[Intel-gfx] [RFC 0/6] DP Phy compliace auto test.

[Animesh Manna]

Driver changes mainly to process the request coming from Test equipment
as short pulse hpd interrupt to change link-pattern/v-swing/pre-emphasis
Complete auto test suite takes much lesser time than manual run.

Overall design:
--------------
Automate test request will come to source device as HDP short pulse
interrupt from test scope.
Read DPCD 0x201, Check for bit 1 for automated test request.
If set continue and read DPCD 0x218.
Check for bit 3 for phy test pattern, If set continue.
Get the requested test pattern through DPCD 0x248.
Compute requested voltage swing level and pre-emphasis level
from DPCD 0x206 and 0x207
Set signal level through vswing programming sequence.
Write DDI_COMP_CTL and DDI_COMP_PATx as per requested pattern.
Configure the link and write the new test pattern through DPCD.

High level patch description.
-----------------------------
patch 1: drm level api added to get/set test pattern as per vesa
DP spec. This maybe useful for other driver so added in drm layer.
patch 2: vswing/preemphasis adjustment calculation is needed during
phy compliance request processing along with existing link training
process, so moved the same function in intel_dp.c.
patch 3: Parse the test scope request regarding test rquested pattern,
vswing level, preemphasis level.
patch 4: Register difnition of DP compliance register added.
patch 5: Funcion added to update the pattern in source side.
patch 6: This patch os mainly processing the request.

Currently through prototyping patch able to run DP compliance where
vswing, preemphasis and test pattern is changing fine but complete
test is under process. In parallel want to start design discussion
so sending the above patches as RFC.

Animesh Manna (6):
  drm/dp: get/set phy compliance pattern.
  drm/i915/dp: Move vswing/pre-emphasis adjustment calculation
  drm/i915/dp: Preparation for DP phy compliance auto test.
  drm/i915/dp: Register definition for DP compliance register.
  drm/i915/dp: Update the pattern as per request.
  drm/i915/dp: Program vswing, pre-emphasis, test-pattern

 drivers/gpu/drm/drm_dp_helper.c               |  77 ++++++++
 .../drm/i915/display/intel_display_types.h    |   1 +
 drivers/gpu/drm/i915/display/intel_dp.c       | 178 ++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_dp.h       |   3 +
 .../drm/i915/display/intel_dp_link_training.c |  32 ----
 drivers/gpu/drm/i915/i915_reg.h               |  20 ++
 include/drm/drm_dp_helper.h                   |  28 +++
 7 files changed, 307 insertions(+), 32 deletions(-)

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2.22.0