This commit makes the low-level flash C functions usable by code other than
flashbdev.c (eg by mboot). Changes in this commit are:
- flash_erase() and flash_write() now return an errno error code, a
negative value on error.
- flash_erase() now automatically locks the flash, as well as unlocking it.
- flash_write() now automatically unlocks the flash, as well as locking it.
- flashbdev.c is modified for the above changes.
Signed-off-by: Damien George <damien@micropython.org>
Currently all usages of mp_hal_pin_config_alt_static() set the pin speed to
"high" (50Mhz). The SDRAM interface typically runs much faster than this
so should be set to the maximum pin speed.
This commit adds mp_hal_pin_config_alt_static_speed() which allows setting
the pin speed along with the other alternate function details.
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.