[PATCH 00/15] YCBCR 4:2:0 handling in DRM layer

[Shashank Sharma]

Following YCBCR 4:4:4 and 4:2:2, YCBCR 4:2:0 is a new output format,
which is currently supported on HDMI 2.0 sources/sinks. Due to lower
chroma sub-sampling rate, YCBCR 4:2:0 can drive the video modes at half
the pixel clock than YCBCR 4:4:4 or RGB 8:8:8 outputs. For example, a CEA
4K at 60, RGB 8:8:8 mode needs a clock of appx 594Mhz, but it can be driven at
297Mhz using YCBCR 4:2:0 output.

Of course, the lower rate of chroma subsampling, causes the quality of YCBCR
4:2:0 to be lower than YCBCR 4:4:4 or RGB 8:8:8.

This patch series adds support for YCBCR 4:2:0 output in DRM layer.

- First 2 patches, complete the CEA mode-db in drm driver, by adding
  new 4k modes. Current CEA mode-db contains 64 modes only (VIC 1-64),
  whereas CEA-861-F defined VICs up to 107, including 4k modes, from VIC
  range 93-107. First patch makes sure that inclusion of these modes doesn't
  break existing HDMI 1.4 monitors, across various drivers.

- Next 5 patches focus on parsing new YCBCR 4:2:0 EDID blocks, and adding
  YCBCR 4:2:0 modes in connector. They also contain a prune function, which
  will cleanup the YCBCR 4:2:0 modes from list, if the connector doesn't
  declare them supported.

- Next 2 patches add helper functions for identifing YCBCR 4:2:0 modes and
  setup the color space in AVI infoframes.

- Next 6 patches add code for I915 layer handling of YCBCR 4:2:0 output.

This patch series was initially published as a complete framework to handle
all YCBCR outputs (4:4:4, 4:2:2, 4:2:0), but based on the code reviews, now
its been published as YCBCR 4:2:0 handling series only.

The previous discussion and reviews can be found here:
    V5: https://patchwork.freedesktop.org/series/26815/
    V1-V4: https://patchwork.freedesktop.org/series/22683/

Now re-publishing this patch series as YCBCR 4:2:0 handling series here.
This series has been tested with drm-tip code with following setup:
Source: Intel Geminilake device.
Sink: ACER S277HK HDMI 2.0 monitor.
Protocol testing: Astro VA-1844A HDMI analyzer.

Shashank Sharma (15):
  drm: handle HDMI 2.0 VICs in AVI info-frames
  drm/edid: complete CEA modedb(VIC 1-107)
  drm/edid: parse sink information before CEA blocks
  drm/edid: cleanup patch for CEA extended-tag macro
  drm/edid: parse YCBCR420 videomodes from EDID
  drm: add helper to validate YCBCR420 modes
  drm/edid: parse ycbcr 420 deep color information
  drm: set output colorspace in AVI infoframe
  drm: add helper functions for YCBCR420 handling
  drm/i915: add config function for YCBCR420 outputs
  drm/i915: prepare scaler for YCBCR420 modeset
  drm/i915: prepare pipe for YCBCR420 output
  drm/i915: prepare csc unit for YCBCR420 output
  drm/i915: set colorspace for YCBCR420 outputs
  drm/i915/glk: set HDMI 2.0 identifier

 drivers/gpu/drm/amd/amdgpu/dce_v10_0.c    |   2 +-
 drivers/gpu/drm/amd/amdgpu/dce_v11_0.c    |   2 +-
 drivers/gpu/drm/amd/amdgpu/dce_v6_0.c     |   2 +-
 drivers/gpu/drm/amd/amdgpu/dce_v8_0.c     |   2 +-
 drivers/gpu/drm/bridge/analogix-anx78xx.c |   3 +-
 drivers/gpu/drm/bridge/sii902x.c          |   2 +-
 drivers/gpu/drm/bridge/synopsys/dw-hdmi.c |   2 +-
 drivers/gpu/drm/drm_edid.c                | 469 +++++++++++++++++++++++++++++-
 drivers/gpu/drm/drm_modes.c               | 102 +++++++
 drivers/gpu/drm/drm_probe_helper.c        |   4 +
 drivers/gpu/drm/exynos/exynos_hdmi.c      |   2 +-
 drivers/gpu/drm/i2c/tda998x_drv.c         |   2 +-
 drivers/gpu/drm/i915/i915_reg.h           |   3 +
 drivers/gpu/drm/i915/intel_atomic.c       |   6 +
 drivers/gpu/drm/i915/intel_color.c        |  47 ++-
 drivers/gpu/drm/i915/intel_display.c      |  48 +++
 drivers/gpu/drm/i915/intel_drv.h          |  13 +-
 drivers/gpu/drm/i915/intel_hdmi.c         |  74 ++++-
 drivers/gpu/drm/i915/intel_panel.c        |   3 +-
 drivers/gpu/drm/i915/intel_sdvo.c         |   3 +-
 drivers/gpu/drm/mediatek/mtk_hdmi.c       |   2 +-
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c    |   2 +-
 drivers/gpu/drm/nouveau/nv50_display.c    |   3 +-
 drivers/gpu/drm/omapdrm/omap_encoder.c    |   3 +-
 drivers/gpu/drm/radeon/radeon_audio.c     |   2 +-
 drivers/gpu/drm/rockchip/inno_hdmi.c      |   2 +-
 drivers/gpu/drm/sti/sti_hdmi.c            |   2 +-
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c    |   2 +-
 drivers/gpu/drm/tegra/hdmi.c              |   2 +-
 drivers/gpu/drm/tegra/sor.c               |   2 +-
 drivers/gpu/drm/vc4/vc4_hdmi.c            |   2 +-
 drivers/gpu/drm/zte/zx_hdmi.c             |   2 +-
 include/drm/drm_connector.h               |  32 ++
 include/drm/drm_edid.h                    |  17 +-
 include/drm/drm_modes.h                   |  11 +
 35 files changed, 837 insertions(+), 40 deletions(-)

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2.7.4