On Wed, Sep 5, 2018 at 5:01 PM Jiri Kosina <jikos@xxxxxxxxxx> wrote:
>
> On Wed, 8 Aug 2018, Tatsunosuke Tobita wrote:
>
> > Some system may want to know if a detected digitizer
> > device is either an integrated or an external device.
> > In order to distinguish such condition, setting either
> > INPUT_PROP_DIRECT or INPUT_PROP_POINTER is required, checking
> > the member, "application", in "hid_field" structure.
> >
> > Signed-off-by: Tatsunosuke Tobita <tobita.tatsunosuke@xxxxxxxxxxx>
> > ---
> > drivers/hid/hid-input.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
> > index 930652c..3e98537 100644
> > --- a/drivers/hid/hid-input.c
> > +++ b/drivers/hid/hid-input.c
> > @@ -758,6 +758,11 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
> > break;
> >
> > case HID_UP_DIGITIZER:
> > + if ((field->application & 0xff) == 0x01) /* Digitizer */
> > + __set_bit(INPUT_PROP_POINTER, input->propbit);
> > + else if ((field->application & 0xff) == 0x02) /* Pen */
> > + __set_bit(INPUT_PROP_DIRECT, input->propbit);
The one thing I am worried here is that the specification for "pen"
usage states:
"A digitizer with an integrated display that allows use of a stylus.
The system must ensure that the sensed stylus position and the display
representations of that position are the same. A pen digitizer has
enough time and space resolution for handwriting input. "
This is good, its corresponds to the patch.
However, it then says in the same paragraph: "A digitizer that *may or
may not* be in an integrated display application should use the more
generic Digitizer collection usage. "
So as I read it, "Pen" implies PROP_DIRECT, but "Digitizer" doesn't
imply INPUT_PROP_POINTER.
This might be the usage, so I don't know if am I just bikeshedding or
if I am raising a valid point...
Cheers,
Benjamin
> > +
> > switch (usage->hid & 0xff) {
> > case 0x00: /* Undefined */
> > goto ignore;
>
> Makes sense.
>
> Queued for 4.20, thanks.
>
> --
> Jiri Kosina
> SUSE Labs
>
