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Message-ID: <4C722ECF.5020706@euromail.se>
Date: Mon, 23 Aug 2010 10:18:23 +0200
From: Henrik Rydberg <rydberg@...omail.se>
To: Peter Hutterer <peter.hutterer@...-t.net>
CC: linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
pinglinux@...il.com
Subject: Re: [PATCH 3/3] input: add multitouch slot support to w8001.
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@...-t.net>
> CC: Henrik Rydberg <rydberg@...omail.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?
> +
> /* 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?
Thanks,
Henrik
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