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diff --git a/Documentation/media/v4l-drivers/imx.rst b/Documentation/media/v4l-drivers/imx.rst new file mode 100644 index 000000000..65d3d15eb --- /dev/null +++ b/Documentation/media/v4l-drivers/imx.rst @@ -0,0 +1,617 @@ +i.MX Video Capture Driver +========================= + +Introduction +------------ + +The Freescale i.MX5/6 contains an Image Processing Unit (IPU), which +handles the flow of image frames to and from capture devices and +display devices. + +For image capture, the IPU contains the following internal subunits: + +- Image DMA Controller (IDMAC) +- Camera Serial Interface (CSI) +- Image Converter (IC) +- Sensor Multi-FIFO Controller (SMFC) +- Image Rotator (IRT) +- Video De-Interlacing or Combining Block (VDIC) + +The IDMAC is the DMA controller for transfer of image frames to and from +memory. Various dedicated DMA channels exist for both video capture and +display paths. During transfer, the IDMAC is also capable of vertical +image flip, 8x8 block transfer (see IRT description), pixel component +re-ordering (for example UYVY to YUYV) within the same colorspace, and +even packed <--> planar conversion. It can also perform a simple +de-interlacing by interleaving even and odd lines during transfer +(without motion compensation which requires the VDIC). + +The CSI is the backend capture unit that interfaces directly with +camera sensors over Parallel, BT.656/1120, and MIPI CSI-2 busses. + +The IC handles color-space conversion, resizing (downscaling and +upscaling), horizontal flip, and 90/270 degree rotation operations. + +There are three independent "tasks" within the IC that can carry out +conversions concurrently: pre-process encoding, pre-process viewfinder, +and post-processing. Within each task, conversions are split into three +sections: downsizing section, main section (upsizing, flip, colorspace +conversion, and graphics plane combining), and rotation section. + +The IPU time-shares the IC task operations. The time-slice granularity +is one burst of eight pixels in the downsizing section, one image line +in the main processing section, one image frame in the rotation section. + +The SMFC is composed of four independent FIFOs that each can transfer +captured frames from sensors directly to memory concurrently via four +IDMAC channels. + +The IRT carries out 90 and 270 degree image rotation operations. The +rotation operation is carried out on 8x8 pixel blocks at a time. This +operation is supported by the IDMAC which handles the 8x8 block transfer +along with block reordering, in coordination with vertical flip. + +The VDIC handles the conversion of interlaced video to progressive, with +support for different motion compensation modes (low, medium, and high +motion). The deinterlaced output frames from the VDIC can be sent to the +IC pre-process viewfinder task for further conversions. The VDIC also +contains a Combiner that combines two image planes, with alpha blending +and color keying. + +In addition to the IPU internal subunits, there are also two units +outside the IPU that are also involved in video capture on i.MX: + +- MIPI CSI-2 Receiver for camera sensors with the MIPI CSI-2 bus + interface. This is a Synopsys DesignWare core. +- Two video multiplexers for selecting among multiple sensor inputs + to send to a CSI. + +For more info, refer to the latest versions of the i.MX5/6 reference +manuals [#f1]_ and [#f2]_. + + +Features +-------- + +Some of the features of this driver include: + +- Many different pipelines can be configured via media controller API, + that correspond to the hardware video capture pipelines supported in + the i.MX. + +- Supports parallel, BT.565, and MIPI CSI-2 interfaces. + +- Concurrent independent streams, by configuring pipelines to multiple + video capture interfaces using independent entities. + +- Scaling, color-space conversion, horizontal and vertical flip, and + image rotation via IC task subdevs. + +- Many pixel formats supported (RGB, packed and planar YUV, partial + planar YUV). + +- The VDIC subdev supports motion compensated de-interlacing, with three + motion compensation modes: low, medium, and high