3 files changed, 28 insertions, 0 deletions

diff --git a/drivers/hid/hid-chicony.c b/drivers/hid/hid-chicony.c
index b613d5a79684..bc3cec199fee 100644
--- a/drivers/hid/hid-chicony.c
+++ b/drivers/hid/hid-chicony.c
@@ -20,6 +20,7 @@
 #include <linux/input.h>
 #include <linux/hid.h>
 #include <linux/module.h>
+#include <linux/usb.h>
 
 #include "hid-ids.h"
 
@@ -57,10 +58,34 @@ static int ch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
         return 1;
 }
 
+static __u8 *ch_switch12_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+                unsigned int *rsize)
+{
+        struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+        
+        if (intf->cur_altsetting->desc.bInterfaceNumber == 1) {
+                /* Change usage maximum and logical maximum from 0x7fff to
+                 * 0x2fff, so they don't exceed HID_MAX_USAGES */
+                switch (hdev->product) {
+                case USB_DEVICE_ID_CHICONY_ACER_SWITCH12:
+                        if (*rsize >= 128 && rdesc[64] == 0xff && rdesc[65] == 0x7f
+                                        && rdesc[69] == 0xff && rdesc[70] == 0x7f) {
+                                hid_info(hdev, "Fixing up report descriptor\n");
+                                rdesc[65] = rdesc[70] = 0x2f;
+                        }
+                        break;
+                }
+
+        }
+        return rdesc;
+}
+
+
 static const struct hid_device_id ch_devices[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_TACTICAL_PAD) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS2) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_AK1D) },
+        { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_ACER_SWITCH12) },
         { }
 };
 MODULE_DEVICE_TABLE(hid, ch_devices);
@@ -68,6 +93,7 @@ MODULE_DEVICE_TABLE(hid, ch_devices);
 static struct hid_driver ch_driver = {
         .name = "chicony",
         .id_table = ch_devices,
+        .report_fixup = ch_switch12_report_fixup,
         .input_mapping = ch_input_mapping,
 };
 module_hid_driver(ch_driver);
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 157c62775053..a77d30388b4d 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1804,6 +1804,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_WIRELESS2) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_AK1D) },
+        { HID_USB_DEVICE(USB_VENDOR_ID_CHICONY, USB_DEVICE_ID_CHICONY_ACER_SWITCH12) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CREATIVELABS, USB_DEVICE_ID_PRODIKEYS_PCMIDI) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CYGNAL, USB_DEVICE_ID_CYGNAL_CP2112) },
         { HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS, USB_DEVICE_ID_CYPRESS_BARCODE_1) },
diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index b04b0820d816..7c712dff2ca1 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -230,6 +230,7 @@
 #define USB_DEVICE_ID_CHICONY_PIXART_USB_OPTICAL_MOUSE  0x1053
 #define USB_DEVICE_ID_CHICONY_WIRELESS2 0x1123
 #define USB_DEVICE_ID_CHICONY_AK1D      0x1125
+#define USB_DEVICE_ID_CHICONY_ACER_SWITCH12     0x1421
 
 #define USB_VENDOR_ID_CHUNGHWAT         0x2247
 #define USB_DEVICE_ID_CHUNGHWAT_MULTITOUCH      0x0001