dt-bindings: firmware: arm,scmi: Convert to json schema

System Control and Management Interface (SCMI) Message Protocol

----------------------------------------------------------

The SCMI is intended to allow agents such as OSPM to manage various functions

that are provided by the hardware platform it is running on, including power

and performance functions.

This binding is intended to define the interface the firmware implementing

the SCMI as described in ARM document number ARM DEN 0056A ("ARM System Control

and Management Interface Platform Design Document")[0] provide for OSPM in

the device tree.

Required properties:

The scmi node with the following properties shall be under the /firmware/ node.

- compatible : shall be "arm,scmi" or "arm,scmi-smc" for smc/hvc transports

- mboxes: List of phandle and mailbox channel specifiers. It should contain

	  exactly one or two mailboxes, one for transmitting messages("tx")

	  and another optional for receiving the notifications("rx") if

	  supported.

- shmem : List of phandle pointing to the shared memory(SHM) area as per

	  generic mailbox client binding.

- #address-cells : should be '1' if the device has sub-nodes, maps to

	  protocol identifier for a given sub-node.

- #size-cells : should be '0' as 'reg' property doesn't have any size

	  associated with it.

- arm,smc-id : SMC id required when using smc or hvc transports

Optional properties:

- mbox-names: shall be "tx" or "rx" depending on mboxes entries.

- interrupts : when using smc or hvc transports, this optional

	 property indicates that msg completion by the platform is indicated

	 by an interrupt rather than by the return of the smc call. This

	 should not be used except when the platform requires such behavior.

- interrupt-names : if "interrupts" is present, interrupt-names must also

	 be present and have the value "a2p".

See Documentation/devicetree/bindings/mailbox/mailbox.txt for more details

about the generic mailbox controller and client driver bindings.

The mailbox is the only permitted method of calling the SCMI firmware.

Mailbox doorbell is used as a mechanism to alert the presence of a

messages and/or notification.

Each protocol supported shall have a sub-node with corresponding compatible

as described in the following sections. If the platform supports dedicated

communication channel for a particular protocol, the 3 properties namely:

mboxes, mbox-names and shmem shall be present in the sub-node corresponding

to that protocol.

Clock/Performance bindings for the clocks/OPPs based on SCMI Message Protocol

------------------------------------------------------------

This binding uses the common clock binding[1].

Required properties:

- #clock-cells : Should be 1. Contains the Clock ID value used by SCMI commands.

Power domain bindings for the power domains based on SCMI Message Protocol

------------------------------------------------------------

This binding for the SCMI power domain providers uses the generic power

domain binding[2].

Required properties:

 - #power-domain-cells : Should be 1. Contains the device or the power

			 domain ID value used by SCMI commands.

Regulator bindings for the SCMI Regulator based on SCMI Message Protocol

------------------------------------------------------------

An SCMI Regulator is permanently bound to a well defined SCMI Voltage Domain,

and should be always positioned as a root regulator.

It does not support any current operation.

SCMI Regulators are grouped under a 'regulators' node which in turn is a child

of the SCMI Voltage protocol node inside the desired SCMI instance node.

This binding uses the common regulator binding[6].

Required properties:

 - reg : shall identify an existent SCMI Voltage Domain.

Sensor bindings for the sensors based on SCMI Message Protocol

--------------------------------------------------------------

SCMI provides an API to access the various sensors on the SoC.

Required properties:

- #thermal-sensor-cells: should be set to 1. This property follows the

			 thermal device tree bindings[3].

			 Valid cell values are raw identifiers (Sensor ID)

			 as used by the firmware. Refer to  platform details

			 for your implementation for the IDs to use.

Reset signal bindings for the reset domains based on SCMI Message Protocol

------------------------------------------------------------

This binding for the SCMI reset domain providers uses the generic reset

signal binding[5].

Required properties:

 - #reset-cells : Should be 1. Contains the reset domain ID value used

		  by SCMI commands.

[0] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/index.html

[1] Documentation/devicetree/bindings/clock/clock-bindings.txt

[2] Documentation/devicetree/bindings/power/power-domain.yaml

[3] Documentation/devicetree/bindings/thermal/thermal*.yaml

[4] Documentation/devicetree/bindings/sram/sram.yaml

[5] Documentation/devicetree/bindings/reset/reset.txt

[6] Documentation/devicetree/bindings/regulator/regulator.yaml

Example:

sram@50000000 {

	compatible = "mmio-sram";

	reg = <0x0 0x50000000 0x0 0x10000>;

	#address-cells = <1>;

	#size-cells = <1>;

	ranges = <0 0x0 0x50000000 0x10000>;

	cpu_scp_lpri: scp-shmem@0 {

		compatible = "arm,scmi-shmem";

		reg = <0x0 0x200>;

	};

	cpu_scp_hpri: scp-shmem@200 {

		compatible = "arm,scmi-shmem";

		reg = <0x200 0x200>;

	};

};

mailbox@40000000 {

	....