motion. Pipelines are + defined that allow sending frames to the VDIC subdev directly from the + CSI. There is also support in the future for sending frames to the + VDIC from memory buffers via a output/mem2mem devices. + +- Includes a Frame Interval Monitor (FIM) that can correct vertical sync + problems with the ADV718x video decoders. + + +Entities +-------- + +imx6-mipi-csi2 +-------------- + +This is the MIPI CSI-2 receiver entity. It has one sink pad to receive +the MIPI CSI-2 stream (usually from a MIPI CSI-2 camera sensor). It has +four source pads, corresponding to the four MIPI CSI-2 demuxed virtual +channel outputs. Multiple source pads can be enabled to independently +stream from multiple virtual channels. + +This entity actually consists of two sub-blocks. One is the MIPI CSI-2 +core. This is a Synopsys Designware MIPI CSI-2 core. The other sub-block +is a "CSI-2 to IPU gasket". The gasket acts as a demultiplexer of the +four virtual channels streams, providing four separate parallel buses +containing each virtual channel that are routed to CSIs or video +multiplexers as described below. + +On i.MX6 solo/dual-lite, all four virtual channel buses are routed to +two video multiplexers. Both CSI0 and CSI1 can receive any virtual +channel, as selected by the video multiplexers. + +On i.MX6 Quad, virtual channel 0 is routed to IPU1-CSI0 (after selected +by a video mux), virtual channels 1 and 2 are hard-wired to IPU1-CSI1 +and IPU2-CSI0, respectively, and virtual channel 3 is routed to +IPU2-CSI1 (again selected by a video mux). + +ipuX_csiY_mux +------------- + +These are the video multiplexers. They have two or more sink pads to +select from either camera sensors with a parallel interface, or from +MIPI CSI-2 virtual channels from imx6-mipi-csi2 entity. They have a +single source pad that routes to a CSI (ipuX_csiY entities). + +On i.MX6 solo/dual-lite, there are two video mux entities. One sits +in front of IPU1-CSI0 to select between a parallel sensor and any of +the four MIPI CSI-2 virtual channels (a total of five sink pads). The +other mux sits in front of IPU1-CSI1, and again has five sink pads to +select between a parallel sensor and any of the four MIPI CSI-2 virtual +channels. + +On i.MX6 Quad, there are two video mux entities. One sits in front of +IPU1-CSI0 to select between a parallel sensor and MIPI CSI-2 virtual +channel 0 (two sink pads). The other mux sits in front of IPU2-CSI1 to +select between a parallel sensor and MIPI CSI-2 virtual channel 3 (two +sink pads). + +ipuX_csiY +--------- + +These are the CSI entities. They have a single sink pad receiving from +either a video mux or from a MIPI CSI-2 virtual channel as described +above. + +This entity has two source pads. The first source pad can link directly +to the ipuX_vdic entity or the ipuX_ic_prp entity, using hardware links +that require no IDMAC memory buffer transfer. + +When the direct source pad is routed to the ipuX_ic_prp entity, frames +from the CSI can be processed by one or both of the IC pre-processing +tasks. + +When the direct source pad is routed to the ipuX_vdic entity, the VDIC +will carry out motion-compensated de-interlace using "high motion" mode +(see description of ipuX_vdic entity). + +The second source pad sends video frames directly to memory buffers +via the SMFC and an IDMAC channel, bypassing IC pre-processing. This +source pad is routed to a capture device node, with a node name of the +format "ipuX_csiY capture". + +Note that since the IDMAC source pad makes use of an IDMAC channel, it +can do pixel reordering within the same colorspace. For example, the +sink pad can take UYVY2X8, but the IDMAC source pad can output YUYV2X8. +If the sink pad is receiving YUV, the output at the capture device can +also be converted to a planar YUV format such as YUV420. + +It will also perform simple de-interlace without motion compensation, +which is activated if the sink pad's field type is an interlaced type, +and the IDMAC source pad field type is set to none. + +This subdev can generate the following event when enabling the second +IDMAC source pad: + +- V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR + +The user application can