xref: /linux/Documentation/devicetree/bindings/clock/st,stm32mp1-rcc.yaml (revision a4eb44a6435d6d8f9e642407a4a06f65eb90ca04) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/clock/st,stm32mp1-rcc.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: Reset Clock Controller Binding
8
9maintainers:
10  - Gabriel Fernandez <gabriel.fernandez@foss.st.com>
11
12description: |
13  The RCC IP is both a reset and a clock controller.
14  RCC makes also power management (resume/supend and wakeup interrupt).
15  Please also refer to reset.txt for common reset controller binding usage.
16
17  This binding uses common clock bindings
18  Documentation/devicetree/bindings/clock/clock-bindings.txt
19
20  Specifying clocks
21  =================
22
23  All available clocks are defined as preprocessor macros in
24  dt-bindings/clock/stm32mp1-clks.h header and can be used in device
25  tree sources.
26
27  Specifying softreset control of devices
28  =======================================
29
30  Device nodes should specify the reset channel required in their "resets"
31  property, containing a phandle to the reset device node and an index specifying
32  which channel to use.
33  The index is the bit number within the RCC registers bank, starting from RCC
34  base address.
35  It is calculated as: index = register_offset / 4 * 32 + bit_offset.
36  Where bit_offset is the bit offset within the register.
37
38  For example on STM32MP1, for LTDC reset:
39     ltdc = APB4_RSTSETR_offset / 4 * 32 + LTDC_bit_offset
40          = 0x180 / 4 * 32 + 0 = 3072
41
42  The list of valid indices for STM32MP1 is available in:
43  include/dt-bindings/reset-controller/stm32mp1-resets.h
44
45  This file implements defines like:
46  #define LTDC_R	3072
47
48properties:
49  "#clock-cells":
50    const: 1
51
52  "#reset-cells":
53    const: 1
54
55  compatible:
56    items:
57      - enum:
58          - st,stm32mp1-rcc-secure
59          - st,stm32mp1-rcc
60      - const: syscon
61
62  reg:
63    maxItems: 1
64
65required:
66  - "#clock-cells"
67  - "#reset-cells"
68  - compatible
69  - reg
70
71additionalProperties: false
72
73examples:
74  - |
75    rcc: rcc@50000000 {
76        compatible = "st,stm32mp1-rcc-secure", "syscon";
77        reg = <0x50000000 0x1000>;
78        #clock-cells = <1>;
79        #reset-cells = <1>;
80    };
81...
82