Add a binding description for the Realtek RTL8231, a GPIO and LED expander chip commonly used in ethernet switches based on a Realtek switch SoC. These chips can be addressed via an MDIO or SMI bus, or used as a plain 36-bit shift register. This binding only describes the feature set provided by the MDIO/SMI configuration, and covers the GPIO, PWM, and pin control properties. The LED properties are defined in a separate binding. Signed-off-by: Sander Vanheule <sander@xxxxxxxxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> --- v4: - Add Rob's and Linus' review tags --- .../bindings/mfd/realtek,rtl8231.yaml | 190 ++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 Documentation/devicetree/bindings/mfd/realtek,rtl8231.yaml diff --git a/Documentation/devicetree/bindings/mfd/realtek,rtl8231.yaml b/Documentation/devicetree/bindings/mfd/realtek,rtl8231.yaml new file mode 100644 index 000000000000..4e2326401560 --- /dev/null +++ b/Documentation/devicetree/bindings/mfd/realtek,rtl8231.yaml @@ -0,0 +1,190 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mfd/realtek,rtl8231.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Realtek RTL8231 GPIO and LED expander. + +maintainers: + - Sander Vanheule <sander@xxxxxxxxxxxxx> + +description: | + The RTL8231 is a GPIO and LED expander chip, providing up to 37 GPIOs, up to + 88 LEDs, and up to one PWM output. This device is frequently used alongside + Realtek switch SoCs, to provide additional I/O capabilities. + + To manage the RTL8231's features, its strapping pins can be used to configure + it in one of three modes: shift register, MDIO device, or SMI device. The + shift register mode does not need special support. In MDIO or SMI mode, most + pins can be configured as a GPIO output, LED matrix scan line/column, or as a + PWM output. + + The GPIO, PWM, and pin control are part of the main node. LED support is + configured as a sub-node. + +properties: + compatible: + const: realtek,rtl8231 + + reg: + description: MDIO or SMI device address. + maxItems: 1 + + # GPIO support + gpio-controller: true + + "#gpio-cells": + const: 2 + description: | + The first cell is the pin number and the second cell is used to specify + the GPIO active state. + + gpio-ranges: + description: | + Must reference itself, and provide a zero-based mapping for 37 pins. + maxItems: 1 + + # Pin muxing and configuration + drive-strength: + description: | + Common drive strength used for all GPIO output pins, must be 4mA or 8mA. + On reset, this value will default to 8mA. + enum: [4, 8] + + # LED scanning matrix + led-controller: + $ref: ../leds/realtek,rtl8231-leds.yaml# + + # PWM output + "#pwm-cells": + description: | + Twos cells with PWM index (must be 0) and PWM frequency in Hz. To use + the PWM output, gpio35 must be muxed to its 'pwm' function. Valid + frequency values for consumers are 1200, 1600, 2000, 2400, 2800, 3200, + 4000, and 4800. + const: 2 + +patternProperties: + "-pins$": + type: object + $ref: ../pinctrl/pinmux-node.yaml# + + properties: + pins: + items: + enum: ["gpio0", "gpio1", "gpio2", "gpio3", "gpio4", "gpio5", "gpio6", + "gpio7", "gpio8", "gpio9", "gpio10", "gpio11", "gpio12", "gpio13", + "gpio14", "gpio15", "gpio16", "gpio17", "gpio18", "gpio19", "gpio20", + "gpio21", "gpio22", "gpio23", "gpio24", "gpio25", "gpio26", "gpio27", + "gpio28", "gpio29", "gpio30", "gpio31", "gpio32", "gpio33", "gpio34", + "gpio35", "gpio36"] + minItems: 1 + maxItems: 37 + function: + description: | + Select which function to use. "gpio" is supported for all pins, "led" is supported + for pins 0-34, "pwm" is supported for pin 35. + enum: ["gpio", "led", "pwm"] + + required: + - pins + - function + +required: + - compatible + - reg + - gpio-controller + - "#gpio-cells" + - gpio-ranges + +additionalProperties: false + +examples: + - | + // Minimal example + mdio { + #address-cells = <1>; + #size-cells = <0>; + + expander0: expander@0 { + compatible = "realtek,rtl8231"; + reg = <0>; + + gpio-controller; + #gpio-cells = <2>; + gpio-ranges = <&expander0 0 0 37>; + }; + }; + - | + // All bells and whistles included + #include <dt-bindings/leds/common.h> + mdio { + #address-cells = <1>; + #size-cells = <0>; + + expander1: expander@1 { + compatible = "realtek,rtl8231"; + reg = <1>; + + gpio-controller; + #gpio-cells = <2>; + gpio-ranges = <&expander1 0 0 37>; + + #pwm-cells = <2>; + + drive-strength = <4>; + + button-pins { + pins = "gpio36"; + function = "gpio"; + input-debounce = "100000"; + }; + + pwm-pins { + pins = "gpio35"; + function = "pwm"; + }; + + led-pins { + pins = "gpio0", "gpio1", "gpio3", "gpio4"; + function = "led"; + }; + + led-controller { + compatible = "realtek,rtl8231-leds"; + #address-cells = <2>; + #size-cells = <0>; + + realtek,led-scan-mode = "single-color"; + + led@0,0 { + reg = <0 0>; + color = <LED_COLOR_ID_GREEN>; + function = LED_FUNCTION_LAN; + function-enumerator = <0>; + }; + + led@0,1 { + reg = <0 1>; + color = <LED_COLOR_ID_AMBER>; + function = LED_FUNCTION_LAN; + function-enumerator = <0>; + }; + + led@1,0 { + reg = <1 0>; + color = <LED_COLOR_ID_GREEN>; + function = LED_FUNCTION_LAN; + function-enumerator = <1>; + }; + + led@1,1 { + reg = <1 1>; + color = <LED_COLOR_ID_AMBER>; + function = LED_FUNCTION_LAN; + function-enumerator = <1>; + }; + }; + }; + }; -- 2.31.1
