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>

1 files changed, 65 insertions, 0 deletions

diff --git a/include/media/soc_mediabus.h b/include/media/soc_mediabus.h
new file mode 100644
index 000000000000..037cd7be001e
--- /dev/null
+++ b/include/media/soc_mediabus.h
@@ -0,0 +1,65 @@
+/*
+ * SoC-camera Media Bus API extensions
+ *
+ * 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 SOC_MEDIABUS_H
+#define SOC_MEDIABUS_H
+
+#include <linux/videodev2.h>
+
+#include <media/v4l2-mediabus.h>
+
+/**
+ * enum soc_mbus_packing - data packing types on the media-bus
+ * @SOC_MBUS_PACKING_NONE:      no packing, bit-for-bit transfer to RAM
+ * @SOC_MBUS_PACKING_2X8_PADHI: 16 bits transferred in 2 8-bit samples, in the
+ *                              possibly incomplete byte high bits are padding
+ * @SOC_MBUS_PACKING_2X8_PADLO: as above, but low bits are padding
+ * @SOC_MBUS_PACKING_EXTEND16:  sample width (e.g., 10 bits) has to be extended
+ *                              to 16 bits
+ */
+enum soc_mbus_packing {
+        SOC_MBUS_PACKING_NONE,
+        SOC_MBUS_PACKING_2X8_PADHI,
+        SOC_MBUS_PACKING_2X8_PADLO,
+        SOC_MBUS_PACKING_EXTEND16,
+};
+
+/**
+ * enum soc_mbus_order - sample order on the media bus
+ * @SOC_MBUS_ORDER_LE:          least significant sample first
+ * @SOC_MBUS_ORDER_BE:          most significant sample first
+ */
+enum soc_mbus_order {
+        SOC_MBUS_ORDER_LE,
+        SOC_MBUS_ORDER_BE,
+};
+
+/**
+ * struct soc_mbus_pixelfmt - Data format on the media bus
+ * @name:               Name of the format
+ * @fourcc:             Fourcc code, that will be obtained if the data is
+ *                      stored in memory in the following way:
+ * @packing:            Type of sample-packing, that has to be used
+ * @order:              Sample order when storing in memory
+ * @bits_per_sample:    How many bits the bridge has to sample
+ */
+struct soc_mbus_pixelfmt {
+        const char              *name;
+        u32                     fourcc;
+        enum soc_mbus_packing   packing;
+        enum soc_mbus_order     order;
+        u8                      bits_per_sample;
+};
+
+const struct soc_mbus_pixelfmt *soc_mbus_get_fmtdesc(
+        enum v4l2_mbus_pixelcode code);
+s32 soc_mbus_bytes_per_line(u32 width, const struct soc_mbus_pixelfmt *mf);
+
+#endif