On 1/8/2025 6:31 AM, Abel Vesa wrote:
According to the DisplayPort standard, LTTPRs have two operating
modes:
- non-transparent - it replies to DPCD LTTPR field specific AUX
requests, while passes through all other AUX requests
- transparent - it passes through all AUX requests.
Switching between this two modes is done by the DPTX by issuing
an AUX write to the DPCD PHY_REPEATER_MODE register.
Add a generic helper that allows switching between these modes.
Also add a generic wrapper for the helper that handles the explicit
disabling of non-transparent mode and its disable->enable sequence
mentioned in the DP Standard v2.0 section 3.6.6.1. Do this in order
to move this handling out of the vendor specific driver implementation
into the generic framework.
Tested-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Signed-off-by: Abel Vesa <abel.vesa@xxxxxxxxxx>
---
drivers/gpu/drm/display/drm_dp_helper.c | 62 +++++++++++++++++++++++++++++++++
include/drm/display/drm_dp_helper.h | 2 ++
2 files changed, 64 insertions(+)
Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
