Doug / smarc-fsl-linux-kernel

02 Oct, 2011

2 commits

  • ce26c5bb9   PM / devfreq: Add basic governors ... Browse Code »

    Four cpufreq-like governors are provided as examples.

    powersave: use the lowest frequency possible. The user (device) should
    set the polling_ms as 0 because polling is useless for this governor.

    performance: use the highest freqeuncy possible. The user (device)
    should set the polling_ms as 0 because polling is useless for this
    governor.

    userspace: use the user specified frequency stored at
    devfreq.user_set_freq. With sysfs support in the following patch, a user
    may set the value with the sysfs interface.

    simple_ondemand: simplified version of cpufreq's ondemand governor.

    When a user updates OPP entries (enable/disable/add), OPP framework
    automatically notifies devfreq to update operating frequency
    accordingly. Thus, devfreq users (device drivers) do not need to update
    devfreq manually with OPP entry updates or set polling_ms for powersave
    , performance, userspace, or any other "static" governors.

    Note that these are given only as basic examples for governors and any
    devices with devfreq may implement their own governors with the drivers
    and use them.

    Signed-off-by: MyungJoo Ham
    Signed-off-by: Kyungmin Park
    Reviewed-by: Mike Turquette
    Acked-by: Kevin Hilman
    Signed-off-by: Rafael J. Wysocki

    MyungJoo Ham
     
  • 9005b6509   PM / devfreq: Add common sysfs interfaces ... Browse Code »

    Device specific sysfs interface /sys/devices/.../power/devfreq_*
    - governor R: name of governor
    - cur_freq R: current frequency
    - polling_interval R: polling interval in ms given with devfreq profile
    W: update polling interval.
    - central_polling R: 1 if polling is managed by devfreq framework

    Signed-off-by: MyungJoo Ham
    Signed-off-by: Kyungmin Park
    Reviewed-by: Mike Turquette
    Acked-by: Kevin Hilman
    Signed-off-by: Rafael J. Wysocki
    --
    Documentation/ABI/testing/sysfs-class-devfreq | 44 ++++++++++++++++
    drivers/devfreq/devfreq.c | 69 ++++++++++++++++++++++++++
    2 files changed, 113 insertions(+)
    create mode 100644 Documentation/ABI/testing/sysfs-class-devfreq

    MyungJoo Ham