1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
2 # Copyright 2021 ARM Ltd.
3 %YAML 1.2
4 ---
5 $id: http://devicetree.org/schemas/firmware/arm,scpi.yaml#
6 $schema: http://devicetree.org/meta-schemas/core.yaml#
7
8 title: System Control and Power Interface (SCPI) Message Protocol
9
10 maintainers:
11 - Sudeep Holla <sudeep.holla@arm.com>
12
13 description: |
14 Firmware implementing the SCPI described in ARM document number ARM DUI
15 0922B ("ARM Compute Subsystem SCP: Message Interface Protocols")[0] can be
16 used by Linux to initiate various system control and power operations.
17
18 This binding is intended to define the interface the firmware implementing
19 the SCPI provide for OSPM in the device tree.
20
21 [0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
22
23 properties:
24 $nodename:
25 const: scpi
26
27 compatible:
28 description:
29 SCPI compliant firmware complying to SCPI v1.0 and above OR
30 SCPI compliant firmware complying to all unversioned releases
31 prior to SCPI v1.0
32 oneOf:
33 - const: arm,scpi # SCPI v1.0 and above
34 - const: arm,scpi-pre-1.0 # Unversioned SCPI before v1.0
35 - items:
36 - enum:
37 - amlogic,meson-gxbb-scpi
38 - const: arm,scpi-pre-1.0
39
40 mboxes:
41 description:
42 List of phandle and mailbox channel specifiers. All the channels reserved
43 by remote SCP firmware for use by SCPI message protocol should be
44 specified in any order.
45 minItems: 1
46 maxItems: 4
47
48 shmem:
49 description:
50 List of phandle pointing to the shared memory(SHM) area between the
51 processors using these mailboxes for IPC, one for each mailbox SHM can
52 be any memory reserved for the purpose of this communication between the
53 processors.
54 minItems: 1
55 maxItems: 4
56
57 power-controller:
58 type: object
59 description:
60 This sub-node represents SCPI power domain controller.
61
62 properties:
63 compatible:
64 const: arm,scpi-power-domains
65
66 '#power-domain-cells':
67 const: 1
68
69 num-domains:
70 $ref: /schemas/types.yaml#/definitions/uint32
71 description:
72 Total number of power domains provided by SCPI. This is needed as
73 the SCPI message protocol lacks a mechanism to query this
74 information at runtime.
75
76 required:
77 - compatible
78 - '#power-domain-cells'
79 - num-domains
80
81 additionalProperties: false
82
83 sensors:
84 type: object
85 description: |
86 This sub-node represents SCPI sensors controller.
87
88 properties:
89 compatible:
90 oneOf:
91 - const: arm,scpi-sensors
92 - items:
93 - enum:
94 - amlogic,meson-gxbb-scpi-sensors
95 - const: arm,scpi-sensors
96
97 '#thermal-sensor-cells':
98 const: 1
99
100 required:
101 - compatible
102 - '#thermal-sensor-cells'
103
104 additionalProperties: false
105
106 clocks:
107 type: object
108 description:
109 This is the container node. Each sub-node represents one of the types
110 of clock controller - indexed or full range.
111
112 properties:
113 compatible:
114 const: arm,scpi-clocks
115
116 patternProperties:
117 "^clocks-[0-9a-f]+$":
118 type: object
119 description: |
120 This sub-node represents one of the types of clock controller
121 - indexed or full range.
122
123 "arm,scpi-dvfs-clocks" - all the clocks that are variable and index
124 based. These clocks don't provide an entire range of values between
125 the limits but only discrete points within the range. The firmware
126 provides the mapping for each such operating frequency and the index
127 associated with it. The firmware also manages the voltage scaling
128 appropriately with the clock scaling.
129
130 "arm,scpi-variable-clocks" - all the clocks that are variable and
131 provide full range within the specified range. The firmware provides
132 the range of values within a specified range.
133
134 properties:
135 compatible:
136 enum:
137 - arm,scpi-dvfs-clocks
138 - arm,scpi-variable-clocks
139
140 '#clock-cells':
141 const: 1
142
143 clock-output-names: true
144
145 clock-indices:
146 $ref: /schemas/types.yaml#/definitions/uint32-array
147 description:
148 The identifying number for the clocks(i.e.clock_id) in the node.
149 It can be non linear and hence provide the mapping of identifiers
150 into the clock-output-names array.
151
152 required:
153 - compatible
154 - '#clock-cells'
155 - clock-output-names
156 - clock-indices
157
158 additionalProperties: false
159
160 required:
161 - compatible
162
163 additionalProperties: false
164
165 additionalProperties: false
166
167 required:
168 - compatible
169 - mboxes
170 - shmem
171
172 examples:
173 - |
174 firmware {
175 scpi {
176 compatible = "arm,scpi";
177 mboxes = <&mhuA 1>;
178 shmem = <&cpu_scp_hpri>; /* HP-NonSecure */
179
180 scpi_devpd: power-controller {
181 compatible = "arm,scpi-power-domains";
182 num-domains = <2>;
183 #power-domain-cells = <1>;
184 };
185
186 clocks {
187 compatible = "arm,scpi-clocks";
188
189 scpi_dvfs: clocks-0 {
190 compatible = "arm,scpi-dvfs-clocks";
191 #clock-cells = <1>;
192 clock-indices = <0>, <1>, <2>;
193 clock-output-names = "atlclk", "aplclk","gpuclk";
194 };
195
196 scpi_clk: clocks-1 {
197 compatible = "arm,scpi-variable-clocks";
198 #clock-cells = <1>;
199 clock-indices = <3>, <4>;
200 clock-output-names = "pxlclk0", "pxlclk1";
201 };
202 };
203
204 scpi_sensors: sensors {
205 compatible = "arm,scpi-sensors";
206 #thermal-sensor-cells = <1>;
207 };
208
209 };
210 };
211
212 soc {
213 #address-cells = <2>;
214 #size-cells = <2>;
215
216 sram@50000000 {
217 compatible = "mmio-sram";
218 reg = <0x0 0x50000000 0x0 0x10000>;
219
220 #address-cells = <1>;
221 #size-cells = <1>;
222 ranges = <0 0x0 0x50000000 0x10000>;
223
224 cpu_scp_lpri: scp-sram-section@0 {
225 compatible = "arm,scp-shmem";
226 reg = <0x0 0x200>;
227 };
228
229 cpu_scp_hpri: scp-sram-section@200 {
230 compatible = "arm,scp-shmem";
231 reg = <0x200 0x200>;
232 };
233 };
234 };
235
236 - |
237 firmware {
238 scpi {
239 compatible = "amlogic,meson-gxbb-scpi", "arm,scpi-pre-1.0";
240 mboxes = <&mailbox 1>, <&mailbox 2>;
241 shmem = <&cpu_scp_lpri>, <&cpu_scp_hpri>;
242
243 scpi_sensors1: sensors {
244 compatible = "amlogic,meson-gxbb-scpi-sensors", "arm,scpi-sensors";
245 #thermal-sensor-cells = <1>;
246 };
247 };
248 };
249 ...
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