This patch series is to enable CPU idle states for Hi6220. Hi6220 uses PSCIv0.2 compliance interface, so directly use ARM's generic CPUIdle driver. Patch 1 is to reserve memory regions so make sure MCU can work well to handle power controlling; Patch 2/3 enable sp804 timer as broadcast timer during idle states; Patch 4 registers CPU power down state and cluster power down state. Patch 1 "arm64: dts: Reserve memory regions for hi6220" reserves memory regions by carve out from memory node; This follows up Mark Rutland's suggestion to avoid risks, such like kernel's linear mapping for reserved secure memory region may introduce speculative accesses triggering aborts from trustzone controller (TZC) and potential cache alias problem. Rob Herring expressed reservations for this method and says "regions should be marked as reserved, it's not really worth holding up this platform further", so appreciate Rob helped to make progress for this series. The resend patch series have been rebased on mainline kernel, and tested on Hikey board. During testing I found CPUIdle menu governor is broken, this bug has been reported by Sudeep; Rafael J. Wysocki already has committed patch [1] to fix this issue. Testing pass after applied Rafael's patch. Changes from v1: * According to Sudeep's review, fix binding for idle-states * According to Rob's review, due timers share same clock source with apb clock, so just only pass one clock phandle [1] http://article.gmane.org/gmane.linux.kernel.commits.head/573361 Leo Yan (4): arm64: dts: Reserve memory regions for hi6220 arm64: Kconfig: select sp804 timer for ARCH_HISI arm64: dts: add sp804 timer node for Hi6220 arm64: dts: enable idle states for Hi6220 arch/arm64/Kconfig.platforms | 1 + arch/arm64/boot/dts/hisilicon/hi6220-hikey.dts | 16 ++++++++--- arch/arm64/boot/dts/hisilicon/hi6220.dtsi | 40 ++++++++++++++++++++++++++ 3 files changed, 53 insertions(+), 4 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
