During the galaxy s3 days samsung sold an "audiodock" with the model number EDD-D200BEGSTA, it very likely houses an audio card that would only power from micro usb connected to the dock. It IDs itself with a 64.9K ohm resister on id pin, and once a samsung device detects it, it will go into a special dock mode where usb data pins are in host mode, but vbus would stay as a client device, effectively "otg while charging".
I'm a little scared of this however, because I don't know why samsung disabled the audiodock in dts (same for s6, driver support is there but disabled in dts).
To enable audiodock (id - 64.9K ohm - gnd):
echo 1 > /sys/devices/virtual/sec/switch/force_enable_audiodock
Other than that, this commit also allows one to spoof normal otg as audiodock. That would allow an OTG cable with an active vbus but without a resister mod to provide charging to the device with otg enabled. The active vbus would also be powering client devices.
To enable otg audiodock spoofing:
echo 1 > /sys/devices/virtual/sec/switch/force_otg_audiodock
During the galaxy s3 days samsung sold an "audiodock" with the model number EDD-D200BEGSTA, it very likely houses an audio card that would only power from micro usb connected to the dock. It IDs itself with a 64.9K ohm resister on id pin, and once a samsung device detects it, it will go into a special dock mode where usb data pins are in host mode, but vbus would stay as a client device, effectively "otg while charging".
I'm a little scared of this however, because I don't know why samsung disabled the audiodock in dts (same for s6, driver support is there but disabled in dts).
To enable audiodock (id - 64.9K ohm - gnd): echo 1 > /sys/devices/virtual/sec/switch/force_enable_audiodock
Other than that, this commit also allows one to spoof normal otg as audiodock. That would allow an OTG cable with an active vbus but without a resister mod to provide charging to the device with otg enabled. The active vbus would also be powering client devices.
To enable otg audiodock spoofing: echo 1 > /sys/devices/virtual/sec/switch/force_otg_audiodock