Touch Panel

Overview

The touch driver allows the process to interract with a touch panel.

Command

• Command number: 0

  Description: Does the driver exist?

  Argument 1: unused

  Argument 2: unused

  Returns: Success if it exists, otherwise NODEVICE

• Command number: 1

  Description: Enable the single touch function of the panel. This will enable the touch panel if at least one app enables it.

  Argument 1: unused

  Argument 2: unused

  Returns: Ok(())

• Command number: 2

  Description: Disable the single touch function of panel. This will disable the touch panel if all apps disable it.

  Argument 1: unused

  Argument 2: unused

  Returns: Ok(())

• Command number: 10

  Description: Acknowledge that the multi touch buffer has been read. Multi touch events are reported by filling a previously allows_readwrite buffer. When receving a callback with the notification for a multi touch event, the app must acknowledge it before it can recevie another callback.

  Argument 1: unused

  Argument 2: unused

  Returns: Ok(())

• Command number: 11

  Description: Enable the multi touch function of the panel. This will enable the touch panel if at least one app enables it.

  Argument 1: unused

  Argument 2: unused

  Returns: Ok(())

• Command number: 12

  Description: Disable the multi touch function of panel. This will disable the touch panel if all apps disable it.

  Argument 1: unused

  Argument 2: unused

  Returns: Ok(())

• Command number: 100

  Description: Get the number of touch points available

  Argument 1: unused

  Argument 2: unused

  Returns: SUCCESS_U32 with U32 being the number of available touches

Subscribe

• Subscribe number: 0

  Description: Subscribe to single touch.

  Callback signature:

  • data1: status
  • data2: x (16 bit LE) | y (16 bit LE)
  • data3: pressure (16 bit LE) | area (16 bit LE)

  Returns: Ok(()) if the subscribe was successful.

• Subscribe number: 1

  Description: Subscribe to gestures.

  Callback signature:

  • data1: gesture

  Returns: Ok(()) if the subscribe was successful.

• Subscribe number: 2

  Description: Subscribe to multi touch events.

  Callback signature:

  • data1: number of touch events
  • data2: number of dropped callback (ack sent too slow?)
  • data3: number of dropped touch events (shared buffer too small?)

  Returns: Ok(()) if the subscribe was successful.

Allow ReadWrite

• Allow number: 0

  Description: Buffer to write multi touch events

  Buffer format:

  Copy

  0         1           2                  4                  6           7             8         ...
  +---------+-----------+------------------+------------------+-----------+---------------+--------- ...
  | id (u8) | type (u8) | x (u16)          | y (u16)          | size (u8) | pressure (u8) |          ...
  +---------+-----------+------------------+------------------+-----------+---------------+--------- ...
  | Touch 0                                                                               | Touch 1  ...
  

  Returns: Ok(()) if the subscribe was successful, INVAL if the buffer's length is not a multiple of the color depth length.