Hi Peter, On Tue, 2026-06-16 at 14:24 +1000, Peter Hutterer wrote: > Hi Rong, > > On Tue, Jun 02, 2026 at 01:25:57AM +0800, Rong Zhang wrote: > > > > Hi all, > > > > Hopefully I'm not too late to show up here. > > > > > From: Peter Hutterer <[email protected]> > > > > > > A Digitizer/Button Type value of 1 indicates the device is a > > > pressurepad, see > > > https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-windows-precision-touchpad-collection#device-capabilities-feature-report > > > > > > Signed-off-by: Peter Hutterer <[email protected]> > > > --- > > > drivers/hid/hid-multitouch.c | 12 +++++++++++- > > > 1 file changed, 11 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c > > > index > > > 179dc316b4b518d78bdc900d9fd15756c5eba83e..382e6f50c4f7e663af7d028abb8be7cb2e6e7b8e > > > 100644 > > > --- a/drivers/hid/hid-multitouch.c > > > +++ b/drivers/hid/hid-multitouch.c > > > @@ -81,6 +81,7 @@ MODULE_LICENSE("GPL"); > > > #define MT_INPUTMODE_TOUCHPAD 0x03 > > > > > > #define MT_BUTTONTYPE_CLICKPAD 0 > > > +#define MT_BUTTONTYPE_PRESSUREPAD 1 > > > > > > enum latency_mode { > > > HID_LATENCY_NORMAL = 0, > > > @@ -179,6 +180,7 @@ struct mt_device { > > > __u8 inputmode_value; /* InputMode HID feature value */ > > > __u8 maxcontacts; > > > bool is_buttonpad; /* is this device a button pad? */ > > > + bool is_pressurepad; /* is this device a pressurepad? */ > > > bool is_haptic_touchpad; /* is this device a haptic touchpad? */ > > > bool serial_maybe; /* need to check for serial protocol */ > > > > > > @@ -530,8 +532,14 @@ static void mt_feature_mapping(struct hid_device > > > *hdev, > > > } > > > > > > mt_get_feature(hdev, field->report); > > > - if (field->value[usage->usage_index] == MT_BUTTONTYPE_CLICKPAD) > > > + switch (field->value[usage->usage_index]) { > > > + case MT_BUTTONTYPE_CLICKPAD: > > > td->is_buttonpad = true; > > > + break; > > > + case MT_BUTTONTYPE_PRESSUREPAD: > > > + td->is_pressurepad = true; > > > + break; > > > + } > > > > > > break; > > > case 0xff0000c5: > > > @@ -1393,6 +1401,8 @@ static int mt_touch_input_configured(struct > > > hid_device *hdev, > > > > > > if (td->is_buttonpad) > > > __set_bit(INPUT_PROP_BUTTONPAD, input->propbit); > > > + if (td->is_pressurepad) > > > + __set_bit(INPUT_PROP_PRESSUREPAD, input->propbit); > > > > I noticed that this leads to dual reporting on my device. > > > > Consider previous checks: > > > > if (application == HID_DG_TOUCHPAD) { > > mt_application->mt_flags |= INPUT_MT_POINTER; > > td->inputmode_value = MT_INPUTMODE_TOUCHPAD; > > } > > > > ... > > > > /* check for clickpads */ > > if ((app->mt_flags & INPUT_MT_POINTER) && > > (app->buttons_count == 1)) > > td->is_buttonpad = true; > > > > ... where `td->is_buttonpad' is set to true when a pressure pad has only > > one button, i.e., the "touchpad button integrated with digitizer" [1]. > > Most (if not all) pressure pads fall into this category. As a result, > > the presence of INPUT_PROP_PRESSUREPAD is always accompanied by the > > presence of INPUT_PROP_BUTTONPAD. > > Yes, this is intended, see commit > ae8966b7b5bd69b86209cc34bcca1ba9f18b68e6 which lists this in the commit > message: > > ``` > This means: > - clickpad: INPUT_PROP_BUTTONPAD > - pressurepad: INPUT_PROP_BUTTONPAD + INPUT_PROP_PRESSUREPAD > - pressurepad with configurable haptics: > INPUT_PROP_BUTTONPAD + INPUT_PROP_PRESSUREPAD + FF_HAPTIC > ``` > > We have to keep setting BUTTONPAD on all pressurepads because otherwise > we'd break existing userspace which relies on this.
Thanks a lot for your explanation. It makes sense to me. Thanks, Rong > > Cheers, > Peter >
