| .. SPDX-License-Identifier: GPL-2.0 |
| |
| 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 |
| |
| .. code-block:: none |
| |
| 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 |
