V4L/DVB (13658): v4l: add a media-bus API for configuring v4l2 subdev pixel and frame formats

Video subdevices, like cameras, decoders, connect to video bridges over
specialised busses. Data is being transferred over these busses in various
formats, which only loosely correspond to fourcc codes, describing how video
data is stored in RAM. This is not a one-to-one correspondence, therefore we
cannot use fourcc codes to configure subdevice output data formats. This patch
adds codes for several such on-the-bus formats and an API, similar to the
familiar .s_fmt(), .g_fmt(), .try_fmt(), .enum_fmt() API for configuring those
codes. After all users of the old API in struct v4l2_subdev_video_ops are
converted, it will be removed. Also add helper routines to support generic
pass-through mode for the soc-camera framework.

 create mode 100644 drivers/media/video/soc_mediabus.c
 create mode 100644 include/media/soc_mediabus.h
 create mode 100644 include/media/v4l2-mediabus.h

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/media/v4l2-mediabus.h b/include/media/v4l2-mediabus.h
new file mode 100644
index 0000000..0dbe02a
--- /dev/null
+++ b/include/media/v4l2-mediabus.h
@@ -0,0 +1,61 @@
+/*
+ * Media Bus API header
+ *
+ * Copyright (C) 2009, Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef V4L2_MEDIABUS_H
+#define V4L2_MEDIABUS_H
+
+/*
+ * These pixel codes uniquely identify data formats on the media bus. Mostly
+ * they correspond to similarly named V4L2_PIX_FMT_* formats, format 0 is
+ * reserved, V4L2_MBUS_FMT_FIXED shall be used by host-client pairs, where the
+ * data format is fixed. Additionally, "2X8" means that one pixel is transferred
+ * in two 8-bit samples, "BE" or "LE" specify in which order those samples are
+ * transferred over the bus: "LE" means that the least significant bits are
+ * transferred first, "BE" means that the most significant bits are transferred
+ * first, and "PADHI" and "PADLO" define which bits - low or high, in the
+ * incomplete high byte, are filled with padding bits.
+ */
+enum v4l2_mbus_pixelcode {
+	V4L2_MBUS_FMT_FIXED = 1,
+	V4L2_MBUS_FMT_YUYV8_2X8_LE,
+	V4L2_MBUS_FMT_YVYU8_2X8_LE,
+	V4L2_MBUS_FMT_YUYV8_2X8_BE,
+	V4L2_MBUS_FMT_YVYU8_2X8_BE,
+	V4L2_MBUS_FMT_RGB555_2X8_PADHI_LE,
+	V4L2_MBUS_FMT_RGB555_2X8_PADHI_BE,
+	V4L2_MBUS_FMT_RGB565_2X8_LE,
+	V4L2_MBUS_FMT_RGB565_2X8_BE,
+	V4L2_MBUS_FMT_SBGGR8_1X8,
+	V4L2_MBUS_FMT_SBGGR10_1X10,
+	V4L2_MBUS_FMT_GREY8_1X8,
+	V4L2_MBUS_FMT_Y10_1X10,
+	V4L2_MBUS_FMT_SBGGR10_2X8_PADHI_LE,
+	V4L2_MBUS_FMT_SBGGR10_2X8_PADLO_LE,
+	V4L2_MBUS_FMT_SBGGR10_2X8_PADHI_BE,
+	V4L2_MBUS_FMT_SBGGR10_2X8_PADLO_BE,
+};
+
+/**
+ * struct v4l2_mbus_framefmt - frame format on the media bus
+ * @width:	frame width
+ * @height:	frame height
+ * @code:	data format code
+ * @field:	used interlacing type
+ * @colorspace:	colorspace of the data
+ */
+struct v4l2_mbus_framefmt {
+	__u32				width;
+	__u32				height;
+	enum v4l2_mbus_pixelcode	code;
+	enum v4l2_field			field;
+	enum v4l2_colorspace		colorspace;
+};
+
+#endif