tjh.dev
Linux kernel mirror (for testing)
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linux
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: STMicroelectronics STM32MP1 Reset Clock Controller
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 include/dt-bindings/reset-controller/stm32mp13-resets.h
45
46 This file implements defines like:
47 #define LTDC_R 3072
48
49properties:
50 "#clock-cells":
51 const: 1
52
53 "#reset-cells":
54 const: 1
55
56 compatible:
57 items:
58 - enum:
59 - st,stm32mp1-rcc-secure
60 - st,stm32mp1-rcc
61 - st,stm32mp13-rcc
62 - const: syscon
63
64 clocks:
65 minItems: 1
66 maxItems: 5
67
68 clock-names:
69 minItems: 1
70 maxItems: 5
71
72 reg:
73 maxItems: 1
74
75required:
76 - "#clock-cells"
77 - "#reset-cells"
78 - compatible
79 - reg
80
81if:
82 properties:
83 compatible:
84 contains:
85 enum:
86 - st,stm32mp1-rcc-secure
87 - st,stm32mp13-rcc
88then:
89 properties:
90 clocks:
91 description: Specifies oscillators.
92 maxItems: 5
93
94 clock-names:
95 items:
96 - const: hse
97 - const: hsi
98 - const: csi
99 - const: lse
100 - const: lsi
101 required:
102 - clocks
103 - clock-names
104else:
105 properties:
106 clocks:
107 description:
108 Specifies the external RX clock for ethernet MAC.
109 maxItems: 1
110
111 clock-names:
112 const: ETH_RX_CLK/ETH_REF_CLK
113
114additionalProperties: false
115
116examples:
117 - |
118 #include <dt-bindings/clock/stm32mp1-clks.h>
119 rcc: rcc@50000000 {
120 compatible = "st,stm32mp1-rcc-secure", "syscon";
121 reg = <0x50000000 0x1000>;
122 #clock-cells = <1>;
123 #reset-cells = <1>;
124 clock-names = "hse", "hsi", "csi", "lse", "lsi";
125 clocks = <&scmi_clk CK_SCMI_HSE>,
126 <&scmi_clk CK_SCMI_HSI>,
127 <&scmi_clk CK_SCMI_CSI>,
128 <&scmi_clk CK_SCMI_LSE>,
129 <&scmi_clk CK_SCMI_LSI>;
130 };
131...