[v6,0/4] drm/bridge: reuse DRM HDMI Audio helpers for DisplayPort bridges

Message

Dmitry Baryshkov March 14, 2025, 9:36 a.m. UTC

A lot of DisplayPort bridges use HDMI Codec in order to provide audio
support. Present DRM HDMI Audio support has been written with the HDMI
and in particular DRM HDMI Connector framework support, however those
audio helpers can be easily reused for DisplayPort drivers too.

Patches by Hermes Wu that targeted implementing HDMI Audio support in
the iTE IT6506 driver pointed out the necessity of allowing one to use
generic audio helpers for DisplayPort drivers, as otherwise each driver
has to manually (and correctly) implement the get_eld() and plugged_cb
support.

Implement necessary integration in drm_bridge_connector and provide an
example implementation in the msm/dp driver.

The plan is to land core parts via the drm-misc-next tree and MSM DP
patch via the msm-next tree.

NOTE: The first patch now depends on the drm-misc-next _and_ msm-next
trees, as MSM HDMI driver was switched to DRM_BRIDGE_OP_HDMI. The
easiest option is to wait for msm-next to be merged to drm-misc-next
(through drm-next).

Signed-off-by: Dmitry Baryshkov <[e-mail]>
---
Changes in v6:
- Added DRM_BRIDGE_OP_DP_AUDIO and separate set of DisplayPort audio
  callbacks to the drm_bridge interface (Maxime)
- Link to v5: https://lore.kernel.org/r/[e-mail]

Changes in v5:
- Rebased on top of linux-next, also handling HDMI audio piece of the
  MSM HDMI driver.
- Link to v4: https://lore.kernel.org/r/[e-mail]

Changes in v4:
- Rebased on linux-next, adding DRM_BRIDGE_OP_HDMI_AUDIO to Synopsys QP
  HDMI driver.
- Drop outdated comment regarding subconnector from the commit message.
- Link to v3: https://lore.kernel.org/r/[e-mail]

Changes in v3:
- Dropped DRM_BRIDGE_OP_DisplayPort, added DRM_BRIDGE_OP_HDMI_AUDIO
  (Laurent, Maxime)
- Dropped the subconnector patch (again)
- Link to v2: https://lore.kernel.org/r/[e-mail]

Changes in v2:
- Added drm_connector_attach_dp_subconnector_property() patches
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Dmitry Baryshkov (4):
      drm/bridge: split HDMI Audio from DRM_BRIDGE_OP_HDMI
      drm/bridge: add function interface for DisplayPort audio implementation
      drm/bridge-connector: hook DisplayPort audio support
      drm/msm/dp: reuse generic HDMI codec implementation

 drivers/gpu/drm/bridge/lontium-lt9611.c        |   2 +-
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c   |   1 +
 drivers/gpu/drm/display/drm_bridge_connector.c | 160 +++++++++++++++++++------
 drivers/gpu/drm/msm/Kconfig                    |   1 +
 drivers/gpu/drm/msm/dp/dp_audio.c              | 131 ++------------------
 drivers/gpu/drm/msm/dp/dp_audio.h              |  27 +----
 drivers/gpu/drm/msm/dp/dp_display.c            |  28 +----
 drivers/gpu/drm/msm/dp/dp_display.h            |   6 -
 drivers/gpu/drm/msm/dp/dp_drm.c                |   8 ++
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c         |   1 +
 include/drm/drm_bridge.h                       | 122 +++++++++++++++++--
 11 files changed, 268 insertions(+), 219 deletions(-)
---
base-commit: 613af589b566093ce7388bf3202fca70d742c166
change-id: 20250206-dp-hdmi-audio-15d9fdbebb9f

Best regards,