Re: [PATCH 3/3] input: add multitouch slot support to w8001.

[Ping Cheng <pinglinux@gmail.com>]

On Mon, Aug 23, 2010 at 10:18 AM, Henrik Rydberg <rydberg@euromail.se> wrote:
> Hi Peter,
>
> thanks for the patches. Comments inline.
>
>> Some serial wacom devices support two-finger touch. Test for this during
>
>> init and parse the touch packets accordingly. Touch packets are
>> processed using Protocol B (MT Slots).
>>
>> Note: there are several wacom versions that do touch but not two-finger
>> touch. These are not catered for here, touch events for these are simply
>> discarded.
>>
>> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
>> CC: Henrik Rydberg <rydberg@euromail.se>
>> ---
>>  drivers/input/touchscreen/wacom_w8001.c |   99 ++++++++++++++++++++++++++++++-
>>  1 files changed, 96 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
>> index c302cc3..a38a3aa 100644
>> --- a/drivers/input/touchscreen/wacom_w8001.c
>> +++ b/drivers/input/touchscreen/wacom_w8001.c
>> @@ -60,6 +60,17 @@ struct w8001_coord {
>>       u8 tilt_y;
>>  };
>>
>> +/* touch data packet */
>> +struct w8001_touch {
>> +     u8 f1_status;
>> +     u16 f1_x;
>> +     u16 f1_y;
>> +     /* only some tablets have 2FG info */
>> +     u8 f2_status;
>> +     u16 f2_x;
>> +     u16 f2_y;
>> +};
>
>
> No pressure information from this device?

No useful pressure/capacity available for this device.

