Overdue revision of this new feature, some changes required additional thought and rework. The most important change is in the way power sequences are expressed in the device tree. In order to avoid having to specify #address-cells, #size-cells and reg properties, the @ notation in the step names is dropped, and instead a fixed, sequential naming is adopted. The type of the resource used by a step is decided by the presence of some recognized properties: power-on-sequence { step0 { regulator = "power"; enable; }; step1 { delay = <10000>; }; step2 { pwm = "backlight"; enable; }; ... To me this looks safe, clear and close to the platform data representation, but needs approval from DT experts. Resources are still referenced by name instead of having their phandles defined directly inside the sequences, as previous discussion came to the conclusion that doing so would require controversial changes to the regulator and PWM frameworks, and that having the resources declared at the device level was making sense logically speaking. Other changes/fixes since last revision: * Move to drivers/power/ (hope this is ok with the maintainers?) * Use microseconds for delay * Use devm for PWM resources and remove cleanup function as all resources are devm-managed * Remove "-gpio" suffix for GPIO reference in the driver * Remove params structure * Make power_seq structure private * Number of steps in a sequence is explicitly stated instead of resorting to a "stop" sequence step * Delays are a step instead of being a step parameter * Use flexible member arrays to limit number of memory allocations * Add documentation to DT bindings There was a lot of feedback on the previous version (thanks!) so if I forgot to address some important point, please bring it to my attention again. Alexandre Courbot (3): Runtime Interpreted Power Sequences pwm_backlight: use power sequences tegra: add pwm backlight device tree nodes .../devicetree/bindings/power_seq/power_seq.txt | 101 +++++ .../bindings/video/backlight/pwm-backlight.txt | 62 ++- Documentation/power/power_seq.txt | 129 +++++++ arch/arm/boot/dts/tegra20-ventana.dts | 58 +++ arch/arm/boot/dts/tegra20.dtsi | 2 +- drivers/power/Kconfig | 3 + drivers/power/Makefile | 1 + drivers/power/power_seq.c | 420 +++++++++++++++++++++ drivers/video/backlight/Kconfig | 1 + drivers/video/backlight/pwm_bl.c | 192 +++++++--- include/linux/power_seq.h | 142 +++++++ include/linux/pwm_backlight.h | 16 +- 12 files changed, 1071 insertions(+), 56 deletions(-) create mode 100644 Documentation/devicetree/bindings/power_seq/power_seq.txt create mode 100644 Documentation/power/power_seq.txt create mode 100644 drivers/power/power_seq.c create mode 100644 include/linux/power_seq.h -- 1.7.11.4 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html