Input: st1232 - switch to using MT-B protocol

Switch the driver to the slotted variant of multitouch protocol (MT-B)
with in-kernel tracking of the contacts.

Tested-by: Matthias Fend <Matthias.Fend@wolfvision.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index a4a3b82..63b29c7 100644 (file)
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -14,23 +14,19 @@
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pm_qos.h>
 #include <linux/slab.h>
 #include <linux/types.h>
-#include <linux/input/touchscreen.h>
 
 #define ST1232_TS_NAME "st1232-ts"
 #define ST1633_TS_NAME "st1633-ts"
 
-struct st1232_ts_finger {
-       u16 x;
-       u16 y;
-       u8 t;
-       bool is_valid;
-};
+#define ST_TS_MAX_FINGERS      10
 
 struct st_chip_info {
        bool    have_z;
@@ -50,12 +46,10 @@ struct st1232_ts_data {
        const struct st_chip_info *chip_info;
        int read_buf_len;
        u8 *read_buf;
-       struct st1232_ts_finger fingers[];
 };
 
 static int st1232_ts_read_data(struct st1232_ts_data *ts)
 {
-       struct st1232_ts_finger *finger = ts->fingers;
        struct i2c_client *client = ts->client;
        u8 start_reg = ts->chip_info->start_reg;
        struct i2c_msg msg[] = {
@@ -72,59 +66,69 @@ static int st1232_ts_read_data(struct st1232_ts_data *ts)
                }
        };
        int ret;
-       int i;
-       u8 *buf;
 
        ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
        if (ret != ARRAY_SIZE(msg))
                return ret < 0 ? ret : -EIO;
 
+       return 0;
+}
+
+static int st1232_ts_parse_and_report(struct st1232_ts_data *ts)
+{
+       struct input_dev *input = ts->input_dev;
+       struct input_mt_pos pos[ST_TS_MAX_FINGERS];
+       u8 z[ST_TS_MAX_FINGERS];
+       int slots[ST_TS_MAX_FINGERS];
+       int n_contacts = 0;
+       int i;
+
        for (i = 0; i < ts->chip_info->max_fingers; i++) {
-               buf = &ts->read_buf[i * 4];
-               finger[i].is_valid = buf[0] >> 7;
-               if (finger[i].is_valid) {
-                       finger[i].x = ((buf[0] & 0x70) << 4) | buf[1];
-                       finger[i].y = ((buf[0] & 0x07) << 8) | buf[2];
+               u8 *buf = &ts->read_buf[i * 4];
+
+               if (buf[0] & BIT(7)) {
+                       unsigned int x = ((buf[0] & 0x70) << 4) | buf[1];
+                       unsigned int y = ((buf[0] & 0x07) << 8) | buf[2];
+
+                       touchscreen_set_mt_pos(&pos[n_contacts],
+                                              &ts->prop, x, y);
 
                        /* st1232 includes a z-axis / touch strength */
                        if (ts->chip_info->have_z)
-                               finger[i].t = ts->read_buf[i + 6];
+                               z[n_contacts] = ts->read_buf[i + 6];
+
+                       n_contacts++;
                }
        }
 
-       return 0;
+       input_mt_assign_slots(input, slots, pos, n_contacts, 0);
+       for (i = 0; i < n_contacts; 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);
+               if (ts->chip_info->have_z)
+                       input_report_abs(input, ABS_MT_TOUCH_MAJOR, z[i]);
+       }
+
+       input_mt_sync_frame(input);
+       input_sync(input);
+
+       return n_contacts;
 }
 
 static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
 {
        struct st1232_ts_data *ts = dev_id;
-       struct st1232_ts_finger *finger = ts->fingers;
-       struct input_dev *input_dev = ts->input_dev;
-       int count = 0;
-       int i, ret;
-
-       ret = st1232_ts_read_data(ts);
-       if (ret < 0)
-               goto end;
-
-       /* multi touch protocol */
-       for (i = 0; i < ts->chip_info->max_fingers; i++) {
-               if (!finger[i].is_valid)
-                       continue;
+       int count;
+       int error;
 
-               if (ts->chip_info->have_z)
-                       input_report_abs(input_dev, ABS_MT_TOUCH_MAJOR,
-                                        finger[i].t);
+       error = st1232_ts_read_data(ts);
+       if (error)
+               goto out;
 
-               touchscreen_report_pos(input_dev, &ts->prop,
-                                       finger[i].x, finger[i].y, true);
-               input_mt_sync(input_dev);
-               count++;
-       }
-
-       /* SYN_MT_REPORT only if no contact */
+       count = st1232_ts_parse_and_report(ts);
        if (!count) {
-               input_mt_sync(input_dev);
                if (ts->low_latency_req.dev) {
                        dev_pm_qos_remove_request(&ts->low_latency_req);
                        ts->low_latency_req.dev = NULL;
@@ -136,10 +140,7 @@ static irqreturn_t st1232_ts_irq_handler(int irq, void *dev_id)
                                                DEV_PM_QOS_RESUME_LATENCY, 100);
        }
 
-       /* SYN_REPORT */
-       input_sync(input_dev);
-
-end:
+out:
        return IRQ_HANDLED;
 }
 
@@ -198,9 +199,7 @@ static int st1232_ts_probe(struct i2c_client *client,
                return -EINVAL;
        }
 
-       ts = devm_kzalloc(&client->dev,
-                         struct_size(ts, fingers, match->max_fingers),
-                         GFP_KERNEL);
+       ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
        if (!ts)
                return -ENOMEM;
 
@@ -240,11 +239,6 @@ static int st1232_ts_probe(struct i2c_client *client,
        input_dev->name = "st1232-touchscreen";
        input_dev->id.bustype = BUS_I2C;
 
-       __set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
-       __set_bit(EV_SYN, input_dev->evbit);
-       __set_bit(EV_KEY, input_dev->evbit);
-       __set_bit(EV_ABS, input_dev->evbit);
-
        if (ts->chip_info->have_z)
                input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0,
                                     ts->chip_info->max_area, 0, 0);
@@ -256,6 +250,14 @@ static int st1232_ts_probe(struct i2c_client *client,
 
        touchscreen_parse_properties(input_dev, true, &ts->prop);
 
+       error = input_mt_init_slots(input_dev, ts->chip_info->max_fingers,
+                                   INPUT_MT_DIRECT | INPUT_MT_TRACK |
+                                       INPUT_MT_DROP_UNUSED);
+       if (error) {
+               dev_err(&client->dev, "failed to initialize MT slots\n");
+               return error;
+       }
+
        error = devm_request_threaded_irq(&client->dev, client->irq,
                                          NULL, st1232_ts_irq_handler,
                                          IRQF_ONESHOT,