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Diffstat (limited to 'Documentation/devicetree/bindings/serial/serial.yaml')
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diff --git a/Documentation/devicetree/bindings/serial/serial.yaml b/Documentation/devicetree/bindings/serial/serial.yaml new file mode 100644 index 000000000000..ffc9198ae214 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/serial.yaml @@ -0,0 +1,153 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/serial/serial.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Serial Interface Generic + +maintainers: + - Rob Herring <robh@kernel.org> + - Greg Kroah-Hartman <gregkh@linuxfoundation.org> + +description: + This document lists a set of generic properties for describing UARTs in a + device tree. Whether these properties apply to a particular device depends + on the DT bindings for the actual device. + + Each enabled UART may have an optional "serialN" alias in the "aliases" node, + where N is the port number (non-negative decimal integer) as printed on the + label next to the physical port. + +properties: + $nodename: + pattern: "^serial(@.*)?$" + + label: true + + cts-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's CTS line. + + dcd-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's DCD line. + + dsr-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's DSR line. + + dtr-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's DTR line. + + rng-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's RNG line. + + rts-gpios: + maxItems: 1 + description: + Must contain a GPIO specifier, referring to the GPIO pin to be used as + the UART's RTS line. + + uart-has-rtscts: + $ref: /schemas/types.yaml#/definitions/flag + description: + The presence of this property indicates that the UART has dedicated lines + for RTS/CTS hardware flow control, and that they are available for use + (wired and enabled by pinmux configuration). This depends on both the + UART hardware and the board wiring. + + rx-tx-swap: + type: boolean + description: RX and TX pins are swapped. + + cts-rts-swap: + type: boolean + description: CTS and RTS pins are swapped. + + rx-threshold: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + RX FIFO threshold configuration (in bytes). + + tx-threshold: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + TX FIFO threshold configuration (in bytes). + +patternProperties: + "^(bluetooth|bluetooth-gnss|gnss|gps|mcu|onewire)$": + if: + type: object + then: + description: + Serial attached devices shall be a child node of the host UART device + the slave device is attached to. It is expected that the attached + device is the only child node of the UART device. The slave device node + name shall reflect the generic type of device for the node. + + properties: + compatible: + description: + Compatible of the device connected to the serial port. + + max-speed: + $ref: /schemas/types.yaml#/definitions/uint32 + description: + The maximum baud rate the device operates at. + This should only be present if the maximum is less than the slave + device can support. For example, a particular board has some + signal quality issue or the host processor can't support higher + baud rates. + + current-speed: + $ref: /schemas/types.yaml#/definitions/uint32 + description: | + The current baud rate the device operates at. + This should only be present in case a driver has no chance to know + the baud rate of the slave device. + Examples: + * device supports auto-baud + * the rate is setup by a bootloader and there is no way to reset + the device + * device baud rate is configured by its firmware but there is no + way to request the actual settings + + required: + - compatible + +if: + required: + - uart-has-rtscts +then: + properties: + cts-gpios: false + rts-gpios: false + +additionalProperties: true + +examples: + - | + serial@1234 { + compatible = "ns16550a"; + reg = <0x1234 0x20>; + interrupts = <1>; + + bluetooth { + compatible = "brcm,bcm4330-bt"; + interrupt-parent = <&gpio>; + interrupts = <10>; + }; + }; |