1# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) 2# Copyright 2019 BayLibre, SAS 3%YAML 1.2 4--- 5$id: http://devicetree.org/schemas/serial/amlogic,meson-uart.yaml# 6$schema: http://devicetree.org/meta-schemas/core.yaml# 7 8title: Amlogic Meson SoC UART Serial Interface 9 10maintainers: 11 - Neil Armstrong <neil.armstrong@linaro.org> 12 13description: | 14 The Amlogic Meson SoC UART Serial Interface is present on a large range 15 of SoCs, and can be present either in the "Always-On" power domain or the 16 "Everything-Else" power domain. 17 18 The particularity of the "Always-On" Serial Interface is that the hardware 19 is active since power-on and does not need any clock gating and is usable 20 as very early serial console. 21 22allOf: 23 - $ref: serial.yaml# 24 25properties: 26 compatible: 27 oneOf: 28 - description: Always-on power domain UART controller 29 items: 30 - enum: 31 - amlogic,meson6-uart 32 - amlogic,meson8-uart 33 - amlogic,meson8b-uart 34 - amlogic,meson-gx-uart 35 - amlogic,meson-s4-uart 36 - amlogic,meson-a1-uart 37 - const: amlogic,meson-ao-uart 38 - description: Always-on power domain UART controller on G12A SoCs 39 items: 40 - const: amlogic,meson-g12a-uart 41 - const: amlogic,meson-gx-uart 42 - const: amlogic,meson-ao-uart 43 - description: Everything-Else power domain UART controller 44 enum: 45 - amlogic,meson6-uart 46 - amlogic,meson8-uart 47 - amlogic,meson8b-uart 48 - amlogic,meson-gx-uart 49 - amlogic,meson-s4-uart 50 - amlogic,meson-a1-uart 51 - description: Everything-Else power domain UART controller on G12A SoCs 52 items: 53 - const: amlogic,meson-g12a-uart 54 - const: amlogic,meson-gx-uart 55 - description: UART controller on S4 compatible SoCs 56 items: 57 - enum: 58 - amlogic,a4-uart 59 - amlogic,a9-uart 60 - amlogic,s6-uart 61 - amlogic,s7-uart 62 - amlogic,s7d-uart 63 - amlogic,t7-uart 64 - const: amlogic,meson-s4-uart 65 66 reg: 67 maxItems: 1 68 69 interrupts: 70 maxItems: 1 71 72 clocks: 73 items: 74 - description: external xtal clock identifier 75 - description: the bus core clock, either the clk81 clock or the gate clock 76 - description: the source of the baudrate generator, can be either the xtal or the pclk 77 78 clock-names: 79 items: 80 - const: xtal 81 - const: pclk 82 - const: baud 83 84 fifo-size: 85 description: The fifo size supported by the UART channel. 86 $ref: /schemas/types.yaml#/definitions/uint32 87 enum: [64, 128] 88 89required: 90 - compatible 91 - reg 92 - interrupts 93 - clocks 94 - clock-names 95 96unevaluatedProperties: false 97 98examples: 99 - | 100 serial@84c0 { 101 compatible = "amlogic,meson-gx-uart"; 102 reg = <0x84c0 0x14>; 103 interrupts = <26>; 104 clocks = <&xtal>, <&pclk>, <&xtal>; 105 clock-names = "xtal", "pclk", "baud"; 106 }; 107