need help to enable ARM AMBA PL031 RTC - Kernel

This is a discussion on need help to enable ARM AMBA PL031 RTC - Kernel ; I all, I am working on customized arm versatile board and i am trying to use ARM AMBA PL031 RTC. i enabled CONFIG_RTC_DRV_PL031=y But the date never changes or updates. / # cat /sys/class/rtc/rtc0/time 00:00:00 When i went through the ...

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Thread: need help to enable ARM AMBA PL031 RTC

  1. need help to enable ARM AMBA PL031 RTC


    I all,

    I am working on customized arm versatile board and i am trying to use ARM
    AMBA PL031 RTC.

    i enabled CONFIG_RTC_DRV_PL031=y

    But the date never changes or updates.

    / # cat /sys/class/rtc/rtc0/time
    00:00:00

    When i went through the Ref Manual of ARM AMBA PL031 RTC i found that we
    need to enable or set high to RTC START bit (bit 0) in RTC Control Register
    ( 0x0C ).

    but in rtc-pl031.c, RTC_START is no where set in RTC CONTROL Register.

    I think we need to enable it in rtc_probe func after rtc_device_register
    returns success.

    #define RTC_CR_MIE (1 << 0)

    __raw_writel(RTC_CR_MIE, ldata->base + RTC_CR);

    Kindly Comment.

    Regards
    Gururaja


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  2. Re: need help to enable ARM AMBA PL031 RTC

    On Tue, Jul 15, 2008 at 03:43:14AM -0700, Hebbar wrote:
    >
    > I all,
    >
    > I am working on customized arm versatile board and i am trying to use ARM
    > AMBA PL031 RTC.


    linux-arm-kernel@lists.arm.linux.org.uk is the right place to
    discuss this, although I belive it is moderated for non-subscribers.

    > i enabled CONFIG_RTC_DRV_PL031=y
    >
    > But the date never changes or updates.
    >
    > / # cat /sys/class/rtc/rtc0/time
    > 00:00:00
    >
    > When i went through the Ref Manual of ARM AMBA PL031 RTC i found that we
    > need to enable or set high to RTC START bit (bit 0) in RTC Control Register
    > ( 0x0C ).
    >
    > but in rtc-pl031.c, RTC_START is no where set in RTC CONTROL Register.
    >
    > I think we need to enable it in rtc_probe func after rtc_device_register
    > returns success.
    >
    > #define RTC_CR_MIE (1 << 0)
    >
    > __raw_writel(RTC_CR_MIE, ldata->base + RTC_CR);
    >
    > Kindly Comment.
    >
    > Regards
    > Gururaja
    >
    >
    > --
    > View this message in context: http://www.nabble.com/need-help-to-e...p18462244.html
    > Sent from the linux-kernel mailing list archive at Nabble.com.
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/


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