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| -rw-r--r-- | Documentation/userspace-api/media/v4l/meta-formats.rst | 1 | ||||
| -rw-r--r-- | Documentation/userspace-api/media/v4l/v4l2-isp.rst | 67 | ||||
| -rw-r--r-- | MAINTAINERS | 1 |
3 files changed, 69 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/meta-formats.rst b/Documentation/userspace-api/media/v4l/meta-formats.rst index d9868ee88a07..7b758ea9eb4a 100644 --- a/Documentation/userspace-api/media/v4l/meta-formats.rst +++ b/Documentation/userspace-api/media/v4l/meta-formats.rst @@ -25,3 +25,4 @@ These formats are used for the :ref:`metadata` interface only. metafmt-vivid metafmt-vsp1-hgo metafmt-vsp1-hgt + v4l2-isp diff --git a/Documentation/userspace-api/media/v4l/v4l2-isp.rst b/Documentation/userspace-api/media/v4l/v4l2-isp.rst new file mode 100644 index 000000000000..facf6dba1ca7 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/v4l2-isp.rst @@ -0,0 +1,67 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later + +.. _v4l2-isp: + +************************ +Generic V4L2 ISP formats +************************ + +Generic ISP formats are metadata formats that define a mechanism to pass ISP +parameters and statistics between userspace and drivers in V4L2 buffers. They +are designed to allow extending them in a backward-compatible way. + +ISP parameters +============== + +The generic ISP configuration parameters format is realized by a defining a +single C structure that contains a header, followed by a binary buffer where +userspace programs a variable number of ISP configuration data block, one for +each supported ISP feature. + +The :c:type:`v4l2_isp_params_buffer` structure defines the buffer header which +is followed by a binary buffer of ISP configuration data. Userspace shall +correctly populate the buffer header with the generic parameters format version +and with the size (in bytes) of the binary data buffer where it will store the +ISP blocks configuration. + +Each *ISP configuration block* is preceded by an header implemented by the +:c:type:`v4l2_isp_params_block_header` structure, followed by the configuration +parameters for that specific block, defined by the ISP driver specific data +types. + +Userspace applications are responsible for correctly populating each block's +header fields (type, flags and size) and the block-specific parameters. + +ISP block enabling, disabling and configuration +----------------------------------------------- + +When userspace wants to configure and enable an ISP block it shall fully +populate the block configuration and set the V4L2_ISP_PARAMS_FL_BLOCK_ENABLE +bit in the block header's `flags` field. + +When userspace simply wants to disable an ISP block the +V4L2_ISP_PARAMS_FL_BLOCK_DISABLE bit should be set in block header's `flags` +field. Drivers accept a configuration parameters block with no additional +data after the header in this case. + +If the configuration of an already active ISP block has to be updated, +userspace shall fully populate the ISP block parameters and omit setting the +V4L2_ISP_PARAMS_FL_BLOCK_ENABLE and V4L2_ISP_PARAMS_FL_BLOCK_DISABLE bits in the +header's `flags` field. + +Setting both the V4L2_ISP_PARAMS_FL_BLOCK_ENABLE and +V4L2_ISP_PARAMS_FL_BLOCK_DISABLE bits in the flags field is not allowed and +returns an error. + +Extension to the parameters format can be implemented by adding new blocks +definition without invalidating the existing ones. + +ISP statistics +============== + +Support for generic statistics format is not yet implemented in Video4Linux2. + +V4L2 ISP uAPI data types +======================== + +.. kernel-doc:: include/uapi/linux/media/v4l2-isp.h diff --git a/MAINTAINERS b/MAINTAINERS index 97c8a4cdbc2c..a22249166e4a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -26889,6 +26889,7 @@ V4L2 GENERIC ISP PARAMETERS AND STATISTIC FORMATS M: Jacopo Mondi <jacopo.mondi@ideasonboard.com> L: linux-media@vger.kernel.org S: Maintained +F: Documentation/userspace-api/media/v4l/v4l2-isp.rst F: include/uapi/linux/media/v4l2-isp.h VF610 NAND DRIVER |