+++ /dev/null
-System Control and Power Interface (SCPI) Message Protocol
-----------------------------------------------------------
-
-Firmware implementing the SCPI described in ARM document number ARM DUI 0922B
-("ARM Compute Subsystem SCP: Message Interface Protocols")[0] can be used
-by Linux to initiate various system control and power operations.
-
-Required properties:
-
-- compatible : should be
- * "arm,scpi" : For implementations complying to SCPI v1.0 or above
- * "arm,scpi-pre-1.0" : For implementations complying to all
- unversioned releases prior to SCPI v1.0
-- mboxes: List of phandle and mailbox channel specifiers
- All the channels reserved by remote SCP firmware for use by
- SCPI message protocol should be specified in any order
-- shmem : List of phandle pointing to the shared memory(SHM) area between the
- processors using these mailboxes for IPC, one for each mailbox
- SHM can be any memory reserved for the purpose of this communication
- between the processors.
-
-See Documentation/devicetree/bindings/mailbox/mailbox.txt
-for more details about the generic mailbox controller and
-client driver bindings.
-
-Clock bindings for the clocks based on SCPI Message Protocol
-------------------------------------------------------------
-
-This binding uses the common clock binding[1].
-
-Container Node
-==============
-Required properties:
-- compatible : should be "arm,scpi-clocks"
- All the clocks provided by SCP firmware via SCPI message
- protocol much be listed as sub-nodes under this node.
-
-Sub-nodes
-=========
-Required properties:
-- compatible : shall include one of the following
- "arm,scpi-dvfs-clocks" - all the clocks that are variable and index based.
- These clocks don't provide an entire range of values between the
- limits but only discrete points within the range. The firmware
- provides the mapping for each such operating frequency and the
- index associated with it. The firmware also manages the
- voltage scaling appropriately with the clock scaling.
- "arm,scpi-variable-clocks" - all the clocks that are variable and provide full
- range within the specified range. The firmware provides the
- range of values within a specified range.
-
-Other required properties for all clocks(all from common clock binding):
-- #clock-cells : Should be 1. Contains the Clock ID value used by SCPI commands.
-- clock-output-names : shall be the corresponding names of the outputs.
-- clock-indices: The identifying number for the clocks(i.e.clock_id) in the
- node. It can be non linear and hence provide the mapping of identifiers
- into the clock-output-names array.
-
-Sensor bindings for the sensors based on SCPI Message Protocol
---------------------------------------------------------------
-SCPI provides an API to access the various sensors on the SoC.
-
-Required properties:
-- compatible : should be "arm,scpi-sensors".
-- #thermal-sensor-cells: should be set to 1. This property follows the
- thermal device tree bindings[2].
-
- 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.
-
-Power domain bindings for the power domains based on SCPI Message Protocol
-------------------------------------------------------------
-
-This binding uses the generic power domain binding[4].
-
-PM domain providers
-===================
-
-Required properties:
- - #power-domain-cells : Should be 1. Contains the device or the power
- domain ID value used by SCPI commands.
- - num-domains: Total number of power domains provided by SCPI. This is
- needed as the SCPI message protocol lacks a mechanism to
- query this information at runtime.
-
-PM domain consumers
-===================
-
-Required properties:
- - power-domains : A phandle and PM domain specifier as defined by bindings of
- the power controller specified by phandle.
-
-[0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
-[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
-[2] Documentation/devicetree/bindings/thermal/thermal*.yaml
-[3] Documentation/devicetree/bindings/sram/sram.yaml
-[4] Documentation/devicetree/bindings/power/power-domain.yaml
-
-Example:
-
-sram: sram@50000000 {
- compatible = "arm,juno-sram-ns", "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,juno-scp-shmem";
- reg = <0x0 0x200>;
- };
-
- cpu_scp_hpri: scp-shmem@200 {
- compatible = "arm,juno-scp-shmem";
- reg = <0x200 0x200>;
- };
-};
-
-mailbox: mailbox0@40000000 {
- ....
