mbed RTC specifications now dictate that the RTC needs to retain and keep on counting through reset. On Silicon Labs parts, this means the RTC API can not be backed by the Silicon Labs RTC peripheral, since that doesn't provide retention functionality.
Therefore:
* On EFM32GG, EFM32WG, EFM32LG: mbed RTC API is now backed by BURTC.
* On EFM32PG, EFR32MG, EFM32PG12, EFR32MG12: mbed RTC API is now backed by RTCC.
* On EFM32ZG, EFM32HG: mbed RTC API is sadly no longer supported, since these chips don't have retained memory.
I implemented the RTC feature.
The mainly changing is here.
- rtc_init()
Previously, I have initialized the time information register in the function, so the time count was cleaned by every calling rtc_init().
Currently, rtc_init() doesn't stop RTC from counting, and rtc_init() is safe to call repeatedly.
Therefore in order to satisfy specifications,I removed the initialization process of the time information register in the function.
- rtc_free()
Previously, I have initialized the RTC related register same as rtc_init(), so the time count was cleaned by calling rtc_free().
Currently, rtc_free() doesn't stop RTC from counting.
Therefore in order to satisfy specifications,I removed the process and decided not to do anything in the function.
If powerdown the RTC, Supply of the clock to the RTC is stopped, cannot keeping the count.
Make rtc_isenabled() to return 1 if the RTC is initialized and the time has been set; 0 otherwise.
Disable clock gate on exit from this function if RTC was initialized.
RTC reset test was failing when board has been just powered and RTC reset test was executed for the first time (issue has been detected on CI). In such case RTC initialization takes more time than in futher rtc_init calls. This has impact on green-tea communication. Commands send by host immediately after init command (write, read) were not handled on the device side and no response to the host was provided.
To fix this problem test communication flow has been modified. Device sends ack to the host after RTC init is done. Host sends further RTC commands when ack from the device has been received.
Edit:
There are still some communication issues on the CI. Add ack from the device after each executed command. Increase test timeout and wait after reset.
Since some platforms use RTC for low power timer RTC may be already enabled.
Because of that we will only verify if rtc_isenabled() returns 1 in case when init is done and RTC time is set.
Keep the RTC code if either DEVICE_RTC or DEVICE_LOWPOWERTIMER is
defined on the devices which use the RTC for both the rtc api and the
low power timer api. This allows DEVICE_LOWPOWERTIMER to be enabled while
DEVICE_RTC is turned off.
Keep the prototypes in rtc_api.h even when DEVICE_RTC is not defined.
This allows devices that aren't fully compliant with the RTC API to
still use the header and prototypes.
Test inserts event into the TimerEvent object which is scheduled 50 ms in the future. Then test thread hangs on the semaphore for 51 ms and after that time we expect that event handler has been executed. This test fails sometimes on NRF51_DK, NRF52_DK since different clocks are used for event handling and delay. TimerEvent class uses fast us ticker and semaphores are based on lp ticker (NRF51_DK) or System Tick Timer (NRF52_DK).
We assume that ticker measurement error is 10% and our 1 [ms] extra corresponds to 2% error. I suggest to increase delay to 2 [ms] (4%). This should be enough for all boards at this moment.
It is possible that the difference between base and next tick count on some platforms is greater than 1, in this case we need to repeat counting with the reduced number of cycles (for slower boards).
If number of cycles has been reduced than base tick count needs to be redefined. This operation is missing and is added by this patch.
Bartek Szatkowski
Przemyslaw Stekiel
Martin Kojtal
Edmund Hsu
Mahesh Mahadevan
Steven Cooreman
TomoYamanaka
Russ Butler
Cruz Monrreal
adbridge
Ashok Rao
Jesse Marroquin