[media] uvcvideo: Add quirk to force the Oculus DK2 IR tracker to grayscale

This patch adds a quirk to force Y8 pixel format even if the camera reports
half-width YUYV.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/usb/uvc/uvc_driver.c

@@ -331,6 +331,7 @@ static int uvc_parse_format(struct uvc_device *dev,
 	struct uvc_format_desc *fmtdesc;
 	struct uvc_frame *frame;
 	const unsigned char *start = buffer;
+	unsigned int width_multiplier = 1;
 	unsigned int interval;
 	unsigned int i, n;
 	__u8 ftype;
@@ -366,6 +367,20 @@ static int uvc_parse_format(struct uvc_device *dev,
 		}
 
 		format->bpp = buffer[21];
+
+		/* Some devices report a format that doesn't match what they
+		 * really send.
+		 */
+		if (dev->quirks & UVC_QUIRK_FORCE_Y8) {
+			if (format->fcc == V4L2_PIX_FMT_YUYV) {
+				strlcpy(format->name, "Greyscale 8-bit (Y8  )",
+					sizeof(format->name));
+				format->fcc = V4L2_PIX_FMT_GREY;
+				format->bpp = 8;
+				width_multiplier = 2;
+			}
+		}
+
 		if (buffer[2] == UVC_VS_FORMAT_UNCOMPRESSED) {
 			ftype = UVC_VS_FRAME_UNCOMPRESSED;
 		} else {
@@ -474,7 +489,8 @@ static int uvc_parse_format(struct uvc_device *dev,
 
 		frame->bFrameIndex = buffer[3];
 		frame->bmCapabilities = buffer[4];
-		frame->wWidth = get_unaligned_le16(&buffer[5]);
+		frame->wWidth = get_unaligned_le16(&buffer[5])
+			      * width_multiplier;
 		frame->wHeight = get_unaligned_le16(&buffer[7]);
 		frame->dwMinBitRate = get_unaligned_le32(&buffer[9]);
 		frame->dwMaxBitRate = get_unaligned_le32(&buffer[13]);
@@ -2504,6 +2520,15 @@ static struct usb_device_id uvc_ids[] = {
 	  .bInterfaceProtocol	= 0,
 	  .driver_info		= UVC_QUIRK_PROBE_MINMAX
 				| UVC_QUIRK_IGNORE_SELECTOR_UNIT },
+	/* Oculus VR Positional Tracker DK2 */
+	{ .match_flags		= USB_DEVICE_ID_MATCH_DEVICE
+				| USB_DEVICE_ID_MATCH_INT_INFO,
+	  .idVendor		= 0x2833,
+	  .idProduct		= 0x0201,
+	  .bInterfaceClass	= USB_CLASS_VIDEO,
+	  .bInterfaceSubClass	= 1,
+	  .bInterfaceProtocol	= 0,
+	  .driver_info		= UVC_QUIRK_FORCE_Y8 },
 	/* Generic USB Video Class */
 	{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },
 	{}

drivers/media/usb/uvc/uvcvideo.h

@@ -148,6 +148,7 @@
 #define UVC_QUIRK_PROBE_DEF		0x00000100
 #define UVC_QUIRK_RESTRICT_FRAME_RATE	0x00000200
 #define UVC_QUIRK_RESTORE_CTRLS_ON_INIT	0x00000400
+#define UVC_QUIRK_FORCE_Y8		0x00000800
 
 /* Format flags */
 #define UVC_FMT_FLAG_COMPRESSED		0x00000001