ID" command (0xF2) and waits for the response;
@5. FSP will respond 0x04.

Packet 1
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |Y|X|y|x|1|M|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 | | |B|F|W|W|W|W|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7 => Y overflow
        Bit6 => X overflow
        Bit5 => Y sign bit
        Bit4 => X sign bit
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X Movement(9-bit 2's complement integers)
Byte 3: Y Movement(9-bit 2's complement integers)
Byte 4: Bit3~Bit0 => the scrolling wheel's movement since the last data report.
                     valid values, -8 ~ +7
        Bit4 => 1 = 4th mouse button is pressed, Forward one page.
                0 = 4th mouse button is not pressed.
        Bit5 => 1 = 5th mouse button is pressed, Backward one page.
                0 = 5th mouse button is not pressed.

B) MSID 6: Horizontal and Vertical scrolling.
@ Set bit 1 in register 0x40 to 1

# FSP replaces scrolling wheel's movement as 4 bits to show horizontal and
  vertical scrolling.

Packet 1
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |Y|X|y|x|1|M|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 | | |B|F|r|l|u|d|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7 => Y overflow
        Bit6 => X overflow
        Bit5 => Y sign bit
        Bit4 => X sign bit
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X Movement(9-bit 2's complement integers)
Byte 3: Y Movement(9-bit 2's complement integers)
Byte 4: Bit0 => the Vertical scrolling movement downward.
	Bit1 => the Vertical scrolling movement upward.
	Bit2 => the Horizontal scrolling movement leftward.
	Bit3 => the Horizontal scrolling movement rightward.
        Bit4 => 1 = 4th mouse button is pressed, Forward one page.
                0 = 4th mouse button is not pressed.
        Bit5 => 1 = 5th mouse button is pressed, Backward one page.
                0 = 5th mouse button is not pressed.

C) MSID 7:
# FSP uses 2 packets (8 Bytes) to represent Absolute Position.
  so we have PACKET NUMBER to identify packets.
  If PACKET NUMBER is 0, the packet is Packet 1.
  If PACKET NUMBER is 1, the packet is Packet 2.
  Please count this number in program.

# MSID6 special packet will be enable at the same time when enable MSID 7.

==============================================================================
* Absolute position for STL3886-G0.
==============================================================================
@ Set bit 2 or 3 in register 0x40 to 1
@ Set bit 6 in register 0x40 to 1

Packet 1 (ABSOLUTE POSITION)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|V|1|1|M|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |r|l|d|u|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
        Bit5 => valid bit
        Bit4 => 1
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
        Bit3~Bit2 => X coordinate (ypos[1:0])
        Bit4 => scroll up
        Bit5 => scroll down
        Bit6 => scroll left
        Bit7 => scroll right

Notify Packet for G0
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |1|0|0|1|1|M|R|L|  2  |C|C|C|C|C|C|C|C|  3 |M|M|M|M|M|M|M|M|  4 |0|0|0|0|0|0|0|0|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
        Bit5 => 0
        Bit4 => 1
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message Type => 0x5A (Enable/Disable status packet)
        Mode Type => 0xA5 (Normal/Icon mode status)
Byte 3: Message Type => 0x00 (Disabled)
                     => 0x01 (Enabled)
        Mode Type    => 0x00 (Normal)
                     => 0x01 (Icon)
Byte 4: Bit7~Bit0 => Don't Care

==============================================================================
* Absolute position for STL3888-Ax.
==============================================================================
Packet 1 (ABSOLUTE POSITION)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|V|A|1|L|0|1|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |x|x|y|y|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
                When both fingers are up, the last two reports have zero valid
                bit.
        Bit4 => arc
        Bit3 => 1
        Bit2 => Left Button, 1 is pressed, 0 is released.
        Bit1 => 0
        Bit0 => 1
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
        Bit3~Bit2 => X coordinate (ypos[1:0])
        Bit5~Bit4 => y1_g
        Bit7~Bit6 => x1_g

