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

[Gareth Randall <gareth.randall@virgin.net>]

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@garethrandall.com>
---
  drivers/input/touchscreen/elo.c | 81 ++++++++++++++++++++++++++++++++-
  1 file changed, 80 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/elo.c b/drivers/input/touchscreen/elo.c
index 96173232e53f..b233869ffa2a 100644
--- a/drivers/input/touchscreen/elo.c
+++ b/drivers/input/touchscreen/elo.c
@@ -26,6 +26,27 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
  MODULE_DESCRIPTION(DRIVER_DESC);
  MODULE_LICENSE("GPL");

+static uint gt_abs_x_min;
+module_param(gt_abs_x_min, uint, 0444);
+MODULE_PARM_DESC(gt_abs_x_min, "abs_x min value in General Touch mode (default: 0)");
+
+static uint gt_abs_x_max = 4095;
+module_param(gt_abs_x_max, uint, 0444);
+MODULE_PARM_DESC(gt_abs_x_max, "abs_x max value in General Touch mode (default: 4095)");
+
+static uint gt_abs_y_min;
+module_param(gt_abs_y_min, uint, 0444);
+MODULE_PARM_DESC(gt_abs_y_min, "abs_y min value in General Touch mode (default: 0)");
+
+static uint gt_abs_y_max = 4095;
+module_param(gt_abs_y_max, uint, 0444);
+MODULE_PARM_DESC(gt_abs_y_max, "abs_y max value in General Touch mode (default: 4095)");
+
+static bool gt_mode_override;
+module_param(gt_mode_override, bool, 0444);
+MODULE_PARM_DESC(gt_mode_override, "force the use of General Touch mode (default: false)");
+
+
  /*
   * Definitions & global arrays.
   */
@@ -44,6 +65,8 @@ 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 +224,7 @@ static irqreturn_t elo_interrupt(struct serio *serio,

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

@@ -255,6 +279,50 @@ 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 -EIO;
+
+	input_set_abs_params(dev, ABS_X, gt_abs_x_min, gt_abs_x_max, 0, 0);
+	input_set_abs_params(dev, ABS_Y, gt_abs_y_min, gt_abs_y_max, 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" };
@@ -273,7 +341,7 @@ static int elo_setup_10(struct elo *elo)

  	dev_info(&elo->serio->dev,
  		 "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
-		 elo_types[(packet[1] -'0') & 0x03],
+		 elo_types[(packet[1] - '0') & 0x03],
  		 packet[5], packet[4], packet[3], packet[7]);

  	return 0;
@@ -332,12 +400,16 @@ static int elo_connect(struct serio *serio, struct serio_driver *drv)

  	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
  	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);

  	serio_set_drvdata(serio, elo);
  	err = serio_open(serio, drv);
  	if (err)
  		goto fail2;

+	if (gt_mode_override)
+		elo->id = 4;
+
  	switch (elo->id) {

  	case 0: /* 10-byte protocol */
@@ -361,6 +433,13 @@ 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