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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-04 08:15:19 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-04 08:15:19 -0800 |
| commit | d7aa60d966461ca6114dc348e97889dc8850ff7f (patch) | |
| tree | c694b0027c5cfdaf4a737a6fd6c2c7a55d3f898e /Documentation/driver-api | |
| parent | 559e608c46553c107dbba19dae0854af7b219400 (diff) | |
| parent | 1f2353f5a1af995efbf7bea44341aa0d03460b28 (diff) | |
| download | linux-d7aa60d966461ca6114dc348e97889dc8850ff7f.tar.gz | |
Merge tag 'media/v6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- New drivers:
- Mali-C55 ISP
- Rockchip VICAP (RKCIF)
- RKVDEC HEVC Decoder
- Renesas RZV2H IVC
- Sony IMX111 CMOS sensor driver
- Removed STi C8SECTPFE Driver
- Added a V4L2 ISP generic framework
- Usual set of cleanup, fixes and driver improvements
* tag 'media/v6.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (249 commits)
media: rockchip: rkcif: add support for rk3568 vicap mipi capture
media: rockchip: rkcif: add support for rk3568 vicap dvp capture
media: rockchip: rkcif: add support for px30 vip dvp capture
media: rockchip: rkcif: add abstraction for dma blocks
media: rockchip: rkcif: add abstraction for interface and crop blocks
media: rockchip: add driver for the rockchip camera interface
media: dt-bindings: add rockchip rk3568 vicap
media: dt-bindings: add rockchip px30 vip
media: dt-bindings: video-interfaces: add defines for sampling modes
Documentation: admin-guide: media: add rockchip camera interface
media: mali-c55: Mark pm handlers as __maybe_unused
media: mali-c55: Assert ISP blocks size correctness
media: v4l2-isp: Rename block_info to block_type_info
MAINTAINERS: Add entry for rzv2h-ivc driver
media: platform: Add Renesas Input Video Control block driver
dt-bindings: media: Add bindings for the RZ/V2H(P) IVC block
Documentation: media: mali-c55: Document the mali-c55 parameter setting
media: platform: Add mali-c55 parameters video node
media: uapi: Add parameters structs to mali-c55-config.h
media: mali-c55: Add image formats for Mali-C55 parameters buffer
...
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/media/v4l2-core.rst | 1 | ||||
| -rw-r--r-- | Documentation/driver-api/media/v4l2-isp.rst | 49 |
2 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/driver-api/media/v4l2-core.rst b/Documentation/driver-api/media/v4l2-core.rst index ad987c34ad2a84..a5f5102c64cca5 100644 --- a/Documentation/driver-api/media/v4l2-core.rst +++ b/Documentation/driver-api/media/v4l2-core.rst @@ -27,3 +27,4 @@ Video4Linux devices v4l2-common v4l2-tveeprom v4l2-jpeg + v4l2-isp diff --git a/Documentation/driver-api/media/v4l2-isp.rst b/Documentation/driver-api/media/v4l2-isp.rst new file mode 100644 index 00000000000000..618ae614ff7942 --- /dev/null +++ b/Documentation/driver-api/media/v4l2-isp.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0 + +V4L2 generic ISP parameters and statistics support +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Design rationale +================ + +ISP configuration parameters and statistics are processed and collected by +drivers and exchanged with userspace through data types that usually +reflect the ISP peripheral registers layout. + +Each ISP driver defines its own metadata output format for parameters and +a metadata capture format for statistics. The buffer layout is realized by a +set of C structures that reflects the registers layout. The number and types +of C structures is fixed by the format definition and becomes part of the Linux +kernel uAPI/uABI interface. + +Because of the hard requirement of backward compatibility when extending the +user API/ABI interface, modifying an ISP driver capture or output metadata +format after it has been accepted by mainline is very hard if not impossible. + +It generally happens, in fact, that after the first accepted revision of an ISP +driver the buffers layout need to be modified, either to support new hardware +blocks, to fix bugs or to support different revisions of the hardware. + +Each of these situations would require defining a new metadata format, making it +really hard to maintain and extend drivers and requiring userspace to use +the correct format depending on the kernel revision in use. + +V4L2 ISP configuration parameters +================================= + +For these reasons, Video4Linux2 defines generic types for ISP configuration +parameters and statistics. Drivers are still expected to define their own +formats for their metadata output and capture nodes, but the buffers layout can +be defined using the extensible and versioned types defined by +include/uapi/linux/media/v4l2-isp.h. + +Drivers are expected to provide the definitions of their supported ISP blocks +and the expected maximum size of a buffer. + +For driver developers a set of helper functions to assist them with validation +of the buffer received from userspace is available in +drivers/media/v4l2-core/v4l2-isp.c + +V4L2 ISP support driver documentation +===================================== +.. kernel-doc:: include/media/v4l2-isp.h |