[PATCH v7 0/2] Add no-hpd property to the cadence bridge

[Yashas D]

This series adds 'no-hpd' device tree property support to the Cadence
MHDP8546 bridge driver for boards where the HPD line cannot be used for
hotplug detection.

On TI J721S2 EVMs, the DP0 HPD resistor is DNI from factory, so the HPD
signal is not physically connected to SoC pin AA24 by default. AA24 must
still be in DP0_HPD mux mode for the MHDP firmware to operate.

When 'no-hpd' is set, DRM_BRIDGE_OP_HPD is omitted and the framework
falls back to polling .detect() every ~10 seconds. Presence is detected
by reading DP_DPCD_REV (0x000) over AUX, with an early exit when the
monitor is stably connected to avoid re-programming the stream each poll.

Changes since v6:
  - Reverted back to dev_dbg instead of dev_err for the normal hpd case.
  - Picked up Acked-by from Krzysztof Kozlowski from v6 on the bindings patch.

Link to v6: https://lore.kernel.org/all/20260802153825.1570435-1-y-d@xxxxxx/

Rahul T R (2):
  dt-bindings: display: bridge: cdns,mhdp8546: Add no-hpd property to
    the cadence bridge
  drm: bridge: cdns-mhdp8546: Add no-hpd property

 .../display/bridge/cdns,mhdp8546.yaml         | 11 +++
 .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 69 +++++++++++++++++--
 .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  1 +
 3 files changed, 75 insertions(+), 6 deletions(-)

-- 
2.34.1