Re: [PATCH v2 09/11] HID: hid-multitouch: support for hoveringdevices

From: Henrik Rydberg
Date: Mon Oct 29 2012 - 18:26:21 EST


Hi Benjamin,

> Win8 devices supporting hovering must provides InRange HID field.
> The information that the finger is here but is not touching the surface
> is sent to the user space through ABS_MT_DISTANCE as required by the
> multitouch protocol.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxx>
> ---
> drivers/hid/hid-multitouch.c | 21 +++++++++++++++++++--
> 1 file changed, 19 insertions(+), 2 deletions(-)

I suppose the idea here is to send position and distance values even
when there is no touch, but the code does not seem to do that?

>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index bd23f19..c0ab1c6 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -55,7 +55,7 @@ MODULE_LICENSE("GPL");
> #define MT_QUIRK_WIN_8_CERTIFIED (1 << 10)
>
> struct mt_slot {
> - __s32 x, y, cx, cy, p, w, h;
> + __s32 x, y, cx, cy, z, p, w, h;
> __s32 contactid; /* the device ContactID assigned to this slot */
> bool touch_state; /* is the touch valid? */
> };
> @@ -394,6 +394,12 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
> case HID_UP_DIGITIZER:
> switch (usage->hid) {
> case HID_DG_INRANGE:
> + if (cls->quirks & MT_QUIRK_WIN_8_CERTIFIED) {
> + hid_map_usage(hi, usage, bit, max,
> + EV_ABS, ABS_MT_DISTANCE);
> + input_set_abs_params(hi->input,
> + ABS_MT_DISTANCE, 0, 1, 0, 0);
> + }
> mt_store_field(usage, td, hi);
> td->last_field_index = field->index;
> return 1;
> @@ -511,6 +517,11 @@ static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
> struct mt_slot *s = &td->curdata;
>
> if (td->mtclass.quirks & MT_QUIRK_WIN_8_CERTIFIED &&
> + !test_bit(ABS_MT_DISTANCE, input->absbit))
> + /* If InRange is not present, rely on TipSwitch */
> + s->touch_state = !s->z;
> +
> + if (td->mtclass.quirks & MT_QUIRK_WIN_8_CERTIFIED &&
> !s->touch_state) {
> struct input_mt_slot *slot = &input->mt->slots[slotnum];
> int prv_x = input_mt_get_value(slot, ABS_MT_POSITION_X);
> @@ -543,6 +554,7 @@ static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
> input_event(input, EV_ABS, ABS_MT_TOOL_Y,
> s->cy);
> }
> + input_event(input, EV_ABS, ABS_MT_DISTANCE, s->z);

This only happens if touch_state is true?

> input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
> input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
> input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
> @@ -575,11 +587,16 @@ static int mt_event(struct hid_device *hid, struct hid_field *field,
> case HID_DG_INRANGE:
> if (quirks & MT_QUIRK_VALID_IS_INRANGE)
> td->curvalid = value;
> + if (quirks & MT_QUIRK_WIN_8_CERTIFIED)
> + td->curdata.touch_state = value;
> break;
> case HID_DG_TIPSWITCH:
> if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
> td->curvalid = value;
> - td->curdata.touch_state = value;
> + if (quirks & MT_QUIRK_WIN_8_CERTIFIED)
> + td->curdata.z = !value;

Here, z is a boolean?

> + else
> + td->curdata.touch_state = value;
> break;
> case HID_DG_CONFIDENCE:
> if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
> --
> 1.7.11.7
>

Henrik
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