# Copyright 2020 Lubomir Rintel <lkundrak@v3.sk>
%YAML 1.2
---
$id: http://devicetree.org/schemas/serial/8250.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: UART (Universal Asynchronous Receiver/Transmitter)
maintainers:
- devicetree@vger.kernel.org
allOf:
- $ref: serial.yaml#
- $ref: /schemas/memory-controllers/mc-peripheral-props.yaml#
- if:
anyOf:
- required:
- aspeed,lpc-io-reg
- required:
- aspeed,lpc-interrupts
- required:
- aspeed,sirq-polarity-sense
then:
properties:
compatible:
const: aspeed,ast2500-vuart
- if:
properties:
compatible:
const: mrvl,mmp-uart
then:
properties:
reg-shift:
const: 2
required:
- reg-shift
- if:
not:
properties:
compatible:
items:
- enum:
- ns8250
- ns16450
- ns16550
- ns16550a
then:
anyOf:
- required: [ clock-frequency ]
- required: [ clocks ]
properties:
compatible:
oneOf:
- const: ns8250
- const: ns16450
- const: ns16550
- const: ns16550a
- const: ns16850
- const: aspeed,ast2400-vuart
- const: aspeed,ast2500-vuart
- const: intel,xscale-uart
- const: mrvl,pxa-uart
- const: nuvoton,wpcm450-uart
- const: nuvoton,npcm750-uart
- const: nvidia,tegra20-uart
- const: nxp,lpc3220-uart
- items:
- enum:
- exar,xr16l2552
- exar,xr16l2551
- exar,xr16l2550
- const: ns8250
- items:
- enum:
- altr,16550-FIFO32
- altr,16550-FIFO64
- altr,16550-FIFO128
- fsl,16550-FIFO64
- fsl,ns16550
- andestech,uart16550
- nxp,lpc1850-uart
- opencores,uart16550-rtlsvn105
- ti,da830-uart
- const: ns16550a
- items:
- enum:
- ns16750
- cavium,octeon-3860-uart
- xlnx,xps-uart16550-2.00.b
- ralink,rt2880-uart
- enum:
- ns16550 # Deprecated, unless the FIFO really is broken
- ns16550a
- items:
- enum:
- nuvoton,npcm845-uart
- const: nuvoton,npcm750-uart
- items:
- enum:
- ralink,mt7620a-uart
- ralink,rt3052-uart
- ralink,rt3883-uart
- const: ralink,rt2880-uart
- enum:
- ns16550 # Deprecated, unless the FIFO really is broken
- ns16550a
- items:
- enum:
- mediatek,mt7622-btif
- mediatek,mt7623-btif
- const: mediatek,mtk-btif
- items:
- const: mrvl,mmp-uart
- const: intel,xscale-uart
- items:
- enum:
- nvidia,tegra30-uart
- nvidia,tegra114-uart
- nvidia,tegra124-uart
- nvidia,tegra210-uart
- nvidia,tegra186-uart
- nvidia,tegra194-uart
- nvidia,tegra234-uart
- const: nvidia,tegra20-uart
reg:
maxItems: 1
interrupts:
maxItems: 1
clock-frequency: true
clocks:
maxItems: 1
resets:
maxItems: 1
current-speed:
$ref: /schemas/types.yaml#/definitions/uint32
description: The current active speed of the UART.
reg-offset:
$ref: /schemas/types.yaml#/definitions/uint32
description: |
Offset to apply to the mapbase from the start of the registers.
reg-shift:
description: Quantity to shift the register offsets by.
reg-io-width:
description: |
The size (in bytes) of the IO accesses that should be performed on the
device. There are some systems that require 32-bit accesses to the
UART (e.g. TI davinci).
used-by-rtas:
type: boolean
description: |
Set to indicate that the port is in use by the OpenFirmware RTAS and
should not be registered.
no-loopback-test:
type: boolean
description: |
Set to indicate that the port does not implement loopback test mode.
fifo-size:
$ref: /schemas/types.yaml#/definitions/uint32
description: The fifo size of the UART.
auto-flow-control:
type: boolean
description: |
One way to enable automatic flow control support. The driver is
allowed to detect support for the capability even without this
property.
tx-threshold:
description: |
Specify the TX FIFO low water indication for parts with programmable
TX FIFO thresholds.
overrun-throttle-ms:
description: |
How long to pause uart rx when input overrun is encountered.
rts-gpios: true
cts-gpios: true
dtr-gpios: true
dsr-gpios: true
rng-gpios: true
dcd-gpios: true
aspeed,sirq-polarity-sense:
$ref: /schemas/types.yaml#/definitions/phandle-array
description: |
Phandle to aspeed,ast2500-scu compatible syscon alongside register
offset and bit number to identify how the SIRQ polarity should be
configured. One possible data source is the LPC/eSPI mode bit. Only
applicable to aspeed,ast2500-vuart.
deprecated: true
aspeed,lpc-io-reg:
$ref: /schemas/types.yaml#/definitions/uint32-array
maxItems: 1
description: |
The VUART LPC address. Only applicable to aspeed,ast2500-vuart.
aspeed,lpc-interrupts:
$ref: /schemas/types.yaml#/definitions/uint32-array
minItems: 2
maxItems: 2
description: |
A 2-cell property describing the VUART SIRQ number and SIRQ
polarity (IRQ_TYPE_LEVEL_LOW or IRQ_TYPE_LEVEL_HIGH). Only
applicable to aspeed,ast2500-vuart.
required:
- reg
- interrupts
unevaluatedProperties: false
examples:
- |
serial@80230000 {
compatible = "ns8250";
reg = <0x80230000 0x100>;
interrupts = <10>;
reg-shift = <2>;
clock-frequency = <48000000>;
};
- |
#include <dt-bindings/gpio/gpio.h>
serial@49042000 {
compatible = "andestech,uart16550", "ns16550a";
reg = <0x49042000 0x400>;
interrupts = <80>;
clock-frequency = <48000000>;
cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
};
- |
#include <dt-bindings/clock/aspeed-clock.h>
#include <dt-bindings/interrupt-controller/irq.h>
serial@1e787000 {
compatible = "aspeed,ast2500-vuart";
reg = <0x1e787000 0x40>;
reg-shift = <2>;
interrupts = <8>;
clocks = <&syscon ASPEED_CLK_APB>;
no-loopback-test;
aspeed,lpc-io-reg = <0x3f8>;
aspeed,lpc-interrupts = <4 IRQ_TYPE_LEVEL_LOW>;
};
...