Re: [RFC] Input: MT - Include win8 support

[Chase Douglas <chasedouglas@gmail.com>]

On 05/05/2012 08:08 AM, Henrik Rydberg wrote:
> The newly released HID protocol for win8 input devices is capable of
> transmitting the same information found in the Apple HID and Linux MT
> protocols. In addition, it includes an extension useful for touch
> alignment. This patch completes the MT protocol with the
> ABS_MT_APPROACH_X/Y events, and documents how to map win8 devices.
> 
> Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
> ---
> Hi all,
> 
> In response to the win8 HID protocol and Benjamin's work on this, here
> is a first draft of the needed extension to the MT protocol. I am
> cc:ing the usual suspects, as this will affect userland. Comments and
> criticism expected. :-)
> 
> Cheers,
> Henrik
> 
>  Documentation/input/multi-touch-protocol.txt |   35 +++++++++++++++++++++++++-
>  include/linux/input.h                        |    4 ++-
>  2 files changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
> index 543101c..504ca6d 100644
> --- a/Documentation/input/multi-touch-protocol.txt
> +++ b/Documentation/input/multi-touch-protocol.txt

[snip]

> @@ -252,6 +254,9 @@ can distinguish between the two axis, but not (uniquely) any values in
>  between. In such cases, the range of ABS_MT_ORIENTATION should be [0, 1]
>  [4].
>  
> +For devices capable of 360 degree orientation, the reported orientation
> +should be twice the given range.

I don't understand what this means. Can you elaborate?

-- Chase