[v4,0/3] media: v4l2-subdev: Support const-awareness in state accessors

Message

Laurent Pinchart May 8, 2024, 9:40 p.m. UTC

This small patch series comes from a mild annoyance I experienced during
a recent patch review, where I wanted to ask for a pointer to a
v4l2_subdev_state used to access the state in a read-only fashion to be
made const. This wasn't possible as the state accessors functions take a
non-const state pointer, in order to return pointers to mutable formats
and selection rectangles.

Patch 1/3 first fixes a small documentation mistake. Patch 2/3 improves
the state accessors to support const states, in the same wait as the
recently introduced container_of_const() macro. The internal macro name
has been subject to a bit of bikeshedding already, so I think we're
reaching a final version. Patch 3/3 then shows how this can be used in
one driver.

Compared to v3, patch 1/3 is new, and patch 2/3 renames the new macro
and updates documentation.

Laurent Pinchart (3):
  media: v4l2-subdev: Fix v4l2_subdev_state_get_format() documentation
  media: v4l2-subdev: Provide const-aware subdev state accessors
  media: rkisp1: Mark subdev state pointers as const

 .../platform/rockchip/rkisp1/rkisp1-isp.c     |  8 +--
 .../platform/rockchip/rkisp1/rkisp1-resizer.c |  8 +--
 include/media/v4l2-subdev.h                   | 50 +++++++++++++------
 3 files changed, 42 insertions(+), 24 deletions(-)


base-commit: e695668af8523b059127dfa8b261c76e7c9cde10