UART控制器

		usart1: serial@4c000000 {
			compatible = "st,stm32h7-uart";
			reg = <0x4c000000 0x400>;
			interrupts-extended = <&exti 26 IRQ_TYPE_LEVEL_HIGH>;
			clocks = <&rcc USART1_K>;
			resets = <&rcc USART1_R>;
			wakeup-source;
			power-domains = <&pd_core_ret>;
			dmas = <&dmamux1 41 0x400 0x5>,
			       <&dmamux1 42 0x400 0x1>;
			dma-names = "rx", "tx";
			status = "disabled";
		};