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 56 reg: 57 maxItems: 1 58 59 interrupts: 60 maxItems: 1 61 62 clocks: 63 items: 64 - description: external xtal clock identifier 65 - description: the bus core clock, either the clk81 clock or the gate clock 66 - description: the source of the baudrate generator, can be either the xtal or the pclk 67 68 clock-names: 69 items: 70 - const: xtal 71 - const: pclk 72 - const: baud 73 74 fifo-size: 75 description: The fifo size supported by the UART channel. 76 $ref: /schemas/types.yaml#/definitions/uint32 77 enum: [64, 128] 78 79required: 80 - compatible 81 - reg 82 - interrupts 83 - clocks 84 - clock-names 85 86unevaluatedProperties: false 87 88examples: 89 - | 90 serial@84c0 { 91 compatible = "amlogic,meson-gx-uart"; 92 reg = <0x84c0 0x14>; 93 interrupts = <26>; 94 clocks = <&xtal>, <&pclk>, <&xtal>; 95 clock-names = "xtal", "pclk", "baud"; 96 }; 97