subscribe to this event from the ipuX_csiY +subdev node. This event is generated by the Frame Interval Monitor +(see below for more on the FIM). + +Cropping in ipuX_csiY +--------------------- + +The CSI supports cropping the incoming raw sensor frames. This is +implemented in the ipuX_csiY entities at the sink pad, using the +crop selection subdev API. + +The CSI also supports fixed divide-by-two downscaling indepently in +width and height. This is implemented in the ipuX_csiY entities at +the sink pad, using the compose selection subdev API. + +The output rectangle at the ipuX_csiY source pad is the same as +the compose rectangle at the sink pad. So the source pad rectangle +cannot be negotiated, it must be set using the compose selection +API at sink pad (if /2 downscale is desired, otherwise source pad +rectangle is equal to incoming rectangle). + +To give an example of crop and /2 downscale, this will crop a +1280x960 input frame to 640x480, and then /2 downscale in both +dimensions to 320x240 (assumes ipu1_csi0 is linked to ipu1_csi0_mux): + +.. code-block:: none + + media-ctl -V "'ipu1_csi0_mux':2[fmt:UYVY2X8/1280x960]" + media-ctl -V "'ipu1_csi0':0[crop:(0,0)/640x480]" + media-ctl -V "'ipu1_csi0':0[compose:(0,0)/320x240]" + +Frame Skipping in ipuX_csiY +--------------------------- + +The CSI supports frame rate decimation, via frame skipping. Frame +rate decimation is specified by setting the frame intervals at +sink and source pads. The ipuX_csiY entity then applies the best +frame skip setting to the CSI to achieve the desired frame rate +at the source pad. + +The following example reduces an assumed incoming 60 Hz frame +rate by half at the IDMAC output source pad: + +.. code-block:: none + + media-ctl -V "'ipu1_csi0':0[fmt:UYVY2X8/640x480@1/60]" + media-ctl -V "'ipu1_csi0':2[fmt:UYVY2X8/640x480@1/30]" + +Frame Interval Monitor in ipuX_csiY +----------------------------------- + +The adv718x decoders can occasionally send corrupt fields during +NTSC/PAL signal re-sync (too little or too many video lines). When +this happens, the IPU triggers a mechanism to re-establish vertical +sync by adding 1 dummy line every frame, which causes a rolling effect +from image to image, and can last a long time before a stable image is +recovered. Or sometimes the mechanism doesn't work at all, causing a +permanent split image (one frame contains lines from two consecutive +captured images). + +From experiment it was found that during image rolling, the frame +intervals (elapsed time between two EOF's) drop below the nominal +value for the current standard, by about one frame time (60 usec), +and remain at that value until rolling stops. + +While the reason for this observation isn't known (the IPU dummy +line mechanism should show an increase in the intervals by 1 line +time every frame, not a fixed value), we can use it to detect the +corrupt fields using a frame interval monitor. If the FIM detects a +bad frame interval, the ipuX_csiY subdev will send the event +V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR. Userland can register with +the FIM event notification on the ipuX_csiY subdev device node. +Userland can issue a streaming restart when this event is received +to correct the rolling/split image. + +The ipuX_csiY subdev includes custom controls to tweak some dials for +FIM. If one of these controls is changed during streaming, the FIM will +be reset and will continue at the new settings. + +- V4L2_CID_IMX_FIM_ENABLE + +Enable/disable the FIM. + +- V4L2_CID_IMX_FIM_NUM + +How many frame interval measurements to average before comparing against +the nominal frame interval reported by the sensor. This can reduce noise +caused by interrupt latency. + +- V4L2_CID_IMX_FIM_TOLERANCE_MIN + +If the averaged intervals fall outside nominal by this amount, in +microseconds, the V4L2_EVENT_IMX_FRAME_INTERVAL_ERROR event is sent. + +- V4L2_CID_IMX_FIM_TOLERANCE_MAX + +If any intervals are higher than this value, those samples are +discarded and do not enter into the average. This can be used to +discard really high interval errors that might be due to interrupt +latency from high system load. + +- V4L2_CID_IMX_FIM_NUM_SKIP + +How many