1Amlogic Meson SoC UART Serial Interface 2======================================= 3 4The Amlogic Meson SoC UART Serial Interface is present on a large range 5of SoCs, and can be present either in the "Always-On" power domain or the 6"Everything-Else" power domain. 7 8The particularity of the "Always-On" Serial Interface is that the hardware 9is active since power-on and does not need any clock gating and is usable 10as very early serial console. 11 12Required properties: 13- compatible : compatible: value should be different for each SoC family as : 14 - Meson6 : "amlogic,meson6-uart" 15 - Meson8 : "amlogic,meson8-uart" 16 - Meson8b : "amlogic,meson8b-uart" 17 - GX (GXBB, GXL, GXM) : "amlogic,meson-gx-uart" 18 eventually followed by : "amlogic,meson-ao-uart" if this UART interface 19 is in the "Always-On" power domain. 20- reg : offset and length of the register set for the device. 21- interrupts : identifier to the device interrupt 22- clocks : a list of phandle + clock-specifier pairs, one for each 23 entry in clock names. 24- clock-names : 25 * "xtal" for external xtal clock identifier 26 * "pclk" for the bus core clock, either the clk81 clock or the gate clock 27 * "baud" for the source of the baudrate generator, can be either the xtal 28 or the pclk. 29 30e.g. 31uart_A: serial@84c0 { 32 compatible = "amlogic,meson-gx-uart"; 33 reg = <0x0 0x84c0 0x0 0x14>; 34 interrupts = <GIC_SPI 26 IRQ_TYPE_EDGE_RISING>; 35 /* Use xtal as baud rate clock source */ 36 clocks = <&xtal>, <&clkc CLKID_UART0>, <&xtal>; 37 clock-names = "xtal", "pclk", "baud"; 38}; 39