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| author | Jason Gerecke <killertofu@gmail.com> | 2012-10-03 17:19:11 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2012-10-03 23:58:15 -0700 |
| commit | 4e90495498cc6f1aa15e7667a695908860938b3e (patch) | |
| tree | be5df2824e3bff577e4d56b368f6c070e040d891 /drivers/input | |
| parent | 7774036808011ceecc88cef01dfafcce39ed9fc5 (diff) | |
| download | lwn-4e90495498cc6f1aa15e7667a695908860938b3e.tar.gz lwn-4e90495498cc6f1aa15e7667a695908860938b3e.zip | |
Input: wacom - report correct touch contact size for I5/Bamboo
This changes how the touch packets for Intuos5 and 3rd-gen Bamboo
are interpreted, so that proper values for the MAJOR and MINOR
axes are reported. Instead of using the amplitude field (data[6]),
we use the size field (data[5]) and do some calculation to
transform it from a scaled-down area into axis lengths.
Note that even though we assume a circular contact, both MAJOR and
MINOR are reported since the resolution of the X and Y axes differ.
Signed-off-by: Jason Gerecke <killertofu@gmail.com>
Reviewed-by: Chris Bagwell <chris@cnpbagwell.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/tablet/wacom_wac.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c index 2a81ce375f75..ea4068b4490b 100644 --- a/drivers/input/tablet/wacom_wac.c +++ b/drivers/input/tablet/wacom_wac.c @@ -25,6 +25,11 @@ #define WACOM_INTUOS_RES 100 #define WACOM_INTUOS3_RES 200 +/* Scale factor relating reported contact size to logical contact area. + * 2^14/pi is a good approximation on Intuos5 and 3rd-gen Bamboo + */ +#define WACOM_CONTACT_AREA_SCALE 2607 + static int wacom_penpartner_irq(struct wacom_wac *wacom) { unsigned char *data = wacom->data; @@ -1043,11 +1048,19 @@ static void wacom_bpt3_touch_msg(struct wacom_wac *wacom, unsigned char *data) if (touch) { int x = (data[2] << 4) | (data[4] >> 4); int y = (data[3] << 4) | (data[4] & 0x0f); - int w = data[6]; + int a = data[5]; + + // "a" is a scaled-down area which we assume is roughly + // circular and which can be described as: a=(pi*r^2)/C. + int x_res = input_abs_get_res(input, ABS_X); + int y_res = input_abs_get_res(input, ABS_Y); + int width = 2 * int_sqrt(a * WACOM_CONTACT_AREA_SCALE); + int height = width * y_res / x_res; input_report_abs(input, ABS_MT_POSITION_X, x); input_report_abs(input, ABS_MT_POSITION_Y, y); - input_report_abs(input, ABS_MT_TOUCH_MAJOR, w); + input_report_abs(input, ABS_MT_TOUCH_MAJOR, width); + input_report_abs(input, ABS_MT_TOUCH_MINOR, height); } } @@ -1533,7 +1546,9 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev, input_mt_init_slots(input_dev, features->touch_max, 0); input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, - 0, 255, 0, 0); + 0, features->x_max, 0, 0); + input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR, + 0, features->y_max, 0, 0); input_set_abs_params(input_dev, ABS_MT_POSITION_X, 0, features->x_max, @@ -1641,7 +1656,10 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev, input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, - 0, 255, 0, 0); + 0, features->x_max, 0, 0); + input_set_abs_params(input_dev, + ABS_MT_TOUCH_MINOR, + 0, features->y_max, 0, 0); } input_set_abs_params(input_dev, ABS_MT_POSITION_X, |