Packet 2 (ABSOLUTE POSITION)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|V|A|1|R|1|0|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |x|x|y|y|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordinates packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
                When both fingers are up, the last two reports have zero valid
                bit.
        Bit4 => arc
        Bit3 => 1
        Bit2 => Right Button, 1 is pressed, 0 is released.
        Bit1 => 1
        Bit0 => 0
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
        Bit3~Bit2 => X coordinate (ypos[1:0])
        Bit5~Bit4 => y2_g
        Bit7~Bit6 => x2_g

Notify Packet for STL3888-Ax
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |1|0|1|P|1|M|R|L|  2  |C|C|C|C|C|C|C|C|  3 |0|0|F|F|0|0|0|i|  4 |r|l|d|u|0|0|0|0|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordinates packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => 1
        Bit4 => when in absolute coordinates mode (valid when EN_PKT_GO is 1):
                0: left button is generated by the on-pad command
                1: left button is generated by the external button
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message Type => 0xB7 (Multi Finger, Multi Coordinate mode)
Byte 3: Bit7~Bit6 => Don't care
        Bit5~Bit4 => Number of fingers
        Bit3~Bit1 => Reserved
        Bit0 => 1: enter gesture mode; 0: leaving gesture mode
Byte 4: Bit7 => scroll right button
        Bit6 => scroll left button
        Bit5 => scroll down button
        Bit4 => scroll up button
            * Note that if gesture and additional button (Bit4~Bit7)
              happen at the same time, the button information will not
              be sent.
        Bit3~Bit0 => Reserved

Sample sequence of Multi-finger, Multi-coordinate mode:

	notify packet (valid bit == 1), abs pkt 1, abs pkt 2, abs pkt 1,
	abs pkt 2, ..., notify packet (valid bit == 0)

==============================================================================
* Absolute position for STL3888-B0.
==============================================================================
Packet 1(ABSOLUTE POSITION)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|V|F|1|0|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |r|l|u|d|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordinates packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
                When both fingers are up, the last two reports have zero valid
                bit.
        Bit4 => finger up/down information. 1: finger down, 0: finger up.
        Bit3 => 1
        Bit2 => finger index, 0 is the first finger, 1 is the second finger.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
        Bit3~Bit2 => X coordinate (ypos[1:0])
        Bit4 => scroll down button
        Bit5 => scroll up button
        Bit6 => scroll left button
        Bit7 => scroll right button

Packet 2 (ABSOLUTE POSITION)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|V|F|1|1|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |r|l|u|d|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => Valid bit, 0 means that the coordinate is invalid or finger up.
                When both fingers are up, the last two reports have zero valid
                bit.
        Bit4 => finger up/down information. 1: finger down, 0: finger up.
        Bit3 => 1
        Bit2 => finger index, 0 is the first finger, 1 is the second finger.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
        Bit3~Bit2 => X coordinate (ypos[1:0])
        Bit4 => scroll down button
        Bit5 => scroll up button
        Bit6 => scroll left button
        Bit7 => scroll right button

Notify Packet for STL3888-B0
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |1|0|1|P|1|M|R|L|  2  |C|C|C|C|C|C|C|C|  3 |0|0|F|F|0|0|0|i|  4 |r|l|u|d|0|0|0|0|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
                  => 11, Normal data packet with on-pad click
        Bit5 => 1
        Bit4 => when in absolute coordinates mode (valid when EN_PKT_GO is 1):
                0: left button is generated by the on-pad command
                1: left button is generated by the external button
        Bit3 => 1
        Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
        Bit1 => Right Button, 1 is pressed, 0 is not pressed.
        Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message Type => 0xB7 (Multi Finger, Multi Coordinate mode)
Byte 3: Bit7~Bit6 => Don't care
        Bit5~Bit4 => Number of fingers
        Bit3~Bit1 => Reserved
        Bit0 => 1: enter gesture mode; 0: leaving gesture mode
Byte 4: Bit7 => scroll right button
        Bit6 => scroll left button
        Bit5 => scroll up button
        Bit4 => scroll down button
            * Note that if gesture and additional button(Bit4~Bit7)
              happen at the same time, the button information will not
              be sent.
        Bit3~Bit0 => Reserved

