[PATCH v7 0/9] Enhancement to intel_dp_aux_backlight driver

[Puthikorn Voravootivat]

This patch set contain 9 patches.
- First five patches fix bug in the driver and allow choosing which
  way to adjust brightness if both PWM pin and AUX are supported
- Next patch adds enable DBC by default
- Next patch makes the driver restore last brightness level after
  turning display off and on.
- Last two patches set the PWM freqency to match data in panel vbt.

This patch set is reviewed by Dhinakaran in patch #1, 2, 5, 7, 8

Change log:
v7:
- Add check in intel_dp_pwm_pin_display_control_capable in patch #4
- Add option in patch #6 to enable DPCD or not
- Change definition in patch #8 and implementation in #9 to use Khz
- Fix compiler warning from build bot in patch #9

v6:
- Address review from Dhinakaran
- Make PWM frequency to have highest value of Pn that make the
  frequency still within 25% of desired frequency.

v5:
- Split first patch in v4 to 3 patches
- Bump priority for "Correctly enable backlight brightness adjustment via DPCD"
- Make logic clearer for the case that both PWM pin and AUX are supported
- Add more log when write to register fail
- Add log when enable DBC

v4:
- Rebase / minor typo fix.

v3:
- Add new implementation of PWM frequency patch

v2:
- Drop PWM frequency patch
- Address suggestion from Jani Nikula


Puthikorn Voravootivat (9):
  drm/i915: Fix cap check for intel_dp_aux_backlight driver
  drm/i915: Correctly enable backlight brightness adjustment via DPCD
  drm/i915: Drop AUX backlight enable check for backlight control
  drm/i915: Allow choosing how to adjust brightness if both supported
  drm/i915: Set backlight mode before enable backlight
  drm/i915: Add option to support dynamic backlight via DPCD
  drm/i915: Restore brightness level in aux backlight driver
  drm: Add definition for eDP backlight frequency
  drm/i915: Set PWM divider to match desired frequency in vbt

 drivers/gpu/drm/i915/i915_params.c            |  13 +-
 drivers/gpu/drm/i915/i915_params.h            |   5 +-
 drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 173 ++++++++++++++++++++++++--
 include/drm/drm_dp_helper.h                   |   2 +
 4 files changed, 176 insertions(+), 17 deletions(-)

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2.13.0.rc2.291.g57267f2277-goog