| SPM AVS Wrapper 2 (SAW2) |
| |
| The SAW2 is a wrapper around the Subsystem Power Manager (SPM) and the |
| Adaptive Voltage Scaling (AVS) hardware. The SPM is a programmable |
| power-controller that transitions a piece of hardware (like a processor or |
| subsystem) into and out of low power modes via a direct connection to |
| the PMIC. It can also be wired up to interact with other processors in the |
| system, notifying them when a low power state is entered or exited. |
| |
| Multiple revisions of the SAW hardware are supported using these Device Nodes. |
| SAW2 revisions differ in the register offset and configuration data. Also, the |
| same revision of the SAW in different SoCs may have different configuration |
| data due the the differences in hardware capabilities. Hence the SoC name, the |
| version of the SAW hardware in that SoC and the distinction between cpu (big |
| or Little) or cache, may be needed to uniquely identify the SAW register |
| configuration and initialization data. The compatible string is used to |
| indicate this parameter. |
| |
| PROPERTIES |
| |
| - compatible: |
| Usage: required |
| Value type: <string> |
| Definition: Must have |
| "qcom,saw2" |
| A more specific value could be one of: |
| "qcom,apq8064-saw2-v1.1-cpu" |
| "qcom,msm8226-saw2-v2.1-cpu" |
| "qcom,msm8974-saw2-v2.1-cpu" |
| "qcom,apq8084-saw2-v2.1-cpu" |
| |
| - reg: |
| Usage: required |
| Value type: <prop-encoded-array> |
| Definition: the first element specifies the base address and size of |
| the register region. An optional second element specifies |
| the base address and size of the alias register region. |
| |
| - regulator: |
| Usage: optional |
| Value type: boolean |
| Definition: Indicates that this SPM device acts as a regulator device |
| device for the core (CPU or Cache) the SPM is attached |
| to. |
| |
| Example 1: |
| |
| power-controller@2099000 { |
| compatible = "qcom,saw2"; |
| reg = <0x02099000 0x1000>, <0x02009000 0x1000>; |
| regulator; |
| }; |
| |
| Example 2: |
| saw0: power-controller@f9089000 { |
| compatible = "qcom,apq8084-saw2-v2.1-cpu", "qcom,saw2"; |
| reg = <0xf9089000 0x1000>, <0xf9009000 0x1000>; |
| }; |