Input: bu21013_ts - switch to using MT-B (slotted) protocol

MT-B protocol is more efficient and everyone expects it. We use in-kernel
tracking to identify contacts.

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/bu21013_ts.c b/drivers/input/touchscreen/bu21013_ts.c
index e617847..2bff3f3 100644 (file)
--- a/drivers/input/touchscreen/bu21013_ts.c
+++ b/drivers/input/touchscreen/bu21013_ts.c
@@ -9,6 +9,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -181,11 +182,13 @@ static int bu21013_read_block_data(struct bu21013_ts *ts, u8 *buf)
 
 static int bu21013_do_touch_report(struct bu21013_ts *ts)
 {
-       u8      buf[LENGTH_OF_BUFFER];
-       unsigned int pos_x[2], pos_y[2];
-       bool    has_x_sensors, has_y_sensors;
-       int     finger_down_count = 0;
-       int     i;
+       struct input_dev *input = ts->in_dev;
+       struct input_mt_pos pos[MAX_FINGERS];
+       int slots[MAX_FINGERS];
+       u8 buf[LENGTH_OF_BUFFER];
+       bool has_x_sensors, has_y_sensors;
+       int finger_down_count = 0;
+       int i;
 
        if (bu21013_read_block_data(ts, buf) < 0)
                return -EINVAL;
@@ -197,39 +200,38 @@ static int bu21013_do_touch_report(struct bu21013_ts *ts)
                return 0;
 
        for (i = 0; i < MAX_FINGERS; i++) {
-               const u8 *p = &buf[4 * i + 3];
-               unsigned int x = p[0] << SHIFT_2 | (p[1] & MASK_BITS);
-               unsigned int y = p[2] << SHIFT_2 | (p[3] & MASK_BITS);
-               if (x == 0 || y == 0)
+               const u8 *data = &buf[4 * i + 3];
+               struct input_mt_pos *p = &pos[finger_down_count];
+
+               p->x = data[0] << SHIFT_2 | (data[1] & MASK_BITS);
+               p->y = data[2] << SHIFT_2 | (data[3] & MASK_BITS);
+               if (p->x == 0 || p->y == 0)
                        continue;
-               pos_x[finger_down_count] = x;
-               pos_y[finger_down_count] = y;
+
                finger_down_count++;
+
+               if (ts->x_flip)
+                       p->x = ts->touch_x_max - p->x;
+               if (ts->y_flip)
+                       p->y = ts->touch_y_max - p->y;
        }
 
-       if (finger_down_count) {
-               if (finger_down_count == 2 &&
-                   (abs(pos_x[0] - pos_x[1]) < DELTA_MIN ||
-                    abs(pos_y[0] - pos_y[1]) < DELTA_MIN)) {
-                       return 0;
-               }
+       if (finger_down_count == 2 &&
+           (abs(pos[0].x - pos[1].x) < DELTA_MIN ||
+            abs(pos[0].y - pos[1].y) < DELTA_MIN)) {
+               return 0;
+       }
 
-               for (i = 0; i < finger_down_count; i++) {
-                       if (ts->x_flip)
-                               pos_x[i] = ts->touch_x_max - pos_x[i];
-                       if (ts->y_flip)
-                               pos_y[i] = ts->touch_y_max - pos_y[i];
-
-                       input_report_abs(ts->in_dev,
-                                        ABS_MT_POSITION_X, pos_x[i]);
-                       input_report_abs(ts->in_dev,
-                                        ABS_MT_POSITION_Y, pos_y[i]);
-                       input_mt_sync(ts->in_dev);
-               }
-       } else
-               input_mt_sync(ts->in_dev);
+       input_mt_assign_slots(input, slots, pos, finger_down_count, DELTA_MIN);
+       for (i = 0; i < finger_down_count; i++) {
+               input_mt_slot(input, slots[i]);
+               input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+               input_report_abs(input, ABS_MT_POSITION_X, pos[i].x);
+               input_report_abs(input, ABS_MT_POSITION_Y, pos[i].y);
+       }
 
-       input_sync(ts->in_dev);
+       input_mt_sync_frame(input);
+       input_sync(input);
 
        return 0;
 }
@@ -443,20 +445,24 @@ static int bu21013_probe(struct i2c_client *client,
                return -ENOMEM;
        }
        ts->in_dev = in_dev;
+       input_set_drvdata(in_dev, ts);
 
        /* register the device to input subsystem */
        in_dev->name = DRIVER_TP;
        in_dev->id.bustype = BUS_I2C;
 
-       __set_bit(EV_SYN, in_dev->evbit);
-       __set_bit(EV_KEY, in_dev->evbit);
-       __set_bit(EV_ABS, in_dev->evbit);
-
        input_set_abs_params(in_dev, ABS_MT_POSITION_X,
                             0, ts->touch_x_max, 0, 0);
        input_set_abs_params(in_dev, ABS_MT_POSITION_Y,
                             0, ts->touch_y_max, 0, 0);
-       input_set_drvdata(in_dev, ts);
+
+       error = input_mt_init_slots(in_dev, MAX_FINGERS,
+                                   INPUT_MT_DIRECT | INPUT_MT_TRACK |
+                                       INPUT_MT_DROP_UNUSED);
+       if (error) {
+               dev_err(&client->dev, "failed to initialize MT slots");
+               return error;
+       }
 
        ts->regulator = devm_regulator_get(&client->dev, "avdd");
        if (IS_ERR(ts->regulator)) {