mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-20 18:23:08 +00:00
1f213ee4db
Implement voltage regulators interfaced by the SCMI voltage domain protocol. The DT bindings are defined in the Linux kernel since SCMI voltage domain and regulators patches [1] and [2] integration in v5.11-rc7. Link: [1]0f80fcec08Link: [2]2add5cacffSigned-off-by: Etienne Carriere <etienne.carriere@linaro.org> Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
231 lines
6.6 KiB
Text
231 lines
6.6 KiB
Text
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.
|
|
|
|
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.
|
|
|
|
SRAM and Shared Memory for SCMI
|
|
-------------------------------
|
|
|
|
A small area of SRAM is reserved for SCMI communication between application
|
|
processors and SCP.
|
|
|
|
The properties should follow the generic mmio-sram description found in [4]
|
|
|
|
Each sub-node represents the reserved area for SCMI.
|
|
|
|
Required sub-node properties:
|
|
- reg : The base offset and size of the reserved area with the SRAM
|
|
- compatible : should be "arm,scmi-shmem" for Non-secure SRAM based
|
|
shared memory
|
|
|
|
[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.txt
|
|
[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>;
|
|
...
|
|
};
|
|
};
|