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..cd1195d391c5 --- /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 +manipulation of the capture frames are less feature rich. + +For image capture the i.MX7 has three units: +- 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 receiver entity. It has one sink pad to receive the pixel +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 supports two D-PHY Rx Data lanes. + +csi_mux +------- + +This is the video multiplexer. It has two sink pads to select from either camera +sensor with a parallel interface or from MIPI CSI-2 virtual channel 0. It has +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 interface directly with Parallel and MIPI CSI-2 buses. It has 256 x 64 FIFO +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 receives from the csi_mux entity and a single +source pad that routes video frames directly to memory 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 +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 diff --git a/Documentation/media/v4l-drivers/index.rst b/Documentation/media/v4l-drivers/index.rst index 679238e786a7..693295bbc53f 100644 --- a/Documentation/media/v4l-drivers/index.rst +++ b/Documentation/media/v4l-drivers/index.rst @@ -44,6 +44,7 @@ For more details see the file COPYING in the source distribution of Linux. davinci-vpbe fimc imx + imx7 ivtv max2175 meye -- 2.19.1
