mirror of
https://github.com/torvalds/linux.git
synced 2026-07-29 10:41:49 +02:00
Linux kernel source tree
e64693248f
Provide helpers that program hardware gamma LUTs. Tha gamma ramp is either provided by the driver or generated by the helper. The DRM driver exports the GAMMA_LUT property with a fixed number of entries per color component, such as 256 on 8-bit-wide components. The entries describe the gamma ramp of each individual component. The new helper drm_crtc_load_gamma_888() loads such gamma ramp to hardware. The hardware uses each displayed pixel's individial components as indices into the hardware gamma table. For color modes with less than 8 bits per color component, the helpers drm_crtc_load_gamma_565_from() and drm_crtc_load_gamma_555_from_888() interpolate the provided gamma ramp to reduce it to the correct number of entries; 5/6/5 for RGB565-like formats and 5/5/5 for XRGB1555-like formats. If no gamma ramp has been provided, drivers can use the new helper drm_crtc_fill_gamma_888() to load a default gamma ramp with 256 entries per color component. For color modes with less bits, the new helpers drm_crtc_fill_gamma_565() and drm_crtc_fill_gamma_555() are available. The default gamma ramp uses a gamma factor of 1. For color modes with palette, drm_crtc_load_palette_8() load an 8-bit palette into the hardware. If no palette has been specified, drm_crtc_fill_palette_8() load a system-specific default palette. This is currently only a grey-scale palette with increasing luminance, but later patches can change this. For PCs, a VGA default palette could be used. v2: - drop comment on gamma factor of 2.2 (Michel, Pekka) - fix typos in commit description (Javier) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com> Acked-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://lore.kernel.org/r/20250520094203.30545-2-tzimmermann@suse.de |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.