Sample sequence of Multi-finger, Multi-coordinate mode:

	notify packet (valid bit == 1), abs pkt 1, abs pkt 2, abs pkt 1,
	abs pkt 2, ..., notify packet (valid bit == 0)

==============================================================================
* Absolute position for STL3888-Cx and STL3888-Dx.
==============================================================================
Single Finger, Absolute Coordinate Mode (SFAC)
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|0|P|1|M|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |r|l|B|F|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordinates packet
                  => 10, Notify packet
	Bit5 => Coordinate mode(always 0 in SFAC mode):
		0: single-finger absolute coordinates (SFAC) mode
		1: multi-finger, multiple coordinates (MFMC) mode
	Bit4 => 0: The LEFT button is generated by on-pad command (OPC)
		1: The LEFT button is generated by external button
		Default is 1 even if the LEFT button is not pressed.
	Bit3 => Always 1, as specified by PS/2 protocol.
	Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
	Bit1 => Right Button, 1 is pressed, 0 is not pressed.
	Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
	Bit3~Bit2 => X coordinate (ypos[1:0])
	Bit4 => 4th mouse button(forward one page)
	Bit5 => 5th mouse button(backward one page)
	Bit6 => scroll left button
	Bit7 => scroll right button

Multi Finger, Multiple Coordinates Mode (MFMC):
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |0|1|1|P|1|F|R|L|  2  |X|X|X|X|X|X|X|X|  3 |Y|Y|Y|Y|Y|Y|Y|Y|  4 |r|l|B|F|X|X|Y|Y|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordination packet
                  => 10, Notify packet
	Bit5 => Coordinate mode (always 1 in MFMC mode):
		0: single-finger absolute coordinates (SFAC) mode
		1: multi-finger, multiple coordinates (MFMC) mode
	Bit4 => 0: The LEFT button is generated by on-pad command (OPC)
		1: The LEFT button is generated by external button
		Default is 1 even if the LEFT button is not pressed.
	Bit3 => Always 1, as specified by PS/2 protocol.
	Bit2 => Finger index, 0 is the first finger, 1 is the second finger.
		If bit 1 and 0 are all 1 and bit 4 is 0, the middle external
		button is pressed.
	Bit1 => Right Button, 1 is pressed, 0 is not pressed.
	Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: X coordinate (xpos[9:2])
Byte 3: Y coordinate (ypos[9:2])
Byte 4: Bit1~Bit0 => Y coordinate (xpos[1:0])
	Bit3~Bit2 => X coordinate (ypos[1:0])
	Bit4 => 4th mouse button(forward one page)
	Bit5 => 5th mouse button(backward one page)
	Bit6 => scroll left button
	Bit7 => scroll right button

  When one of the two fingers is up, the device will output four consecutive
MFMC#0 report packets with zero X and Y to represent 1st finger is up or
four consecutive MFMC#1 report packets with zero X and Y to represent that
the 2nd finger is up.  On the other hand, if both fingers are up, the device
will output four consecutive single-finger, absolute coordinate(SFAC) packets
with zero X and Y.