- #mbox-cells = <1>;
-};
-
-scpi_protocol: scpi@2e000000 {
- compatible = "arm,scpi";
- mboxes = <&mailbox 0 &mailbox 1>;
- shmem = <&cpu_scp_lpri &cpu_scp_hpri>;
-
- clocks {
- compatible = "arm,scpi-clocks";
-
- scpi_dvfs: scpi_clocks@0 {
- compatible = "arm,scpi-dvfs-clocks";
- #clock-cells = <1>;
- clock-indices = <0>, <1>, <2>;
- clock-output-names = "atlclk", "aplclk","gpuclk";
- };
- scpi_clk: scpi_clocks@3 {
- compatible = "arm,scpi-variable-clocks";
- #clock-cells = <1>;
- clock-indices = <3>, <4>;
- clock-output-names = "pxlclk0", "pxlclk1";
- };
- };
-
- scpi_sensors0: sensors {
- compatible = "arm,scpi-sensors";
- #thermal-sensor-cells = <1>;
- };
-
- scpi_devpd: scpi-power-domains {
- compatible = "arm,scpi-power-domains";
- num-domains = <2>;
- #power-domain-cells = <1>;
- };
-};
-
-cpu@0 {
- ...
- reg = <0 0>;
- clocks = <&scpi_dvfs 0>;
-};
-
-hdlcd@7ff60000 {
- ...
- reg = <0 0x7ff60000 0 0x1000>;
- clocks = <&scpi_clk 4>;
- power-domains = <&scpi_devpd 1>;
-};
-
-thermal-zones {
- soc_thermal {
- polling-delay-passive = <100>;
- polling-delay = <1000>;
-
- /* sensor ID */
- thermal-sensors = <&scpi_sensors0 3>;
- ...
- };
-};
-
-In the above example, the #clock-cells is set to 1 as required.
-scpi_dvfs has 3 output clocks namely: atlclk, aplclk, and gpuclk with 0,
-1 and 2 as clock-indices. scpi_clk has 2 output clocks namely: pxlclk0
-and pxlclk1 with 3 and 4 as clock-indices.
-
-The first consumer in the example is cpu@0 and it has '0' as the clock
-specifier which points to the first entry in the output clocks of
-scpi_dvfs i.e. "atlclk".
-
-Similarly the second example is hdlcd@7ff60000 and it has pxlclk1 as input
-clock. '4' in the clock specifier here points to the second entry
-in the output clocks of scpi_clocks i.e. "pxlclk1"
-
-The thermal-sensors property in the soc_thermal node uses the
-temperature sensor provided by SCP firmware to setup a thermal
-zone. The ID "3" is the sensor identifier for the temperature sensor
-as used by the firmware.
-
-The num-domains property in scpi-power-domains domain specifies that
-SCPI provides 2 power domains. The hdlcd node uses the power domain with
-domain ID 1.
--- /dev/null
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright 2021 ARM Ltd.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/firmware/arm,scpi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: System Control and Power Interface (SCPI) Message Protocol bindings
+
+maintainers:
+ - Sudeep Holla <sudeep.holla@arm.com>
+
+description: |
+ Firmware implementing the SCPI described in ARM document number ARM DUI
+ 0922B ("ARM Compute Subsystem SCP: Message Interface Protocols")[0] can be
+ used by Linux to initiate various system control and power operations.
+
+ This binding is intended to define the interface the firmware implementing
+ the SCPI provide for OSPM in the device tree.
+
+ [0] http://infocenter.arm.com/help/topic/com.arm.doc.dui0922b/index.html
+
+properties:
+ $nodename:
+ const: scpi
+
+ compatible:
+ description:
+ SCPI compliant firmware complying to SCPI v1.0 and above OR
+ SCPI compliant firmware complying to all unversioned releases
+ prior to SCPI v1.0
+ oneOf:
+ - const: arm,scpi # SCPI v1.0 and above
+ - const: arm,scpi-pre-1.0 # Unversioned SCPI before v1.0
+
+ mboxes:
+ description:
+ List of phandle and mailbox channel specifiers. All the channels reserved
+ by remote SCP firmware for use by SCPI message protocol should be
+ specified in any order.
+ minItems: 1
+
+ shmem:
+ description:
+ List of phandle pointing to the shared memory(SHM) area between the
+ processors using these mailboxes for IPC, one for each mailbox SHM can
+ be any memory reserved for the purpose of this communication between the
+ processors.
