On some x86 tablets with a silead touchscreen the windows logo on the
front is a capacitive home button. Touching this button results in a touch
with bits 12-15 of the Y coordinates set, while normally only the lower 12
are used.
Detect this and report a KEY_LEFTMETA press when this happens. Note for
now we only respond to the Y coordinate bits 12-15 containing 0x01, on some
tablets *without* a capacative button I've noticed these bits containing
0x04 when crossing the edges of the screen.
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
-Only enable support for the home-button if a "silead,home-button"
boolean device-property is set on the device
Changes in v3:
-Document the new silead,home-button property in:
Documentation/devicetree/bindings/input/touchscreen/goodix.txt
---
.../bindings/input/touchscreen/silead_gsl1680.txt | 2 +
drivers/input/touchscreen/silead.c | 46 ++++++++++++++++------
2 files changed, 37 insertions(+), 11 deletions(-)
diff --git a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
index 6aa625e0cb8d..84752de12412 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/silead_gsl1680.txt
@@ -23,6 +23,8 @@ Optional properties:
- touchscreen-inverted-y : See touchscreen.txt
- touchscreen-swapped-x-y : See touchscreen.txt
- silead,max-fingers : maximum number of fingers the touchscreen can detect
+- silead,home-button : Boolean, set to true on devices which have a
+ capacitive home-button build into the touchscreen
- vddio-supply : regulator phandle for controller VDDIO
- avdd-supply : regulator phandle for controller AVDD
diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
index 0dbcf105f7db..646b1e768e6b 100644
--- a/drivers/input/touchscreen/silead.c
+++ b/drivers/input/touchscreen/silead.c
@@ -56,7 +56,7 @@
#define SILEAD_POINT_Y_MSB_OFF 0x01
#define SILEAD_POINT_X_OFF 0x02
#define SILEAD_POINT_X_MSB_OFF 0x03
-#define SILEAD_TOUCH_ID_MASK 0xF0
+#define SILEAD_EXTRA_DATA_MASK 0xF0
#define SILEAD_CMD_SLEEP_MIN 10000
#define SILEAD_CMD_SLEEP_MAX 20000
@@ -109,6 +109,9 @@ static int silead_ts_request_input_dev(struct silead_ts_data *data)
INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED |
INPUT_MT_TRACK);
+ if (device_property_read_bool(dev, "silead,home-button"))
+ input_set_capability(data->input, EV_KEY, KEY_LEFTMETA);
+
data->input->name = SILEAD_TS_NAME;
data->input->phys = "input/ts";
data->input->id.bustype = BUS_I2C;
@@ -139,7 +142,8 @@ static void silead_ts_read_data(struct i2c_client *client)
struct input_dev *input = data->input;
struct device *dev = &client->dev;
u8 *bufp, buf[SILEAD_TS_DATA_LEN];
- int touch_nr, error, i;
+ int touch_nr, softbutton, error, i;
+ bool softbutton_pressed = false;
error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_DATA,
SILEAD_TS_DATA_LEN, buf);
@@ -148,21 +152,40 @@ static void silead_ts_read_data(struct i2c_client *client)
return;
}
- touch_nr = buf[0];
- if (touch_nr > data->max_fingers) {
+ if (buf[0] > data->max_fingers) {
dev_warn(dev, "More touches reported then supported %d > %d\n",
- touch_nr, data->max_fingers);
- touch_nr = data->max_fingers;
+ buf[0], data->max_fingers);
+ buf[0] = data->max_fingers;
}
+ touch_nr = 0;
bufp = buf + SILEAD_POINT_DATA_LEN;
- for (i = 0; i < touch_nr; i++, bufp += SILEAD_POINT_DATA_LEN) {
- /* Bits 4-7 are the touch id */
- data->id[i] = (bufp[SILEAD_POINT_X_MSB_OFF] &
- SILEAD_TOUCH_ID_MASK) >> 4;
- touchscreen_set_mt_pos(&data->pos[i], &data->prop,
+ for (i = 0; i < buf[0]; i++, bufp += SILEAD_POINT_DATA_LEN) {
+ softbutton = (bufp[SILEAD_POINT_Y_MSB_OFF] &
+ SILEAD_EXTRA_DATA_MASK) >> 4;
+
+ if (softbutton) {
+ /*
+ * For now only respond to softbutton == 0x01, some
+ * tablets *without* a capacative button send 0x04
+ * when crossing the edges of the screen.
+ */
+ if (softbutton == 0x01)
+ softbutton_pressed = true;
+
+ continue;
+ }
+
+ /*
+ * Bits 4-7 are the touch id, note not all models have
+ * hardware touch ids so atm we don't use these.
+ */
+ data->id[touch_nr] = (bufp[SILEAD_POINT_X_MSB_OFF] &
+ SILEAD_EXTRA_DATA_MASK) >> 4;
+ touchscreen_set_mt_pos(&data->pos[touch_nr], &data->prop,
get_unaligned_le16(&bufp[SILEAD_POINT_X_OFF]) & 0xfff,
get_unaligned_le16(&bufp[SILEAD_POINT_Y_OFF]) & 0xfff);
+ touch_nr++;
}
input_mt_assign_slots(input, data->slots, data->pos, touch_nr, 0);
@@ -178,6 +201,7 @@ static void silead_ts_read_data(struct i2c_client *client)
}
input_mt_sync_frame(input);
+ input_report_key(input, KEY_LEFTMETA, softbutton_pressed);
input_sync(input);
}
--
2.14.2
