On Apr 07 2017 or thereabouts, Mauro Carvalho Chehab wrote: > Em Fri, 7 Apr 2017 14:17:51 +0200 > Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> escreveu: > > > Hi Mauro, > > > > On Apr 07 2017 or thereabouts, Mauro Carvalho Chehab wrote: > > > As some devices can produce either low-res or high-res > > > vertical wheel EV_REL events, add a new event to allow > > > userspace to distinguish between them. > > > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx> > > > --- > > > Documentation/input/event-codes.rst | 16 +++++++++++++--- > > > include/uapi/linux/input-event-codes.h | 1 + > > > 2 files changed, 14 insertions(+), 3 deletions(-) > > > > > > diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst > > > index 92db50954169..0c8591d39bc6 100644 > > > --- a/Documentation/input/event-codes.rst > > > +++ b/Documentation/input/event-codes.rst > > > @@ -185,10 +185,20 @@ instead of EV_REL codes. > > > > > > A few EV_REL codes have special meanings: > > > > > > -* REL_WHEEL, REL_HWHEEL: > > > +* REL_WHEEL: > > > > > > - - These codes are used for vertical and horizontal scroll wheels, > > > - respectively. > > > + - These codes are used for vertical scroll wheels. > > > + > > > + - REL_WHEEL is for normal wheel operational mode, e. g. low-resolution > > > + (line-based) scroll. > > > + > > > + - REL_HIRES_WHEEL should be used when the wheel has two resolutions and it > > > + is in high-resolution mode, e. g. the same angular movement that would > > > + produce a single REL_WHEEL will produce multiple REL_HIRES_WHEEL events. > > > + > > > +* REL_HWHEEL: > > > + > > > + - This code is used for horizontal scroll wheels. > > > > > > EV_ABS > > > ------ > > > diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h > > > index 3af60ee69053..23b2d377af59 100644 > > > --- a/include/uapi/linux/input-event-codes.h > > > +++ b/include/uapi/linux/input-event-codes.h > > > @@ -703,6 +703,7 @@ > > > #define REL_DIAL 0x07 > > > #define REL_WHEEL 0x08 > > > #define REL_MISC 0x09 > > > +#define REL_HIRES_WHEEL 0x0a > > > > There is one issue here. The HID input layer has a tendency to map > > usages to REL_MISC +1, +2, +3, etc... When it doesn't know how to map an > > usage, the core layer maps it to the next one. > > > > I am not aware of devices exposing such REL axes, but I wouldn't be > > surprised if the issue will not raise at some point. > > > > We already had an issue with ABS events where ABS_MISC are conflicting > > with ABS_MT_SLOTS. Luckily, we have a little empty space between > > ABS_MISC and ABS_MT_SLOT, which allows userspace to detect such issues. > > > > Could you give the define a bigger number (and maybe reserve a couple of > > REL_MISC-n) to make sure that we do not end up with joysticks exporting > > REL_HIRES_WHEEL? > > Sure. How many REL_MISC-n should be reserved? Not sure. As I mentioned, I haven' t seen such device myself, but maybe we should reserve the rest of the 0x0n range for those (0x0a-0x0f). This would force to bump REL_MAX, but I don't think this is an issue besides recompiling libevdev and others. > > > I'll try the rest of the series on the MX Master today. > > It would be great if you could test it! I found some issues, I'll report in the other patches. Cheers, Benjamin > > Regards, > Mauro -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
