Re: [PATCH 4/7 v3] HID: magicmouse: simplify touch down logic

[Michael Poole <mdpoole@troilus.org>]

On Tue, 2010-08-31 at 21:56 -0400, Chase Douglas wrote:
> From: Chase Douglas <chase.douglas@ubuntu.com>
> 
> For the MT protocol, we need to properly keep track of each down touch.
> This change simplifies the logic, and should make things easier when
> support for the Magic Trackpad is added.
> 
> Signed-off-by: Chase Douglas <chase.douglas@canonical.com>

Thanks, this looks slightly cleaner than what I had in mind.

Acked-by: Michael Poole <mdpoole@troilus.org>

> ---
>  drivers/hid/hid-magicmouse.c |   27 +++++++++------------------
>  1 files changed, 9 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
> index 2ee59a8..0fbca59 100644
> --- a/drivers/hid/hid-magicmouse.c
> +++ b/drivers/hid/hid-magicmouse.c
> @@ -98,7 +98,6 @@ struct magicmouse_sc {
>  		short scroll_x;
>  		short scroll_y;
>  		u8 size;
> -		u8 down;
>  	} touches[16];
>  	int tracking_ids[16];
>  };
> @@ -227,8 +226,6 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
>  
>  	/* Generate the input events for this touch. */
>  	if (report_touches && down) {
> -		msc->touches[id].down = 1;
> -
>  		input_report_abs(input, ABS_MT_TRACKING_ID, id);
>  		input_report_abs(input, ABS_MT_TOUCH_MAJOR, touch_major);
>  		input_report_abs(input, ABS_MT_TOUCH_MINOR, touch_minor);
> @@ -241,6 +238,9 @@ static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tda
>  
>  		input_mt_sync(input);
>  	}
> +
> +	if (down)
> +		msc->ntouches++;
>  }
>  
>  static int magicmouse_raw_event(struct hid_device *hdev,
> @@ -248,7 +248,7 @@ static int magicmouse_raw_event(struct hid_device *hdev,
>  {
>  	struct magicmouse_sc *msc = hid_get_drvdata(hdev);
>  	struct input_dev *input = msc->input;
> -	int x, y, ts, ii, clicks, last_up;
> +	int x, y, ts, ii, clicks, npoints;
>  
>  	switch (data[0]) {
>  	case 0x10:
> @@ -265,22 +265,13 @@ static int magicmouse_raw_event(struct hid_device *hdev,
>  		ts = data[3] >> 6 | data[4] << 2 | data[5] << 10;
>  		msc->delta_time = (ts - msc->last_timestamp) & 0x3ffff;
>  		msc->last_timestamp = ts;
> -		msc->ntouches = (size - 6) / 8;
> -		for (ii = 0; ii < msc->ntouches; ii++)
> +		npoints = (size - 6) / 8;
> +		msc->ntouches = 0;
> +		for (ii = 0; ii < npoints; ii++)
>  			magicmouse_emit_touch(msc, ii, data + ii * 8 + 6);
>  
> -		if (report_touches) {
> -			last_up = 1;
> -			for (ii = 0; ii < ARRAY_SIZE(msc->touches); ii++) {
> -				if (msc->touches[ii].down) {
> -					last_up = 0;
> -					msc->touches[ii].down = 0;
> -				}
> -			}
> -			if (last_up) {
> -				input_mt_sync(input);
> -			}
> -		}
> +		if (report_touches && msc->ntouches == 0)
> +			input_mt_sync(input);
>  
>  		/* When emulating three-button mode, it is important
>  		 * to have the current touch information before