Re: [PATCH 1/2] dt-bindings: soc: qcom: Document CDSP Power Management

[Vignesh Viswanathan <vignesh.viswanathan@oss.qualcomm.com>]

On 5/20/2026 3:29 PM, Konrad Dybcio wrote:
> On 5/19/26 9:05 PM, Vignesh Viswanathan wrote:
>> Add documentation for the CDSP Power Management driver, which handles
>> Dynamic Clock and Voltage Scaling (DCVS) requests via SMEM, manages Low
>> Power Mode (LPM) transitions via MPM handshake, and provides virtual
>> regulators for the remoteproc driver to control CDSP power rails.
>>
>> Signed-off-by: Vignesh Viswanathan <vignesh.viswanathan@oss.qualcomm.com>
>> ---
> 
> [...]
> 
>> +maintainers:
>> +  - Vignesh Viswanathan <vignesh.viswanathan@oss.qualcomm.com>
>> +
>> +description:
>> +  The CDSP Power Management driver provides power management services for the
>> +  Qualcomm Compute DSP (CDSP) subsystem. It handles Dynamic Clock and Voltage
>> +  Scaling (DCVS) requests via SMEM, manages Low Power Mode (LPM) transitions
>> +  via MPM handshake, and provides virtual regulators that are consumed by the
>> +  CDSP remoteproc driver.
>> +
>> +properties:
>> +  compatible:
>> +    const: qcom,cdsp-power
> 
> This really needs to be SoC-specific

Ack, will make it specific to ipq9650.

> 
>> +
>> +  reg:
>> +    items:
>> +      - description: MPM (Modem Power Manager) register region
>> +      - description: RSCC (RSC Configuration) register region
> 
> I was under the impression that these two belong to separate
> universes..

MPM registers are used to control the power mode for the CDSP.
RSCC region has RSCC_BR_EVENT register from where the APSS reads
which mode the CDSP wants to enter and executes the corresponding sequence
in the MPM.

> 
>> +  vdd-cx-supply:
>> +    description:
>> +      Phandle to the CX voltage regulator. This is the actual hardware regulator
>> +      (e.g., from MP8899 PMIC) that supplies power to the CDSP CX rail.
> 
> I believe the second sentence is wholly redundant

Will drop this.

> 
> [...]
> 
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +    #include <dt-bindings/mailbox/qcom-ipcc.h>
>> +
>> +    soc {
>> +        #address-cells = <2>;
>> +        #size-cells = <2>;
>> +
>> +        cdsp_power: cdsp-power@4ae000 {
>> +            compatible = "qcom,cdsp-power";
>> +            reg = <0x0 0x004ae000 0x0 0x1000>,
> 
> MPM is a top-level peripheral, but this is a slice dedicated to the
> CDSP so maybe it'd pass, but..
> 
>> +                  <0x0 0x26018018 0x0 0x4>;
> 
> This is a single random register within the CDSP's register space, so
> we should definitely be able to describe this better..

Will document this more clearly in the next version.

Thanks,
Vignesh
> 
> Konrad