Input: surface3_spi - Prepare to add support for Surface Pen

Surface Pens can be supported by handling a second report type. Prepare
for this change.

Signed-off-by: Stephen Just <stephenjust@gmail.com>
Reviewed-and-tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/surface3_spi.c

@@ -26,6 +26,8 @@
 
 #define SURFACE3_PACKET_SIZE	264
 
+#define SURFACE3_REPORT_TOUCH	0xd2
+
 struct surface3_ts_data {
 	struct spi_device *spi;
 	struct gpio_desc *gpiod_rst[2];
@@ -83,19 +85,10 @@ static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
 	}
 }
 
-static void surface3_spi_process(struct surface3_ts_data *ts_data)
+static void surface3_spi_process_touch(struct surface3_ts_data *ts_data, u8 *data)
 {
-	const char header[] = {0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e,
-			       0x01, 0xd2, 0x00, 0x80, 0x01, 0x03, 0x03};
-	u8 *data = ts_data->rd_buf;
 	u16 timestamp;
 	unsigned int i;
-
-	if (memcmp(header, data, sizeof(header)))
-		dev_err(&ts_data->spi->dev,
-			"%s header error: %*ph, ignoring...\n",
-			__func__, (int)sizeof(header), data);
-
 	timestamp = get_unaligned_le16(&data[15]);
 
 	for (i = 0; i < 13; i++) {
@@ -120,6 +113,26 @@ static void surface3_spi_process(struct surface3_ts_data *ts_data)
 	input_sync(ts_data->input_dev);
 }
 
+static void surface3_spi_process(struct surface3_ts_data *ts_data)
+{
+	const char header[] = {
+		0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e, 0x01
+	};
+	u8 *data = ts_data->rd_buf;
+
+	if (memcmp(header, data, sizeof(header)))
+		dev_err(&ts_data->spi->dev,
+			"%s header error: %*ph, ignoring...\n",
+			__func__, (int)sizeof(header), data);
+
+	if (data[9] == SURFACE3_REPORT_TOUCH)
+		surface3_spi_process_touch(ts_data, data);
+	else
+		dev_err(&ts_data->spi->dev,
+			"%s unknown packet type: %x, ignoring...\n",
+			__func__, data[9]);
+}
+
 static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
 {
 	struct surface3_ts_data *data = dev_id;
@@ -175,7 +188,7 @@ static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
 	return 0;
 }
 
-static int surface3_spi_create_input(struct surface3_ts_data *data)
+static int surface3_spi_create_touch_input(struct surface3_ts_data *data)
 {
 	struct input_dev *input;
 	int error;
@@ -198,7 +211,7 @@ static int surface3_spi_create_input(struct surface3_ts_data *data)
 	input->phys = "input/ts";
 	input->id.bustype = BUS_SPI;
 	input->id.vendor = 0x045e;	/* Microsoft */
-	input->id.product = 0x0000;
+	input->id.product = 0x0001;
 	input->id.version = 0x0000;
 
 	error = input_register_device(input);
@@ -238,7 +251,7 @@ static int surface3_spi_probe(struct spi_device *spi)
 	surface3_spi_power(data, false);
 	surface3_spi_power(data, true);
 
-	error = surface3_spi_create_input(data);
+	error = surface3_spi_create_touch_input(data);
 	if (error)
 		return error;