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STM32 RTC: Extend the RTC interface to support reading subseconds. From Jussi Kivilinna

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This commit is contained in:
Gregory Nutt 2015-02-16 07:18:09 -06:00
parent f357897b6c
commit 47e9b4a272
3 changed files with 94 additions and 4 deletions
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1
arch/arm/src/stm32/Kconfig
View File

@ -608,6 +608,7 @@ config STM32_STM32L15XX
default n
select STM32_HAVE_SPI2
select STM32_HAVE_SPI3
select STM32_HAVE_RTC_SUBSECONDS if !STM32_LOWDENSITY
config STM32_ENERGYLITE
bool

26
arch/arm/src/stm32/stm32_rtc.h
View File

@ -98,6 +98,32 @@ extern "C"
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: stm32_rtc_getdatetime_with_subseconds
*
* Description:
* Get the current date and time from the date/time RTC. This interface
* is only supported by the date/time RTC hardware implementation.
* It is used to replace the system timer. It is only used by the RTOS during
* initialization to set up the system time when CONFIG_RTC and CONFIG_RTC_DATETIME
* are selected (and CONFIG_RTC_HIRES is not).
*
* NOTE: Some date/time RTC hardware is capability of sub-second accuracy. That
* sub-second accuracy is returned through 'nsec'.
*
* Input Parameters:
* tp - The location to return the high resolution time value.
* nsec - The location to return the subsecond time value.
*
* Returned Value:
* Zero (OK) on success; a negated errno on failure
*
************************************************************************************/
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
int stm32_rtc_getdatetime_with_subseconds(FAR struct tm *tp, FAR long *nsec);
#endif
/************************************************************************************
* Name: stm32_rtc_setdatetime
*

71
arch/arm/src/stm32/stm32_rtcc.c
View File

@ -741,7 +741,7 @@ int up_rtcinitialize(void)
}
/************************************************************************************
* Name: up_rtc_getdatetime
* Name: stm32_rtc_getdatetime_with_subseconds
*
* Description:
* Get the current date and time from the date/time RTC. This interface
@ -751,20 +751,26 @@ int up_rtcinitialize(void)
* are selected (and CONFIG_RTC_HIRES is not).
*
* NOTE: Some date/time RTC hardware is capability of sub-second accuracy. That
* sub-second accuracy is lost in this interface. However, since the system time
* is reinitialized on each power-up/reset, there will be no timing inaccuracy in
* the long run.
* sub-second accuracy is returned through 'nsec'.
*
* Input Parameters:
* tp - The location to return the high resolution time value.
* nsec - The location to return the subsecond time value.
*
* Returned Value:
* Zero (OK) on success; a negated errno on failure
*
************************************************************************************/
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
int stm32_rtc_getdatetime_with_subseconds(FAR struct tm *tp, FAR long *nsec)
#else
int up_rtc_getdatetime(FAR struct tm *tp)
#endif
{
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
uint32_t ssr;
#endif
uint32_t dr;
uint32_t tr;
uint32_t tmp;
@ -778,6 +784,9 @@ int up_rtc_getdatetime(FAR struct tm *tp)
{
dr = getreg32(STM32_RTC_DR);
tr = getreg32(STM32_RTC_TR);
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
ssr = getreg32(STM32_RTC_SSR);
#endif
tmp = getreg32(STM32_RTC_DR);
}
while (tmp != dr);
@ -816,10 +825,64 @@ int up_rtc_getdatetime(FAR struct tm *tp)
tmp = (dr & (RTC_DR_YU_MASK|RTC_DR_YT_MASK)) >> RTC_DR_YU_SHIFT;
tp->tm_year = rtc_bcd2bin(tmp) + 100;
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
/* Return RTC sub-seconds if no configured and if a non-NULL value
* of nsec has been provided to receive the sub-second value.
*/
if (nsec)
{
uint32_t prediv_s;
uint32_t usecs;
prediv_s = getreg32(STM32_RTC_PRER) & RTC_PRER_PREDIV_S_MASK;
prediv_s >>= RTC_PRER_PREDIV_S_SHIFT;
ssr &= RTC_SSR_MASK;
/* Maximum prediv_s is 0x7fff, thus we can multiply by 100000 and
* still fit 32-bit unsigned integer. */
usecs = (((prediv_s - ssr) * 100000) / (prediv_s + 1)) * 10;
*nsec = usecs * 1000;
}
#endif /* CONFIG_STM32_HAVE_RTC_SUBSECONDS */
rtc_dumptime(tp, "Returning");
return OK;
}
/************************************************************************************
* Name: up_rtc_getdatetime
*
* Description:
* Get the current date and time from the date/time RTC. This interface
* is only supported by the date/time RTC hardware implementation.
* It is used to replace the system timer. It is only used by the RTOS during
* initialization to set up the system time when CONFIG_RTC and CONFIG_RTC_DATETIME
* are selected (and CONFIG_RTC_HIRES is not).
*
* NOTE: Some date/time RTC hardware is capability of sub-second accuracy. That
* sub-second accuracy is lost in this interface. However, since the system time
* is reinitialized on each power-up/reset, there will be no timing inaccuracy in
* the long run.
*
* Input Parameters:
* tp - The location to return the high resolution time value.
*
* Returned Value:
* Zero (OK) on success; a negated errno on failure
*
************************************************************************************/
#ifdef CONFIG_STM32_HAVE_RTC_SUBSECONDS
int up_rtc_getdatetime(FAR struct tm *tp)
{
return stm32_rtc_getdatetime_with_subseconds(tp, NULL);
}
#endif
/************************************************************************************
* Name: stm32_rtc_setdatetime
*