Documentation/devicetree/bindings/serial/atmel,at91-usart.yaml

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
# Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
%YAML 1.2
---
$id: http://devicetree.org/schemas/serial/atmel,at91-usart.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART)

maintainers:
  - Richard Genoud <richard.genoud@gmail.com>

properties:
  compatible:
    oneOf:
      - enum:
          - atmel,at91rm9200-usart
          - atmel,at91sam9260-usart
          - microchip,sam9x60-usart
      - items:
          - const: atmel,at91rm9200-dbgu
          - const: atmel,at91rm9200-usart
      - items:
          - const: atmel,at91sam9260-dbgu
          - const: atmel,at91sam9260-usart
      - items:
          - const: microchip,sam9x60-dbgu
          - const: microchip,sam9x60-usart
          - const: atmel,at91sam9260-dbgu
          - const: atmel,at91sam9260-usart

  reg:
    maxItems: 1

  interrupts:
    maxItems: 1

  clock-names:
    minItems: 1
    items:
      - const: usart
      - const: gclk

  clocks:
    minItems: 1
    items:
      - description: USART Peripheral Clock
      - description: USART Generic Clock

  dmas:
    items:
      - description: TX DMA Channel
      - description: RX DMA Channel

  dma-names:
    items:
      - const: tx
      - const: rx

  atmel,usart-mode:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Must be either <AT91_USART_MODE_SPI> for SPI or
      <AT91_USART_MODE_SERIAL> for USART (found in dt-bindings/mfd/at91-usart.h).
    enum: [ 0, 1 ]

  atmel,use-dma-rx:
    type: boolean
    description: use of PDC or DMA for receiving data

  atmel,use-dma-tx:
    type: boolean
    description: use of PDC or DMA for transmitting data

  atmel,fifo-size:
    $ref: /schemas/types.yaml#/definitions/uint32
    description:
      Maximum number of data the RX and TX FIFOs can store for FIFO
      capable USARTS.
    enum: [ 16, 32 ]

required:
  - compatible
  - reg
  - interrupts
  - clock-names
  - clocks
  - atmel,usart-mode

allOf:
  - if:
      properties:
        atmel,usart-mode:
          const: 1
    then:
      allOf:
        - $ref: /schemas/spi/spi-controller.yaml#

      properties:
        atmel,use-dma-rx: false

        atmel,use-dma-tx: false

        atmel,fifo-size: false

        "#size-cells":
          const: 0

        "#address-cells":
          const: 1

      required:
        - "#size-cells"
        - "#address-cells"

    else:
      allOf:
        - $ref: /schemas/serial/serial.yaml#
        - $ref: /schemas/serial/rs485.yaml#

unevaluatedProperties: false

examples:
  - |
    #include <dt-bindings/gpio/gpio.h>
    #include <dt-bindings/interrupt-controller/irq.h>
    #include <dt-bindings/mfd/at91-usart.h>
    #include <dt-bindings/dma/at91.h>

    /* use PDC */
    usart0: serial@fff8c000 {
        compatible = "atmel,at91sam9260-usart";
        reg = <0xfff8c000 0x4000>;
        atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
        interrupts = <7>;
        clocks = <&usart0_clk>;
        clock-names = "usart";
        atmel,use-dma-rx;
        atmel,use-dma-tx;
        rts-gpios = <&pioD 15 GPIO_ACTIVE_LOW>;
        cts-gpios = <&pioD 16 GPIO_ACTIVE_LOW>;
        dtr-gpios = <&pioD 17 GPIO_ACTIVE_LOW>;
        dsr-gpios = <&pioD 18 GPIO_ACTIVE_LOW>;
        dcd-gpios = <&pioD 20 GPIO_ACTIVE_LOW>;
        rng-gpios = <&pioD 19 GPIO_ACTIVE_LOW>;
    };

  - |
    #include <dt-bindings/gpio/gpio.h>
    #include <dt-bindings/interrupt-controller/irq.h>
    #include <dt-bindings/mfd/at91-usart.h>
    #include <dt-bindings/dma/at91.h>

    /* use DMA */
    usart1: serial@f001c000 {
        compatible = "atmel,at91sam9260-usart";
        reg = <0xf001c000 0x100>;
        atmel,usart-mode = <AT91_USART_MODE_SERIAL>;
        interrupts = <12 IRQ_TYPE_LEVEL_HIGH 5>;
        clocks = <&usart0_clk>;
        clock-names = "usart";
        atmel,use-dma-rx;
        atmel,use-dma-tx;
        dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(3)>,
               <&dma0 2 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
        dma-names = "tx", "rx";
        atmel,fifo-size = <32>;
    };

  - |
    #include <dt-bindings/gpio/gpio.h>
    #include <dt-bindings/interrupt-controller/irq.h>
    #include <dt-bindings/mfd/at91-usart.h>
    #include <dt-bindings/dma/at91.h>

    /* SPI mode */
    spi0: spi@f001c000 {
        compatible = "atmel,at91sam9260-usart";
        reg = <0xf001c000 0x100>;
        #address-cells = <1>;
        #size-cells = <0>;
        atmel,usart-mode = <AT91_USART_MODE_SPI>;
        interrupts = <12 IRQ_TYPE_LEVEL_HIGH 5>;
        clocks = <&usart0_clk>;
        clock-names = "usart";
        dmas = <&dma0 2 AT91_DMA_CFG_PER_ID(3)>,
               <&dma0 2 (AT91_DMA_CFG_PER_ID(4) | AT91_DMA_CFG_FIFOCFG_ASAP)>;
        dma-names = "tx", "rx";
        cs-gpios = <&pioB 3 GPIO_ACTIVE_HIGH>;
    };