This patchset tries to add support for Mediatek SVS engine. The SVS (Smart Voltage Scaling) engine is a piece of hardware which is used to caculate optimized voltage values of several power domains, e.g. CPU clusters, according to chip process corner, temperatures, and other factors. Then DVFS driver could apply those optimized voltage values to reduce power consumption. This engine takes calibration data stored in on-chip E-Fuse device as configuration input during initialization. Once the initialization is done, SVS engine issues interrupts according to temerature changes of power domains to notify DVFS driver to get calculated voltage values. The configuration registers of SVS engine are shared with Mediatek thermal controller, and those registers are banked for different power domains. In addition, the SVS engine also needs some information from Mediatek thermal controller, e.g. the temperature of a specific power domain, part of the thermal calibration data. Therefore the support for SVS engine is integrated with Mediatek thermal controller driver. Also, for platform specific requirement, to make SVS engine work correctly, the initialization of SVS engine should be later then Mediatek thermal controller, and prior to mt8173-cpufreq driver. Hence, the platform device registration code of mt8173-cpufreq is removed here after SVS initialization is done or skipped to ensure the platform specific initialization flow. The functionality of SVS engine is optional for Mediatek thermal controller. If the required resources of SVS engine is absent or SVS failed during initialization stage, the SVS control flow will be skipped and the thermal controller will function normally. This patchset relies heavily on the runtime voltage adjustment mechanism of OPP introduced by Stephen Boyd's previous work[1]. And it also depends on other MT8173 device drivers that are still under reviewing and not yet merged, e.g. Mediatek thermal controller support [2], Mediatek EFUSE driver[3]. CC: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> [1] https://lkml.org/lkml/2015/9/18/833 [2] https://lkml.org/lkml/2015/11/30/239 [3] https://lkml.org/lkml/2015/11/19/169 Pi-Cheng Chen (5): thermal: MT8173: Replace mutex with spinlock cpufreq: mt8173: Remove platform device registration code dt-bindings: thermal: Add optional properties of Mediatek thermal controller PM / AVS: thermal: MT8173: Introduce support for SVS engine cpufreq: mt8173: Add notifier to handle OPP voltage adjustment .../bindings/thermal/mediatek-thermal.txt | 23 +- drivers/cpufreq/mt8173-cpufreq.c | 68 +- drivers/thermal/mtk_thermal.c | 727 ++++++++++++++++++++- 3 files changed, 782 insertions(+), 36 deletions(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
