This patch is v4 of a previous posting: http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/253693.html Changes in v4: - States sorting using exit-latency - Added cosmetic review comments - Dropped RFC tag - Rebased against 3.15 Changes in v3: - Streamlined the idle states bindings and added them to the series http://www.spinics.net/lists/arm-kernel/msg316299.html - Sorting states through min-residency+exit-latency - Added debug strings formatting - Reworded min-residency-us idle state property - Removed power-domain properties from idle states waiting for code examples requiring them to be defined Changes in v2: - Moved OF parsing code to drivers/cpuidle - Improved states detection and sorting through linked list - Split code in generic and ARM64 specific bits - Moved idle enter function into ARM64 idle driver - Refactored PSCI idle states register function - Renamed suspend operations and moved detection to ARM64 idle driver - Changed the way CPUIDLE_FLAG_TIMER_STOP is handled - Simplified idle state nodes parsing since according to the latest bindings idle state nodes are a flat list, not hierarchical anymore - Used min-residency-us to sort the states, to be further discussed Idle states on most ARM platforms can be characterized by a set of parameters that are platform agnostic and describe the HW idle states features. So far, CPU idle drivers for ARM platforms required the definition of parameters through static tables, duplicating control data for different platforms. Moreover, the lack of standardization on firmware interfaces hampered any standardization effort, resulting in CPU idle drivers for ARM platforms containing duplicated code and platform specific power down routines. The introduction of the PSCI firmware interface, and more in general, well defined suspend back-ends, allows the definition of generic idle states and the respective kernel infrastructure to support them. Building on top of DT idle states bindings, that standardize idle states parameters and corresponding suspend back-ends, this patchset provides code that parses DT idle states nodes and builds at run-time the control data infrastructure required by the ARM CPU idle drivers. Idle states define an entry method (eg PSCI), that requires the respective ARM64 kernel back-end to be invoked to initialize idle states parameters, so that when the idle driver executes the back-end specific entry method a table look-up can be carried out to retrieve the corresponding idle state parameter. On legacy ARM platforms, the OF idle states are just used to initialize states data. The idle states bindings can be extended with new back-ends; the ARM64 CPUidle driver must be updated accordingly so that the corresponding back end initializer can be invoked at boot time for parameters initialization. Patchset has been tested on AEM v8 models, on top of bootwrapper PSCI CPU SUSPEND implementation which provides simulated core power gating. [1] http://www.spinics.net/lists/arm-kernel/msg316299.html Lorenzo Pieralisi (6): Documentation: arm: define DT idle states bindings Documentation: devicetree: psci: define CPU suspend parameter drivers: cpuidle: implement OF based idle states infrastructure arm64: add PSCI CPU_SUSPEND based cpu_suspend support drivers: cpuidle: CPU idle ARM64 driver arm64: boot: dts: update rtsm aemv8 dts with PSCI and idle states Documentation/devicetree/bindings/arm/cpus.txt | 8 + .../devicetree/bindings/arm/idle-states.txt | 507 +++++++++++++++++++++ Documentation/devicetree/bindings/arm/psci.txt | 12 +- arch/arm64/boot/dts/rtsm_ve-aemv8a.dts | 44 +- arch/arm64/include/asm/psci.h | 4 + arch/arm64/kernel/psci.c | 103 +++++ drivers/cpuidle/Kconfig | 14 + drivers/cpuidle/Kconfig.arm64 | 13 + drivers/cpuidle/Makefile | 5 + drivers/cpuidle/cpuidle-arm64.c | 168 +++++++ drivers/cpuidle/of_idle_states.c | 282 ++++++++++++ drivers/cpuidle/of_idle_states.h | 8 + 12 files changed, 1159 insertions(+), 9 deletions(-) create mode 100644 Documentation/devicetree/bindings/arm/idle-states.txt create mode 100644 drivers/cpuidle/Kconfig.arm64 create mode 100644 drivers/cpuidle/cpuidle-arm64.c create mode 100644 drivers/cpuidle/of_idle_states.c create mode 100644 drivers/cpuidle/of_idle_states.h -- 1.8.4 -- 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
