Due to the RIOT_EPOCH of 2020 this overflow will happen in year 2084. It would be scary if IoT devices are still around then.
We can save RAM and ROM. Furthermore, this overflow handling should block BACKUP power mode in order to keep track of the reference year.
There are STM32 families where all models use only the Synopsys DWC2 USB OTG core while others completely use only the USB Device FS core. For these families then either the driver `drivers/usbdev_synopsys_dwc2` or the driver `cpu/stm32/periph/usbdev` is used depending on the respective family. However, the STM32 families F1 and L4 use both cores. The correct driver must therefore be selected depending on the CPU line or CPU model.
Make sure the STATUS register has been synced between the different clock domains.
Especially the LETIMER needs some time to update the STATUS register after it has been enabled. If the LETIMER is started and stopped with just a short delay, pm_layered gets confused because the timer seems to be inactive ...
This allows boards to define different crystal frequencies. The correct frequency is required by the system-related methods to ensure proper function of the underlying emlib.
As implmented, dma_resume assumed that transfers widths were 1 byte and
that the memory address incrmenting was always on and periphial address
incrementing always off. This resulted in memory corruption anytime
these assumptions were not true and a dma was resumed. The DMA module
allows intitiating transfers that did not meet these assumption.
This patch adds proper handling inside dma_resume to safely resume any
transfer. Clearifications and errors are added/fixed in the module's
header file. Also, a few constants are removed from the gobal namespace.
As it was, the calculation of DMA2's IRQ number was inccrorect for some
STM families. The implmentation alocates streams numbers 0 to 7 for the
first DMA controller and 8 and up for the second DMA controller. This
offset of +8 was not accounted for when IRQ's of the second DMA
controller was calculated. This patch corrects this.
