RE: [PATCH] Input: Change BTN_TOOL_FINGER falg when HOVER event trigger

["DusonLin" <dusonlin@emc.com.tw>]

Hello Dmitry,

Please check my response below, thanks.


-----Original Message-----
From: 'Dmitry Torokhov' [mailto:dmitry.torokhov@gmail.com] 
Sent: Wednesday, March 30, 2016 10:31 AM
To: DusonLin
Cc: Linux-kernel@vger.kernel.org; linux-input@vger.kernel.org; 'Charles Mooney'; 'jeff'; 'Phoenix'
Subject: Re: [PATCH] Input: Change BTN_TOOL_FINGER falg when HOVER event trigger

Hi Duson,

On Wed, Mar 30, 2016 at 10:02:02AM +0800, DusonLin wrote:
> Only ABS_DISTANCE is not enough for upper OS  to distiguish hover 
> event be triggered from object form faraway to and close touchpad 
> surface or from object prepare to leave the touchpad surface. We add 
> BNT_TOOL_FINGER to help it.
> 
>                  Object_at_faraway   object_at_hover_area  object_touch_touchpad
>       BTN_TOUCH         0                      0                    1
> BTN_TOOL_FINGER         0                      1                    1
>    ABS_DISTANCE         0                      1                    0
> 
> Signed-off by: Duson Lin <dusonlin@emc.com.tw>
> ---
> drivers/input/mouse/elan_i2c_core.c |   14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/input/mouse/elan_i2c_core.c 
> b/drivers/input/mouse/elan_i2c_core.c
> index 2f58985..9392a8c 100644
> --- a/drivers/input/mouse/elan_i2c_core.c
> +++ b/drivers/input/mouse/elan_i2c_core.c
> @@ -4,7 +4,7 @@
>   * Copyright (c) 2013 ELAN Microelectronics Corp.
>   *
>   * Author: 林政維 (Duson Lin) <dusonlin@emc.com.tw>
> - * Version: 1.6.0
> + * Version: 1.6.1
>   *
>   * Based on cyapa driver:
>   * copyright (c) 2011-2012 Cypress Semiconductor, Inc.
> @@ -845,23 +845,27 @@ static void elan_report_absolute(struct 
> elan_tp_data *data, u8 *packet) {
>       struct input_dev *input = data->input;
>       u8 *finger_data = &packet[ETP_FINGER_DATA_OFFSET];
> -       int i;
> +      int i, valid_count = 0;

This appears all whitespace-damaged.
[duson] will do.

>       u8 tp_info = packet[ETP_TOUCH_INFO_OFFSET];
>       u8 hover_info = packet[ETP_HOVER_INFO_OFFSET];
>       bool contact_valid, hover_event;
> 
> -       hover_event = hover_info & 0x40;
> +      hover_event = (hover_info & 0x40);

We do not need parentheses here.
[duson] will do.

>       for (i = 0; i < ETP_MAX_FINGERS; i++) {
>               contact_valid = tp_info & (1U << (3 + i));
>               elan_report_contact(data, i, contact_valid, 
> finger_data);
> 
> -               if (contact_valid)
> +              if (contact_valid) {
>                       finger_data += ETP_FINGER_DATA_LEN;
> +                      valid_count++;
> +              }
>       }
> 
>        input_report_key(input, BTN_LEFT, tp_info & 0x01);
> +      input_report_key(input, BTN_TOOL_FINGER,
> +                      ((hover_event != 0) | (valid_count > 0)));

You do not want to use "bitwise or" here.

>       input_report_abs(input, ABS_DISTANCE, hover_event != 0);
> -       input_mt_report_pointer_emulation(input, true);
> +      input_mt_report_pointer_emulation(input, false);

I wonder if we should teach input_mt_report_pointer_emulation() to handle hover properly.
[duson] But, it looks like the hover is not standard function and not all of touchpad support this function, 
       Even though, we still teach inpu_mt_report_pointer_emulation() to handle this function?

Thanks.

--
Dmitry