frames to skip after a FIM reset or stream restart before +FIM begins to average intervals. + +- V4L2_CID_IMX_FIM_ICAP_CHANNEL +- V4L2_CID_IMX_FIM_ICAP_EDGE + +These controls will configure an input capture channel as the method +for measuring frame intervals. This is superior to the default method +of measuring frame intervals via EOF interrupt, since it is not subject +to uncertainty errors introduced by interrupt latency. + +Input capture requires hardware support. A VSYNC signal must be routed +to one of the i.MX6 input capture channel pads. + +V4L2_CID_IMX_FIM_ICAP_CHANNEL configures which i.MX6 input capture +channel to use. This must be 0 or 1. + +V4L2_CID_IMX_FIM_ICAP_EDGE configures which signal edge will trigger +input capture events. By default the input capture method is disabled +with a value of IRQ_TYPE_NONE. Set this control to IRQ_TYPE_EDGE_RISING, +IRQ_TYPE_EDGE_FALLING, or IRQ_TYPE_EDGE_BOTH to enable input capture, +triggered on the given signal edge(s). + +When input capture is disabled, frame intervals will be measured via +EOF interrupt. + + +ipuX_vdic +--------- + +The VDIC carries out motion compensated de-interlacing, with three +motion compensation modes: low, medium, and high motion. The mode is +specified with the menu control V4L2_CID_DEINTERLACING_MODE. It has +two sink pads and a single source pad. + +The direct sink pad receives from an ipuX_csiY direct pad. With this +link the VDIC can only operate in high motion mode. + +When the IDMAC sink pad is activated, it receives from an output +or mem2mem device node. With this pipeline, it can also operate +in low and medium modes, because these modes require receiving +frames from memory buffers. Note that an output or mem2mem device +is not implemented yet, so this sink pad currently has no links. + +The source pad routes to the IC pre-processing entity ipuX_ic_prp. + +ipuX_ic_prp +----------- + +This is the IC pre-processing entity. It acts as a router, routing +data from its sink pad to one or both of its source pads. + +It has a single sink pad. The sink pad can receive from the ipuX_csiY +direct pad, or from ipuX_vdic. + +This entity has two source pads. One source pad routes to the +pre-process encode task entity (ipuX_ic_prpenc), the other to the +pre-process viewfinder task entity (ipuX_ic_prpvf). Both source pads +can be activated at the same time if the sink pad is receiving from +ipuX_csiY. Only the source pad to the pre-process viewfinder task entity +can be activated if the sink pad is receiving from ipuX_vdic (frames +from the VDIC can only be processed by the pre-process viewfinder task). + +ipuX_ic_prpenc +-------------- + +This is the IC pre-processing encode entity. It has a single sink +pad from ipuX_ic_prp, and a single source pad. The source pad is +routed to a capture device node, with a node name of the format +"ipuX_ic_prpenc capture". + +This entity performs the IC pre-process encode task operations: +color-space conversion, resizing (downscaling and upscaling), +horizontal and vertical flip, and 90/270 degree rotation. Flip +and rotation are provided via standard V4L2 controls. + +Like the ipuX_csiY IDMAC source, it can also perform simple de-interlace +without motion compensation, and pixel reordering. + +ipuX_ic_prpvf +------------- + +This is the IC pre-processing viewfinder entity. It has a single sink +pad from ipuX_ic_prp, and a single source pad. The source pad is routed +to a capture device node, with a node name of the format +"ipuX_ic_prpvf capture". + +It is identical in operation to ipuX_ic_prpenc, with the same resizing +and CSC operations and flip/rotation controls. It will receive and +process de-interlaced frames from the ipuX_vdic if ipuX_ic_prp is +receiving from ipuX_vdic. + +Like the ipuX_csiY IDMAC source, it can perform simple de-interlace +without motion compensation. However, note that if the ipuX_vdic is +included in the pipeline (ipuX_ic_prp is receiving from ipuX_vdic), +it's not possible to use simple de-interlace in ipuX_ic_prpvf, since +the ipuX_vdic has already carried out de-interlacing (with motion +compensation) and therefore the field type output from ipuX_ic_prp can +only be none. + +Capture