The Thinkpad T14s embeds a transparent 4lanes DP->HDMI transceiver
connected to the third QMP Combo PHY 4 lanes.
The QMP USB3/DP Combo PHY hosts an USB3 phy and a DP PHY on top
of a combo glue to route either lanes to the 4 shared physical lanes.
The routing of the lanes can be:
- 2 DP + 2 USB3
- 4 DP
- 2 USB3
And the layout of the lanes can be swpped depending of an
eventual USB-C connector orientation.
Nevertheless those QMP Comby PHY can be statically used to
drive a DisplayPort connector, DP->HDMI bridge, USB3 A Connector...
But if a 4lanes DP->HDMI bridge is directly connected to the
QMP Comby PHY lanes, in the default routing 2 or the 4 lanes would
probbaly be USB3, making the DP->HDMI bridge non functional.
Support the property set set in which layout mode the QMP Comby PHY
should be as startup.
Finally Add all the data routing in DT, disable mode switching and specify
the QMP Combo PHY should be in DP-Only mode to route the 4 lanes to
the underlying DP phy.
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
Neil Armstrong (3):
dt-bindings: phy: qcom,sc8280xp-qmp-usb43dp-phy: Document default phy mode
phy: qcom: qmp-combo: get default qmpphy_mode from DT
arm64: dts: qcom: x1e78100-lenovo-thinkpad-t14s: add HDMI nodes
.../phy/qcom,sc8280xp-qmp-usb43dp-phy.yaml | 13 +++++++
.../dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi | 44 ++++++++++++++++++++++
drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 20 +++++++++-
3 files changed, 76 insertions(+), 1 deletion(-)
---
base-commit: 7fa4d8dc380fbd81a9d702a855c50690c9c6442c
change-id: 20250821-topic-x1e80100-hdmi-3bd5b5bd2d96
Best regards,
--
Neil Armstrong <neil.armstrong@linaro.org>