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| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-line-mux.yaml | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-line-mux.yaml b/Documentation/devicetree/bindings/gpio/gpio-line-mux.yaml new file mode 100644 index 000000000000..f49c05249ca7 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-line-mux.yaml @@ -0,0 +1,107 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/gpio/gpio-line-mux.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: GPIO line mux + +maintainers: + - Jonas Jelonek <jelonek.jonas@gmail.com> + +description: | + A GPIO controller to provide virtual GPIOs for a 1-to-many input-only mapping + backed by a single shared GPIO and a multiplexer. A simple illustrated + example is: + + +----- A + IN / + <-----o------- B + / |\ + | | +----- C + | | \ + | | +--- D + | | + M1 M0 + + MUX CONTROL + + M1 M0 IN + 0 0 A + 0 1 B + 1 0 C + 1 1 D + + This can be used in case a real GPIO is connected to multiple inputs and + controlled by a multiplexer, and another subsystem/driver does not work + directly with the multiplexer subsystem. + +properties: + compatible: + const: gpio-line-mux + + gpio-controller: true + + "#gpio-cells": + const: 2 + + gpio-line-mux-states: + description: Mux states corresponding to the virtual GPIOs. + $ref: /schemas/types.yaml#/definitions/uint32-array + + gpio-line-names: true + + mux-controls: + maxItems: 1 + description: + Phandle to the multiplexer to control access to the GPIOs. + + ngpios: false + + muxed-gpios: + maxItems: 1 + description: + GPIO which is the '1' in 1-to-many and is shared by the virtual GPIOs + and controlled via the mux. + +required: + - compatible + - gpio-controller + - gpio-line-mux-states + - mux-controls + - muxed-gpios + +additionalProperties: false + +examples: + - | + #include <dt-bindings/gpio/gpio.h> + #include <dt-bindings/mux/mux.h> + + sfp_gpio_mux: mux-controller-1 { + compatible = "gpio-mux"; + mux-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>, + <&gpio0 1 GPIO_ACTIVE_HIGH>; + #mux-control-cells = <0>; + idle-state = <MUX_IDLE_AS_IS>; + }; + + sfp1_gpio: sfp-gpio-1 { + compatible = "gpio-line-mux"; + gpio-controller; + #gpio-cells = <2>; + + mux-controls = <&sfp_gpio_mux>; + muxed-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>; + + gpio-line-mux-states = <0>, <1>, <3>; + }; + + sfp1: sfp-p1 { + compatible = "sff,sfp"; + + i2c-bus = <&sfp1_i2c>; + los-gpios = <&sfp1_gpio 0 GPIO_ACTIVE_HIGH>; + mod-def0-gpios = <&sfp1_gpio 1 GPIO_ACTIVE_LOW>; + tx-fault-gpios = <&sfp1_gpio 2 GPIO_ACTIVE_HIGH>; + }; |