[PATCH v3 2/3] Input: joystick: xpad: Add X-Box Adaptive Controller Layer button

[Nate Yocom <nate@yocom.org>]

Adds a new quirk for controllers that have a Layer button which has 4
states, reflected as an ABS_MISC axis with 4 values.

Signed-off-by: Nate Yocom <nate@yocom.org>
---
 drivers/input/joystick/xpad.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index c8b38bb73d34..83a4f4d07af5 100644
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -80,6 +80,7 @@
 #define MAP_TRIGGERS_TO_BUTTONS		(1 << 1)
 #define MAP_STICKS_TO_NULL		(1 << 2)
 #define MAP_SELECT_BUTTON		(1 << 3)
+#define MAP_LAYER_BUTTON		(1 << 4)
 #define DANCEPAD_MAP_CONFIG	(MAP_DPAD_TO_BUTTONS |			\
 				MAP_TRIGGERS_TO_BUTTONS | MAP_STICKS_TO_NULL)
 
@@ -131,7 +132,7 @@ static const struct xpad_device {
 	{ 0x045e, 0x02e3, "Microsoft X-Box One Elite pad", 0, XTYPE_XBOXONE },
 	{ 0x045e, 0x02ea, "Microsoft X-Box One S pad", 0, XTYPE_XBOXONE },
 	{ 0x045e, 0x0719, "Xbox 360 Wireless Receiver", MAP_DPAD_TO_BUTTONS, XTYPE_XBOX360W },
-	{ 0x045e, 0x0b0a, "Microsoft X-Box Adaptive Controller", 0, XTYPE_XBOXONE },
+	{ 0x045e, 0x0b0a, "Microsoft X-Box Adaptive Controller", MAP_LAYER_BUTTON, XTYPE_XBOXONE },
 	{ 0x045e, 0x0b12, "Microsoft Xbox Series S|X Controller", MAP_SELECT_BUTTON, XTYPE_XBOXONE },
 	{ 0x046d, 0xc21d, "Logitech Gamepad F310", 0, XTYPE_XBOX360 },
 	{ 0x046d, 0xc21e, "Logitech Gamepad F510", 0, XTYPE_XBOX360 },
@@ -927,6 +928,10 @@ static void xpadone_process_packet(struct usb_xpad *xpad, u16 cmd, unsigned char
 				 (__u16) le16_to_cpup((__le16 *)(data + 8)));
 	}
 
+	/* Layer button has a value of 0-4, so it is reported as an axis */
+	if (xpad->mapping & MAP_LAYER_BUTTON)
+		input_report_abs(dev, ABS_MISC, data[34]);
+
 	input_sync(dev);
 }
 
@@ -1623,6 +1628,9 @@ static void xpad_set_up_abs(struct input_dev *input_dev, signed short abs)
 	case ABS_HAT0Y:	/* the d-pad (only if dpad is mapped to axes */
 		input_set_abs_params(input_dev, abs, -1, 1, 0, 0);
 		break;
+	case ABS_MISC: /* 4 value layer button (such as on XAC) */
+		input_set_abs_params(input_dev, abs, 0, 4, 0, 0);
+		break;
 	default:
 		input_set_abs_params(input_dev, abs, 0, 0, 0, 0);
 		break;
@@ -1715,6 +1723,10 @@ static int xpad_init_input(struct usb_xpad *xpad)
 			xpad_set_up_abs(input_dev, xpad_abs_triggers[i]);
 	}
 
+	/* setup layer button as an axis with 4 possible values */
+	if (xpad->mapping & MAP_LAYER_BUTTON)
+		xpad_set_up_abs(input_dev, ABS_MISC);
+
 	error = xpad_init_ff(xpad);
 	if (error)
 		goto err_free_input;
-- 
2.30.2