	#mbox-cells = <1>;

	reg = <0x0 0x40000000 0x0 0x10000>;

};

firmware {

	...

	scmi {

		compatible = "arm,scmi";

		mboxes = <&mailbox 0 &mailbox 1>;

		mbox-names = "tx", "rx";

		shmem = <&cpu_scp_lpri &cpu_scp_hpri>;

		#address-cells = <1>;

		#size-cells = <0>;

		scmi_devpd: protocol@11 {

			reg = <0x11>;

			#power-domain-cells = <1>;

		};

		scmi_dvfs: protocol@13 {

			reg = <0x13>;

			#clock-cells = <1>;

		};

		scmi_clk: protocol@14 {

			reg = <0x14>;

			#clock-cells = <1>;

		};

		scmi_sensors0: protocol@15 {

			reg = <0x15>;

			#thermal-sensor-cells = <1>;

		};

		scmi_reset: protocol@16 {

			reg = <0x16>;

			#reset-cells = <1>;

		};

		scmi_voltage: protocol@17 {

			reg = <0x17>;

			regulators {

				regulator_devX: regulator@0 {

					reg = <0x0>;

					regulator-max-microvolt = <3300000>;

				};

				regulator_devY: regulator@9 {

					reg = <0x9>;

					regulator-min-microvolt = <500000>;

					regulator-max-microvolt = <4200000>;

				};

				...

			};

		};

	};

};

cpu@0 {

	...

	reg = <0 0>;

	clocks = <&scmi_dvfs 0>;

};

hdlcd@7ff60000 {

	...

	reg = <0 0x7ff60000 0 0x1000>;

	clocks = <&scmi_clk 4>;

	power-domains = <&scmi_devpd 1>;

	resets = <&scmi_reset 10>;

};

thermal-zones {

	soc_thermal {

		polling-delay-passive = <100>;

		polling-delay = <1000>;

					/* sensor ID */

		thermal-sensors = <&scmi_sensors0 3>;

		...

	};

};

# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)

# Copyright 2021 ARM Ltd.

%YAML 1.2

---

$id: http://devicetree.org/schemas/firmware/arm,scmi.yaml#

$schema: http://devicetree.org/meta-schemas/core.yaml#

title: System Control and Management Interface (SCMI) Message Protocol bindings

maintainers:

  - Sudeep Holla <sudeep.holla@arm.com>

description: |

  The SCMI is intended to allow agents such as OSPM to manage various functions

  that are provided by the hardware platform it is running on, including power

  and performance functions.

  This binding is intended to define the interface the firmware implementing

  the SCMI as described in ARM document number ARM DEN 0056 ("ARM System Control

  and Management Interface Platform Design Document")[0] provide for OSPM in

  the device tree.

  [0] https://developer.arm.com/documentation/den0056/latest

properties:

  $nodename:

    const: scmi

  compatible:

    oneOf:

      - description: SCMI compliant firmware with mailbox transport

        items:

          - const: arm,scmi

      - description: SCMI compliant firmware with ARM SMC/HVC transport

        items:

          - const: arm,scmi-smc

  interrupts:

    description:

      The interrupt that indicates message completion by the platform

      rather than by the return of the smc call. This should not be used

      except when the platform requires such behavior.

    maxItems: 1

  interrupt-names:

    const: a2p

  mbox-names:

    description:

      Specifies the mailboxes used to communicate with SCMI compliant

      firmware.

    items:

      - const: tx

      - const: rx

  mboxes:

    description:

      List of phandle and mailbox channel specifiers. It should contain

      exactly one or two mailboxes, one for transmitting messages("tx")

      and another optional for receiving the notifications("rx") if supported.

    minItems: 1

    maxItems: 2

  shmem:

    description:

      List of phandle pointing to the shared memory(SHM) area, for each

      transport channel specified.

    minItems: 1

    maxItems: 2

  '#address-cells':

    const: 1

  '#size-cells':

    const: 0

  arm,smc-id:

    $ref: /schemas/types.yaml#/definitions/uint32

    description:

      SMC id required when using smc or hvc transports

  protocol@11:

    type: object

    properties:

      reg:

        const: 0x11

      '#power-domain-cells':

        const: 1

    required:

      - '#power-domain-cells'

  protocol@13:

    type: object

    properties:

      reg:

        const: 0x13

      '#clock-cells':

        const: 1

    required:

      - '#clock-cells'

  protocol@14:

    type: object

    properties:

      reg:

        const: 0x14

      '#clock-cells':

        const: 1

    required:

