# Copyright (c) 2022, Andriy Gelman # SPDX-License-Identifier: Apache-2.0 description: | The Infineon XMC4XXX pin controller is responsible for connecting peripheral outputs to specific port/pins (also known as alternate functions) and configures pin properties. The pinctrl settings are referenced in a device tree peripheral node. For example in a UART node: &usic1ch1 { compatible = "infineon,xmc4xxx-uart"; pinctrl-0 = <&uart_tx_p0_1_u1c1 &uart_rx_p0_0_u1c1>; pinctrl-names = "default"; input-src = "DX0D"; ... }; pinctrl-0 is the phandle that stores the pin settings for two pins: &uart_tx_p0_1_u1c1 and &uart_rx_p0_0_u1c1. These nodes are pre-defined and their naming convention is designed to help the user select the correct pin settings. Note the use of peripheral type, pin direction, port/pin number and USIC in the name. The pre-defined nodes only set the alternate function of the output pin. The configuration for the pin (i.e. drive strength) should be set in the board setup. The set of possible configurations are defined in the properties section below (in addition to the inherited property-allowlist list from pincfg-node.yaml). To create a new pin configuration, the user may append to the &pinctrl node, for example #include &pinctrl { my_node_config: my_node_config { pinmux = ; drive-push-pull; ... other supported pin configurations .. }; where XMC4XXX_PINMUX_SET(PORT, PIN, ALTERNATE_FUNCTION) is a helper macro for setting the alternate function for a given port/pin. Setting ALTERNATE_FUNCTION = 0 means that no alternate function is selected. The pinctrl driver only sets the alternate function for output pins. The input mux is handled by the peripheral drivers. For example the &usic1ch1 node has input-src property for this purpose. There are no pre-defined nodes for the input mux and this must be properly set by the user. Refer to the peripheral .yaml file (i.e. infineon,xmc4xxx-uart.yaml) and XMC4XXX documentation. compatible: "infineon,xmc4xxx-pinctrl" include: base.yaml properties: "#address-cells": required: true const: 1 "#size-cells": required: true const: 1 child-binding: description: Each child node defines the configuration for a particular state. include: - name: pincfg-node.yaml property-allowlist: - bias-pull-down - bias-pull-up - drive-push-pull - drive-open-drain - output-high - output-low properties: pinmux: description: | Encodes port/pin and alternate function. See helper macro XMC4XX_PINMUX_SET(). Alternate function is only set for output pins; It selects ALT1-ALT4 output line in the GPIO element. The alternate function for input pins is handled separately by the peripheral. It is upto the peripheral to configure which input pin to use (For example see parameter input-src in infineon,xmc4xxx-uart.yaml). required: true type: int drive-strength: description: | Drive strength of the output pin. Following options as in XMC_GPIO_OUTPUT_STRENGTH See xmc4_gpio.h. This only has an effect if the pin is in drive-push-pull mode. required: true type: string enum: - "strong-sharp-edge" - "strong-medium-edge" - "strong-soft-edge" - "strong-slow-edge" - "medium" - "medium-unknown1-edge" - "medium-unknown2-edge" - "weak" invert-input: description: Inverts the input. type: boolean hwctrl: description: Pre-assigns hardware control of the pin to a certain peripheral. required: true type: string enum: - "disabled" - "periph1" - "periph2"