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, 17 insertions, 1 deletions

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index a128458dc9eb..9ba99cd39ee7 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -22,6 +22,7 @@
 #define _V4L2_SUBDEV_H
 
 #include <media/v4l2-common.h>
+#include <media/v4l2-mediabus.h>
 
 /* generic v4l2_device notify callback notification values */
 #define V4L2_SUBDEV_IR_RX_NOTIFY                _IOW('v', 0, u32)
@@ -207,7 +208,7 @@ struct v4l2_subdev_audio_ops {
    s_std_output: set v4l2_std_id for video OUTPUT devices. This is ignored by
         video input devices.
 
-  s_crystal_freq: sets the frequency of the crystal used to generate the
+   s_crystal_freq: sets the frequency of the crystal used to generate the
         clocks in Hz. An extra flags field allows device specific configuration
         regarding clock frequency dividers, etc. If not used, then set flags
         to 0. If the frequency is not supported, then -EINVAL is returned.
@@ -230,6 +231,13 @@ struct v4l2_subdev_audio_ops {
 
    g_dv_timings(): Get custom dv timings in the sub device.
 
+   enum_mbus_fmt: enumerate pixel formats, provided by a video data source
+
+   g_mbus_fmt: get the current pixel format, provided by a video data source
+
+   try_mbus_fmt: try to set a pixel format on a video data source
+
+   s_mbus_fmt: set a pixel format on a video data source
  */
 struct v4l2_subdev_video_ops {
         int (*s_routing)(struct v4l2_subdev *sd, u32 input, u32 output, u32 config);
@@ -261,6 +269,14 @@ struct v4l2_subdev_video_ops {
                         struct v4l2_dv_timings *timings);
         int (*g_dv_timings)(struct v4l2_subdev *sd,
                         struct v4l2_dv_timings *timings);
+        int (*enum_mbus_fmt)(struct v4l2_subdev *sd, int index,
+                             enum v4l2_mbus_pixelcode *code);
+        int (*g_mbus_fmt)(struct v4l2_subdev *sd,
+                          struct v4l2_mbus_framefmt *fmt);
+        int (*try_mbus_fmt)(struct v4l2_subdev *sd,
+                            struct v4l2_mbus_framefmt *fmt);
+        int (*s_mbus_fmt)(struct v4l2_subdev *sd,
+                          struct v4l2_mbus_framefmt *fmt);
 };
 
 /**