[PATCH 2/2] Use usb_skelswitch module to switch Logitech G920 Racing Wheel to HID mode.

["Michal Malý" <madcatxster@devoid-pointer.net>]

Tested-by: Elias Vanderstuyft <elias.vds@gmail.com>
Signed-off-by: Michal Malý <madcatxster@devoid-pointer.net>
---
 drivers/usb/common/Kconfig          |  2 ++
 drivers/usb/common/usb-skelswitch.c | 60 +++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/drivers/usb/common/Kconfig b/drivers/usb/common/Kconfig
index 6d9ec79..8ae9a1e 100644
--- a/drivers/usb/common/Kconfig
+++ b/drivers/usb/common/Kconfig
@@ -11,5 +11,7 @@ config USB_SKELSWITCH
 	  appear as a generic USB device.
 
 	  Say Y if you intend to use a device that requires this initial switch.
+	  Devices that currently require this module:
+	   - Logitech G920 Racing Wheel
 
 endif # USB_COMMON
diff --git a/drivers/usb/common/usb-skelswitch.c b/drivers/usb/common/usb-skelswitch.c
index ae72068..fc85c70 100644
--- a/drivers/usb/common/usb-skelswitch.c
+++ b/drivers/usb/common/usb-skelswitch.c
@@ -14,10 +14,70 @@ struct usb_skelswitch_vendor {
 };
 
 static const struct usb_device_id usb_skelswitch_table[] = {
+	{ USB_DEVICE(0x046d, 0xc261) },
 	{ }
 };
 
+MODULE_DEVICE_TABLE(usb, usb_skelswitch_table);
+
+static int usb_skelswitch_lg_g920(struct usb_interface *intf)
+{
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	struct usb_device *udev;
+	int idx;
+	int ret;
+	int xferred;
+	size_t buffer_size;
+	unsigned char cmd[] = { 0x0f, 0x00, 0x01, 0x01, 0x42 };
+	const size_t cmd_len = ARRAY_SIZE(cmd);
+	u8 intr_out_addr = 0;
+
+	udev = usb_get_dev(interface_to_usbdev(intf));
+	iface_desc = intf->cur_altsetting;
+	for (idx = 0; idx < iface_desc->desc.bNumEndpoints; idx++) {
+		endpoint = &iface_desc->endpoint[idx].desc;
+
+		if (usb_endpoint_is_int_out(endpoint)) {
+			intr_out_addr = endpoint->bEndpointAddress;
+			buffer_size = usb_endpoint_maxp(endpoint);
+			break;
+		}
+	}
+
+	if (!intr_out_addr) {
+		dev_err(&udev->dev, "Logitech G920 - No interrupt out endpoint found");
+		return -ENODEV;
+	}
+
+	if (buffer_size < cmd_len) {
+		dev_err(&udev->dev, "usb_skelswitch: Logitech G920 - Output buffer is too small");
+		return -ENODEV;
+	}
+
+
+	ret = usb_interrupt_msg(udev, usb_sndintpipe(udev, intr_out_addr),
+				cmd, cmd_len, &xferred, USB_CTRL_SET_TIMEOUT);
+
+	if (ret) {
+		dev_err(&udev->dev, "LG G920: Failed to submit URB, errno: %d", ret);
+		return ret;
+	}
+	if (xferred != cmd_len) {
+		dev_err(&udev->dev, "LG G920: Incorrect number of bytes transferred: %d", xferred);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static const struct usb_skelswitch_product usb_skelswitch_logitech_devs[] = {
+	{ 0xc261, usb_skelswitch_lg_g920 },
+	{ 0, NULL }
+};
+
 static const struct usb_skelswitch_vendor usb_skelswitch_vendors[] = {
+	{ 0x046d, usb_skelswitch_logitech_devs },
 	{ 0, NULL }
 };
 
-- 
2.7.0