>
>> +
>>  /* touch query reply packet */
>>  struct w8001_touch_query {
>>       u8 panel_res;
>> @@ -85,8 +96,18 @@ struct w8001 {
>>       char phys[32];
>>       int type;
>>       unsigned int pktlen;
>> +     unsigned char tracking_id[2];
>>  };
>>
>> +static int get_next_tracking_id(void)
>> +{
>> +     static unsigned char next_tracking_id;
>> +     next_tracking_id = (next_tracking_id + 1) % 256;
>> +     if (next_tracking_id == 0)
>> +             next_tracking_id = 1;
>> +     return next_tracking_id;
>> +}
>
>
> Zero is part of the valid range from 2.6.36. Can be implemented simply as
> (tracking_id++ & 0xfff), see recent MT slots patches.
>
>> +
>>  static void parse_data(u8 *data, struct w8001_coord *coord)
>>  {
>>       memset(coord, 0, sizeof(*coord));
>> @@ -111,6 +132,26 @@ static void parse_data(u8 *data, struct w8001_coord *coord)
>>       coord->tilt_y = data[8] & 0x7F;
>>  }
>>
>> +static void parse_touch(u8 *data,
>> +                     unsigned int pktlen, struct w8001_touch *touch)
>> +{
>> +     memset(touch, 0, sizeof(*touch));
>> +
>> +     touch->f1_status = data[0] & 0x1;
>> +     touch->f1_x = data[1] << 7;
>> +     touch->f1_x |= data[2];
>> +     touch->f1_y = data[3] << 7;
>> +     touch->f1_y |= data[4];
>
>
> What are data[5] and data[6]? Why is f1_x/y split into several lines?
>
>> +
>> +     if (pktlen >= W8001_PKTLEN_TOUCH2FG) {
>> +             touch->f2_status = (data[0] & 0x2) >> 1;
>> +             touch->f2_x = data[7] << 7;
>> +             touch->f2_x |= data[8];
>> +             touch->f2_y = data[9] << 7;
>> +             touch->f2_y |= data[10];
>> +     }
>
>
> What are data[11] and data[12]?
>
> Since all needed information is available here, there seems to be little reason
> for the w8001_touch structure. Why not complete the report in this function?
>
>> +}
>> +
>>  static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
>>  {
>>       memset(query, 0, sizeof(*query));
>> @@ -128,6 +169,46 @@ static void parse_touchquery(u8 *data, struct w8001_touch_query *query)
>>       query->y |= (data[2] >> 3) & 0x3;
>>  }
>>
>> +static void w8001_mt_event(struct input_dev *dev,
>> +                        int slot, int tid, int x, int y)
>> +{
>> +     input_mt_slot(dev, slot);
>> +     if (tid != 0) {
>> +             input_report_abs(dev, ABS_MT_POSITION_X, x);
>> +             input_report_abs(dev, ABS_MT_POSITION_Y, y);
>> +     }
>> +     input_report_abs(dev, ABS_MT_TRACKING_ID, tid);
>> +     input_report_abs(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER);
>> +     input_mt_sync(dev);
>> +}
>
>> +
>> +static void w8001_track_fingers(struct w8001 *w8001, struct w8001_touch *touch)
>> +{
>> +     struct input_dev *dev = w8001->dev;
>> +
>> +     if (touch->f1_status) {
>> +             if (!w8001->tracking_id[0])
>> +                     w8001->tracking_id[0] = get_next_tracking_id();
>> +             w8001_mt_event(dev, 0, w8001->tracking_id[0],
>> +                            touch->f1_x, touch->f1_y);
>> +     } else if (w8001->tracking_id[0]) {
>> +             w8001->tracking_id[0] = 0;
>> +             w8001_mt_event(dev, 0, 0, touch->f1_x, touch->f1_y);
>> +     }
>
>> +
>> +     if (touch->f2_status) {
>> +             if (!w8001->tracking_id[1])
>> +                     w8001->tracking_id[1] = get_next_tracking_id();
>> +             w8001_mt_event(dev, 1, w8001->tracking_id[1],
>> +                            touch->f2_x, touch->f2_y);
>> +     } else if (w8001->tracking_id[1]) {
>> +             w8001->tracking_id[1] = 0;
>> +             w8001_mt_event(dev, 1, 0, touch->f2_x, touch->f2_y);
>> +     }
>> +
>> +     input_sync(dev);
>> +}
>
>
> Apparently, f1 and f2 represent the slots themselves, i.e., the device uses
> slots internally. Please simplify the logic accordingly. There is an example in
> the recent patch for the Bamboo Touch.
>
>> +
>>  static void report_pen_events(struct w8001 *w8001, struct w8001_coord *coord)
>>  {
>>       struct input_dev *dev = w8001->dev;
>> @@ -172,6 +253,7 @@ static irqreturn_t w8001_interrupt(struct serio *serio,
>>  {
>>       struct w8001 *w8001 = serio_get_drvdata(serio);
>>       struct w8001_coord coord;
>> +     struct w8001_touch touch;
>>       unsigned char tmp;
>>
>>       w8001->data[w8001->idx] = data;
>> @@ -217,10 +299,11 @@ static irqreturn_t w8001_interrupt(struct serio *serio,
>>               complete(&w8001->cmd_done);
>>               break;
>>
>> +     /* 2 finger touch packet */
>>       case W8001_PKTLEN_TOUCH2FG - 1:
>> -             /* ignore two-finger touch packet. */
>> -             if (w8001->pktlen == w8001->idx)
>> -                     w8001->idx = 0;
>> +             w8001->idx = 0;
>> +             parse_touch(w8001->data, w8001->pktlen, &touch);
>> +             w8001_track_fingers(w8001, &touch);
>>               break;
>>       }
>>
>> @@ -282,6 +365,16 @@ static int w8001_setup(struct w8001 *w8001)
>>                       break;
>>               case 5:
>>                       w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
>> +
>> +                     input_mt_create_slots(dev, 2);
>> +                     input_set_abs_params(dev, ABS_MT_TRACKING_ID,
>> +                                             0, 255, 0, 0);
>> +                     input_set_abs_params(dev, ABS_MT_POSITION_X,
>> +                                             0, touch.x, 0, 0);
>> +                     input_set_abs_params(dev, ABS_MT_POSITION_Y,
>> +                                             0, touch.y, 0, 0);
>> +                     input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
>> +                                             0, 0, 0, 0);
>>                       break;
>>               }
>>       }
>
>
> No information about signal-to-noise ratio (fuzz) for this device?

No.

Ping