beagleboard / bb.org-overlays

Device Tree Overlays for bb.org boards
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Pinmux for HDMI audio pins does not work with TI kernels #43

Open machinekoder opened 7 years ago

machinekoder commented 7 years ago

The pins occupied by HDMI audio on the BBB do not work in combination with the TI RT kernels e.g.: Linux beaglebone 4.4.54-ti-rt-r93 #1 SMP PREEMPT RT Fri Mar 17 15:25:04 UTC 2017 armv7l GNU/Linux.

Config pins accessing the state pin reports following error:

sudo config-pin P9_25 in

[sudo] password for machinekit:  
bash: /sys/devices/platform/ocp/ocp*P9_25_pinmux/state: No such file or directory

Cannot write pinmux file: /sys/devices/platform/ocp/ocp*P9_25_pinmux/state

It looks like the driver is not loaded correctly:

machinekit@beaglebone:~$ ls /sys/devices/platform/ocp/ocp*P9_28_pinmux/
driver_override  modalias  of_node  power  subsystem  uevent

I could verify this problem with the following pins:

P9.25
P9.28
P9.29
P9.31
machinekoder commented 7 years ago

I have tested with the universal overlays and the problem occurs with all overlays using the pins. e.g.: