1. 1 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com TI OMAP 3530 power management Gilles Chanteperdrix Free Electrons © Copyright 2004-2010, Free Electrons. Creative Commons BY-SA 3.0 license Latest update: 10/1/2016, Corrections, suggestions, contributions and translations are welcome!

2. 2 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com Introduction OMAP 3530 features for P.M. Separately clocked areas: “clock domains” Separately powered areas: “power domains” Areas controlled by separate regulators: “voltage domains” Power management control companion chip Goal These features may be used to implement various power consumption management techniques, described in T.I. documentation, show their Linux counterparts.

3. 3 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com OMAP 3530 P.M. techniques Active power consumption management: DVFS: Dynamic voltage and frequency scaling AVS: Adaptive voltage scaling DPS: Dynamic power switching Static power consumption management: SLM: Static leakage management

4. 4 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com Dynamic voltage and frequency scaling Define operating performance points (OPP), composed of a frequency and the CPU and DSP voltages needed to reach a certain performance goal. Modulate frequency and voltage according to the OPP needed to handle the current workload. Under Linux, this is what the cpufreq driver should do (currently, seems only implemented on the android fork for omap3). With help from the OMAP PM API.

5. 5 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com Adaptive voltage scaling There are variations in the characteristics of a SoC due to several factors Due to these variations, the operating condition of a processor can be adjusted This is what smartreflex does automatically Under Linux, only implemented in the android fork, enabled and disabled using files under /sys.

6. 6 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com Dynamic power switching Not all parts of the OMAP SoC are needed at all times. Dynamic power switching is switching the unused parts to a low power state. Under Linux, matches the PM_RUNTIME option, but not implemented for OMAP, instead, various clocks and peripherals have an “auto-idle” mode. With here again help from the OMAP PM API. (see Documentation/arm/OMAP/omap_pm)

7. 7 Free Electrons. Kernel, drivers and embedded Linux development, consulting, training and support. http//free-electrons.com Static power consumption management Static leakage management When the SoC is not needed, put it in standby or device-off mode completely. Under Linux, this matches the power management suspend states. Linux clocks and regulators framework Any unused domain can be turned off