need help to enable ARM AMBA PL031 RTC

need help to enable ARM AMBA PL031 RTC

[Hebbar]

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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Re: need help to enable ARM AMBA PL031 RTC

[Ben Dooks]

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-enable-ARM-AMBA-PL031-RTC-tp18462244p18462244.html
> Sent from the linux-kernel mailing list archive at Nabble.com.
> 
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-- 
Ben (ben@fluff.org, http://www.fluff.org/)

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