Uart0 is connected to an MCU on the board that handles system control like the fan-speed. So far no driver for it is available though. Tested-by: Uwe Kleine-König <ukleinek@debian.org> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20240723195538.1133436-4-heiko@sntech.de [ upstream commit: 07ef8be476bebd77cba3ca4804be03cc0dba414f ] (cherry picked from commit aaa5b1c4bd8f0e4327078d513f0eef05cb829bcf) Reviewed-by: Kever Yang <kever.yang@rock-chips.com>