[Intel-gfx] [RFC 0/4] PMIC based Panel and Backlight Control

[Shobhit Kumar]

Hi All,
For quite some time this problem is there in front of us and I am trying to have
a closure on how to go about doing this. This patch set is a crude implementation
to trigger the discussion. 

Daniel sometime back suggested to look at drm_panel for doing this but I was not able
to figure out how the panel driver will be loaded because PMIC probe success does not
really imply that we need to load a PMIC based panel driver. It all depends on the OEM
design if there is a DSI panel. Even then there is a possibility of SoC being usde for
panel control. All this decission can be made from the VBT information. Hence as of now
I have kept this inside i915 to init, if from VBT we know that PMIC controls the panel
enable/disable. Maybe drm_panel is not needed and we can have it internal to i915.

Similar problem is there for backlight control over PMIC as well. For that probably we
need to have independant backlight class driver, but this panel driver can also control
backlight if needed.

Also currently this needs PMIC register read/write capability which is not there in
upstream yet. For my testing I used the crude implementation for the same from a patch 
attached in -
https://bugs.freedesktop.org/show_bug.cgi?id=85977

Requesting your comments to converge on best way of implementing this.

Regards
Shobhit

Shobhit Kumar (4):
  drm/i915: Define a common data structure for Panel Info
  drm/i915: Add a drm_panel over INTEL_SOC_PMIC
  drm/i915/Kconfig: By default select DRM_PANEL
  drm/i915: Enable PMIC panel control as drm_panel for DSI

 drivers/gpu/drm/i915/Kconfig               |   1 +
 drivers/gpu/drm/i915/Makefile              |   1 +
 drivers/gpu/drm/i915/intel_drv.h           |  14 +++
 drivers/gpu/drm/i915/intel_dsi.c           |  20 +++-
 drivers/gpu/drm/i915/intel_dsi.h           |  13 +--
 drivers/gpu/drm/i915/intel_dsi_panel_vbt.c |  11 +-
 drivers/gpu/drm/i915/intel_panel_pmic.c    | 157 +++++++++++++++++++++++++++++
 7 files changed, 202 insertions(+), 15 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/intel_panel_pmic.c

-- 
1.9.1