If a LowPowerTimer is started and then goes out of scope then a
deep sleep lock underflow can occur. This is because the
the variable '_lock_deepsleep' is checked when starting the timer
but is not checked in the destructor, which unconditionally releases
the deep sleep lock.
Release the deep sleep lock when running instances of the Timer class
are deleted. This ensures that deep sleep locks are properly released
by the Timer class.
Add passthrough APIs to enable the flow control and format methods from
SerialBase to be accessed.
Modify the RX data pump so it stops reading data and disables the IRQ
when the buffer is full, to allow UART automatic flow control to work.
In principle it would also be possible as a future enhancement to
provide XON/XOFF flow control, or manual RTS/CTS control using GPIO, but
this commit at least restores the functionality present in Serial,
SerialBase and RawSerial that was missing in UARTSerial.
UARTSerial inherits both FileHandle::readable() [public] and
SerialBase::readable() [private], so calling readable() on a UARTSerial
object produces an ambiguous member error.
Add using declarations to direct towards the FileHandle versions of
readable and writable.
There's currently no ambiguity for writable, as SerialBase uses the
spelling 'writeable', but add a using directive for that anyway, in case
SerialBase gains 'writable' later.
attach/detach can be multiple invoked. Therefore lock/unlock deep sleep
only for the very first time it is invoked (when callbacks
are actually changed).
Any driver with attach or async API should be considered for deep sleep.
Add locking to those that require in most cases
high-frequency clocks:
- CAN
- I2C
- SPI
- Serial
- Ticker/Timeout/Timer
On some platforms, the in-application memory is not memory mapped
and therefore cannot be accessed using memcpy.
The flash_read function added to flash_api.h (with a weak
implementation using memcpy in mbed_flash_api.c) can be used for
reading data from areas that are not memory mapped.
1. Private _acquire() function is added to avoid multiple locking/unlocking
2. format and frequency functions updated to use appropriate function calls
instead of a aquire()
Fixes issue #4537. SerialBase and UARTSerial happened to have same names
for the mutex locking that confused the system of holding a mutex in interrupt context.
UARTSerial has to change so as to provide empty implementations for lock() and unlock()
becuase it uses SerialBase from interrupt context only or from its own critical section,
so no extra locks required.
Private locks for UARTSerial itself are renamed to api_lock() and api_unlock().