[PATCH RESEND 1/1] Add support for touch screens using the General Touch ST6001S controller.

[Gareth Randall <gareth.randall@xxxxxxxxxx>]

Add support for touch screens using the General Touch ST6001S
controller, as found in the GPEG model AOD22WZ-ST monitor.
This controller can output the ELO 10-byte protocol,
but requires different initialisation.

Signed-off-by: Gareth Randall <gareth@xxxxxxxxxxxxxxxxx>
---
 drivers/input/touchscreen/elo.c | 58 +++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/input/touchscreen/elo.c 
b/drivers/input/touchscreen/elo.c
index 96173232e53f..8c15e0eea6b4 100644
--- a/drivers/input/touchscreen/elo.c
+++ b/drivers/input/touchscreen/elo.c
@@ -44,6 +44,8 @@ MODULE_LICENSE("GPL");
 #define ELO10_ACK_PACKET	'A'
 #define ELI10_ID_PACKET		'I'

+#define ELO_GT_INIT_PACKET	"\001XfE\r"
+
 /*
  * Per-touchscreen data.
  */
@@ -201,6 +203,7 @@ static irqreturn_t elo_interrupt(struct serio *serio,

 	switch (elo->id) {
 	case 0:
+	case 4:
 		elo_process_data_10(elo, data);
 		break;

@@ -255,6 +258,54 @@ static int elo_command_10(struct elo *elo, unsigned 
char *packet)
 	return rc;
 }

+/*
+ * Initialise the General Touch ST6001S controller.
+ */
+static int elo_command_10_gt(struct elo *elo)
+{
+	int rc = -1;
+	int i;
+	unsigned char *packet = ELO_GT_INIT_PACKET;
+
+	mutex_lock(&elo->cmd_mutex);
+
+	serio_pause_rx(elo->serio);
+	init_completion(&elo->cmd_done);
+	serio_continue_rx(elo->serio);
+
+	for (i = 0; i < (int)strlen(packet); i++) {
+		if (serio_write(elo->serio, packet[i]))
+			goto out;
+	}
+
+	wait_for_completion_timeout(&elo->cmd_done, HZ);
+	rc = 0;
+
+ out:
+	mutex_unlock(&elo->cmd_mutex);
+	return rc;
+}
+
+static int elo_setup_10_gt(struct elo *elo)
+{
+	struct input_dev *dev = elo->dev;
+
+	if (elo_command_10_gt(elo))
+		return -1;
+
+	__set_bit(INPUT_PROP_DIRECT, dev->propbit);
+
+	// Values taken from a GPEG model AOD22WZ-ST monitor
+	input_set_abs_params(dev, ABS_X, 1365, 5828, 0, 0);
+	// max and min inverted because screen axis is inverted
+	input_set_abs_params(dev, ABS_Y, 5013, 2260, 0, 0);
+
+	dev_info(&elo->serio->dev,
+		 "GeneralTouch ST6001S touchscreen");
+
+	return 0;
+}
+
 static int elo_setup_10(struct elo *elo)
 {
 	static const char *elo_types[] = { "Accu", "Dura", "Intelli", 
"Carroll" };
@@ -361,6 +412,13 @@ static int elo_connect(struct serio *serio, struct 
serio_driver *drv)
 		input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
 		break;
+
+	case 4: /* 10-byte protocol with General Touch initialisation */
+		if (elo_setup_10_gt(elo)) {
+			err = -EIO;
+			goto fail3;
+		}
+		break;
 	}

 	err = input_register_device(elo->dev);
--
2.27.0