85 lines
2.5 KiB
Plaintext
85 lines
2.5 KiB
Plaintext
|
Qualcomm Always-On Subsystem side channel binding
|
||
|
|
|
||
|
|
This binding describes the hardware component responsible for side channel
|
||
|
|
requests to the always-on subsystem (AOSS), used for certain power management
|
||
|
|
requests that is not handled by the standard RPMh interface. Each client in the
|
||
|
|
SoC has it's own block of message RAM and IRQ for communication with the AOSS.
|
||
|
|
The protocol used to communicate in the message RAM is known as Qualcomm
|
||
|
|
Messaging Protocol (QMP)
|
||
|
|
|
||
|
|
The AOSS side channel exposes control over a set of resources, used to control
|
||
|
|
a set of debug related clocks and to affect the low power state of resources
|
||
|
|
related to the secondary subsystems. These resources are exposed as a set of
|
||
|
|
power-domains.
|
||
|
|
|
||
|
|
- compatible:
|
||
|
|
Usage: required
|
||
|
|
Value type: <string>
|
||
|
|
Definition: must be one of:
|
||
|
|
"qcom,sc7180-aoss-qmp"
|
||
|
|
"qcom,sdm845-aoss-qmp"
|
||
|
|
"qcom,sm8150-aoss-qmp"
|
||
|
|
|
||
|
|
- reg:
|
||
|
|
Usage: required
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition: the base address and size of the message RAM for this
|
||
|
|
client's communication with the AOSS
|
||
|
|
|
||
|
|
- interrupts:
|
||
|
|
Usage: required
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition: should specify the AOSS message IRQ for this client
|
||
|
|
|
||
|
|
- mboxes:
|
||
|
|
Usage: required
|
||
|
|
Value type: <prop-encoded-array>
|
||
|
|
Definition: reference to the mailbox representing the outgoing doorbell
|
||
|
|
in APCS for this client, as described in mailbox/mailbox.txt
|
||
|
|
|
||
|
|
- #clock-cells:
|
||
|
|
Usage: optional
|
||
|
|
Value type: <u32>
|
||
|
|
Definition: must be 0
|
||
|
|
The single clock represents the QDSS clock.
|
||
|
|
|
||
|
|
- #power-domain-cells:
|
||
|
|
Usage: optional
|
||
|
|
Value type: <u32>
|
||
|
|
Definition: must be 1
|
||
|
|
The provided power-domains are:
|
||
|
|
CDSP state (0), LPASS state (1), modem state (2), SLPI
|
||
|
|
state (3), SPSS state (4) and Venus state (5).
|
||
|
|
|
||
|
|
= SUBNODES
|
||
|
|
The AOSS side channel also provides the controls for three cooling devices,
|
||
|
|
these are expressed as subnodes of the QMP node. The name of the node is used
|
||
|
|
to identify the resource and must therefor be "cx", "mx" or "ebi".
|
||
|
|
|
||
|
|
- #cooling-cells:
|
||
|
|
Usage: optional
|
||
|
|
Value type: <u32>
|
||
|
|
Definition: must be 2
|
||
|
|
|
||
|
|
= EXAMPLE
|
||
|
|
|
||
|
|
The following example represents the AOSS side-channel message RAM and the
|
||
|
|
mechanism exposing the power-domains, as found in SDM845.
|
||
|
|
|
||
|
|
aoss_qmp: qmp@c300000 {
|
||
|
|
compatible = "qcom,sdm845-aoss-qmp";
|
||
|
|
reg = <0x0c300000 0x100000>;
|
||
|
|
interrupts = <GIC_SPI 389 IRQ_TYPE_EDGE_RISING>;
|
||
|
|
mboxes = <&apss_shared 0>;
|
||
|
|
|
||
|
|
#power-domain-cells = <1>;
|
||
|
|
|
||
|
|
cx_cdev: cx {
|
||
|
|
#cooling-cells = <2>;
|
||
|
|
};
|
||
|
|
|
||
|
|
mx_cdev: mx {
|
||
|
|
#cooling-cells = <2>;
|
||
|
|
};
|
||
|
|
};
|