`rtc_write` must start the RTC. `time()` uses `rtc_write(0)` to start
the RTC if it is not already enabled, but this check made that not
work.
There's no point trying to optimise this case in a HAL - if we wanted
`set_time()` to protect against users making pointless adjustments, the
implementation should be there. But even then, you might want different
levels of hysteresis depending on application, so it's probably best
left to applications.
This reverts commit 9da5e48941.
This fix avoid a long waiting loop in rtc_write function,
which was not acceptable in TICKLESS context.
Implementation comments added.
Global variable name has been updated for easier maintenance:
- LPTICKER_counter is the U32 continuous tick counter
- LPTICKER_RTC_time is the RTC time used to get the time difference
between rtc_read_lp() calls
When both tickless and LPTICKER_DELAY_TICKS are enabled some ST
devices randomly get stuck sleeping forever. This is because the
wake up time passed to the rtc is ignored if the previous match is
about to occur. This causes the device to get stuck in sleep.
This patch prevents matches from getting dropped by the rtc by
deactivating the rtc wake up timer before setting a new value.
Events leading up to this failure for the RTC:
-1st call to lp_ticker_set_interrupt
-delay until ticker interrupt is about to fire
-2nd call to lp_ticker_set_interrupt
-interrupt for 1st call fires and match time for 2nd call is dropped
-LowPowerTickerWrapper gets ticker interrupt but treats it as a
spurious interrupt and drops it since it comes in too early
-device enters sleep without a wakeup source and locks up
Date is managed only by SW
within CUBE functions HAL_RTC_GetDate and HAL_RTC_SetDate.
They are then replaced by functions that saved counters in HW registers.
RTC_ReadTimeCounter and RTC_WriteTimeCounter are then added to the ST API.
- RTC_SSR for the subseconds
- RTC_TR for the time
- RTC_DR for the date
These registers were accessed through shadow registers which are synchronized with PCLK1 (APB1 clock).
They are now accessed directly in order to avoid waiting for the synchronization duration.
STM32L0, L4, F7 and few F4 chip are supporting LPTIM feature.
We propose to allow user to use LPTIM for MBED LowPowerTimer API instead of using RTC wakeup timers.
By default, all targets that are supporting this feature have been configured.
Add RSF synchro during init
Set a better WakeUp clock for long wake up period in order to stay in sleep mode
Use rtc_isenabled function before init as rtc_init is called at each set_time call
lp_ticker driver is the known registered user of RTC handler API.
In case, a lp_ticker is set in the past, the lp_ticker_fire_interrupt
will be called which itself sets the RTC interrupt as pending by calling
NVIC_SetPendingIRQ(RTC_WKUP_IRQn). This all happens without actual
programing of the RTC wake-up.
As a result the RTC HW and corresponding HAL layer doesn't expect an
interrupt to happen and will not call HAL_RTCEx_WakeUpTimerEventCallback.
To sove this situation, we will not use HAL_RTCEx_WakeUpTimerEventCallback
weak definition but rather call handler whenever an RTC interrupt fires.
The use of mktime was causing a fault when called in interrupt handler because on GCC it lock the mutex protecting the environment, To overcome this issue, this patch add dedicated routine to convert a time_t into a tm and vice versa.
In the process mktime has been optimized and is now an order of magnitude faster than the routines present in the C library.
Kevin Bracey
Martin Kojtal
jeromecoutant
Cruz Monrreal
Bartek Szatkowski
Cruz Monrreal
Martin Kojtal
Przemyslaw Stekiel
Jimmy Brisson
Laurent MEUNIER
bcostm
Sam Grove
Vincent Coubard