Newer versions of the HAL use names which are cleaner and more
self-consistent amongst the HAL itself. This patch switches to use those
names in most places so it is easier to update the HAL in the future.
Upon boot the RTC early-init function should detect if LSE or LSI is
already selected/running and, if so, use it. When the LSI has previously
(in the previous reset cycle) been selected as the clock source the only
way to reliably tell is if the RTCSEL bits of the RCC_BDCR are set to the
correct LSI value. In particular the RCC_CSR bits for LSI control do not
indicate if the LSI is ready even if it is selected.
This patch removes the check on the RCC_CSR bits for the LSI being on and
ready and only uses the check on the RCC_BDCR to see if the LSI should be
used straightaway. This was tested on a PYBLITEv1.0 and with the patch the
LSI persists correctly as the RTC source as long as the backup domain
remains powered.
Previously, if LSE is selected but fails and the RTC falls back to LSI,
then the rtc_info flags would incorrectly state that LSE is used. This
patch fixes that by setting the bit in rtc_info only after the clock is
ready.
This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.