v1->v2: - re-order patches to introduce parameters buffer caching for the existing "fixed" format before introducing the "extensible" format - align all structures to 64-bit boundaries in the uAPI - remove NO_CHANGE enablement state and cache a bitmask of enabled blocks - address review comments in documentation The VeriSilicon ISP8000 IP, supported through the rkisp1 driver in the Linux kernel, is integrated in several SoCs from different vendors. Different revisions of the IP differ in the number of supported features and in the register space location assigned to specific ISP blocks. The current configuration parameters format, defined in include/uapi/linux/rkisp1-config.h is realized by a C structure (struct rkisp1_params_cfg) which wraps other structures that allows to configure specific ISP blocks. The layout of the parameters buffer is part of the Linux kernel uAPI and can hardly be extended or modified to adapt it to different revisions of the same IP. This series proposes the introduction of a new parameters format for the RkISP1 (without dropping support for the existing one) which is designed with the goals of being: 1) versioned: can be changed without breaking existing applications 2) extensible: new blocks and parameters can be added without breaking the uABI To do so, a new 'struct rkisp1_ext_params_cfg' type is introduced. It wraps an header and a data buffer, which userspace fills with configuration blocks for each ISP block it intends to configure. The parameters buffer is thus of different effective sizes, depending on the number of blocks userspace intends to configure. The kernel driver parses the data block and decides, based on the versioning number and the platform it operates on, how to handle each block. The parameters format is very similar to the parameters format implemented in the in-review Mali C55 ISP driver [1] I considered sending this out as RFC, but the implementation has been tested with a libcamera version ported to use the newly introduced format [2] and works as expected, so I considered it good enough to send a proper patch series A kernel branch for the interested ones is available at [3] with an associated CI pipeline [4] [1] https://lore.kernel.org/linux-media/20240529152858.183799-15-dan.scally@xxxxxxxxxxxxxxxx/ [2] https://gitlab.freedesktop.org/camera/libcamera/-/commits/imx8mp/extensible-format?ref_type=heads [3] https://gitlab.freedesktop.org/linux-media/users/jmondi/-/commits/imx8mp/media-state/extensible-format-v2 [4] https://gitlab.freedesktop.org/linux-media/users/jmondi/-/pipelines/1207025 Jacopo Mondi (7): uapi: rkisp1-config: Add extensible parameters format uapi: videodev2: Add V4L2_META_FMT_RK_ISP1_EXT_PARAMS media: rkisp1: Add struct rkisp1_params_buffer media: rkisp1: Copy the parameters buffer media: rkisp1: Cache the currently active format media: rkisp1: Implement extensible params support media: rkisp1: Implement s_fmt/try_fmt Documentation/admin-guide/media/rkisp1.rst | 11 +- .../media/v4l/metafmt-rkisp1.rst | 57 +- .../platform/rockchip/rkisp1/rkisp1-common.h | 25 +- .../platform/rockchip/rkisp1/rkisp1-params.c | 727 ++++++++++++++++-- drivers/media/v4l2-core/v4l2-ioctl.c | 1 + include/uapi/linux/rkisp1-config.h | 497 ++++++++++++ include/uapi/linux/videodev2.h | 1 + 7 files changed, 1249 insertions(+), 70 deletions(-) -- 2.45.2
