On Pi4 (and Pi5) the answer is largely no.
The hotplug detect signal goes directly into the HDMI block, and can't be reconfigured.
Pi0-3 do use normal GPIOs for HPD, so in theory you could reroute it or otherwise abuse the interface.
The code does check for a GPIO first before looking at the board variant for reading HPD, so I think you'll find that if you do add a hpd-gpios define to DT, then it will read that GPIO to the exclusion of the hardware signal.
https://github.com/raspberrypi/linux/bl ... #L505-L514 is the code of interest, and Pi4 and 5 define "hp_detect = vc5_hdmi_hp_detect;" for reading the hardware block.
The hotplug detect signal goes directly into the HDMI block, and can't be reconfigured.
Pi0-3 do use normal GPIOs for HPD, so in theory you could reroute it or otherwise abuse the interface.
The code does check for a GPIO first before looking at the board variant for reading HPD, so I think you'll find that if you do add a hpd-gpios define to DT, then it will read that GPIO to the exclusion of the hardware signal.
https://github.com/raspberrypi/linux/bl ... #L505-L514 is the code of interest, and Pi4 and 5 define "hp_detect = vc5_hdmi_hp_detect;" for reading the hardware block.
Statistics: Posted by 6by9 — Tue Dec 10, 2024 12:00 pm