[Intel-gfx] [MIPI CABC 0/2] CABC patch list

Deepak M m.deepak at intel.com
Tue Mar 22 05:41:08 UTC 2016

CABC stands for the Content Adaptive Backlight Control.
In the normal display the backlight which we see is due to the
backlight which is being modulated by the filter, which is inturn
dependent on the image. In brief the CABC does the histogram
analysis of the image and then controls the filter and backlight.
For example in CABC to display the dark image the backlight is dimmed
and then controlls the filter to allow more light, because of
which is power consuption will be reduced.

Below are the initial set of patches which supports the CABC.
A field exists in the mipi configuration of the VBT which
when enabled indicates the CABC is supported. Depending on
this field the backlight control function pointer are
initialized in the intel_panel.c file.

In case of dual link panels depending on the panel
the DCS commands have to be send to either PORT A,
PORT C or both PORT A and PORT C. Again a field is
added in the VBT to get this data from the version 197 onwards.
One of the below patches parses these fields from the

Addressed the review comments of Jani, which were mentioned in
the below link

Cc: Jani Nikula <jani.nikula at intel.com>
Cc: Daniel Vetter <daniel.vetter at intel.com>
Cc: Yetunde Adebisi <yetundex.adebisi at intel.com>

Deepak M (2):
  drm/i915: Parsing the PWM cntrl and CABC ON/OFF fileds in VBT
  drm/i915: CABC support for backlight control

 drivers/gpu/drm/i915/Makefile         |   1 +
 drivers/gpu/drm/i915/i915_drv.h       |   2 +-
 drivers/gpu/drm/i915/intel_bios.c     |  10 ++
 drivers/gpu/drm/i915/intel_bios.h     |   5 +-
 drivers/gpu/drm/i915/intel_dsi.c      |  19 +++-
 drivers/gpu/drm/i915/intel_dsi.h      |  13 +++
 drivers/gpu/drm/i915/intel_dsi_cabc.c | 179 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_panel.c    |   4 +
 8 files changed, 229 insertions(+), 4 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_dsi_cabc.c


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