Sentelic Touchpad

Intellimouse MSID 4·6·7 모드

이 문서는 Sentelic Finger Sensing Pad(FSP) 터치패드의 PS/2 패킷과 프로그래밍 절차를 설명하며 마지막 갱신일은 2011년 12월 7일입니다. 첫 절은 스크롤 휠과 4·5번 버튼을 포함한 Intellimouse 호환 모드를 다룹니다.

MSID 4를 선택하려면 sample rate를 200, 200, 80 순서로 설정한 뒤 `Get device ID` 명령 `0xF2`를 보내 응답을 기다립니다. FSP가 `0x04`를 반환하면 4바이트 패킷에서 상대 X/Y, 세 기본 버튼, 휠 이동, 앞으로·뒤로 버튼을 읽습니다.

MSID 6은 레지스터 `0x40` bit 1을 1로 설정합니다. 첫 세 바이트는 MSID 4와 같고, byte 4의 하위 네 비트가 휠 수치 대신 아래·위·왼쪽·오른쪽 스크롤 버튼을 각각 나타냅니다. bit 4와 5는 계속 Forward와 Backward 버튼입니다.

MSID 7은 절대 위치 하나를 4바이트 패킷 두 개, 총 8바이트로 표현합니다. 프로그램이 packet number 0과 1을 직접 세어 Packet 1과 Packet 2를 구분해야 합니다. MSID 7을 활성화하면 MSID 6의 special packet도 동시에 활성화됩니다.

.. include:: <isonum.txt>

=================
Sentelic Touchpad
=================


:Copyright: |copy| 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.

STL3886-G0와 STL3888-Ax 절대 좌표

STL3886-G0 절대 위치는 레지스터 `0x40`의 bit 2 또는 3을 1로 하고 bit 6도 1로 설정합니다. byte 1의 상위 두 비트는 `00` normal, `01` absolute coordinate, `10` notify를 구분하고 bit 5는 valid입니다.

STL3888-Ax는 두 절대 좌표 패킷을 번갈아 보내며 Packet 1은 왼쪽 버튼과 첫 좌표 보조값 `x1_g`, `y1_g`, Packet 2는 오른쪽 버튼과 `x2_g`, `y2_g`를 담습니다. byte 1의 `01`은 absolute, `10`은 notify, `11`은 on-pad click을 포함한 normal packet입니다.

두 손가락을 모두 떼면 마지막 두 report의 valid bit가 0입니다. Ax notify의 byte 2 `0xB7`은 Multi Finger, Multi Coordinate 모드이고 byte 3 bits 5~4는 손가락 수, bit 0은 gesture mode 진입 1 또는 이탈 0입니다.

Absolute position for STL3886-G0
================================

1. Set bit 2 or 3 in register 0x40 to 1
2. 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)

STL3888-B0 손가락 인덱스와 통지

STL3888-B0의 Packet 1과 Packet 2는 같은 비트 배치를 사용하지만 byte 1 bit 2의 finger index가 각각 0과 1입니다. bit 5는 좌표 valid, bit 4는 finger down 1 또는 finger up 0이며 bits 1·0은 Right와 Left 버튼입니다.

두 손가락을 모두 떼면 마지막 두 report의 valid bit가 0입니다. B0 notify는 byte 2 `0xB7`, byte 3 bits 5~4의 손가락 수, bit 0의 gesture 진입·이탈을 사용합니다. byte 4의 추가 버튼 순서는 right, left, up, down이며 Ax와 down/up 순서가 다릅니다.

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)

STL3888-Cx·Dx SFAC와 MFMC 패킷

Cx와 Dx는 single-finger absolute coordinate(SFAC)와 multi-finger multiple coordinates(MFMC)를 byte 1 bit 5로 구분합니다. SFAC에서는 bit 5가 항상 0이고 bit 2는 Middle 버튼입니다. MFMC에서는 bit 5가 항상 1이고 bit 2는 first/second finger index입니다.

Byte 1 bit 4가 0이면 LEFT는 on-pad command(OPC), 1이면 external button에서 생성됩니다. 기본값은 LEFT를 누르지 않아도 1입니다. MFMC에서 bit 1과 0이 모두 1이고 bit 4가 0이면 외부 middle 버튼이 눌린 것으로 해석합니다.

한 손가락만 떼면 해당 finger index의 MFMC 패킷을 X=0, Y=0으로 네 번 연속 보냅니다. 첫 손가락은 MFMC#0, 둘째는 MFMC#1입니다. 두 손가락을 모두 떼면 X=0, Y=0인 SFAC 패킷을 네 번 연속 보냅니다.

Notify byte 1 bit 5는 항상 0이고 bit 4는 LEFT 출처, bits 2~0은 Middle·Right·Left 버튼입니다. MFMC 모드에서 호스트는 finger index 0과 1의 절대 좌표 패킷을 교차 수신합니다.