Notify Packet for STL3888-Cx/Dx
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |1|0|0|P|1|M|R|L|  2  |C|C|C|C|C|C|C|C|  3 |0|0|F|F|0|0|0|i|  4 |r|l|u|d|0|0|0|0|
      |---------------|     |---------------|    |---------------|    |---------------|

Byte 1: Bit7~Bit6 => 00, Normal data packet
                  => 01, Absolute coordinates packet
                  => 10, Notify packet
	Bit5 => Always 0
	Bit4 => 0: The LEFT button is generated by on-pad command(OPC)
		1: The LEFT button is generated by external button
		Default is 1 even if the LEFT button is not pressed.
	Bit3 => 1
	Bit2 => Middle Button, 1 is pressed, 0 is not pressed.
	Bit1 => Right Button, 1 is pressed, 0 is not pressed.
	Bit0 => Left Button, 1 is pressed, 0 is not pressed.
Byte 2: Message type:
	0xba => gesture information
	0xc0 => one finger hold-rotating gesture
Byte 3: The first parameter for the received message:
	0xba => gesture ID (refer to the 'Gesture ID' section)
	0xc0 => region ID
Byte 4: The second parameter for the received message:
	0xba => N/A
	0xc0 => finger up/down information

Sample sequence of Multi-finger, Multi-coordinates mode:

	notify packet (valid bit == 1), MFMC packet 1 (byte 1, bit 2 == 0),
	MFMC packet 2 (byte 1, bit 2 == 1), MFMC packet 1, MFMC packet 2,
	..., notify packet (valid bit == 0)

	That is, when the device is in MFMC mode, the host will receive
	interleaved absolute coordinate packets for each finger.

==============================================================================
* FSP Enable/Disable packet
==============================================================================
   Bit 7 6 5 4 3 2 1 0       7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0      7 6 5 4 3 2 1 0
BYTE  |---------------|BYTE |---------------|BYTE|---------------|BYTE|---------------|
  1   |Y|X|0|0|1|M|R|L|  2  |0|1|0|1|1|0|1|E|  3 | | | | | | | | |  4 | | | | | | | | |
      |---------------|     |---------------|    |---------------|    |---------------|

FSP will send out enable/disable packet when FSP receive PS/2 enable/disable
command. Host will receive the packet which Middle, Right, Left button will
be set. The packet only use byte 0 and byte 1 as a pattern of original packet.
Ignore the other bytes of the packet.

Byte 1: Bit7 => 0, Y overflow
        Bit6 => 0, X overflow
	Bit5 => 0, Y sign bit
        Bit4 => 0, X sign bit
	Bit3 => 1
	Bit2 => 1, Middle Button
        Bit1 => 1, Right Button
        Bit0 => 1, Left Button
Byte 2: Bit7~1 => (0101101b)
        Bit0 => 1 = Enable
		0 = Disable
Byte 3: Don't care
Byte 4: Don't care (MOUSE ID 3, 4)
Byte 5~8: Don't care (Absolute packet)

==============================================================================
* PS/2 Command Set
==============================================================================

FSP supports basic PS/2 commanding set and modes, refer to following URL for
details about PS/2 commands:

http://www.computer-engineering.org/ps2mouse/

==============================================================================
* Programming Sequence for Determining Packet Parsing Flow
==============================================================================
1. Identify FSP by reading device ID(0x00) and version(0x01) register

2a. For FSP version < STL3888 Cx, determine number of buttons by reading
    the 'test mode status' (0x20) register:

	buttons = reg[0x20] & 0x30

	if buttons == 0x30 or buttons == 0x20:
		# two/four buttons
		Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
		section A for packet parsing detail(ignore byte 4, bit ~ 7)
	elif buttons == 0x10:
		# 6 buttons
		Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
		section B for packet parsing detail
	elif buttons == 0x00:
		# 6 buttons
		Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
		section A for packet parsing detail

2b. For FSP version >= STL3888 Cx:
	Refer to 'Finger Sensing Pad PS/2 Mouse Intellimouse'
	section A for packet parsing detail (ignore byte 4, bit ~ 7)

==============================================================================
* Programming Sequence for Register Reading/Writing
==============================================================================

Register inversion requirement:

  Following values needed to be inverted(the '~' operator in C) before being
sent to FSP:

	0xe8, 0xe9, 0xee, 0xf2, 0xf3 and 0xff.

