[PATCH 2/2] Input: xpad - add Logitech G923 Xbox variant

[Erica Taylor]

This includes device information for the G923 as well as
code to perform a protocol change to HID++.

Many features do not work as-is with the xpad driver. Almost everything
apart from TrueForce works under the logitech-hidpp driver.

What works:
- Face buttons, D-pad, Xbox button, LB, RB, switch and menu
- Paddle shifters
- One pedal axis

What does not work:
- Force feedback
- TrueForce
- Shifter positions
- Dial and centre button
- +/- buttons
- Steering wheel rotation
- The other two pedal axes

Signed-off-by: Erica Taylor <rickytaylor26@xxxxxxxxx>
---
 drivers/input/joystick/xpad.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index d69d7657ab12..930283433615 100644
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -79,6 +79,7 @@
 #define MAP_DPAD_TO_BUTTONS		(1 << 0)
 #define MAP_TRIGGERS_TO_BUTTONS		(1 << 1)
 #define MAP_STICKS_TO_NULL		(1 << 2)
+#define HIDPP_CAPABLE			BIT(3)
 #define DANCEPAD_MAP_CONFIG	(MAP_DPAD_TO_BUTTONS |			\
 				MAP_TRIGGERS_TO_BUTTONS | MAP_STICKS_TO_NULL)
 
@@ -104,6 +105,10 @@ static bool auto_poweroff = true;
 module_param(auto_poweroff, bool, S_IWUSR | S_IRUGO);
 MODULE_PARM_DESC(auto_poweroff, "Power off wireless controllers on suspend");
 
+static bool switch_to_hidpp = true;
+module_param(switch_to_hidpp, bool, 0444);
+MODULE_PARM_DESC(switch_to_hidpp, "Switch appropriate devices over to the HID++ protocol");
+
 static const struct xpad_device {
 	u16 idVendor;
 	u16 idProduct;
@@ -333,6 +338,8 @@ static const struct xpad_device {
 	{ 0x24c6, 0x5d04, "Razer Sabertooth", 0, XTYPE_XBOX360 },
 	{ 0x24c6, 0xfafe, "Rock Candy Gamepad for Xbox 360", 0, XTYPE_XBOX360 },
 	{ 0x3767, 0x0101, "Fanatec Speedster 3 Forceshock Wheel", 0, XTYPE_XBOX },
+	{ 0x046d, 0xc262, "Logitech G920 Wheel (Xbox Mode)", HIDPP_CAPABLE, XTYPE_XBOXONE },
+	{ 0x046d, 0xc26d, "Logitech G923 Wheel (Xbox Mode)", HIDPP_CAPABLE, XTYPE_XBOXONE },
 	{ 0xffff, 0xffff, "Chinese-made Xbox Controller", 0, XTYPE_XBOX },
 	{ 0x0000, 0x0000, "Generic X-Box pad", 0, XTYPE_UNKNOWN }
 };
@@ -420,6 +427,7 @@ static const struct usb_device_id xpad_table[] = {
 	XPAD_XBOX360_VENDOR(0x045e),		/* Microsoft X-Box 360 controllers */
 	XPAD_XBOXONE_VENDOR(0x045e),		/* Microsoft X-Box One controllers */
 	XPAD_XBOX360_VENDOR(0x046d),		/* Logitech X-Box 360 style controllers */
+	XPAD_XBOXONE_VENDOR(0x046d),		/* Logitech X-Box One style controllers */
 	XPAD_XBOX360_VENDOR(0x056e),		/* Elecom JC-U3613M */
 	XPAD_XBOX360_VENDOR(0x06a3),		/* Saitek P3600 */
 	XPAD_XBOX360_VENDOR(0x0738),		/* Mad Catz X-Box 360 controllers */
@@ -558,6 +566,17 @@ static const struct xboxone_init_packet xboxone_init_packets[] = {
 	XBOXONE_INIT_PKT(0x24c6, 0x543a, xboxone_rumbleend_init),
 };
 
+/*
+ * A magic packet sent to Logitech devices to tell them to change to the HID++
+ * protocol. This is preferred when in use on a PC.
+ *
+ * After receiving this packet, the device will disconnect and reappear with
+ * a different productId, which will be picked up by the Logitech HID++ driver.
+ */
+static const u8 switch_to_hidpp_cmd[] = {
+	0x0f, 0x00, 0x01, 0x01, 0x42
+};
+
 struct xpad_output_packet {
 	u8 data[XPAD_PKT_LEN];
 	u8 len;
@@ -998,6 +1017,14 @@ static bool xpad_prepare_next_init_packet(struct usb_xpad *xpad)
 		return true;
 	}
 
+	if (switch_to_hidpp && xpad->mapping & HIDPP_CAPABLE) {
+		dev_dbg(&xpad->intf->dev, "%s - switching to HID++", __func__);
+		memcpy(xpad->odata, g923_hidpp_init, ARRAY_SIZE(g923_hidpp_init));
+		xpad->irq_out->transfer_buffer_length = ARRAY_SIZE(g923_hidpp_init);
+		xpad->odata[2] = xpad->odata_serial++;
+		return true;
+	}
+
 	return false;
 }
 
-- 
2.31.1