Re: [PATCH 4/4] input: mt: Add pressure to pointer emulation code

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, Nov 29, 2010 at 08:13:22AM +0100, Henrik Rydberg wrote:
> Some MT devices report pressure per contact. This patch adds
> ABS_PRESSURE to the pointer emulation code.
> 
> Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
> ---
>  drivers/input/input-mt.c |    7 ++++++-
>  1 files changed, 6 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
> index 08aa682..49ccd15 100644
> --- a/drivers/input/input-mt.c
> +++ b/drivers/input/input-mt.c
> @@ -97,7 +97,8 @@ EXPORT_SYMBOL(input_mt_report_slot_state);
>   * input_mt_report_pointer_emulation() - common pointer emulation
>   * @dev: input device with allocated MT slots
>   *
> - * Performs legacy pointer emulation via BTN_TOUCH, ABS_X and ABS_Y.
> + * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
> + * ABS_PRESSURE.
>   */
>  void input_mt_report_pointer_emulation(struct input_dev *dev)
>  {
> @@ -124,9 +125,13 @@ void input_mt_report_pointer_emulation(struct input_dev *dev)
>  	if (oldest) {
>  		int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
>  		int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
> +		int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);

What if device does not report ABS_MT_PRESSURE/ABS_PRESSURE? Do we rely
on input core to suppress unsupported events? A comment would be nice...

Also, is there a gelper to set up pointer emulation capabilities for MT
device?

>  
>  		input_event(dev, EV_ABS, ABS_X, x);
>  		input_event(dev, EV_ABS, ABS_Y, y);
> +		input_event(dev, EV_ABS, ABS_PRESSURE, p);
> +	} else {
> +		input_event(dev, EV_ABS, ABS_PRESSURE, 0);
>  	}
>  }
>  EXPORT_SYMBOL(input_mt_report_pointer_emulation);
> -- 
> 1.7.1
> 

-- 
Dmitry