TOD/RTC questions

[Joel Sherrill]

On 8/29/2014 10:38 AM, Alan Cudmore wrote:
> I was able to get the ds1307 i2c part working on the Pi. The tod.c 
> driver shell was calling setRealTimeToRTEMS() but it was failing in 
> rtems_clock_set because my driver was not returning the correct 
> rtems_tod format.
> Now when I boot the Pi, the rtems time is synced to the battery backed RTC.
That's great news!

--joel
> Thanks,
> Alan
>
> On 8/28/2014 1:26 PM, Joel Sherrill wrote:
>> On 8/28/2014 12:16 PM, Alan Cudmore wrote:
>>> I am testing out the Raspberry Pi I2C interface by implementing a
>>> DS1307 RTC driver.
>>>
>>> I started with the libchip/rtc/ds1375.c driver, since it is very close
>>> to the 1307.
>>>
>>> In the Raspberry Pi BSP, I added code to i2c_init.c to create a raw
>>> device node for the RTC device, then I added the tod/todcfg.h similar
>>> to the powerpc/mvme3100 BSP.
>>>
>>> Using the test functions I can read and write the device, but is there
>>> anything else I need to do in order to tie it to the RTEMS time functions?
>>>
>>> For example:
>>> In the shell ( main_date.c ) , the time() function just returns the
>>> 1998 epoch. Also, the shell rtc command ( main_rtc.c ) calls
>>> rtems_clock_get_tod, but returns a error. If I use the RTC command and
>>> set the time, it does try to write to my device and subsequent calls
>>> to rtems_clock_tod do not return an error.
>>>
>>> Am I missing any setup here?
>>>
>>> Finally, is RTC the same as TOD for RTEMS?
>>>
>> It is a source to set the TOD from. There are some ugly APIs provided
>> by the RTC driver shell code. They really need new names but I haven't
>> had any good ideas. :(
>>
>> See libbsp/shared/tod.c.
>>
>> setRealTimeFromRTEMS() is probably the missing call you are looking
>> for.
>>> Thanks,
>>> Alan

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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