V4L/DVB (10197): uvcvideo: Whitespace and comments cleanup, copyright updates.

[mirror_ubuntu-bionic-kernel.git] / drivers / media / video / uvc / uvc_video.c

diff --git a/drivers/media/video/uvc/uvc_video.c b/drivers/media/video/uvc/uvc_video.c
index e7c31995527f3d520d50283b8246e5cc5a312b6c..f9eb0e9740511b3a9cd5a6c397e013e96e59b478 100644 (file)
--- a/drivers/media/video/uvc/uvc_video.c
+++ b/drivers/media/video/uvc/uvc_video.c
@@ -1,7 +1,7 @@
 /*
  *      uvc_video.c  --  USB Video Class driver - Video handling
  *
- *      Copyright (C) 2005-2008
+ *      Copyright (C) 2005-2009
  *          Laurent Pinchart (laurent.pinchart@skynet.be)
  *
  *      This program is free software; you can redistribute it and/or modify
@@ -12,7 +12,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/version.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/usb.h>
@@ -160,7 +159,7 @@ static int uvc_get_video_ctrl(struct uvc_video_device *video,
        }
 
        /* Some broken devices return a null or wrong dwMaxVideoFrameSize.
-        * Try to get the value from the format and frame descriptor.
+        * Try to get the value from the format and frame descriptors.
         */
        uvc_fixup_buffer_size(video, ctrl);
        ret = 0;
@@ -191,9 +190,6 @@ static int uvc_set_video_ctrl(struct uvc_video_device *video,
        *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
        *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
        *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
-       /* Note: Some of the fields below are not required for IN devices (see
-        * UVC spec, 4.3.1.1), but we still copy them in case support for OUT
-        * devices is added in the future. */
        put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
        put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
 
@@ -400,7 +396,7 @@ static int uvc_video_decode_start(struct uvc_video_device *video,
         *
         * Empty buffers (bytesused == 0) don't trigger end of frame detection
         * as it doesn't make sense to return an empty buffer. This also
-        * avoids detecting and of frame conditions at FID toggling if the
+        * avoids detecting end of frame conditions at FID toggling if the
         * previous payload had the EOF bit set.
         */
        if (fid != video->last_fid && buf->buf.bytesused != 0) {
@@ -453,6 +449,17 @@ static void uvc_video_decode_end(struct uvc_video_device *video,
        }
 }
 
+/* Video payload encoding is handled by uvc_video_encode_header() and
+ * uvc_video_encode_data(). Only bulk transfers are currently supported.
+ *
+ * uvc_video_encode_header is called at the start of a payload. It adds header
+ * data to the transfer buffer and returns the header size. As the only known
+ * UVC output device transfers a whole frame in a single payload, the EOF bit
+ * is always set in the header.
+ *
+ * uvc_video_encode_data is called for every URB and copies the data from the
+ * video buffer to the transfer buffer.
+ */
 static int uvc_video_encode_header(struct uvc_video_device *video,
                struct uvc_buffer *buf, __u8 *data, int len)
 {
@@ -953,7 +960,7 @@ int uvc_video_suspend(struct uvc_video_device *video)
 }
 
 /*
- * Reconfigure the video interface and restart streaming if it was enable
+ * Reconfigure the video interface and restart streaming if it was enabled
  * before suspend.
  *
  * If an error occurs, disable the video queue. This will wake all pending
@@ -985,8 +992,8 @@ int uvc_video_resume(struct uvc_video_device *video)
  */
 
 /*
- * Initialize the UVC video device by retrieving the default format and
- * committing it.
+ * Initialize the UVC video device by switching to alternate setting 0 and
+ * retrieve the default format.
  *
  * Some cameras (namely the Fuji Finepix) set the format and frame
  * indexes to zero. The UVC standard doesn't clearly make this a spec
@@ -1014,7 +1021,7 @@ int uvc_video_init(struct uvc_video_device *video)
         */
        usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
 
-       /* Some webcams don't suport GET_DEF request on the probe control. We
+       /* Some webcams don't suport GET_DEF requests on the probe control. We
         * fall back to GET_CUR if GET_DEF fails.
         */
        if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 &&