Pipelines +----------------- + +The following describe the various use-cases supported by the pipelines. + +The links shown do not include the backend sensor, video mux, or mipi +csi-2 receiver links. This depends on the type of sensor interface +(parallel or mipi csi-2). So these pipelines begin with: + +sensor -> ipuX_csiY_mux -> ... + +for parallel sensors, or: + +sensor -> imx6-mipi-csi2 -> (ipuX_csiY_mux) -> ... + +for mipi csi-2 sensors. The imx6-mipi-csi2 receiver may need to route +to the video mux (ipuX_csiY_mux) before sending to the CSI, depending +on the mipi csi-2 virtual channel, hence ipuX_csiY_mux is shown in +parenthesis. + +Unprocessed Video Capture: +-------------------------- + +Send frames directly from sensor to camera device interface node, with +no conversions, via ipuX_csiY IDMAC source pad: + +-> ipuX_csiY:2 -> ipuX_csiY capture + +IC Direct Conversions: +---------------------- + +This pipeline uses the preprocess encode entity to route frames directly +from the CSI to the IC, to carry out scaling up to 1024x1024 resolution, +CSC, flipping, and image rotation: + +-> ipuX_csiY:1 -> 0:ipuX_ic_prp:1 -> 0:ipuX_ic_prpenc:1 -> ipuX_ic_prpenc capture + +Motion Compensated De-interlace: +-------------------------------- + +This pipeline routes frames from the CSI direct pad to the VDIC entity to +support motion-compensated de-interlacing (high motion mode only), +scaling up to 1024x1024, CSC, flip, and rotation: + +-> ipuX_csiY:1 -> 0:ipuX_vdic:2 -> 0:ipuX_ic_prp:2 -> 0:ipuX_ic_prpvf:1 -> ipuX_ic_prpvf capture + + +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 FIM controls are available either from the ipuX_csiY +subdevs or from the active capture device. + +The following are specific usage notes for the Sabre* reference +boards: + + +SabreLite with OV5642 and OV5640 +-------------------------------- + +This platform requires the OmniVision OV5642 module with a parallel +camera interface, and the OV5640 module with a MIPI CSI-2 +interface. Both modules are available from Boundary Devices: + +- https://boundarydevices.com/product/nit6x_5mp +- https://boundarydevices.com/product/nit6x_5mp_mipi + +Note that if only one camera module is available, the other sensor +node can be disabled in the device tree. + +The OV5642 module is connected to the parallel bus input on the i.MX +internal video mux to IPU1 CSI0. It's i2c bus connects to i2c bus 2. + +The MIPI CSI-2 OV5640 module is connected to the i.MX internal MIPI CSI-2 +receiver, and the four virtual channel outputs from the receiver are +routed as follows: vc0 to the IPU1 CSI0 mux, vc1 directly to IPU1 CSI1, +vc2 directly to IPU2 CSI0, and vc3 to the IPU2 CSI1 mux. The OV5640 is +also connected to i2c bus 2 on the SabreLite, therefore the OV5642 and +OV5640 must not share the same i2c slave address. + +The following basic example configures unprocessed video capture +pipelines for both sensors. The OV5642 is routed to ipu1_csi0, and +the OV5640, transmitting on MIPI CSI-2 virtual channel 1 (which is +imx6-mipi-csi2 pad 2), is routed to ipu1_csi1. Both sensors are +configured to output 640x480, and the OV5642 outputs YUYV2X8, the +OV5640 UYVY2X8: + +.. code-block:: none + + # Setup links for OV5642 + media-ctl -l "'ov5642 1-0042':0 -> 'ipu1_csi0_mux':1[1]" + media-ctl -l "'ipu1_csi0_mux':2 -> 'ipu1_csi0':0[1]" + media-ctl -l "'ipu1_csi0':2 -> 'ipu1_csi0 capture':0[1]" + # Setup links for OV5640 + media-ctl -l "'ov5640 1-0040':0 -> 'imx6-mipi-csi2':0[1]" + media-ctl -l "'imx6-mipi-csi2':2 -> 'ipu1_csi1':0[1]" + media-ctl -l "'ipu1_csi1':2 -> 'ipu1_csi1 capture':0[1]" + # Configure pads for OV5642 pipeline + media-ctl -V "'ov5642 1-0042':0 [fmt:YUYV2X8/640x480 field:none]" + media-ctl -V "'ipu1_csi0_mux':2 [fmt:YUYV2X8/640x480 field:none]" + media-ctl -V "'ipu1_csi0':2 [fmt:AYUV32/640x480 field:none]" + # Configure pads for OV5640 pipeline + media-ctl -V "'ov5640 1-0040':0 [fmt:UYVY2X8/640x480 field:none]" + media-ctl -V "'imx6-mipi-csi2':2 [fmt:UYVY2X8/640x480 field:none]" + media-ctl -V "'ipu1_csi1':2 [fmt:AYUV32/640x480 field:none]" + +Streaming can then begin independently on the capture device nodes +"ipu1_csi0 capture" and "ipu1_csi1 capture". The v4l2-ctl tool