SPMI

The System Power Management Interface (SPMI) is a high-speed, low-latency, bi-directional, two-wire serial bus suitable for real-time control of voltage and frequency scaled multi-core application processors and its power management of auxiliary components. SPMI obsoletes a number of legacy, custom point-to-point interfaces and provides a low pin count, high-speed control bus for up to 4 Master and 16 Slave devices.

SPMI is specified by the MIPI (Mobile Industry Process Interface) Alliance.

Documentation/devicetree/bindings/spmi/qcom,spmi-pmic-arb.txtDocumentation/devicetree/bindings/spmi/spmi.txtdrivers/spmi/Kconfigdrivers/spmi/Makefiledrivers/spmi/spmi-dbgfs.cdrivers/spmi/spmi-dbgfs.hdrivers/spmi/spmi-pmic-arb.cdrivers/spmi/spmi.cinclude/linux/spmi.h

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Overview

The MIPI System Power Management Interface, MIPI SPMI℠, specifies the hardware interface between baseband or application processors and peripheral components to support advanced power management techniques. The specification also reduces design costs and shortens time to market of mobile devices by simplifying the interconnection of devices from different manufacturers. It is used in smartphones, tablets, and other portable devices.

The MIPI System Power Management Interface is a two-wire serial interface that uses CMOS I/Os for the physical layer. The interface connects the integrated power controller of a system-on-chip (SoC) processor system with one or more power management IC voltage regulation systems. The interface can be used to accurately monitor and control processor performance levels required for a given workload or application and dynamically control the various supply voltages in real time based on the performance levels.

Features include a low pin count and low gate count, high speed, low latency, ability to support multiple processor devices on the same shared bus, priority management by traffic classes, and command acknowledgement.

The interface is developed by the MIPI Alliance System Power Management Working Group. The current release, v2.0, was released in 2012.