media: v4l: Add Intel IPU3 meta buffer formats

Add IPU3-specific meta formats for processing parameters and
3A statistics.

  V4L2_META_FMT_IPU3_PARAMS
  V4L2_META_FMT_IPU3_STAT_3A
Signed-off-by: Yong Zhi <yong.zhi@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/uapi/v4l/meta-formats.rst

@@ -19,6 +19,7 @@ These formats are used for the :ref:`metadata` interface only.
 .. toctree::
     :maxdepth: 1
 
+    pixfmt-meta-intel-ipu3
     pixfmt-meta-d4xx
     pixfmt-meta-uvc
     pixfmt-meta-vsp1-hgo

Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst

+.. -*- coding: utf-8; mode: rst -*-
+
+.. _v4l2-meta-fmt-params:
+.. _v4l2-meta-fmt-stat-3a:
+
+******************************************************************
+V4L2_META_FMT_IPU3_PARAMS ('ip3p'), V4L2_META_FMT_IPU3_3A ('ip3s')
+******************************************************************
+
+.. c:type:: ipu3_uapi_stats_3a
+
+3A statistics
+=============
+
+For IPU3 ImgU, the 3A statistics accelerators collect different statistics over
+an input bayer frame. Those statistics, defined in data struct :c:type:`ipu3_uapi_stats_3a`,
+are obtained from "ipu3-imgu 3a stat" metadata capture video node, which are then
+passed to user space for statistics analysis using :c:type:`v4l2_meta_format` interface.
+
+The statistics collected are AWB (Auto-white balance) RGBS (Red, Green, Blue and
+Saturation measure) cells, AWB filter response, AF (Auto-focus) filter response,
+and AE (Auto-exposure) histogram.
+
+struct :c:type:`ipu3_uapi_4a_config` saves configurable parameters for all above.
+
+.. code-block:: c
+
+	struct ipu3_uapi_stats_3a {
+		struct ipu3_uapi_awb_raw_buffer awb_raw_buffer;
+		struct ipu3_uapi_ae_raw_buffer_aligned ae_raw_buffer[IPU3_UAPI_MAX_STRIPES];
+		struct ipu3_uapi_af_raw_buffer af_raw_buffer;
+		struct ipu3_uapi_awb_fr_raw_buffer awb_fr_raw_buffer;
+		struct ipu3_uapi_4a_config stats_4a_config;
+		__u32 ae_join_buffers;
+		__u8 padding[28];
+		struct ipu3_uapi_stats_3a_bubble_info_per_stripe stats_3a_bubble_per_stripe;
+		struct ipu3_uapi_ff_status stats_3a_status;
+	};
+
+.. c:type:: ipu3_uapi_params
+
+Pipeline parameters
+===================
+
+IPU3 pipeline has a number of image processing stages, each of which takes a
+set of parameters as input. The major stages of pipelines are shown here:
+
+Raw pixels -> Bayer Downscaling -> Optical Black Correction ->
+
+Linearization -> Lens Shading Correction -> White Balance / Exposure /
+
+Focus Apply -> Bayer Noise Reduction -> ANR -> Demosaicing -> Color
+
+Correction Matrix -> Gamma correction -> Color Space Conversion ->
+
+Chroma Down Scaling -> Chromatic Noise Reduction -> Total Color
+
+Correction -> XNR3 -> TNR -> DDR
+
+The table below presents a description of the above algorithms.
+
+======================== =======================================================
+Name			 Description
+======================== =======================================================
+Optical Black Correction Optical Black Correction block subtracts a pre-defined
+			 value from the respective pixel values to obtain better
+			 image quality.
+			 Defined in :c:type:`ipu3_uapi_obgrid_param`.
+Linearization		 This algo block uses linearization parameters to
+			 address non-linearity sensor effects. The Lookup table
+			 table is defined in
+			 :c:type:`ipu3_uapi_isp_lin_vmem_params`.
+SHD			 Lens shading correction is used to correct spatial
+			 non-uniformity of the pixel response due to optical
+			 lens shading. This is done by applying a different gain
+			 for each pixel. The gain, black level etc are
+			 configured in :c:type:`ipu3_uapi_shd_config_static`.
+BNR			 Bayer noise reduction block removes image noise by
+			 applying a bilateral filter.
+			 See :c:type:`ipu3_uapi_bnr_static_config` for details.
+ANR			 Advanced Noise Reduction is a block based algorithm
+			 that performs noise reduction in the Bayer domain. The
+			 convolution matrix etc can be found in
+			 :c:type:`ipu3_uapi_anr_config`.
+Demosaicing		 Demosaicing converts raw sensor data in Bayer format
+			 into RGB (Red, Green, Blue) presentation. Then add
+			 outputs of estimation of Y channel for following stream
