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| author | Nicolas Frattaroli <nicolas.frattaroli@collabora.com> | 2026-06-09 14:43:54 +0200 |
|---|---|---|
| committer | Daniel Stone <daniels@collabora.com> | 2026-06-09 21:03:50 +0100 |
| commit | 3f0f770ccc8d724fa3b1f5b4bde5addfc4b843b8 (patch) | |
| tree | 053e161237fa9af0dbe4ac937a81bd7954477c4e /include | |
| parent | f5873533bf99ee98237141f33ba15e04170498f4 (diff) | |
| download | linux-3f0f770ccc8d724fa3b1f5b4bde5addfc4b843b8.tar.gz linux-3f0f770ccc8d724fa3b1f5b4bde5addfc4b843b8.zip | |
drm/atomic-helper: Add HDMI bridge output bus formats helper
The drm_bridge_funcs atomic_get_output_bus_fmts operation should be the
same for likely every HDMI connector bridge, unless such an HDMI
connector bridge has some special hardware restrictions that I cannot
envision yet.
To avoid code duplication and standardize on a set of media bus formats
that the HDMI output color formats translate to, add a common helper
function that implements this operation to the drm bridge helpers.
The function returns a list of output bus formats based on the HDMI
bridge's current output bits-per-component, and its bitmask of supported
color formats.
To guard against future expansion of DRM_OUTPUT_COLOR_FORMAT outgrowing
the hweight8 call, add a BUILD_BUG_ON statement where it's used that
checks for DRM_OUTPUT_COLOR_FORMAT_COUNT. The justification for not
using hweight32 in all cases is that not all ISAs have a popcount
instruction, and will benefit from a smaller/faster software
implementation that doesn't have to operate across all bits.
The justification for not defining an hweight_color depending on the
value of DRM_OUTPUT_COLOR_FORMAT_COUNT is that this count enum value is
only known at compile time, not at preprocessor time.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Link: https://patch.msgid.link/20260609-color-format-v17-7-35739b5782cc@collabora.com
Signed-off-by: Daniel Stone <daniels@collabora.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/drm/drm_atomic_helper.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index b84152810abb..4cfeec70d648 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -295,4 +295,11 @@ drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge, u32 output_fmt, unsigned int *num_input_fmts); +u32 * +drm_atomic_helper_bridge_get_hdmi_output_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + unsigned int *num_output_fmts); + #endif /* DRM_ATOMIC_HELPER_H_ */ |