kbdif: Define "feature-raw-pointer" and "request-raw-pointer"

Backends set "feature-raw-pointer" if its capable of reporting
absolute positions without scaling the coordinates to screen
size. This should be set during the backend init.
Frontends set "request-raw-pointer" to request that backends
do not rescale absolute coordinates to screen size, and the
coordinates remain in the range [0, 0x7fff]. This request is
only applicable if "request-abs-pointer" is also set. Frontends
should set this value before setting Connected.

Signed-off-by: Owen Smith <owen.smith@citrix.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

xen/include/public/io/kbdif.h

@@ -63,6 +63,13 @@
  *      Backends, which support reporting of multi-touch events
  *      should set this to 1.
  *
+ * feature-raw-pointer
+ *      Values:        <uint>
+ *
+ *      Backends, which support reporting raw (unscaled) absolute coordinates
+ *      for pointer devices should set this to 1. Raw (unscaled) values have
+ *      a range of [0, 0x7fff].
+ *
  *------------------------- Pointer Device Parameters ------------------------
  *
  * width
@@ -98,6 +105,13 @@
  *
  *      Request backend to report multi-touch events.
  *
+ * request-raw-pointer
+ *      Values:         <uint>
+ *
+ *      Request backend to report raw unscaled absolute pointer coordinates.
+ *      This option is only valid if request-abs-pointer is also set.
+ *      Raw unscaled coordinates have the range [0, 0x7fff]
+ *
  *----------------------- Request Transport Parameters -----------------------
  *
  * event-channel