Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / media / usb / uvc / uvc_isight.c

diff --git a/kernel/drivers/media/usb/uvc/uvc_isight.c b/kernel/drivers/media/usb/uvc/uvc_isight.c
new file mode 100644 (file)
index 0000000..8510e72
--- /dev/null
+++ b/kernel/drivers/media/usb/uvc/uvc_isight.c
@@ -0,0 +1,137 @@
+/*
+ *      uvc_isight.c  --  USB Video Class driver - iSight support
+ *
+ *     Copyright (C) 2006-2007
+ *             Ivan N. Zlatev <contact@i-nz.net>
+ *     Copyright (C) 2008-2009
+ *             Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+
+#include <linux/usb.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include "uvcvideo.h"
+
+/* Built-in iSight webcams implements most of UVC 1.0 except a
+ * different packet format. Instead of sending a header at the
+ * beginning of each isochronous transfer payload, the webcam sends a
+ * single header per image (on its own in a packet), followed by
+ * packets containing data only.
+ *
+ * Offset   Size (bytes)       Description
+ * ------------------------------------------------------------------
+ * 0x00        1       Header length
+ * 0x01        1       Flags (UVC-compliant)
+ * 0x02        4       Always equal to '11223344'
+ * 0x06        8       Always equal to 'deadbeefdeadface'
+ * 0x0e        16      Unknown
+ *
+ * The header can be prefixed by an optional, unknown-purpose byte.
+ */
+
+static int isight_decode(struct uvc_video_queue *queue, struct uvc_buffer *buf,
+               const __u8 *data, unsigned int len)
+{
+       static const __u8 hdr[] = {
+               0x11, 0x22, 0x33, 0x44,
+               0xde, 0xad, 0xbe, 0xef,
+               0xde, 0xad, 0xfa, 0xce
+       };
+
+       unsigned int maxlen, nbytes;
+       __u8 *mem;
+       int is_header = 0;
+
+       if (buf == NULL)
+               return 0;
+
+       if ((len >= 14 && memcmp(&data[2], hdr, 12) == 0) ||
+           (len >= 15 && memcmp(&data[3], hdr, 12) == 0)) {
+               uvc_trace(UVC_TRACE_FRAME, "iSight header found\n");
+               is_header = 1;
+       }
+
+       /* Synchronize to the input stream by waiting for a header packet. */
+       if (buf->state != UVC_BUF_STATE_ACTIVE) {
+               if (!is_header) {
+                       uvc_trace(UVC_TRACE_FRAME, "Dropping packet (out of "
+                                 "sync).\n");
+                       return 0;
+               }
+
+               buf->state = UVC_BUF_STATE_ACTIVE;
+       }
+
+       /* Mark the buffer as done if we're at the beginning of a new frame.
+        *
+        * Empty buffers (bytesused == 0) don't trigger end of frame detection
+        * as it doesn't make sense to return an empty buffer.
+        */
+       if (is_header && buf->bytesused != 0) {
+               buf->state = UVC_BUF_STATE_DONE;
+               return -EAGAIN;
+       }
+
+       /* Copy the video data to the buffer. Skip header packets, as they
+        * contain no data.
+        */
+       if (!is_header) {
+               maxlen = buf->length - buf->bytesused;
+               mem = buf->mem + buf->bytesused;
+               nbytes = min(len, maxlen);
+               memcpy(mem, data, nbytes);
+               buf->bytesused += nbytes;
+
+               if (len > maxlen || buf->bytesused == buf->length) {
+                       uvc_trace(UVC_TRACE_FRAME, "Frame complete "
+                                 "(overflow).\n");
+                       buf->state = UVC_BUF_STATE_DONE;
+               }
+       }
+
+       return 0;
+}
+
+void uvc_video_decode_isight(struct urb *urb, struct uvc_streaming *stream,
+               struct uvc_buffer *buf)
+{
+       int ret, i;
+
+       for (i = 0; i < urb->number_of_packets; ++i) {
+               if (urb->iso_frame_desc[i].status < 0) {
+                       uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
+                                 "lost (%d).\n",
+                                 urb->iso_frame_desc[i].status);
+               }
+
+               /* Decode the payload packet.
+                * uvc_video_decode is entered twice when a frame transition
+                * has been detected because the end of frame can only be
+                * reliably detected when the first packet of the new frame
+                * is processed. The first pass detects the transition and
+                * closes the previous frame's buffer, the second pass
+                * processes the data of the first payload of the new frame.
+                */
+               do {
+                       ret = isight_decode(&stream->queue, buf,
+                                       urb->transfer_buffer +
+                                       urb->iso_frame_desc[i].offset,
+                                       urb->iso_frame_desc[i].actual_length);
+
+                       if (buf == NULL)
+                               break;
+
+                       if (buf->state == UVC_BUF_STATE_DONE ||
+                           buf->state == UVC_BUF_STATE_ERROR)
+                               buf = uvc_queue_next_buffer(&stream->queue,
+                                                       buf);
+               } while (ret == -EAGAIN);
+       }
+}