can +be used to select any supported YUV pixelformat on the capture device +nodes, including planar. + +SabreAuto with ADV7180 decoder +------------------------------ + +On the 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, with Motion +Compensated de-interlacing. Pad field types assume the adv7180 outputs +"interlaced". $outputfmt can be any format supported by the ipu1_ic_prpvf +entity at its output pad: + +.. code-block:: none + + # Setup links + media-ctl -l "'adv7180 3-0021':0 -> 'ipu1_csi0_mux':1[1]" + media-ctl -l "'ipu1_csi0_mux':2 -> 'ipu1_csi0':0[1]" + media-ctl -l "'ipu1_csi0':1 -> 'ipu1_vdic':0[1]" + media-ctl -l "'ipu1_vdic':2 -> 'ipu1_ic_prp':0[1]" + media-ctl -l "'ipu1_ic_prp':2 -> 'ipu1_ic_prpvf':0[1]" + media-ctl -l "'ipu1_ic_prpvf':1 -> 'ipu1_ic_prpvf capture':0[1]" + # Configure pads + media-ctl -V "'adv7180 3-0021':0 [fmt:UYVY2X8/720x480]" + media-ctl -V "'ipu1_csi0_mux':2 [fmt:UYVY2X8/720x480 field:interlaced]" + media-ctl -V "'ipu1_csi0':1 [fmt:AYUV32/720x480 field:interlaced]" + media-ctl -V "'ipu1_vdic':2 [fmt:AYUV32/720x480 field:none]" + media-ctl -V "'ipu1_ic_prp':2 [fmt:AYUV32/720x480 field:none]" + media-ctl -V "'ipu1_ic_prpvf':1 [fmt:$outputfmt field:none]" + +Streaming can then begin on the capture device node at +"ipu1_ic_prpvf capture". The v4l2-ctl tool can be used to select any +supported YUV or RGB pixelformat on the capture device node. + +This platform accepts Composite Video analog inputs to the ADV7180 on +Ain1 (connector J42). + +SabreSD with MIPI CSI-2 OV5640 +------------------------------ + +Similarly to SabreLite, the SabreSD supports a parallel interface +OV5642 module on IPU1 CSI0, and a MIPI CSI-2 OV5640 module. The OV5642 +connects to i2c bus 1 and the OV5640 to i2c bus 2. + +The device tree for SabreSD includes OF graphs for both the parallel +OV5642 and the MIPI CSI-2 OV5640, but as of this writing only the MIPI +CSI-2 OV5640 has been tested, so the OV5642 node is currently disabled. +The OV5640 module connects to MIPI connector J5 (sorry I don't have the +compatible module part number or URL). + +The following example configures a direct conversion pipeline to capture +from the OV5640, transmitting on MIPI CSI-2 virtual channel 1. $sensorfmt +can be any format supported by the OV5640. $sensordim is the frame +dimension part of $sensorfmt (minus the mbus pixel code). $outputfmt can +be any format supported by the ipu1_ic_prpenc entity at its output pad: + +.. code-block:: none + + # Setup links + media-ctl -l "'ov5640 1-003c':0 -> 'imx6-mipi-csi2':0[1]" + media-ctl -l "'imx6-mipi-csi2':2 -> 'ipu1_csi1':0[1]" + media-ctl -l "'ipu1_csi1':1 -> 'ipu1_ic_prp':0[1]" + media-ctl -l "'ipu1_ic_prp':1 -> 'ipu1_ic_prpenc':0[1]" + media-ctl -l "'ipu1_ic_prpenc':1 -> 'ipu1_ic_prpenc capture':0[1]" + # Configure pads + media-ctl -V "'ov5640 1-003c':0 [fmt:$sensorfmt field:none]" + media-ctl -V "'imx6-mipi-csi2':2 [fmt:$sensorfmt field:none]" + media-ctl -V "'ipu1_csi1':1 [fmt:AYUV32/$sensordim field:none]" + media-ctl -V "'ipu1_ic_prp':1 [fmt:AYUV32/$sensordim field:none]" + media-ctl -V "'ipu1_ic_prpenc':1 [fmt:$outputfmt field:none]" + +Streaming can then begin on "ipu1_ic_prpenc capture" node. The v4l2-ctl +tool can be used to select any supported YUV or RGB pixelformat on the +capture device node. + + +Known Issues +------------ + +1. When using 90 or 270 degree rotation control at capture resolutions + near the IC resizer limit of 1024x1024, and combined with planar + pixel formats (YUV420, YUV422p), frame capture will often fail with + no end-of-frame interrupts from the IDMAC channel. To work around + this, use lower resolution and/or packed formats (YUYV, RGB3, etc.) + when 90 or 270 rotations are needed. + + +File list +--------- + +drivers/staging/media/imx/ +include/media/imx.h +include/linux/imx-media.h + +References +---------- + +.. [#f1] http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf +.. [#f2] http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SDLRM.pdf + + +Authors +------- + +- Steve Longerbeam <steve_longerbeam@mentor.com> +- Philipp Zabel <kernel@pengutronix.de> +- Russell King <linux@armlinux.org.uk> + +Copyright (C) 2012-2017 Mentor Graphics Inc. |