Input: ektf2127 - add support for eKTF2132 touchscreen

The eKTF2132 is a touchscreen controller found, for example, in the Kobo
Aura ebook reader. It is similar to the ektf2127, but it uses a different
packet type to report touch events.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201106112412.390724-3-j.neuschaefer@gmx.netSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/ektf2127.c

@@ -28,6 +28,7 @@
 #define EKTF2127_RESPONSE		0x52
 #define EKTF2127_REQUEST		0x53
 #define EKTF2127_HELLO			0x55
+#define EKTF2127_REPORT2		0x5a
 #define EKTF2127_REPORT			0x5d
 #define EKTF2127_CALIB_DONE		0x66
 
@@ -95,6 +96,29 @@ static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
 	input_sync(ts->input);
 }
 
+static void ektf2127_report2_contact(struct ektf2127_ts *ts, int slot,
+				     const u8 *buf, bool active)
+{
+	input_mt_slot(ts->input, slot);
+	input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, active);
+
+	if (active) {
+		int x = (buf[0] & 0xf0) << 4 | buf[1];
+		int y = (buf[0] & 0x0f) << 8 | buf[2];
+
+		touchscreen_report_pos(ts->input, &ts->prop, x, y, true);
+	}
+}
+
+static void ektf2127_report2_event(struct ektf2127_ts *ts, const u8 *buf)
+{
+	ektf2127_report2_contact(ts, 0, &buf[1], !!(buf[7] & 2));
+	ektf2127_report2_contact(ts, 1, &buf[4], !!(buf[7] & 4));
+
+	input_mt_sync_frame(ts->input);
+	input_sync(ts->input);
+}
+
 static irqreturn_t ektf2127_irq(int irq, void *dev_id)
 {
 	struct ektf2127_ts *ts = dev_id;
@@ -113,6 +137,10 @@ static irqreturn_t ektf2127_irq(int irq, void *dev_id)
 		ektf2127_report_event(ts, buf);
 		break;
 
+	case EKTF2127_REPORT2:
+		ektf2127_report2_event(ts, buf);
+		break;
+
 	case EKTF2127_NOISE:
 		if (buf[1] == EKTF2127_ENV_NOISY)
 			dev_dbg(dev, "Environment is electrically noisy\n");
@@ -305,6 +333,7 @@ static int ektf2127_probe(struct i2c_client *client,
 #ifdef CONFIG_OF
 static const struct of_device_id ektf2127_of_match[] = {
 	{ .compatible = "elan,ektf2127" },
+	{ .compatible = "elan,ektf2132" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, ektf2127_of_match);
@@ -312,6 +341,7 @@ MODULE_DEVICE_TABLE(of, ektf2127_of_match);
 
 static const struct i2c_device_id ektf2127_i2c_id[] = {
 	{ "ektf2127", 0 },
+	{ "ektf2132", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
@@ -327,6 +357,6 @@ static struct i2c_driver ektf2127_driver = {
 };
 module_i2c_driver(ektf2127_driver);
 
-MODULE_DESCRIPTION("ELAN eKTF2127 I2C Touchscreen Driver");
+MODULE_DESCRIPTION("ELAN eKTF2127/eKTF2132 I2C Touchscreen Driver");
 MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
 MODULE_LICENSE("GPL");