Display histogram is a hardware functionality where a statistics for 'x' number of frames is generated to form a histogram data. This is notified to the user via histogram event. Compositor will then upon sensing the histogram event will read the histogram data from KMD via crtc property. A library can be developed to take this generated histogram as an input and apply some algorithm to generate an Image EnhancemenT(IET). This is further fed back to the KMD via crtc property. KMD will use this IET as a multiplicand factor to multiply with the incoming pixels at the end of the pipe which is then pushed onto the display. One such library Global Histogram Enhancement(GHE) will take the histogram as input and applied the algorithm to enhance the density and then return the enhanced factor. This library can be located @ https://github.com/intel/ghe The corresponding mutter changes to enable/disable histogram, read the histogram data, communicate with the library and write the enhanced data back to the KMD is also pushed for review at https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3873 and https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3873/diffs?commit_id=270808ca7c8be48513553d95b4a47541f5d40206 The IGT changes for validating the histogram event and reading the histogram is also pushed for review at https://patchwork.freedesktop.org/series/135789/ Test-with: 20240705091333.328322-1-mohammed.thasleem@xxxxxxxxx Arun R Murthy (10): drm/crtc: Add histogram properties drm/crtc: Expose API to create drm crtc property for histogram drm/i915/histogram: Define registers for histogram drm/i915/histogram: Add support for histogram drm/xe: Add histogram support to Xe builds drm/i915/histogram: histogram interrupt handling drm/i915/display: handle drm-crtc histogram property updates drm/i915/histogram: histogram delay counter doesnt reset drm/i915/histogram: Histogram changes for Display 20+ drm/i915/histogram: Enable pipe dithering drivers/gpu/drm/drm_atomic_state_helper.c | 6 + drivers/gpu/drm/drm_atomic_uapi.c | 17 + drivers/gpu/drm/drm_crtc.c | 30 ++ drivers/gpu/drm/i915/Makefile | 1 + drivers/gpu/drm/i915/display/intel_atomic.c | 1 + drivers/gpu/drm/i915/display/intel_crtc.c | 7 + drivers/gpu/drm/i915/display/intel_display.c | 17 + .../gpu/drm/i915/display/intel_display_irq.c | 6 +- .../drm/i915/display/intel_display_types.h | 4 + .../gpu/drm/i915/display/intel_histogram.c | 380 ++++++++++++++++++ .../gpu/drm/i915/display/intel_histogram.h | 40 ++ .../drm/i915/display/intel_histogram_regs.h | 75 ++++ drivers/gpu/drm/i915/i915_reg.h | 5 +- drivers/gpu/drm/xe/Makefile | 1 + include/drm/drm_crtc.h | 49 +++ include/uapi/drm/drm_mode.h | 11 + 16 files changed, 647 insertions(+), 3 deletions(-) create mode 100644 drivers/gpu/drm/i915/display/intel_histogram.c create mode 100644 drivers/gpu/drm/i915/display/intel_histogram.h create mode 100644 drivers/gpu/drm/i915/display/intel_histogram_regs.h -- 2.25.1
