Input: goodix - add support for more then one touch-key

Some devices with a goodix touchscreen have more then 1 capacitive
touch-key. This commit replaces the current support for a single
touch-key, which ignored the reported key-code. With support for
up to 7 touch-keys, based upon checking the key-code which is
post-fixed to any reported touch-data.

KEY_LEFTMETA is assigned to the first touch-key (it will still be
the default keycode for devices with a single touch-key).
KEY_F1, KEY_F2... are assigned as default keycode for the other
touch-keys.

This commit also add supports for keycode remapping, so that
systemd-udev's hwdb can be used to remap the codes to send
keycodes to match the icons on the buttons for devices with more
then 1 touch-key.

Signed-off-by: Dmitry Mastykin <dmastykin@astralinux.ru>
Reviewed-by: Bastien Nocera <hadess@hadess.net>
Link: https://lore.kernel.org/r/20200316075302.3759-1-dmastykin@astralinux.ru
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c
index 4cfebdd..9805372 100644 (file)
--- a/drivers/input/touchscreen/goodix.c
+++ b/drivers/input/touchscreen/goodix.c
@@ -38,6 +38,7 @@
 #define GOODIX_CONTACT_SIZE            8
 #define GOODIX_MAX_CONTACT_SIZE                9
 #define GOODIX_MAX_CONTACTS            10
+#define GOODIX_MAX_KEYS                        7
 
 #define GOODIX_CONFIG_MIN_LENGTH       186
 #define GOODIX_CONFIG_911_LENGTH       186
@@ -55,6 +56,7 @@
 #define GOODIX_REG_ID                  0x8140
 
 #define GOODIX_BUFFER_STATUS_READY     BIT(7)
+#define GOODIX_HAVE_KEY                        BIT(4)
 #define GOODIX_BUFFER_STATUS_TIMEOUT   20
 
 #define RESOLUTION_LOC         1
@@ -100,6 +102,7 @@ struct goodix_ts_data {
        enum goodix_irq_pin_access_method irq_pin_access_method;
        unsigned int contact_size;
        u8 config[GOODIX_CONFIG_MAX_LENGTH];
+       unsigned short keymap[GOODIX_MAX_KEYS];
 };
 
 static int goodix_check_cfg_8(struct goodix_ts_data *ts,
@@ -302,6 +305,13 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
        unsigned long max_timeout;
        int touch_num;
        int error;
+       u16 addr = GOODIX_READ_COOR_ADDR;
+       /*
+        * We are going to read 1-byte header,
+        * ts->contact_size * max(1, touch_num) bytes of coordinates
+        * and 1-byte footer which contains the touch-key code.
+        */
+       const int header_contact_keycode_size = 1 + ts->contact_size + 1;
 
        /*
         * The 'buffer status' bit, which indicates that the data is valid, is
@@ -310,8 +320,8 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
         */
        max_timeout = jiffies + msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
        do {
-               error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR,
-                                       data, ts->contact_size + 1);
+               error = goodix_i2c_read(ts->client, addr, data,
+                                       header_contact_keycode_size);
                if (error) {
                        dev_err(&ts->client->dev, "I2C transfer error: %d\n",
                                        error);
@@ -324,11 +334,10 @@ static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
                                return -EPROTO;
 
                        if (touch_num > 1) {
-                               data += 1 + ts->contact_size;
+                               addr += header_contact_keycode_size;
+                               data += header_contact_keycode_size;
                                error = goodix_i2c_read(ts->client,
-                                               GOODIX_READ_COOR_ADDR +
-                                                       1 + ts->contact_size,
-                                               data,
+                                               addr, data,
                                                ts->contact_size *
                                                        (touch_num - 1));
                                if (error)
@@ -378,6 +387,25 @@ static void goodix_ts_report_touch_9b(struct goodix_ts_data *ts, u8 *coor_data)
        input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
 }
 
+static void goodix_ts_report_key(struct goodix_ts_data *ts, u8 *data)
+{
+       int touch_num;
+       u8 key_value;
+       int i;
+
+       if (data[0] & GOODIX_HAVE_KEY) {
+               touch_num = data[0] & 0x0f;
+               key_value = data[1 + ts->contact_size * touch_num];
+               for (i = 0; i < GOODIX_MAX_KEYS; i++)
+                       if (key_value & BIT(i))
+                               input_report_key(ts->input_dev,
+                                                ts->keymap[i], 1);
+       } else {
+               for (i = 0; i < GOODIX_MAX_KEYS; i++)
+                       input_report_key(ts->input_dev, ts->keymap[i], 0);
+       }
+}
+
 /**
  * goodix_process_events - Process incoming events
  *
@@ -388,7 +416,7 @@ static void goodix_ts_report_touch_9b(struct goodix_ts_data *ts, u8 *coor_data)
  */
 static void goodix_process_events(struct goodix_ts_data *ts)
 {
-       u8  point_data[1 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
+       u8  point_data[2 + GOODIX_MAX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
        int touch_num;
        int i;
 
@@ -396,11 +424,7 @@ static void goodix_process_events(struct goodix_ts_data *ts)
        if (touch_num < 0)
                return;
 
-       /*
-        * Bit 4 of the first byte reports the status of the capacitive
-        * Windows/Home button.
-        */
-       input_report_key(ts->input_dev, KEY_LEFTMETA, point_data[0] & BIT(4));
+       goodix_ts_report_key(ts, point_data);
 
        for (i = 0; i < touch_num; i++)
                if (ts->contact_size == 9)
@@ -986,6 +1010,7 @@ static int goodix_i2c_test(struct i2c_client *client)
 static int goodix_configure_dev(struct goodix_ts_data *ts)
 {
        int error;
+       int i;
 
        ts->int_trigger_type = GOODIX_INT_TRIGGER;
        ts->max_touch_num = GOODIX_MAX_CONTACTS;
@@ -1003,8 +1028,19 @@ static int goodix_configure_dev(struct goodix_ts_data *ts)
        ts->input_dev->id.product = ts->id;
        ts->input_dev->id.version = ts->version;
 
+       ts->input_dev->keycode = ts->keymap;
+       ts->input_dev->keycodesize = sizeof(ts->keymap[0]);
+       ts->input_dev->keycodemax = GOODIX_MAX_KEYS;
+
        /* Capacitive Windows/Home button on some devices */
-       input_set_capability(ts->input_dev, EV_KEY, KEY_LEFTMETA);
+       for (i = 0; i < GOODIX_MAX_KEYS; ++i) {
+               if (i == 0)
+                       ts->keymap[i] = KEY_LEFTMETA;
+               else
+                       ts->keymap[i] = KEY_F1 + (i - 1);
+
+               input_set_capability(ts->input_dev, EV_KEY, ts->keymap[i]);
+       }
 
        input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_X);
        input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_Y);