The warnings appeared after the -fno-builtin compiler flag was removed (#17898),
but the code is looking fine and tests/periph_cpuid shows correct results.
Setting up a DMA transfer can take longer than sending out a buffer
byte by byte if the buffer is small.
DMA only shows advantages for large buffers, using it for every transfer
will cause a net slowdown.
Since we did not come up with a good way to determine the treshold based
on the SPI frequency, just use a fixed buffer for now so that DMA can be
used without slowing things down overall.
Some periph_rtt implementations do not provide `rtt_set_counter()`. This
adds `periph_rtt_set_counter` as feature to allow testing for its
availability. The feature is provided at CPU level if periph_rtt is
provided by the board for all CPUs implementing `rtt_set_counter()`.
flashpage currently requires pagewise implementation with an optional
extension for per block writes (flashpage_raw). Most implementations
with flashpage_raw implement the pagewise access via the flashpage_raw
functions. This commit makes the flashpage raw the main access method
and adds an extension feature for the pagewise access.
The functions and defines are renamed to reflect this. The API is also
extended with a dedicated function for erasing a sector.
On samd5x only the RTC can wake the CPU from Deep Sleep (pm modes 0 & 1).
The external interrupt controller is disabled, but we can use the tamper
detection of the RTC.
If an gpio interrupt is configured on one of the five tamper detect pins,
those can be used to wake the CPU from Deep Sleep / Hibernate.
The expandable GPIO API requires the comparison of structured GPIO types. This means that inline functions must be used instead of direct comparisons. For the migration process, drivers must first be changed so that they use the inline comparison functions.
This changes the prefixes of the symbols generated from USEMODULE and
USEPKG variables. The changes are as follow:
KCONFIG_MODULE_ => KCONFIG_USEMODULE_
KCONFIG_PKG_ => KCONFIG_USEPKG_
MODULE_ => USEMODULE_
PKG_ => USEPKG_
