[PATCH v2 0/2] drm/dp: Make DP AUX bus usage easier; use it on ps8640

[Douglas Anderson]

This patch is v2 of the first 2 patches from my RFC series ("drm/dp: Improvements
for DP AUX channel") [1]. I've broken the series in two so we can make
progress on the two halves separately.

v2 of this series tries to incorporate all the feedback from v1. Hopefully
things are less confusing and simpler this time around. The one thing that got
slightly more confusing is that the done_probing() callback can't return
-EPROBE_DEFER in most cases so we have to adjust drivers a little more.

The idea for this series came up during the review process of
Sankeerth's series trying to add eDP for Qualcomm SoCs [2].

This _doesn't_ attempt to fix the Analogix driver. If this works out,
ideally someone can post a patch up to do that.

[1] https://lore.kernel.org/r/20220409023628.2104952-1-dianders@xxxxxxxxxxxx/
[2] https://lore.kernel.org/r/1648656179-10347-2-git-send-email-quic_sbillaka@xxxxxxxxxxx/

Changes in v2:
- Change to assume exactly one device.
- Have a probe callback instead of an extra sub device.
- Rewrote atop new method introduced by patch #1.

Douglas Anderson (2):
  drm/dp: Add callbacks to make using DP AUX bus properly easier
  drm/bridge: parade-ps8640: Handle DP AUX more properly

 drivers/gpu/drm/bridge/parade-ps8640.c   |  77 +++++---
 drivers/gpu/drm/display/drm_dp_aux_bus.c | 215 +++++++++++++++--------
 include/drm/display/drm_dp_aux_bus.h     |  24 ++-
 3 files changed, 216 insertions(+), 100 deletions(-)

-- 
2.36.0.464.gb9c8b46e94-goog