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    SubjectRe: [PATCH] mmc: append a file to change host clock at run time
    From
    On Tue, Oct 12, 2010 at 6:17 PM, Andy Shevchenko
    <andy.shevchenko@gmail.com> wrote:
    > For debugging power managment features there is quite convenient to have a
    > possibility to change MMC host controller clock at run time. This patch adds
    > 'clock' file under MMC host root of debugfs.
    >
    > Usage as follows:
    >
    >        # cat /sys/kernel/debug/mmc0/clock
    >        24000000
    Actually this value should be 52000000 here.

    >
    >        # echo "1000000000" > /sys/kernel/debug/mmc0/clock
    >        # cat /sys/kernel/debug/mmc0/clock
    >        52000000
    >
    >        # echo "48000000" > /sys/kernel/debug/mmc0/clock
    >        # cat /sys/kernel/debug/mmc0/clock
    >        48000000
    >
    > The second piece of example shows limits which are applied accordingly to used
    > host driver.


    --
    With Best Regards,
    Andy Shevchenko
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