RE: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event trigger

[廖崇榮]

Hi Dmitry,

Thanks for your confirmation.

I think the best and simplest way is to add below code to emit BTN_TOOL_FINGER 
if hover condition meets.

input_report_key(dev, BTN_TOOL_FINGER, input_mt_get_value(dev, ABS_DISTANCE));

Is it ok for you?

        if (use_count) {
                if (count == 0 &&
                    !test_bit(ABS_MT_DISTANCE, dev->absbit) &&
                    test_bit(ABS_DISTANCE, dev->absbit) &&
                    input_abs_get_val(dev, ABS_DISTANCE) != 0) {

                        /* Emit BTN_TOOL_FINGER*/
                        input_report_key(dev, BTN_TOOL_FINGER, 
input_mt_get_value(dev, ABS_DISTANCE));

                        count = 1;
                }

B.R  KT
-----Original Message-----
From: 'Dmitry Torokhov' [mailto:dmitry.torok...@gmail.com] 
Sent: Friday, May 20, 2016 8:52 AM
To: 廖崇榮
Cc: linux-in...@vger.kernel.org; linux-kernel@vger.kernel.org; 
zac.hs...@emc.com.tw; '黃世鵬 經理'; 'Charles Mooney'; 'Agnes Cheng'; 'jeff'
Subject: Re: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event trigger

On Tue, May 17, 2016 at 10:20:40PM +0800, 廖崇榮 wrote:
> Hi Dmitry,
> 
> I want to confirm my thought for your idea to avoid misunderstanding.
> I think you want to encapsulate " BTN_TOOL_FINGER" in the 
> [input_mt_report_pointer_emulation] if hover happen.
> Vendor driver only report "ABS_DISTANCE" and let 
> [input_mt_report_pointer_emulation] emit BTN_TOOL_FINGER report without 
> change function parameter.
> 
> Please let me know if my misunderstand about your idea.

Yes, that is correct. Something like this:

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 
54fce56..a1bbec9 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -218,8 +218,23 @@ void input_mt_report_pointer_emulation(struct input_dev 
*dev, bool use_count)
        }
 
        input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
-       if (use_count)
+
+       if (use_count) {
+               if (count == 0 &&
+                   !test_bit(ABS_MT_DISTANCE, dev->absbit) &&
+                   test_bit(ABS_DISTANCE, dev->absbit) &&
+                   input_abs_get_val(dev, ABS_DISTANCE) != 0) {
+                       /*
+                        * Force reporting BTN_TOOL_FINGER for devices that
+                        * only report general hover (and not per-contact
+                        * distance) when contact is in proximity but not
+                        * on the surface.
+                        */
+                       count = 1;
+               }
+
                input_mt_report_finger_count(dev, count);
+       }
 
        if (oldest) {
                int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);

--
Dmitry