Register swapping requirement:

  Following values needed to have their higher 4 bits and lower 4 bits being
swapped before being sent to FSP:

	10, 20, 40, 60, 80, 100 and 200.

Register reading sequence:

	1. send 0xf3 PS/2 command to FSP;

	2. send 0x66 PS/2 command to FSP;

	3. send 0x88 PS/2 command to FSP;

	4. send 0xf3 PS/2 command to FSP;

	5. if the register address being to read is not required to be
	inverted(refer to the 'Register inversion requirement' section),
	goto step 6

	5a. send 0x68 PS/2 command to FSP;

	5b. send the inverted register address to FSP and goto step 8;

	6. if the register address being to read is not required to be
	swapped(refer to the 'Register swapping requirement' section),
	goto step 7

	6a. send 0xcc PS/2 command to FSP;

	6b. send the swapped register address to FSP and goto step 8;

	7. send 0x66 PS/2 command to FSP;

	7a. send the original register address to FSP and goto step 8;

	8. send 0xe9(status request) PS/2 command to FSP;

	9. the 4th byte of the response read from FSP should be the
	requested register value(?? indicates don't care byte):

		host: 0xe9
		3888: 0xfa (??) (??) (val)

	* Note that since the Cx release, the hardware will return 1's
	complement of the register value at the 3rd byte of status request
	result:

		host: 0xe9
		3888: 0xfa (??) (~val) (val)

Register writing sequence:

	1. send 0xf3 PS/2 command to FSP;

	2. if the register address being to write is not required to be
	inverted(refer to the 'Register inversion requirement' section),
	goto step 3

	2a. send 0x74 PS/2 command to FSP;

	2b. send the inverted register address to FSP and goto step 5;

	3. if the register address being to write is not required to be
	swapped(refer to the 'Register swapping requirement' section),
	goto step 4

	3a. send 0x77 PS/2 command to FSP;

	3b. send the swapped register address to FSP and goto step 5;

	4. send 0x55 PS/2 command to FSP;

	4a. send the register address to FSP and goto step 5;

	5. send 0xf3 PS/2 command to FSP;

	6. if the register value being to write is not required to be
	inverted(refer to the 'Register inversion requirement' section),
	goto step 7

	6a. send 0x47 PS/2 command to FSP;

	6b. send the inverted register value to FSP and goto step 9;

	7. if the register value being to write is not required to be
	swapped(refer to the 'Register swapping requirement' section),
	goto step 8

	7a. send 0x44 PS/2 command to FSP;

	7b. send the swapped register value to FSP and goto step 9;

	8. send 0x33 PS/2 command to FSP;

	8a. send the register value to FSP;

	9. the register writing sequence is completed.

	* Note that since the Cx release, the hardware will return 1's
	complement of the register value at the 3rd byte of status request
	result. Host can optionally send another 0xe9 (status request) PS/2
	command to FSP at the end of register writing to verify that the
	register writing operation is successful (?? indicates don't care
	byte):

		host: 0xe9
		3888: 0xfa (??) (~val) (val)

==============================================================================
* Programming Sequence for Page Register Reading/Writing
==============================================================================

  In order to overcome the limitation of maximum number of registers
supported, the hardware separates register into different groups called
'pages.' Each page is able to include up to 255 registers.

  The default page after power up is 0x82; therefore, if one has to get
access to register 0x8301, one has to use following sequence to switch
to page 0x83, then start reading/writing from/to offset 0x01 by using
the register read/write sequence described in previous section.

Page register reading sequence:

	1. send 0xf3 PS/2 command to FSP;

	2. send 0x66 PS/2 command to FSP;

	3. send 0x88 PS/2 command to FSP;

	4. send 0xf3 PS/2 command to FSP;

	5. send 0x83 PS/2 command to FSP;

	6. send 0x88 PS/2 command to FSP;

	7. send 0xe9(status request) PS/2 command to FSP;

	8. the response read from FSP should be the requested page value.

