RK3328 : color space & sdr/hdr path missing

[Kwiboo]

The 4.4 kernel tree is missing csc / hdr2sdr code for rk3328 resulting in video colors looking bad compared to Android and the 3.10.104 kernel. Colorspace path appears to be implemented only for rk3399 in 4.4.

[yanghanxing]

This feature is WIP. I will notice you to update once it completed.

[mcerveny]

I think that it is sometimes working. Example HDR->SDR:

• input: win0 plane with NA12 (Y420-10bit), COLOR_SPACE=V4L2_COLORSPACE_BT2020, EOTF=SMPTE_ST2084
• plane_conversion: y2r[1] (YUV to RGB), CSC[3] is CSC_BT2020
• post_conversion: hdr2sdr[1], CSC[1] is CSC_BT709L
• output: RGB 8 bit

  # cat /sys/kernel/debug/dri/0/summary
  VOP [ff370000.vop]: ACTIVE
  Connector: HDMI-A
  overlay_mode[0] bus_format[100a] output_mode[f] color_space[0]
  Display mode: 1280x1024p60
  clk[108000] real_clk[108000] type[48] flag[5]
  H: 1280 1328 1440 1688
  V: 1024 1025 1028 1066
  win0-0: ACTIVE
  format: NA12 little-endian (0x3231414e) HDR[1] color_space[10]
  csc: y2r[1] r2r[0] r2y[0] csc mode[3]
  zpos: 0
  src: pos[0x0] rect[3840x2160]
  dst: pos[0x152] rect[1280x720]
  buf[0]: addr: 0x0000000001eb6000 pitch: 4864 offset: 0
  buf[1]: addr: 0x0000000001eb6000 pitch: 4864 offset: 10506240
  win1-0: DISABLED
  win2-0: DISABLED
  post: sdr2hdr[0] hdr2sdr[1]
  pre : sdr2hdr[0]
  post CSC: r2y[0] y2r[0] CSC mode[1]
  # cat /sys/kernel/debug/dw-hdmi/status 
  PHY: enabled            Mode: DVI
  Pixel Clk: 108000000Hz      TMDS Clk: 108000000Hz
  Color Format: RGB       Color Depth: 8 bit
  Colorimetry: ITU.BT709      EOTF: Off

  For more examples (HDR->SDR->HDR) and (HDR->passthrough->HDR) check here.

But, I looked to rockchip-linux code and some up-conversion (like SDR2HDR_FOR_HLG_HDR), down-conversion and whole HDR cross-coversion code missing (between different plane and connector EOTF>0 (PQ<->HLG<->LOG) check slide 15).