[PATCH] HID: kye: Add report fixup for Genius Gx Imperator Keyboard

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Genius Gx Imperator Keyboard presents the same problem in its report
descriptors than Genius Gila Gaming Mouse.
Use the same fixup for both.

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=928561

Reported-and-tested-by: Honza Brazdil <jbrazdil@redhat.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

Hi Jiri,

I have been reported this broken Genius device too.
The patch applies on top of the branch for-3.11/upstream, but feel free to
schedule it for 3.11 or 3.12. This time, only the multimedia (and macros) keys
are broken. The core keyboard part is working fine without the patch.

Cheers,
Benjamin

 drivers/hid/hid-ids.h |  1 +
 drivers/hid/hid-kye.c | 45 ++++++++++++++++++++++++++++-----------------
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index b2b692e..1f28df9 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -475,6 +475,7 @@
 #define USB_VENDOR_ID_KYE		0x0458
 #define USB_DEVICE_ID_KYE_ERGO_525V	0x0087
 #define USB_DEVICE_ID_GENIUS_GILA_GAMING_MOUSE	0x0138
+#define USB_DEVICE_ID_GENIUS_GX_IMPERATOR	0x4018
 #define USB_DEVICE_ID_KYE_GPEN_560	0x5003
 #define USB_DEVICE_ID_KYE_EASYPEN_I405X	0x5010
 #define USB_DEVICE_ID_KYE_MOUSEPEN_I608X	0x5011
diff --git a/drivers/hid/hid-kye.c b/drivers/hid/hid-kye.c
index 1e2ee2aa..7384512 100644
--- a/drivers/hid/hid-kye.c
+++ b/drivers/hid/hid-kye.c
@@ -268,6 +268,26 @@ static __u8 easypen_m610x_rdesc_fixed[] = {
 	0xC0                          /*  End Collection                  */
 };
 
+static __u8 *kye_consumer_control_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize, int offset, const char *device_name) {
+	/*
+	 * the fixup that need to be done:
+	 *   - change Usage Maximum in the Comsumer Control
+	 *     (report ID 3) to a reasonable value
+	 */
+	if (*rsize >= offset + 31 &&
+	    /* Usage Page (Consumer Devices) */
+	    rdesc[offset] == 0x05 && rdesc[offset + 1] == 0x0c &&
+	    /* Usage (Consumer Control) */
+	    rdesc[offset + 2] == 0x09 && rdesc[offset + 3] == 0x01 &&
+	    /*   Usage Maximum > 12287 */
+	    rdesc[offset + 10] == 0x2a && rdesc[offset + 12] > 0x2f) {
+		hid_info(hdev, "fixing up %s report descriptor\n", device_name);
+		rdesc[offset + 12] = 0x2f;
+	}
+	return rdesc;
+}
+
 static __u8 *kye_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		unsigned int *rsize)
 {
@@ -315,23 +335,12 @@ static __u8 *kye_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		}
 		break;
 	case USB_DEVICE_ID_GENIUS_GILA_GAMING_MOUSE:
-		/*
-		 * the fixup that need to be done:
-		 *   - change Usage Maximum in the Comsumer Control
-		 *     (report ID 3) to a reasonable value
-		 */
-		if (*rsize >= 135 &&
-			/* Usage Page (Consumer Devices) */
-			rdesc[104] == 0x05 && rdesc[105] == 0x0c &&
-			/* Usage (Consumer Control) */
-			rdesc[106] == 0x09 && rdesc[107] == 0x01 &&
-			/*   Usage Maximum > 12287 */
-			rdesc[114] == 0x2a && rdesc[116] > 0x2f) {
-			hid_info(hdev,
-				 "fixing up Genius Gila Gaming Mouse "
-				 "report descriptor\n");
-			rdesc[116] = 0x2f;
-		}
+		rdesc = kye_consumer_control_fixup(hdev, rdesc, rsize, 104,
+					"Genius Gila Gaming Mouse");
+		break;
+	case USB_DEVICE_ID_GENIUS_GX_IMPERATOR:
+		rdesc = kye_consumer_control_fixup(hdev, rdesc, rsize, 83,
+					"Genius Gx Imperator Keyboard");
 		break;
 	}
 	return rdesc;
@@ -428,6 +437,8 @@ static const struct hid_device_id kye_devices[] = {
 				USB_DEVICE_ID_KYE_EASYPEN_M610X) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_KYE,
 				USB_DEVICE_ID_GENIUS_GILA_GAMING_MOUSE) },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_KYE,
+				USB_DEVICE_ID_GENIUS_GX_IMPERATOR) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, kye_devices);
-- 
1.8.3.1