media: imx.rst: Provide instructions for the i.MX6DL sabreauto

The i.MX6DL sabreauto has different numbering on the I2C bus and
I2C muxes compared to the i.MX6Q as shown in the kernel log below:

[    5.159423] imx-media: ipu1_csi0_mux:5 -> ipu1_csi0:0
[    5.164618] imx-media: ipu1_csi1_mux:5 -> ipu1_csi1:0
[    5.169953] imx-media: adv7180 4-0021:0 -> ipu1_csi0_mux:4

To avoid confusion, add an entry that shows how to setup the links and
configure the pads that are specific to the i.MX6DL sabreauto.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/v4l-drivers/imx.rst

@@ -572,6 +572,64 @@ supported YUV or RGB pixelformat on the capture device node.
 This platform accepts Composite Video analog inputs to the ADV7180 on
 Ain1 (connector J42).
 
+i.MX6DL SabreAuto with ADV7180 decoder
+--------------------------------------
+
+On the i.MX6DL SabreAuto, an on-board ADV7180 SD decoder is connected to the
+parallel bus input on the internal video mux to IPU1 CSI0.
+
+The following example configures a pipeline to capture from the ADV7180
+video decoder, assuming NTSC 720x480 input signals, using simple
+interweave (unconverted and without motion compensation). The adv7180
+must output sequential or alternating fields (field type 'seq-bt' for
+NTSC, or 'alternate'):
+
+.. code-block:: none
+
+   # Setup links
+   media-ctl -l "'adv7180 4-0021':0 -> 'ipu1_csi0_mux':4[1]"
+   media-ctl -l "'ipu1_csi0_mux':5 -> 'ipu1_csi0':0[1]"
+   media-ctl -l "'ipu1_csi0':2 -> 'ipu1_csi0 capture':0[1]"
+   # Configure pads
+   media-ctl -V "'adv7180 4-0021':0 [fmt:UYVY2X8/720x480 field:seq-bt]"
+   media-ctl -V "'ipu1_csi0_mux':5 [fmt:UYVY2X8/720x480]"
+   media-ctl -V "'ipu1_csi0':2 [fmt:AYUV32/720x480]"
+   # Configure "ipu1_csi0 capture" interface (assumed at /dev/video0)
+   v4l2-ctl -d0 --set-fmt-video=field=interlaced_bt
+
+Streaming can then begin on /dev/video0. The v4l2-ctl tool can also be
+used to select any supported YUV pixelformat on /dev/video0.
+
+This example configures a pipeline to capture from the ADV7180
+video decoder, assuming PAL 720x576 input signals, with Motion
+Compensated de-interlacing. The adv7180 must output sequential or
+alternating fields (field type 'seq-tb' for PAL, or 'alternate').
+
+.. code-block:: none
+
+   # Setup links
+   media-ctl -l "'adv7180 4-0021':0 -> 'ipu1_csi0_mux':4[1]"
+   media-ctl -l "'ipu1_csi0_mux':5 -> 'ipu1_csi0':0[1]"
+   media-ctl -l "'ipu1_csi0':1 -> 'ipu1_vdic':0[1]"
+   media-ctl -l "'ipu1_vdic':2 -> 'ipu1_ic_prp':0[1]"
+   media-ctl -l "'ipu1_ic_prp':2 -> 'ipu1_ic_prpvf':0[1]"
+   media-ctl -l "'ipu1_ic_prpvf':1 -> 'ipu1_ic_prpvf capture':0[1]"
+   # Configure pads
+   media-ctl -V "'adv7180 4-0021':0 [fmt:UYVY2X8/720x576 field:seq-tb]"
+   media-ctl -V "'ipu1_csi0_mux':5 [fmt:UYVY2X8/720x576]"
+   media-ctl -V "'ipu1_csi0':1 [fmt:AYUV32/720x576]"
+   media-ctl -V "'ipu1_vdic':2 [fmt:AYUV32/720x576 field:none]"
+   media-ctl -V "'ipu1_ic_prp':2 [fmt:AYUV32/720x576 field:none]"
+   media-ctl -V "'ipu1_ic_prpvf':1 [fmt:AYUV32/720x576 field:none]"
+   # Configure "ipu1_ic_prpvf capture" interface (assumed at /dev/video2)
+   v4l2-ctl -d2 --set-fmt-video=field=none
+
+Streaming can then begin on /dev/video2. The v4l2-ctl tool can also be
+used to select any supported YUV pixelformat on /dev/video2.
+
+This platform accepts Composite Video analog inputs to the ADV7180 on
+Ain1 (connector J42).
+
 SabreSD with MIPI CSI-2 OV5640
 ------------------------------