1 System Control and Management Interface (SCMI) Message Protocol
2 ----------------------------------------------------------
4 The SCMI is intended to allow agents such as OSPM to manage various functions
5 that are provided by the hardware platform it is running on, including power
6 and performance functions.
8 This binding is intended to define the interface the firmware implementing
9 the SCMI as described in ARM document number ARM DEN 0056A ("ARM System Control
10 and Management Interface Platform Design Document")[0] provide for OSPM in
15 The scmi node with the following properties shall be under the /firmware/ node.
17 - compatible : shall be "arm,scmi" or "arm,scmi-smc" for smc/hvc transports,
18 or "linaro,scmi-optee" for OP-TEE transport.
19 - mboxes: List of phandle and mailbox channel specifiers. It should contain
20 exactly one or two mailboxes, one for transmitting messages("tx")
21 and another optional for receiving the notifications("rx") if
23 - shmem : List of phandle pointing to the shared memory(SHM) area as per
24 generic mailbox client binding.
25 - #address-cells : should be '1' if the device has sub-nodes, maps to
26 protocol identifier for a given sub-node.
27 - #size-cells : should be '0' as 'reg' property doesn't have any size
29 - arm,smc-id : SMC id required when using smc or hvc transports
30 - linaro,optee-channel-id : Channel specifier required when using OP-TEE
35 - mbox-names: shall be "tx" or "rx" depending on mboxes entries.
37 See Documentation/devicetree/bindings/mailbox/mailbox.txt for more details
38 about the generic mailbox controller and client driver bindings.
39 Mailbox doorbell is used as a mechanism to alert the presence of a
40 messages and/or notification.
42 Each protocol supported shall have a sub-node with corresponding compatible
43 as described in the following sections. If the platform supports dedicated
44 communication channel for a particular protocol, properties shall be present
45 in the sub-node corresponding to that protocol. These properties are:
46 - mboxes, mbox-names and shmem for mailbox transport
47 - arm,smc-id and shmem for smc/hvc transport
48 - linaro,optee-channel-id and possibly shmem for OP-TEE transport
50 Clock/Performance bindings for the clocks/OPPs based on SCMI Message Protocol
51 ------------------------------------------------------------
53 This binding uses the common clock binding[1].
56 - #clock-cells : Should be 1. Contains the Clock ID value used by SCMI commands.
58 Power domain bindings for the power domains based on SCMI Message Protocol
59 ------------------------------------------------------------
61 This binding for the SCMI power domain providers uses the generic power
65 - #power-domain-cells : Should be 1. Contains the device or the power
66 domain ID value used by SCMI commands.
68 Regulator bindings for the SCMI Regulator based on SCMI Message Protocol
69 ------------------------------------------------------------
70 An SCMI Regulator is permanently bound to a well defined SCMI Voltage Domain,
71 and should be always positioned as a root regulator.
72 It does not support any current operation.
74 SCMI Regulators are grouped under a 'regulators' node which in turn is a child
75 of the SCMI Voltage protocol node inside the desired SCMI instance node.
77 This binding uses the common regulator binding[6].
80 - reg : shall identify an existent SCMI Voltage Domain.
82 Sensor bindings for the sensors based on SCMI Message Protocol
83 --------------------------------------------------------------
84 SCMI provides an API to access the various sensors on the SoC.
87 - #thermal-sensor-cells: should be set to 1. This property follows the
88 thermal device tree bindings[3].
90 Valid cell values are raw identifiers (Sensor ID)
91 as used by the firmware. Refer to platform details
92 for your implementation for the IDs to use.
94 Reset signal bindings for the reset domains based on SCMI Message Protocol
95 ------------------------------------------------------------
97 This binding for the SCMI reset domain providers uses the generic reset
101 - #reset-cells : Should be 1. Contains the reset domain ID value used
104 SRAM and Shared Memory for SCMI
105 -------------------------------
107 A small area of SRAM is reserved for SCMI communication between application
110 The properties should follow the generic mmio-sram description found in [4]
112 Each sub-node represents the reserved area for SCMI.
114 Required sub-node properties:
115 - reg : The base offset and size of the reserved area with the SRAM
116 - compatible : should be "arm,scmi-shmem" for Non-secure SRAM based
119 [0] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/index.html
120 [1] Documentation/devicetree/bindings/clock/clock-bindings.txt
121 [2] Documentation/devicetree/bindings/power/power-domain.yaml
122 [3] Documentation/devicetree/bindings/thermal/thermal.txt
123 [4] Documentation/devicetree/bindings/sram/sram.yaml
124 [5] Documentation/devicetree/bindings/reset/reset.txt
125 [6] Documentation/devicetree/bindings/regulator/regulator.yaml
130 compatible = "mmio-sram";
131 reg = <0x0 0x50000000 0x0 0x10000>;
133 #address-cells = <1>;
135 ranges = <0 0x0 0x50000000 0x10000>;
137 cpu_scp_lpri: scp-shmem@0 {
138 compatible = "arm,scmi-shmem";
142 cpu_scp_hpri: scp-shmem@200 {
143 compatible = "arm,scmi-shmem";
151 reg = <0x0 0x40000000 0x0 0x10000>;
159 compatible = "arm,scmi";
160 mboxes = <&mailbox 0 &mailbox 1>;
161 mbox-names = "tx", "rx";
162 shmem = <&cpu_scp_lpri &cpu_scp_hpri>;
163 #address-cells = <1>;
166 scmi_devpd: protocol@11 {
168 #power-domain-cells = <1>;
171 scmi_dvfs: protocol@13 {
176 scmi_clk: protocol@14 {
181 scmi_sensors0: protocol@15 {
183 #thermal-sensor-cells = <1>;
186 scmi_reset: protocol@16 {
191 scmi_voltage: protocol@17 {
195 regulator_devX: regulator@0 {
197 regulator-max-microvolt = <3300000>;
200 regulator_devY: regulator@9 {
202 regulator-min-microvolt = <500000>;
203 regulator-max-microvolt = <4200000>;
215 clocks = <&scmi_dvfs 0>;
220 reg = <0 0x7ff60000 0 0x1000>;
221 clocks = <&scmi_clk 4>;
222 power-domains = <&scmi_devpd 1>;
223 resets = <&scmi_reset 10>;
228 polling-delay-passive = <100>;
229 polling-delay = <1000>;
231 thermal-sensors = <&scmi_sensors0 3>;