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.
There is an easy default implementation of spi_master_block_write that
just calls spi_master_write in a loop, so the default implementation
of spi_master_block_write has been added to all targets.
Add sleep/deepsleep functions to platform layer which are replacing HAL
functions with the same name, rename existing symbols in HAL layer
to hal_sleep/hal_deepsleep. This way sleep functions
are always available, even if target doesn't implement them, which makes
the code using sleep clearer. It also enables us to make decision on in
which builds (debug/release) the sleep will be enabled.
Jimmy Brisson
Sam Grove
Vincent Coubard
Bartek Szatkowski
Christopher Haster