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 통지와 PS/2 명령 집합

FSP는 PS/2 enable 또는 disable 명령을 받으면 전용 패킷을 보냅니다. 이 패킷은 원래 형식의 byte 1과 byte 2만 패턴으로 사용하므로 나머지 바이트는 무시해야 합니다.

FSP는 기본 PS/2 명령 집합과 모드를 지원합니다. 상세 PS/2 명령은 원문 참조 주소 `http://www.computer-engineering.org/ps2mouse/`에 연결되어 있습니다.

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/

패킷 형식 결정과 레지스터 읽기·쓰기

패킷 파싱을 결정할 때 먼저 register `0x00`의 device ID와 `0x01`의 version을 읽어 FSP를 식별합니다. STL3888 Cx보다 오래된 버전은 test mode status `0x20`의 bits `0x30`으로 버튼 구성을 판별하고, Cx 이상은 Intellimouse section A 형식을 사용하면서 byte 4 bits 4~7을 무시합니다.

레지스터 읽기는 고정 접두 명령 `0xF3, 0x66, 0x88, 0xF3` 뒤 주소의 변환 종류에 따라 분기합니다. 반전 대상이면 `0x68`과 반전 주소, swap 대상이면 `0xCC`와 swap 주소, 일반 주소면 `0x66`과 원본 주소를 보냅니다. 마지막 `0xE9` status request 응답의 네 번째 바이트가 값입니다.

Cx 이후 하드웨어는 status request 응답의 세 번째 바이트에 register value의 1의 보수 `~val`, 네 번째 바이트에 `val`을 반환합니다. 형식은 ACK `0xFA`, don't-care, `~val`, `val`입니다.

레지스터 쓰기는 먼저 주소를 인코딩하고 다시 값을 인코딩합니다. 주소는 반전이면 `0x74`, swap이면 `0x77`, 일반이면 `0x55`를 사용합니다. 이어 `0xF3` 뒤 값은 반전이면 `0x47`, swap이면 `0x44`, 일반이면 `0x33`을 사용해 전송합니다.

Programming Sequence for Determining Packet Parsing Flow
========================================================

1. Identify FSP by reading device ID(0x00) and version(0x01) register

2. 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

3. 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

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

          b. 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

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

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

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

          a. 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

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

          b. 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

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

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

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

          a. 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

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

          b. 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

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

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

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

          a. send the register value to FSP;

        9. the register writing sequence is completed.

        * 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)

페이지 레지스터 전환과 Gesture ID

하드웨어는 최대 레지스터 수 제한을 넘기 위해 레지스터를 page 그룹으로 나눕니다. 각 page는 최대 255개 레지스터를 포함합니다. 전원 인가 후 기본 page는 `0x82`이며, 예를 들어 `0x8301`에 접근하려면 먼저 page를 `0x83`으로 바꾸고 offset `0x01`을 앞 절의 일반 읽기·쓰기 절차로 처리합니다.

Page 쓰기는 접두 `0xF3, 0x38, 0x88, 0xF3` 뒤 page 주소를 변환해 보냅니다. 반전 대상이면 `0x47`과 반전 주소, swap 대상이면 `0x44`와 swap 주소, 일반 주소면 `0x33` 뒤 원본 page 주소를 보냅니다.

일부 장치처럼 여러 손가락 좌표를 호스트에 그대로 보내는 대신, FSP는 내부에서 다중 손가락 좌표를 처리해 8비트 정수 Gesture ID로 변환할 수 있습니다.

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

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

          b. 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

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

          b. 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
        ======= ==================================

16비트 레지스터 주소와 Cx 이전 제어

레지스터는 16비트 값으로 표기하며 상위 8비트가 page 주소, 하위 8비트가 그 page 내부 offset입니다. 따라서 `0x8200`은 page `0x82`의 offset `0x00`이고, 다른 page를 쓰려면 앞 절의 page 전환 절차가 필요합니다.

Clock gating bit를 먼저 켜지 않아도 쓸 수 있는 예외 register offset은 `05 06 07 08 09 0c 0f 10 11 12 16 17 18 23 2e 40 41 42 43`입니다. Gesture mode가 켜진 동안에는 `0x8210` bit 5가 반드시 1이어야 합니다.

Bit 6은 패킷 형식만 선택하며 실제 absolute 또는 relative 출력은 bits 2·3에 달려 있습니다. 둘 중 하나가 1이면 절대 좌표를 받고, 모두 0이면 상대 좌표만 받습니다.

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

On-pad 제어와 Cx 이후 software control

`0x8243` bit 0이 0이면 bits 3과 5는 효과가 없습니다. 이 레지스터의 기능은 Cx 이전 하드웨어에만 해당합니다.

Page `0x83`의 `0x833D` bit 7은 Cx 이후 on-pad command detection을 활성화하며 기본값은 1입니다. `0x833E` bit 7은 on-pad command의 left-button-down tag를 활성화하지만 hardware-based PS/2 data packet mode에서만 동작합니다.

 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