We do not have a software driver porting guide for Android 9. We do have a reference driver for MAX3421E, which may be helpful. You can find it here:
https://github.com/torvalds/linux/blob/master/drivers/usb/host/max3421-hcd.c
We do not have a software driver porting guide for Android 9. We do have a reference driver for MAX3421E, which may be helpful. You can find it here:
https://github.com/torvalds/linux/blob/master/drivers/usb/host/max3421-hcd.c