      - '#clock-cells'

  protocol@15:

    type: object

    properties:

      reg:

        const: 0x15

      '#thermal-sensor-cells':

        const: 1

    required:

      - '#thermal-sensor-cells'

  protocol@16:

    type: object

    properties:

      reg:

        const: 0x16

      '#reset-cells':

        const: 1

    required:

      - '#reset-cells'

  protocol@17:

    type: object

    properties:

      reg:

        const: 0x17

      regulators:

        type: object

        description:

          The list of all regulators provided by this SCMI controller.

        patternProperties:

          '^regulators@[0-9a-f]+$':

            type: object

            $ref: "../regulator/regulator.yaml#"

            properties:

              reg:

                maxItems: 1

                description: Identifier for the voltage regulator.

            required:

              - reg

additionalProperties: false

patternProperties:

  '^protocol@[0-9a-f]+$':

    type: object

    description:

      Each sub-node represents a protocol supported. If the platform

      supports a dedicated communication channel for a particular protocol,

      then the corresponding transport properties must be present.

    properties:

      reg:

        maxItems: 1

      mbox-names:

        items:

          - const: tx

          - const: rx

      mboxes:

        minItems: 1

        maxItems: 2

      shmem:

        minItems: 1

        maxItems: 2

    required:

      - reg

required:

  - compatible

  - shmem

if:

  properties:

    compatible:

      contains:

        const: arm,scmi

then:

  properties:

    interrupts: false

    interrupt-names: false

  required:

    - mboxes

else:

  if:

    properties:

      compatible:

        contains:

          const: arm,scmi-smc

  then:

    required:

      - arm,smc-id

examples:

  - |

    firmware {

        scmi {

            compatible = "arm,scmi";

            mboxes = <&mhuB 0 0>,

                     <&mhuB 0 1>;

            mbox-names = "tx", "rx";

            shmem = <&cpu_scp_lpri0>,

                    <&cpu_scp_lpri1>;

            #address-cells = <1>;

            #size-cells = <0>;

            scmi_devpd: protocol@11 {

                reg = <0x11>;

                #power-domain-cells = <1>;

            };

            scmi_dvfs: protocol@13 {

                reg = <0x13>;

                #clock-cells = <1>;

                mboxes = <&mhuB 1 0>,

                         <&mhuB 1 1>;

                mbox-names = "tx", "rx";

                shmem = <&cpu_scp_hpri0>,

                        <&cpu_scp_hpri1>;

            };

            scmi_clk: protocol@14 {

                reg = <0x14>;

                #clock-cells = <1>;

            };

            scmi_sensors: protocol@15 {

                reg = <0x15>;

                #thermal-sensor-cells = <1>;

            };

            scmi_reset: protocol@16 {

                reg = <0x16>;

                #reset-cells = <1>;

            };

            scmi_voltage: protocol@17 {

                reg = <0x17>;

                regulators {

                    #address-cells = <1>;

                    #size-cells = <0>;

                    regulator_devX: regulator@0 {

                        reg = <0x0>;

                        regulator-max-microvolt = <3300000>;

                    };

                    regulator_devY: regulator@9 {

                        reg = <0x9>;

                        regulator-min-microvolt = <500000>;

                        regulator-max-microvolt = <4200000>;

                    };

                };

            };

        };

    };

    soc {

        #address-cells = <2>;

        #size-cells = <2>;

        sram@50000000 {

            compatible = "mmio-sram";

            reg = <0x0 0x50000000 0x0 0x10000>;

            #address-cells = <1>;

            #size-cells = <1>;

            ranges = <0 0x0 0x50000000 0x10000>;

            cpu_scp_lpri0: scp-sram-section@0 {

                compatible = "arm,scmi-shmem";

                reg = <0x0 0x80>;

            };

            cpu_scp_lpri1: scp-sram-section@80 {

                compatible = "arm,scmi-shmem";

                reg = <0x80 0x80>;

            };

            cpu_scp_hpri0: scp-sram-section@100 {

                compatible = "arm,scmi-shmem";

                reg = <0x100 0x80>;

            };

            cpu_scp_hpri2: scp-sram-section@180 {

                compatible = "arm,scmi-shmem";

                reg = <0x180 0x80>;

            };

        };

    };

  - |

    firmware {

        scmi {

            compatible = "arm,scmi-smc";

            shmem = <&cpu_scp_lpri0 &cpu_scp_lpri1>;

            arm,smc-id = <0xc3000001>;

            #address-cells = <1>;

            #size-cells = <0>;

            scmi_devpd1: protocol@11 {

                reg = <0x11>;

                #power-domain-cells = <1>;

            };

        };

    };

...