input: mt: Move tracking and pointer emulation to input-mt

The drivers using the type B protocol all report tracking information
the same way. The contact id is semantically equivalent to
ABS_MT_SLOT, and the handling of ABS_MT_TRACKING_ID only complicates
the driver. The situation can be improved upon by providing a common
pointer emulation code, thereby removing the need for the tracking id
in the driver.  This patch moves all tracking event handling over to
the input core, simplifying both the existing drivers and the ones
currently in preparation.

Acked-by: Ping Cheng <pingc@wacom.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

2 files changed, 5 insertions, 22 deletions

diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index f26e2238f6c..0b052548671 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -863,19 +863,21 @@ static int wacom_bpt_touch(struct wacom_wac *wacom)
         struct wacom_features *features = &wacom->features;
         struct input_dev *input = wacom->input;
         unsigned char *data = wacom->data;
-        int sp = 0, sx = 0, sy = 0, count = 0;
         int i;
 
         for (i = 0; i < 2; i++) {
                 int p = data[9 * i + 2];
+                bool touch = p && !wacom->shared->stylus_in_proximity;
+
                 input_mt_slot(input, i);
+                input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
                 /*
                  * Touch events need to be disabled while stylus is
                  * in proximity because user's hand is resting on touchpad
                  * and sending unwanted events.  User expects tablet buttons
                  * to continue working though.
                  */
-                if (p && !wacom->shared->stylus_in_proximity) {
+                if (touch) {
                         int x = get_unaligned_be16(&data[9 * i + 3]) & 0x7ff;
                         int y = get_unaligned_be16(&data[9 * i + 5]) & 0x7ff;
                         if (features->quirks & WACOM_QUIRK_BBTOUCH_LOWRES) {
@@ -885,23 +887,10 @@ static int wacom_bpt_touch(struct wacom_wac *wacom)
                         input_report_abs(input, ABS_MT_PRESSURE, p);
                         input_report_abs(input, ABS_MT_POSITION_X, x);
                         input_report_abs(input, ABS_MT_POSITION_Y, y);
-                        if (wacom->id[i] < 0)
-                                wacom->id[i] = wacom->trk_id++ & MAX_TRACKING_ID;
-                        if (!count++)
-                                sp = p, sx = x, sy = y;
-                } else {
-                        wacom->id[i] = -1;
                 }
-                input_report_abs(input, ABS_MT_TRACKING_ID, wacom->id[i]);
         }
 
-        input_report_key(input, BTN_TOUCH, count > 0);
-        input_report_key(input, BTN_TOOL_FINGER, count == 1);
-        input_report_key(input, BTN_TOOL_DOUBLETAP, count == 2);
-
-        input_report_abs(input, ABS_PRESSURE, sp);
-        input_report_abs(input, ABS_X, sx);
-        input_report_abs(input, ABS_Y, sy);
+        input_mt_report_pointer_emulation(input, true);
 
         input_report_key(input, BTN_LEFT, (data[1] & 0x08) != 0);
         input_report_key(input, BTN_FORWARD, (data[1] & 0x04) != 0);
@@ -1283,8 +1272,6 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
                         input_set_abs_params(input_dev, ABS_MT_PRESSURE,
                                              0, features->pressure_max,
                                              features->pressure_fuzz, 0);
-                        input_set_abs_params(input_dev, ABS_MT_TRACKING_ID, 0,
-                                             MAX_TRACKING_ID, 0, 0);
                 } else if (features->device_type == BTN_TOOL_PEN) {
                         __set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
                         __set_bit(BTN_TOOL_PEN, input_dev->keybit);
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index 00ca01541d8..b1310ec9720 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -42,9 +42,6 @@
 #define WACOM_QUIRK_MULTI_INPUT         0x0001
 #define WACOM_QUIRK_BBTOUCH_LOWRES      0x0002
 
-/* largest reported tracking id */
-#define MAX_TRACKING_ID                 0xfff
-
 enum {
         PENPARTNER = 0,
         GRAPHIRE,
@@ -100,7 +97,6 @@ struct wacom_wac {
         int id[3];
         __u32 serial[2];
         int last_finger;
-        int trk_id;
         struct wacom_features features;
         struct wacom_shared *shared;
         struct input_dev *input;