HID: Add support for side buttons of Xiaomi Mi Dual Mode Wireless Mouse Silent

This patch enables side-buttons of Xiaomi Bluetooth mouse (specifically Xiaomi
Mi Dual Mode Wireless Mouse Silent Edition).

The mouse sends invalid button count in its HID Report Descriptor and this
patch just replaces its descriptor with corrected one. With this driver side
buttons work as expected acting like Back/Forward buttons.
Signed-off-by: Ilya Skriblovsky <ilyaskriblovsky@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -468,6 +468,13 @@ config HID_VIEWSONIC
 	help
 	  Support for ViewSonic/Signotec PD1011 signature pad.
 
+config HID_XIAOMI
+	tristate "Xiaomi"
+	depends on HID
+	help
+	  Adds support for side buttons of Xiaomi Mi Dual Mode Wireless
+	  Mouse Silent Edition.
+
 config HID_GYRATION
 	tristate "Gyration remote control"
 	depends on HID

drivers/hid/Makefile

@@ -125,6 +125,7 @@ hid-uclogic-objs		:= hid-uclogic-core.o \
 obj-$(CONFIG_HID_UCLOGIC)	+= hid-uclogic.o
 obj-$(CONFIG_HID_UDRAW_PS3)	+= hid-udraw-ps3.o
 obj-$(CONFIG_HID_LED)		+= hid-led.o
+obj-$(CONFIG_HID_XIAOMI)	+= hid-xiaomi.o
 obj-$(CONFIG_HID_XINMO)		+= hid-xinmo.o
 obj-$(CONFIG_HID_ZEROPLUS)	+= hid-zpff.o
 obj-$(CONFIG_HID_ZYDACRON)	+= hid-zydacron.o

drivers/hid/hid-ids.h

@@ -1298,6 +1298,9 @@
 #define USB_VENDOR_ID_XAT	0x2505
 #define USB_DEVICE_ID_XAT_CSR	0x0220
 
+#define USB_VENDOR_ID_XIAOMI		0x2717
+#define USB_DEVICE_ID_MI_SILENT_MOUSE	0x5014
+
 #define USB_VENDOR_ID_XIN_MO			0x16c0
 #define USB_DEVICE_ID_XIN_MO_DUAL_ARCADE	0x05e1
 #define USB_DEVICE_ID_THT_2P_ARCADE		0x75e1

drivers/hid/hid-xiaomi.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HID driver for Xiaomi Mi Dual Mode Wireless Mouse Silent Edition
+ *
+ * Copyright (c) 2021 Ilya Skriblovsky
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/hid.h>
+
+#include "hid-ids.h"
+
+/* Fixed Mi Silent Mouse report descriptor */
+/* Button's Usage Maximum changed from 3 to 5 to make side buttons work */
+#define MI_SILENT_MOUSE_ORIG_RDESC_LENGTH   87
+static __u8 mi_silent_mouse_rdesc_fixed[] = {
+	0x05, 0x01,         /*  Usage Page (Desktop),               */
+	0x09, 0x02,         /*  Usage (Mouse),                      */
+	0xA1, 0x01,         /*  Collection (Application),           */
+	0x85, 0x03,         /*      Report ID (3),                  */
+	0x09, 0x01,         /*      Usage (Pointer),                */
+	0xA1, 0x00,         /*      Collection (Physical),          */
+	0x05, 0x09,         /*          Usage Page (Button),        */
+	0x19, 0x01,         /*          Usage Minimum (01h),        */
+	0x29, 0x05, /* X */ /*          Usage Maximum (05h),        */
+	0x15, 0x00,         /*          Logical Minimum (0),        */
+	0x25, 0x01,         /*          Logical Maximum (1),        */
+	0x75, 0x01,         /*          Report Size (1),            */
+	0x95, 0x05,         /*          Report Count (5),           */
+	0x81, 0x02,         /*          Input (Variable),           */
+	0x75, 0x03,         /*          Report Size (3),            */
+	0x95, 0x01,         /*          Report Count (1),           */
+	0x81, 0x01,         /*          Input (Constant),           */
+	0x05, 0x01,         /*          Usage Page (Desktop),       */
+	0x09, 0x30,         /*          Usage (X),                  */
+	0x09, 0x31,         /*          Usage (Y),                  */
+	0x15, 0x81,         /*          Logical Minimum (-127),     */
+	0x25, 0x7F,         /*          Logical Maximum (127),      */
+	0x75, 0x08,         /*          Report Size (8),            */
+	0x95, 0x02,         /*          Report Count (2),           */
+	0x81, 0x06,         /*          Input (Variable, Relative), */
+	0x09, 0x38,         /*          Usage (Wheel),              */
+	0x15, 0x81,         /*          Logical Minimum (-127),     */
+	0x25, 0x7F,         /*          Logical Maximum (127),      */
+	0x75, 0x08,         /*          Report Size (8),            */
+	0x95, 0x01,         /*          Report Count (1),           */
+	0x81, 0x06,         /*          Input (Variable, Relative), */
+	0xC0,               /*      End Collection,                 */
+	0xC0,               /*  End Collection,                     */
+	0x06, 0x01, 0xFF,   /*  Usage Page (FF01h),                 */
+	0x09, 0x01,         /*  Usage (01h),                        */
+	0xA1, 0x01,         /*  Collection (Application),           */
+	0x85, 0x05,         /*      Report ID (5),                  */
+	0x09, 0x05,         /*      Usage (05h),                    */
+	0x15, 0x00,         /*      Logical Minimum (0),            */
+	0x26, 0xFF, 0x00,   /*      Logical Maximum (255),          */
+	0x75, 0x08,         /*      Report Size (8),                */
+	0x95, 0x04,         /*      Report Count (4),               */
+	0xB1, 0x02,         /*      Feature (Variable),             */
+	0xC0                /*  End Collection                      */
+};
+
+static __u8 *xiaomi_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+				 unsigned int *rsize)
+{
+	switch (hdev->product) {
+	case USB_DEVICE_ID_MI_SILENT_MOUSE:
+		if (*rsize == MI_SILENT_MOUSE_ORIG_RDESC_LENGTH) {
+			hid_info(hdev, "fixing up Mi Silent Mouse report descriptor\n");
+			rdesc = mi_silent_mouse_rdesc_fixed;
+			*rsize = sizeof(mi_silent_mouse_rdesc_fixed);
+		}
+		break;
+	}
+	return rdesc;
+}
+
+static const struct hid_device_id xiaomi_devices[] = {
+	{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_XIAOMI, USB_DEVICE_ID_MI_SILENT_MOUSE) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, xiaomi_devices);
+
+static struct hid_driver xiaomi_driver = {
+	.name = "xiaomi",
+	.id_table = xiaomi_devices,
+	.report_fixup = xiaomi_report_fixup,
+};
+module_hid_driver(xiaomi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Ilya Skriblovsky <IlyaSkriblovsky@gmail.com>");
+MODULE_DESCRIPTION("Fixing side buttons of Xiaomi Mi Silent Mouse");