Page register writing sequence:

	1. send 0xf3 PS/2 command to FSP;

	2. send 0x38 PS/2 command to FSP;

	3. send 0x88 PS/2 command to FSP;

	4. send 0xf3 PS/2 command to FSP;

	5. if the page address being written is not required to be
	inverted(refer to the 'Register inversion requirement' section),
	goto step 6

	5a. send 0x47 PS/2 command to FSP;

	5b. send the inverted page address to FSP and goto step 9;

	6. if the page address being written is not required to be
	swapped(refer to the 'Register swapping requirement' section),
	goto step 7

	6a. send 0x44 PS/2 command to FSP;

	6b. send the swapped page address to FSP and goto step 9;

	7. send 0x33 PS/2 command to FSP;

	8. send the page address to FSP;

	9. the page register writing sequence is completed.

==============================================================================
* Gesture ID
==============================================================================

  Unlike other devices which sends multiple fingers' coordinates to host,
FSP processes multiple fingers' coordinates internally and convert them
into a 8 bits integer, namely 'Gesture ID.'  Following is a list of
supported gesture IDs:

	ID	Description
	0x86	2 finger straight up
	0x82	2 finger straight down
	0x80	2 finger straight right
	0x84	2 finger straight left
	0x8f	2 finger zoom in
	0x8b	2 finger zoom out
	0xc0	2 finger curve, counter clockwise
	0xc4	2 finger curve, clockwise
	0x2e	3 finger straight up
	0x2a	3 finger straight down
	0x28	3 finger straight right
	0x2c	3 finger straight left
	0x38	palm

==============================================================================
* Register Listing
==============================================================================

  Registers are represented in 16 bits values. The higher 8 bits represent
the page address and the lower 8 bits represent the relative offset within
that particular page.  Refer to the 'Programming Sequence for Page Register
Reading/Writing' section for instructions on how to change current page
address.

offset	width		default	r/w	name
0x8200	bit7~bit0	0x01	RO	device ID

0x8201	bit7~bit0		RW	version ID
					0xc1: STL3888 Ax
					0xd0 ~ 0xd2: STL3888 Bx
					0xe0 ~ 0xe1: STL3888 Cx
					0xe2 ~ 0xe3: STL3888 Dx

0x8202	bit7~bit0	0x01	RO	vendor ID

0x8203	bit7~bit0	0x01	RO	product ID

0x8204	bit3~bit0	0x01	RW	revision ID

0x820b					test mode status 1
	bit3		1	RO	0: rotate 180 degree
					1: no rotation
					*only supported by H/W prior to Cx

0x820f					register file page control
	bit2		0	RW	1: rotate 180 degree
					0: no rotation
					*supported since Cx

	bit0		0	RW	1 to enable page 1 register files
					*only supported by H/W prior to Cx

0x8210				RW	system control 1
	bit0		1	RW	Reserved, must be 1
	bit1		0	RW	Reserved, must be 0
	bit4		0	RW	Reserved, must be 0
	bit5		1	RW	register clock gating enable
					0: read only, 1: read/write enable
	(Note that following registers does not require clock gating being
	enabled prior to write: 05 06 07 08 09 0c 0f 10 11 12 16 17 18 23 2e
	40 41 42 43.  In addition to that, this bit must be 1 when gesture
	mode is enabled)

0x8220					test mode status
	bit5~bit4		RO	number of buttons
					11 => 2, lbtn/rbtn
					10 => 4, lbtn/rbtn/scru/scrd
					01 => 6, lbtn/rbtn/scru/scrd/scrl/scrr
					00 => 6, lbtn/rbtn/scru/scrd/fbtn/bbtn
					*only supported by H/W prior to Cx

0x8231				RW	on-pad command detection
	bit7		0	RW	on-pad command left button down tag
					enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

