Hi Sameer > Thanks Morimoto-san for references. I need a lot more understanding on > "card2" before commenting anything further. Right now I look to > continue using "card" driver and have an easy DT extension, if > possible, without disturbing existing Tegra users. I hope it would be > fine to push changes to "card" without affecting existing users. "card" and "card2" are indeed different, but similar I think. I hope you can use "card2", but if you want to use "card", you can use "custome card" feature which is zero effect to existing "card" users. "tegra_audio_graph_card.c" is already using this feature. see audio_graph_parse_of() Thank you for your help !! Best regards --- Renesas Electronics Ph.D. Kuninori Morimoto