STM32L1, STM32L4 RTC: add periodic interrupts, update L1 RTC implementation
* STM32L4 RTC: add support experimental CONFIG_RTC_PERIODIC
* STM32 RTC: separate STM32L1 RTC into a separate file
STM32L1 RTC is very close to F4 or L4 versions, with two alarms
and periodic wakeup support so backported L4 peripheral to L1.
* RTC: add periodic alarms to upper and lower halves
Approved-by: Gregory Nutt <gnutt@nuttx.org>
STM32L4 RTC, PM: small fixes to subseconds handling, ADC power-management hooks
* STM32L4 ADC: add PM hooks from Motorola MDK
* STM32L4 RTC: add up_rtc_getdatetime_with_subseconds
* STM32 RTC: workaround for potential subseconds race condition
In all recent STM32 chips reading either RTC_SSR or RTC_TR is supposed to lock
the values in the higher-order calendar shadow registers until RTC_DR is read.
However many old chips have in their errata this silicon bug (at least F401xB/C,
F42xx, F43xx, L15xxE, L15xVD and likely others):
"When reading the calendar registers with BYPSHAD=0, the RTC_TR and RTC_DR
registers may not be locked after reading the RTC_SSR register. This happens
if the read operation is initiated one APB clock period before the shadow
registers are updated. This can result in a non-consistency of the three
registers. Similarly, RTC_DR register can be updated after reading the RTC_TR
register instead of being locked."
* STM32L4 RTC: correct RTC_SSR and RTC_TR read ordering
In all recent STM32 chips reading either RTC_SSR or RTC_TR is supposed to lock
the values in the higher-order calendar shadow registers until RTC_DR is read.
Change the register read ordering to match this and don't keep a workaround
for a hypothetical race condition (not in any L4 errata, lets for once assume
ST's silicon works as it is documented...)
* STM32L4 PM: remove useless #ifdefs and old non-L4 STM32 code
Approved-by: Gregory Nutt <gnutt@nuttx.org>
- compile issues because of missing RTC_MAGIC #defines
- missing functionality based on RTC_MAGIC in RTC based on stm32_rtcounter.c
- IRQ setup from up_rtc_initialize was later reset in up_irqinitialize
- write access to backup registers without enabling access to backup domain
- possible races in set/cancel alarm
tested with STM32F103C8 only
device now wakes up from forced STANDBY mode by alarm
Add clock_resynchronize for better synchronization of CLOCK_REALTIME and CLOCK_MONOTONIC to match RTC after resume from low-power state.
Add up_rtc_getdatetime_with_subseconds under CONFIG_ARCH_HAVE_RTC_SUBSECONDS to allow initializing (and resynchronizing) system clock with subseconds accuracy RTC.
New interface allows checking if RTC time has been set. This allows to application to detect if RTC has valid time (after
reset) or should application attempt to get real time by other means (for example, by launching ntpclient or GPS).
Provide a user defined callback context for irq's, such that when
registering a callback users can provide a pointer that will get
passed back when the isr is called.
In stm32_rtcc.c the up_rtcinitialize() logic doesn't work with the LSI. The check on RTC_MAGIC on the BK0R register lead to rtc_setup() call that rightfully enables the lsi clock; but the next times, when the rtc is already setup, the rtc_resume() call does NOT start the lsi clock!
The right place to put LSE/LSI initialisation is inside stm32_stdclockconfig() in stm32fxxxxx_rcc.c. Doing this I checked the possible uses of the LSI and the LSE sources: the LSI can be used for RTC and/or the IWDG, while the LSE only for the RTC (and to output the MCO1 pin)..
This change is not verifed for any other platforms.
From Leo Aloe3132
Add a skeleton implementation of the RTC lower half interface at arch/arm/src/stm32/stm32_rtc_lowerhalf.c. This is just the framework for the RTC lower half. None of the interface methods have yet been implemetned.
Some boards do not have the external 32khz oscillator installed, for those boards we must fallback to the crummy to the crummy internal RC clock. Turn on by defining CONFIG_RTC_LSICLOCK.
From Kevin Hester <kevinh@geeksville.com> via Lorenz Meier.