+ minItems: 1
+
+ power-controller:
+ type: object
+ description:
+ This sub-node represents SCPI power domain controller.
+
+ properties:
+ compatible:
+ const: arm,scpi-power-domains
+
+ '#power-domain-cells':
+ const: 1
+
+ num-domains:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ Total number of power domains provided by SCPI. This is needed as
+ the SCPI message protocol lacks a mechanism to query this
+ information at runtime.
+
+ required:
+ - compatible
+ - '#power-domain-cells'
+ - num-domains
+
+ additionalProperties: false
+
+ sensors:
+ type: object
+ description: |
+ This sub-node represents SCPI sensors controller.
+
+ properties:
+ compatible:
+ const: arm,scpi-sensors
+
+ '#thermal-sensor-cells':
+ const: 1
+
+ required:
+ - compatible
+ - '#thermal-sensor-cells'
+
+ additionalProperties: false
+
+ clocks:
+ type: object
+ description:
+ This is the container node. Each sub-node represents one of the types
+ of clock controller - indexed or full range.
+
+ properties:
+ compatible:
+ const: arm,scpi-clocks
+
+ patternProperties:
+ "^clocks-[0-9a-f]+$":
+ type: object
+ description: |
+ This sub-node represents one of the types of clock controller
+ - indexed or full range.
+
+ "arm,scpi-dvfs-clocks" - all the clocks that are variable and index
+ based. These clocks don't provide an entire range of values between
+ the limits but only discrete points within the range. The firmware
+ provides the mapping for each such operating frequency and the index
+ associated with it. The firmware also manages the voltage scaling
+ appropriately with the clock scaling.
+
+ "arm,scpi-variable-clocks" - all the clocks that are variable and
+ provide full range within the specified range. The firmware provides
+ the range of values within a specified range.
+
+ properties:
+ compatible:
+ oneOf:
+ - const: arm,scpi-dvfs-clocks
+ - const: arm,scpi-variable-clocks
+
+ '#clock-cells':
+ const: 1
+
+ clock-output-names: true
+
+ clock-indices:
+ $ref: /schemas/types.yaml#/definitions/uint32-array
+ description:
+ The identifying number for the clocks(i.e.clock_id) in the node.
+ It can be non linear and hence provide the mapping of identifiers
+ into the clock-output-names array.
+
+ required:
+ - compatible
+ - '#clock-cells'
+ - clock-output-names
+ - clock-indices
+
+ additionalProperties: false
+
+ required:
+ - compatible
+
+ additionalProperties: false
+
+additionalProperties: false
+
+required:
+ - compatible
+ - mboxes
+ - shmem
+
+examples:
+ - |
+ firmware {
+ scpi {
+ compatible = "arm,scpi";
+ mboxes = <&mhuA 1>;
+ shmem = <&cpu_scp_hpri>; /* HP-NonSecure */
+
+ scpi_devpd: power-controller {
+ compatible = "arm,scpi-power-domains";
+ num-domains = <2>;
+ #power-domain-cells = <1>;
+ };
+
+ clocks {
+ compatible = "arm,scpi-clocks";
+
+ scpi_dvfs: clocks-0 {
+ compatible = "arm,scpi-dvfs-clocks";
+ #clock-cells = <1>;
+ clock-indices = <0>, <1>, <2>;
+ clock-output-names = "atlclk", "aplclk","gpuclk";
+ };
+
+ scpi_clk: clocks-1 {
+ compatible = "arm,scpi-variable-clocks";
+ #clock-cells = <1>;
+ clock-indices = <3>, <4>;
+ clock-output-names = "pxlclk0", "pxlclk1";
+ };
+ };
+
+ scpi_sensors: sensors {
+ compatible = "arm,scpi-sensors";
+ #thermal-sensor-cells = <1>;
+ };
+
+ };
+ };
+
+ 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_lpri: scp-sram-section@0 {
+ compatible = "arm,scp-shmem";
+ reg = <0x0 0x200>;
+ };
+
+ cpu_scp_hpri: scp-sram-section@200 {
+ compatible = "arm,scp-shmem";
+ reg = <0x200 0x200>;
+ };
+ };
+ };
+
+...
projects / linux-2.6-microblaze.git / commitdiff