Hi, On many SoCs such as OMAP, hardware blocks are isolated into voltage domains allowing for individual tweaks for optimal power-performance tradeoffs. Frameworks such as cpufreq, devfreq provide a top level control of these hardware blocks. Most SoCs have different knobs to fine tune the voltages. They may supply multiple supplies to various voltage planes on the same voltage domains. Regulator framework provides us a with an appropriate representation of consumer model, however, we lack the abstraction necessary to isolate the necessary sequencing for a specific voltage domain. There has been few attempts previously taken such as [3] [4], this series is a further development of of Mike's series[1] where cpufreq-cpu0 driver was first targetted with clk notifiers. While I do understand the concerns Mike has in [2], this could be a base on which further work may be done. In a nutshell, this (for cpufreq-cpu0 as an example): maintains the legacy definitions used by cpufreq/devfreq such as: &cpu0 { cpu0-supply = <®ulator_x>; }; on other SoCs where this might turn out to be a more detailed implementation, &cpu0 { cpu0-voltdm = <&voltdm_x>; }; To enure this is split off from clk framework, I chose drivers/power/voltdm as the location for the new files, I'd love to hear opinions and suggestions on the approach. The series is based on 3.14-rc3 and is available here: https://github.com/nmenon/linux-2.6-playground/commits/push/voltdm-notifier-rfc A testing branch for Beagle-XM (OMAP3630 as testbed): https://github.com/nmenon/linux-2.6-playground/commits/testing/beagle-xm-voltdm-notifier-rfc Log: http://slexy.org/view/s20TgkN7kf NOTE: TI platforms potentially need further development, however, this forms the basis of the development. Mike Turquette (2): PM / Voltagedomain: Add generic clk notifier handler for regulator based dynamic voltage scaling cpufreq: cpufreq-cpu0: use clk rate-change notifiers Nishanth Menon (4): PM / Voltagedomain: introduce voltage domain driver support devicetree: bindings: add documentation for voltagedomain PM / Voltagedomain: introduce basic voltage domain support for OMAP devicetree: bindings: voltagedomain: add bindings for OMAP compatible SoCs .../bindings/power/voltdm/voltage_domain.txt | 65 +++ .../bindings/power/voltdm/voltdm_omap.txt | 24 + drivers/cpufreq/Kconfig | 1 + drivers/cpufreq/cpufreq-cpu0.c | 140 ++---- drivers/power/Kconfig | 1 + drivers/power/Makefile | 1 + drivers/power/voltdm/Kconfig | 19 + drivers/power/voltdm/Makefile | 6 + drivers/power/voltdm/core.c | 508 ++++++++++++++++++++ drivers/power/voltdm/voltage_domain_private.h | 86 ++++ drivers/power/voltdm/voltdm_omap.c | 287 +++++++++++ include/linux/pm_voltage_domain.h | 47 ++ 12 files changed, 1086 insertions(+), 99 deletions(-) create mode 100644 Documentation/devicetree/bindings/power/voltdm/voltage_domain.txt create mode 100644 Documentation/devicetree/bindings/power/voltdm/voltdm_omap.txt create mode 100644 drivers/power/voltdm/Kconfig create mode 100644 drivers/power/voltdm/Makefile create mode 100644 drivers/power/voltdm/core.c create mode 100644 drivers/power/voltdm/voltage_domain_private.h create mode 100644 drivers/power/voltdm/voltdm_omap.c create mode 100644 include/linux/pm_voltage_domain.h [1] https://lkml.org/lkml/2013/7/7/110 (original RFC) [2] http://marc.info/?l=linux-arm-kernel&m=137947787621572&w=2 (runtime pm should enable regulator) [3] http://marc.info/?t=136603111700006&r=1&w=2 [4] http://git.omapzoom.org/?p=kernel/omap.git;a=blob;f=arch/arm/mach-omap2/dvfs.c;hb=p-linux-omap-3.4 -- 1.7.9.5 -- 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