+			 processing by Firmware. The struct is defined as
+			 :c:type:`ipu3_uapi_dm_config`. (TODO)
+Color Correction	 Color Correction algo transforms sensor specific color
+			 space to the standard "sRGB" color space. This is done
+			 by applying 3x3 matrix defined in
+			 :c:type:`ipu3_uapi_ccm_mat_config`.
+Gamma correction	 Gamma correction :c:type:`ipu3_uapi_gamma_config` is a
+			 basic non-linear tone mapping correction that is
+			 applied per pixel for each pixel component.
+CSC			 Color space conversion transforms each pixel from the
+			 RGB primary presentation to YUV (Y: brightness,
+			 UV: Luminance) presentation. This is done by applying
+			 a 3x3 matrix defined in
+			 :c:type:`ipu3_uapi_csc_mat_config`
+CDS			 Chroma down sampling
+			 After the CSC is performed, the Chroma Down Sampling
+			 is applied for a UV plane down sampling by a factor
+			 of 2 in each direction for YUV 4:2:0 using a 4x2
+			 configurable filter :c:type:`ipu3_uapi_cds_params`.
+CHNR			 Chroma noise reduction
+			 This block processes only the chrominance pixels and
+			 performs noise reduction by cleaning the high
+			 frequency noise.
+			 See struct :c:type:`ipu3_uapi_yuvp1_chnr_config`.
+TCC			 Total color correction as defined in struct
+			 :c:type:`ipu3_uapi_yuvp2_tcc_static_config`.
+XNR3			 eXtreme Noise Reduction V3 is the third revision of
+			 noise reduction algorithm used to improve image
+			 quality. This removes the low frequency noise in the
+			 captured image. Two related structs are  being defined,
+			 :c:type:`ipu3_uapi_isp_xnr3_params` for ISP data memory
+			 and :c:type:`ipu3_uapi_isp_xnr3_vmem_params` for vector
+			 memory.
+TNR			 Temporal Noise Reduction block compares successive
+			 frames in time to remove anomalies / noise in pixel
+			 values. :c:type:`ipu3_uapi_isp_tnr3_vmem_params` and
+			 :c:type:`ipu3_uapi_isp_tnr3_params` are defined for ISP
+			 vector and data memory respectively.
+======================== =======================================================
+
+A few stages of the pipeline will be executed by firmware running on the ISP
+processor, while many others will use a set of fixed hardware blocks also
+called accelerator cluster (ACC) to crunch pixel data and produce statistics.
+
+ACC parameters of individual algorithms, as defined by
+:c:type:`ipu3_uapi_acc_param`, can be chosen to be applied by the user
+space through struct :c:type:`ipu3_uapi_flags` embedded in
+:c:type:`ipu3_uapi_params` structure. For parameters that are configured as
+not enabled by the user space, the corresponding structs are ignored by the
+driver, in which case the existing configuration of the algorithm will be
+preserved.
+
+Both 3A statistics and pipeline parameters described here are closely tied to
+the underlying camera sub-system (CSS) APIs. They are usually consumed and
+produced by dedicated user space libraries that comprise the important tuning
+tools, thus freeing the developers from being bothered with the low level
+hardware and algorithm details.
+
+It should be noted that IPU3 DMA operations require the addresses of all data
+structures (that includes both input and output) to be aligned on 32 byte
+boundaries.
+
+The meta data :c:type:`ipu3_uapi_params` will be sent to "ipu3-imgu parameters"
+video node in ``V4L2_BUF_TYPE_META_CAPTURE`` format.
+
+.. code-block:: c
+
+	struct ipu3_uapi_params {
+		/* Flags which of the settings below are to be applied */
+		struct ipu3_uapi_flags use;
+
+		/* Accelerator cluster parameters */
+		struct ipu3_uapi_acc_param acc_param;
+
+		/* ISP vector address space parameters */
+		struct ipu3_uapi_isp_lin_vmem_params lin_vmem_params;
+		struct ipu3_uapi_isp_tnr3_vmem_params tnr3_vmem_params;
+		struct ipu3_uapi_isp_xnr3_vmem_params xnr3_vmem_params;
+
+		/* ISP data memory (DMEM) parameters */
+		struct ipu3_uapi_isp_tnr3_params tnr3_dmem_params;
+		struct ipu3_uapi_isp_xnr3_params xnr3_dmem_params;
+
+		/* Optical black level compensation */
+		struct ipu3_uapi_obgrid_param obgrid_param;
+	};
+
+Intel IPU3 ImgU uAPI data types
+===============================
+
+.. kernel-doc:: include/uapi/linux/intel-ipu3.h