# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) # Copyright (C) 2020 SiFive, Inc. %YAML 1.2 --- $id: http://devicetree.org/schemas/pwm/pwm-sifive.yaml# $schema: http://devicetree.org/meta-schemas/core.yaml# title: SiFive PWM controller maintainers: - Paul Walmsley description: Unlike most other PWM controllers, the SiFive PWM controller currently only supports one period for all channels in the PWM. All PWMs need to run at the same period. The period also has significant restrictions on the values it can achieve, which the driver rounds to the nearest achievable period. PWM RTL that corresponds to the IP block version numbers can be found here - https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/pwm allOf: - $ref: pwm.yaml# properties: compatible: items: - enum: - sifive,fu540-c000-pwm - sifive,fu740-c000-pwm - const: sifive,pwm0 description: Should be "sifive,-pwm" and "sifive,pwm". Supported compatible strings are "sifive,fu540-c000-pwm" and "sifive,fu740-c000-pwm" for the SiFive PWM v0 as integrated onto the SiFive FU540 and FU740 chip respectively, and "sifive,pwm0" for the SiFive PWM v0 IP block with no chip integration tweaks. Please refer to sifive-blocks-ip-versioning.txt for details. reg: maxItems: 1 clocks: maxItems: 1 "#pwm-cells": const: 3 interrupts: maxItems: 4 description: Each PWM instance in FU540-C000 has 4 comparators. One interrupt per comparator. required: - compatible - reg - clocks - interrupts additionalProperties: false examples: - | pwm: pwm@10020000 { compatible = "sifive,fu540-c000-pwm", "sifive,pwm0"; reg = <0x10020000 0x1000>; clocks = <&tlclk>; interrupt-parent = <&plic>; interrupts = <42>, <43>, <44>, <45>; #pwm-cells = <3>; };