Hi,
I have a few editing suggestions below...
On 05/07/2018 09:21 AM, Rui Miguel Silva wrote:
> Add rst document to describe the i.MX7 media driver and also a working example
> from the Warp7 board usage with a OV2680 sensor.
>
> Signed-off-by: Rui Miguel Silva <rui.silva@xxxxxxxxxx>
> ---
> Documentation/media/v4l-drivers/imx7.rst | 157 ++++++++++++++++++++++
> Documentation/media/v4l-drivers/index.rst | 1 +
> 2 files changed, 158 insertions(+)
> create mode 100644 Documentation/media/v4l-drivers/imx7.rst
>
> diff --git a/Documentation/media/v4l-drivers/imx7.rst b/Documentation/media/v4l-drivers/imx7.rst
> new file mode 100644
> index 000000000000..64b97b442277
> --- /dev/null
> +++ b/Documentation/media/v4l-drivers/imx7.rst
> @@ -0,0 +1,157 @@
> +i.MX7 Video Capture Driver
> +==========================
> +
> +Introduction
> +------------
> +
> +The i.MX7 contrary to the i.MX5/6 family does not contain an Image Processing
> +Unit (IPU), because of that the capabilities to perform operations or
s/,/;/
> +manipulation of the capture frames is less feature rich.
are less
> +
> +For image capture the i.MX7 have three units:
has
> +- CMOS Sensor Interface (CSI)
> +- Video Multiplexer
> +- MIPI CSI-2 Receiver
> +
> +::
> + |\
> + MIPI Camera Input ---> MIPI CSI-2 --- > | \
> + | \
> + | M |
> + | U | ------> CSI ---> Capture
> + | X |
> + | /
> + Parallel Camera Input ----------------> | /
> + |/
> +
> +For additional information, please refer to the latest versions of the i.MX7
> +reference manual [#f1]_.
> +
> +Entities
> +--------
> +
> +imx7-mipi-csi2
> +--------------
> +
> +This is the MIPI CSI-2 recevier entity. It has one sink pad to receive the pixel
receiver
> +data from MIPI CSI-2 camera sensor. It has one source pad, corresponding to the
> +virtual channel 0. This module is compliant to previous version of Samsung
> +D-phy, and support two D-PHY Rx Data lanes.
supports
> +
> +csi_mux
> +-------
> +
> +This is the video multiplexer. It has two sink pads to select from either camera
> +sensors with a parallel interface or from MIPI CSI-2 virtual channel 0. It has
sensor
> +a single source pad that routes to the CSI.
> +
> +csi
> +---
> +
> +The CSI enables the chip to connect directly to external CMOS image sensor. CSI
> +can interfaces directly with Parallel and MIPI CSI-2 buses. It has 256 x 64 FIFO
interface
> +to store received image pixel data and embedded DMA controllers to transfer data
> +from the FIFO through AHB bus.
> +
> +This entity has one sink pad that receive from the csi_mux entity and a single
receives
> +source pad that route video frames directly to memory buffers, this pad is
routes buffers. This pad is
> +routed to a capture device node.
> +
> +Usage Notes
> +-----------
> +
> +To aid in configuration and for backward compatibility with V4L2 applications
> +that access controls only from video device nodes, the capture device interfaces
> +inherit controls from the active entities in the current pipeline, so controls
> +can be accessed either directly from the subdev or from the active capture
> +device interface. For example, the sensor controls are available either from the
> +sensor subdevs or from the active capture device.
> +
> +Warp7 with OV2680
> +-----------------
> +
> +On this platform an OV2680 MIPI CSI-2 module is connected to the internal MIPI
> +CSI-2 receiver. The following example configures a video capture pipeline with
> +an output of 800x600, and BGGR 10 bit bayer format:
> +
> +.. code-block:: none
> + # Setup links
> + media-ctl -l "'ov2680 1-0036':0 -> 'imx7-mipi-csis.0':0[1]"
> + media-ctl -l "'imx7-mipi-csis.0':1 -> 'csi_mux':1[1]"
> + media-ctl -l "'csi_mux':2 -> 'csi':0[1]"
> + media-ctl -l "'csi':1 -> 'csi capture':0[1]"
> +
> + # Configure pads for pipeline
> + media-ctl -V "'ov2680 1-0036':0 [fmt:SBGGR10_1X10/800x600 field:none]"
> + media-ctl -V "'csi_mux':1 [fmt:SBGGR10_1X10/800x600 field:none]"
> + media-ctl -V "'csi_mux':2 [fmt:SBGGR10_1X10/800x600 field:none]"
> + media-ctl -V "'imx7-mipi-csis.0':0 [fmt:SBGGR10_1X10/800x600 field:none]"
> + media-ctl -V "'csi':0 [fmt:SBGGR10_1X10/800x600 field:none]"
> +
> +After this streaming can start, the v4l2-ctl tool can be used to select any of
can start. The
> +the resolutions supported by the sensor.
> +
> +.. code-block:: none
> + root@imx7s-warp:~# media-ctl -p
> + Media controller API version 4.17.0
> +
> + Media device information
> + ------------------------
> + driver imx-media
> + model imx-media
> + serial
> + bus info
> + hw revision 0x0
> + driver version 4.17.0
> +
> + Device topology
> + - entity 1: csi (2 pads, 2 links)
> + type V4L2 subdev subtype Unknown flags 0
> + device node name /dev/v4l-subdev0
> + pad0: Sink
> + [fmt:SBGGR10_1X10/800x600 field:none]
> + <- "csi_mux":2 [ENABLED]
> + pad1: Source
> + [fmt:SBGGR10_1X10/800x600 field:none]
> + -> "csi capture":0 [ENABLED]
> +
> + - entity 4: csi capture (1 pad, 1 link)
> + type Node subtype V4L flags 0
> + device node name /dev/video0
> + pad0: Sink
> + <- "csi":1 [ENABLED]
> +
> + - entity 10: csi_mux (3 pads, 2 links)
> + type V4L2 subdev subtype Unknown flags 0
> + device node name /dev/v4l-subdev1
> + pad0: Sink
> + [fmt:unknown/0x0]
> + pad1: Sink
> + [fmt:unknown/800x600 field:none]
> + <- "imx7-mipi-csis.0":1 [ENABLED]
> + pad2: Source
> + [fmt:unknown/800x600 field:none]
> + -> "csi":0 [ENABLED]
> +
> + - entity 14: imx7-mipi-csis.0 (2 pads, 2 links)
> + type V4L2 subdev subtype Unknown flags 0
> + device node name /dev/v4l-subdev2
> + pad0: Sink
> + [fmt:SBGGR10_1X10/800x600 field:none]
> + <- "ov2680 1-0036":0 [ENABLED]
> + pad1: Source
> + [fmt:SBGGR10_1X10/800x600 field:none]
> + -> "csi_mux":1 [ENABLED]
> +
> + - entity 17: ov2680 1-0036 (1 pad, 1 link)
> + type V4L2 subdev subtype Sensor flags 0
> + device node name /dev/v4l-subdev3
> + pad0: Source
> + [fmt:SBGGR10_1X10/800x600 field:none]
> + -> "imx7-mipi-csis.0":0 [ENABLED]
> +
> +
> +References
> +----------
> +
> +.. [#f1] https://www.nxp.com/docs/en/reference-manual/IMX7SRM.pdf
thanks.
--
~Randy
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