| # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) |
| %YAML 1.2 |
| --- |
| $id: http://devicetree.org/schemas/clock/st,stm32mp1-rcc.yaml# |
| $schema: http://devicetree.org/meta-schemas/core.yaml# |
| |
| title: Reset Clock Controller Binding |
| |
| maintainers: |
| - Gabriel Fernandez <gabriel.fernandez@foss.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: |
| - enum: |
| - st,stm32mp1-rcc-secure |
| - 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-secure", "syscon"; |
| reg = <0x50000000 0x1000>; |
| #clock-cells = <1>; |
| #reset-cells = <1>; |
| }; |
| ... |