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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/bindings/clock/st,stm32mp1-rcc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Reset Clock Controller Binding
maintainers:
- Gabriel Fernandez <gabriel.fernandez@st.com>
description: |
The RCC IP is both a reset and a clock controller.
RCC makes also power management (resume/supend and wakeup interrupt).
Please also refer to reset.txt for common reset controller binding usage.
This binding uses common clock bindings
Documentation/devicetree/bindings/clock/clock-bindings.txt
Specifying clocks
=================
All available clocks are defined as preprocessor macros in
dt-bindings/clock/stm32mp1-clks.h header and can be used in device
tree sources.
Specifying softreset control of devices
=======================================
Device nodes should specify the reset channel required in their "resets"
property, containing a phandle to the reset device node and an index specifying
which channel to use.
The index is the bit number within the RCC registers bank, starting from RCC
base address.
It is calculated as: index = register_offset / 4 * 32 + bit_offset.
Where bit_offset is the bit offset within the register.
For example on STM32MP1, for LTDC reset:
ltdc = APB4_RSTSETR_offset / 4 * 32 + LTDC_bit_offset
= 0x180 / 4 * 32 + 0 = 3072
The list of valid indices for STM32MP1 is available in:
include/dt-bindings/reset-controller/stm32mp1-resets.h
This file implements defines like:
#define LTDC_R 3072
properties:
"#clock-cells":
const: 1
"#reset-cells":
const: 1
compatible:
items:
- const: st,stm32mp1-rcc
- const: syscon
reg:
maxItems: 1
required:
- "#clock-cells"
- "#reset-cells"
- compatible
- reg
additionalProperties: false
examples:
- |
rcc: rcc@50000000 {
compatible = "st,stm32mp1-rcc", "syscon";
reg = <0x50000000 0x1000>;
#clock-cells = <1>;
#reset-cells = <1>;
};
...
|