0x8234				RW	on-pad command control 5
	bit4~bit0	0x05	RW	XLO in 0s/4/1, so 03h = 0010.1b = 2.5
	(Note that position unit is in 0.5 scanline)
					*only supported by H/W prior to Cx

	bit7		0	RW	on-pad tap zone enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

0x8235				RW	on-pad command control 6
	bit4~bit0	0x1d	RW	XHI in 0s/4/1, so 19h = 1100.1b = 12.5
	(Note that position unit is in 0.5 scanline)
					*only supported by H/W prior to Cx

0x8236				RW	on-pad command control 7
	bit4~bit0	0x04	RW	YLO in 0s/4/1, so 03h = 0010.1b = 2.5
	(Note that position unit is in 0.5 scanline)
					*only supported by H/W prior to Cx

0x8237				RW	on-pad command control 8
	bit4~bit0	0x13	RW	YHI in 0s/4/1, so 11h = 1000.1b = 8.5
	(Note that position unit is in 0.5 scanline)
					*only supported by H/W prior to Cx

0x8240				RW	system control 5
	bit1		0	RW	FSP Intellimouse mode enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

	bit2		0	RW	movement + abs. coordinate mode enable
					0: disable, 1: enable
	(Note that this function has the functionality of bit 1 even when
	bit 1 is not set. However, the format is different from that of bit 1.
	In addition, when bit 1 and bit 2 are set at the same time, bit 2 will
	override bit 1.)
					*only supported by H/W prior to Cx

	bit3		0	RW	abs. coordinate only mode enable
					0: disable, 1: enable
	(Note that this function has the functionality of bit 1 even when
	bit 1 is not set. However, the format is different from that of bit 1.
	In addition, when bit 1, bit 2 and bit 3 are set at the same time,
	bit 3 will override bit 1 and 2.)
					*only supported by H/W prior to Cx

	bit5		0	RW	auto switch enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

	bit6		0	RW	G0 abs. + notify packet format enable
					0: disable, 1: enable
	(Note that the absolute/relative coordinate output still depends on
	bit 2 and 3.  That is, if any of those bit is 1, host will receive
	absolute coordinates; otherwise, host only receives packets with
	relative coordinate.)
					*only supported by H/W prior to Cx

	bit7		0	RW	EN_PS2_F2: PS/2 gesture mode 2nd
					finger packet enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

0x8243				RW	on-pad control
	bit0		0	RW	on-pad control enable
					0: disable, 1: enable
	(Note that if this bit is cleared, bit 3/5 will be ineffective)
					*only supported by H/W prior to Cx

	bit3		0	RW	on-pad fix vertical scrolling enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

	bit5		0	RW	on-pad fix horizontal scrolling enable
					0: disable, 1: enable
					*only supported by H/W prior to Cx

0x8290				RW	software control register 1
	bit0		0	RW	absolute coordination mode
					0: disable, 1: enable
					*supported since Cx

	bit1		0	RW	gesture ID output
					0: disable, 1: enable
					*supported since Cx

	bit2		0	RW	two fingers' coordinates output
					0: disable, 1: enable
					*supported since Cx

	bit3		0	RW	finger up one packet output
					0: disable, 1: enable
					*supported since Cx

	bit4		0	RW	absolute coordination continuous mode
					0: disable, 1: enable
					*supported since Cx

	bit6~bit5	00	RW	gesture group selection
					00: basic
					01: suite
					10: suite pro
					11: advanced
					*supported since Cx

	bit7		0	RW	Bx packet output compatible mode
					0: disable, 1: enable					*supported since Cx
					*supported since Cx


0x833d				RW	on-pad command control 1
	bit7		1	RW	on-pad command detection enable
					0: disable, 1: enable
					*supported since Cx

0x833e				RW	on-pad command detection
	bit7		0	RW	on-pad command left button down tag
					enable. Works only in H/W based PS/2
					data packet mode.
					0: disable, 1: enable
					*supported since Cx