From Rockchip open source Document
Whether LVDS display card has been registered successfully
If the LVDS display card has been created, it would create a sysfs debug directory.
$ ls /sys/class/drm/card0-LVDS-1</code>
So you just need to check that directory. If that directory is missing in your machine board, please check:
- Whether LVDS have been enabled in DTS files.
- Whether LVDS panel have been registered successfully.
- Whether you have available VOP module for LVDS.
- Check the kernel log for more detail (dmesg | grep lvds)
Check LVDS display card status: status, enabled, modes
$ cd /sys/class/drm/card0-LVDS-1 $ cat status # should printed "connected" or "disconnected" $ cat enabled # should printed "enabled" or "disabled" $ cat modes # should printed the available mode list, like 1536x2048</code>
If you still have no picture on LVDS panel, please check bellow information:
- Check the LVDS panel power supply.
- Check the panel datasheet, ensure you have configured the timing and data format rightly.
- Check the hardware connected status, or test the panel on workable board.