drm/amd/display: hook dp test pattern through debugfs

drm/amd/display: hook dp test pattern through debugfs

 set PHY layer or Link layer test pattern
 PHY test pattern is used for PHY SI check.
 Link layer test will not affect PHY SI.

 - normal video mode
  0 = DP_TEST_PATTERN_VIDEO_MODE

 - PHY test pattern supported
  1 = DP_TEST_PATTERN_D102
  2 = DP_TEST_PATTERN_SYMBOL_ERROR
  3 = DP_TEST_PATTERN_PRBS7
  4 = DP_TEST_PATTERN_80BIT_CUSTOM
  5 = DP_TEST_PATTERN_CP2520_1
  6 = DP_TEST_PATTERN_CP2520_2 = DP_TEST_PATTERN_HBR2_COMPLIANCE_EYE
  7 = DP_TEST_PATTERN_CP2520_3

 - DP PHY Link Training Patterns
  8 = DP_TEST_PATTERN_TRAINING_PATTERN1
  9 = DP_TEST_PATTERN_TRAINING_PATTERN2
  0xa = DP_TEST_PATTERN_TRAINING_PATTERN3
  0xb = DP_TEST_PATTERN_TRAINING_PATTERN4

 - DP Link Layer Test pattern
  0xc = DP_TEST_PATTERN_COLOR_SQUARES
  0xd = DP_TEST_PATTERN_COLOR_SQUARES_CEA
  0xe = DP_TEST_PATTERN_VERTICAL_BARS
  0xf = DP_TEST_PATTERN_HORIZONTAL_BARS
  0x10= DP_TEST_PATTERN_COLOR_RAMP

 debugfs phy_test_pattern is located at /syskernel/debug/dri/0/DP-x

 --- set test pattern
  echo <test pattern #> > test_pattern

 - custom test pattern
  If test pattern # is not supported, NO HW programming will be done
  for DP_TEST_PATTERN_80BIT_CUSTOM, it needs extra 10 bytes of data
  for the user pattern. input 10 bytes data are separated by space

  echo 0x4 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 0x99 0xaa >
  test_pattern

 --- reset test pattern
  echo 0 > test_pattern

 --- HPD detection is disabled when set PHY test pattern

  when PHY test pattern (pattern # within [1,7]) is set, HPD pin of
  HW ASIC is disable. User could unplug DP display from DP connected
  and plug scope to check test pattern PHY SI.
  If there is need unplug scope and plug DP display back, do steps
  below:
  echo 0 > phy_test_pattern
  unplug scope
  plug DP display.

  "echo 0 > phy_test_pattern" will re-enable HPD pin again so that
  video sw driver could detect "unplug scope" and "plug DP display"

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>