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    Subject[PATCH v4 0/3] Runtime Interpreted Power Sequences
    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";
    step1 {
    delay = <10000>;
    step2 {
    pwm = "backlight";

    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
    * 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


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