HID: elecom: add support for EX-G M-XGL20DLBK wireless mouse

Enables three buttons (Fn1, Fn2, and Fn3) on the ELECOM M-XGL20DLBK
wireless mouse.

While this mouse is EX-G brand, report descriptor is a bit different
from EX-G trackball mouse. To enable extra buttons, report should be
rewritten in a similar way to trackballs, but with different position
parameters.
Signed-off-by: YOSHIOKA Takuma <lo48576@hard-wi.red>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-elecom.c

@@ -64,6 +64,16 @@ static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 			rdesc[47] = 0x00;
 		}
 		break;
+	case USB_DEVICE_ID_ELECOM_M_XGL20DLBK:
+		/*
+		 * Report descriptor format:
+		 * 20: button bit count
+		 * 28: padding bit count
+		 * 22: button report size
+		 * 14: button usage maximum
+		 */
+		mouse_button_fixup(hdev, rdesc, *rsize, 20, 28, 22, 14, 8);
+		break;
 	case USB_DEVICE_ID_ELECOM_M_XT3URBK:
 	case USB_DEVICE_ID_ELECOM_M_XT3DRBK:
 	case USB_DEVICE_ID_ELECOM_M_XT4DRBK:
@@ -96,6 +106,7 @@ static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 
 static const struct hid_device_id elecom_devices[] = {
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },

drivers/hid/hid-ids.h

@@ -390,6 +390,7 @@
 
 #define USB_VENDOR_ID_ELECOM		0x056e
 #define USB_DEVICE_ID_ELECOM_BM084	0x0061
+#define USB_DEVICE_ID_ELECOM_M_XGL20DLBK	0x00e6
 #define USB_DEVICE_ID_ELECOM_M_XT3URBK	0x00fb
 #define USB_DEVICE_ID_ELECOM_M_XT3DRBK	0x00fc
 #define USB_DEVICE_ID_ELECOM_M_XT4DRBK	0x00fd

drivers/hid/hid-quirks.c

@@ -366,6 +366,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
 #endif
 #if IS_ENABLED(CONFIG_HID_ELECOM)
 	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_BM084) },
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XGL20DLBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3URBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT3DRBK) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELECOM, USB_DEVICE_ID_ELECOM_M_XT4DRBK) },