Re: [PATCH] Input: wacom - cleanup multitouch code when touch_max is 2

[Jason Gerecke <killertofu@gmail.com>]

On Thu, May 29, 2014 at 1:03 PM, Ping Cheng <pinglinux@gmail.com> wrote:
> Historically we dealt with touch_max equals to 2 differently from
> other MT devices. Now we use input_mt_*() to process all MT events,
> as long as touch_max is greater than 1. So, there is no need to
> take (touch_max == 2) as a special case any more.
>
> Signed-off-by: Ping Cheng <pingc@wacom.com>
> ---
>  drivers/input/tablet/wacom_wac.c | 26 ++++++--------------------
>  1 file changed, 6 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
> index 977d05c..964db47 100644
> --- a/drivers/input/tablet/wacom_wac.c
> +++ b/drivers/input/tablet/wacom_wac.c
> @@ -1217,8 +1217,8 @@ static void wacom_bpt3_touch_msg(struct wacom_wac *wacom, unsigned char *data)
>                          * a=(pi*r^2)/C.
>                          */
>                         int a = data[5];
> -                       int x_res  = input_abs_get_res(input, ABS_X);
> -                       int y_res  = input_abs_get_res(input, ABS_Y);
> +                       int x_res  = input_abs_get_res(input, ABS_MT_POSITION_X);
> +                       int y_res  = input_abs_get_res(input, ABS_MT_POSITION_Y);
>                         width  = 2 * int_sqrt(a * WACOM_CONTACT_AREA_SCALE);
>                         height = width * y_res / x_res;
>                 }
> @@ -1587,7 +1587,7 @@ static void wacom_abs_set_axis(struct input_dev *input_dev,
>                 input_abs_set_res(input_dev, ABS_X, features->x_resolution);
>                 input_abs_set_res(input_dev, ABS_Y, features->y_resolution);
>         } else {
> -               if (features->touch_max <= 2) {
> +               if (features->touch_max == 1) {
>                         input_set_abs_params(input_dev, ABS_X, 0,
>                                 features->x_max, features->x_fuzz, 0);
>                         input_set_abs_params(input_dev, ABS_Y, 0,
> @@ -1815,14 +1815,8 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
>         case MTTPC:
>         case MTTPC_B:
>         case TABLETPC2FG:
> -               if (features->device_type == BTN_TOOL_FINGER) {
> -                       unsigned int flags = INPUT_MT_DIRECT;
> -
> -                       if (wacom_wac->features.type == TABLETPC2FG)
> -                               flags = 0;
> -
> -                       input_mt_init_slots(input_dev, features->touch_max, flags);
> -               }
> +               if ((features->device_type == BTN_TOOL_FINGER) && features->touch_max > 1)
> +                       input_mt_init_slots(input_dev, features->touch_max, INPUT_MT_DIRECT);
>                 /* fall through */
>
>         case TABLETPC:
> @@ -1883,10 +1877,6 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
>                         __set_bit(BTN_RIGHT, input_dev->keybit);
>
>                         if (features->touch_max) {
> -                               /* touch interface */
> -                               unsigned int flags = INPUT_MT_POINTER;
> -
> -                               __set_bit(INPUT_PROP_POINTER, input_dev->propbit);
>                                 if (features->pktlen == WACOM_PKGLEN_BBTOUCH3) {
>                                         input_set_abs_params(input_dev,
>                                                      ABS_MT_TOUCH_MAJOR,
> @@ -1894,12 +1884,8 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
>                                         input_set_abs_params(input_dev,
>                                                      ABS_MT_TOUCH_MINOR,
>                                                      0, features->y_max, 0, 0);
> -                               } else {
> -                                       __set_bit(BTN_TOOL_FINGER, input_dev->keybit);
> -                                       __set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
> -                                       flags = 0;
>                                 }
> -                               input_mt_init_slots(input_dev, features->touch_max, flags);
> +                               input_mt_init_slots(input_dev, features->touch_max, INPUT_MT_POINTER);

I think you want to use 'input_mt_init_slots(input_dev,
features->touch_max + 1, INPUT_MT_POINTER)' instead. This is one more
slot than necessary, but the number of slots is used in deciding which
of the BTN_TOOL_*TAP buttons the kernel will advertise. Our protocol
has the driver sending one more TAP than expected to differentiate
touch and pad (e.g. single-touch device needs DOUBLETAP and two-finger
touch needs TRIPLETAP). Adding one to the number of slots ensures a
high enough TAP is advertised.

Aside from that... Reviewed-by: Jason Gerecke <killertofu@gmail.com>

Jason
---
Now instead of four in the eights place /
you’ve got three, ‘Cause you added one  /
(That is to say, eight) to the two,     /
But you can’t take seven from three,    /
So you look at the sixty-fours....

>                         } else {
>                                 /* buttons/keys only interface */
>                                 __clear_bit(ABS_X, input_dev->absbit);
> --
> 1.9.1
>
> --
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