Re: [PATCH] HID: hid-multitouch: change for touch height/width

From: Benjamin Tissoires
Date: Mon Mar 06 2017 - 03:25:12 EST


On Mar 06 2017 or thereabouts, hn.chen@xxxxxxxxxxxxxxx wrote:
> From: HungNien Chen <hn.chen@xxxxxxxxxxxxxxx>
>
> Just quote from Jonathan Clarke in previous thread(2017/01/24):
> "This division by 2 was added along with the touch width/height
> fields 6 years ago so that those fields 'match the visual scale
> of the touch' for a specific device (3M PCT)"
> "The scaling is also discarding information about touch size
> (1 bit for each of width/height) which is useful for any
> application that wants to know about it."
>
> Jonathan mentioned just what I thought in a new project recently.
> It dosen't make sense to discard 1 bit width/height in general
> case according to the spec in multi-touch-protocol.txt so
> I would like to make a slight change here.
>
> A quirk MT_QUIRK_TOUCH_SIZE_SCALING was added to service
> devices like 3M PCT with a special visual scale and
> the division by 2 only take effect with devices like that.
>
> Signed-off-by: HungNien Chen <hn.chen@xxxxxxxxxxxxxxx>
> ---

Looks good to me:

Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

Thanks for the respin.

Cheers,
Benjamin

> drivers/hid/hid-multitouch.c | 18 ++++++++++++++----
> 1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
> index 6926474..24d5b6d 100644
> --- a/drivers/hid/hid-multitouch.c
> +++ b/drivers/hid/hid-multitouch.c
> @@ -69,6 +69,7 @@
> #define MT_QUIRK_CONTACT_CNT_ACCURATE (1 << 12)
> #define MT_QUIRK_FORCE_GET_FEATURE (1 << 13)
> #define MT_QUIRK_FIX_CONST_CONTACT_ID (1 << 14)
> +#define MT_QUIRK_TOUCH_SIZE_SCALING (1 << 15)
>
> #define MT_INPUTMODE_TOUCHSCREEN 0x02
> #define MT_INPUTMODE_TOUCHPAD 0x03
> @@ -222,7 +223,8 @@ static int cypress_compute_slot(struct mt_device *td)
> */
> { .name = MT_CLS_3M,
> .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
> - MT_QUIRK_SLOT_IS_CONTACTID,
> + MT_QUIRK_SLOT_IS_CONTACTID |
> + MT_QUIRK_TOUCH_SIZE_SCALING,
> .sn_move = 2048,
> .sn_width = 128,
> .sn_height = 128,
> @@ -658,9 +660,17 @@ static void mt_complete_slot(struct mt_device *td, struct input_dev *input)
> if (active) {
> /* this finger is in proximity of the sensor */
> int wide = (s->w > s->h);
> - /* divided by two to match visual scale of touch */
> - int major = max(s->w, s->h) >> 1;
> - int minor = min(s->w, s->h) >> 1;
> + int major = max(s->w, s->h);
> + int minor = min(s->w, s->h);
> +
> + /*
> + * divided by two to match visual scale of touch
> + * for devices with this quirk
> + */
> + if (td->mtclass.quirks & MT_QUIRK_TOUCH_SIZE_SCALING) {
> + major = major >> 1;
> + minor = minor >> 1;
> + }
>
> input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
> input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
> --
> 1.9.1
>