The STATIC macro was introduced a very long time ago in commit
d5df6cd44a. The original reason for this was
to have the option to define it to nothing so that all static functions
become global functions and therefore visible to certain debug tools, so
one could do function size comparison and other things.
This STATIC feature is rarely (if ever) used. And with the use of LTO and
heavy inline optimisation, analysing the size of individual functions when
they are not static is not a good representation of the size of code when
fully optimised.
So the macro does not have much use and it's simpler to just remove it.
Then you know exactly what it's doing. For example, newcomers don't have
to learn what the STATIC macro is and why it exists. Reading the code is
also less "loud" with a lowercase static.
One other minor point in favour of removing it, is that it stops bugs with
`STATIC inline`, which should always be `static inline`.
Methodology for this commit was:
1) git ls-files | egrep '\.[ch]$' | \
xargs sed -Ei "s/(^| )STATIC($| )/\1static\2/"
2) Do some manual cleanup in the diff by searching for the word STATIC in
comments and changing those back.
3) "git-grep STATIC docs/", manually fixed those cases.
4) "rg -t python STATIC", manually fixed codegen lines that used STATIC.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
This commit implements fairly complete support for the DMA controller in
the rp2 series of microcontrollers. It provides a class for accessing the
DMA channels through a high-level, Pythonic interface, and functions for
setting and manipulating the DMA channel configurations.
Creating an instance of the rp2.DMA class claims one of the processor's DMA
channels. A sensible, per-channel default value for the ctrl register can
be fetched from the DMA.pack_ctrl() function, and the components of this
register can be set via keyword arguments to pack_ctrl().
The read, write, count and ctrl attributes of the DMA class provide
read/write access to the respective registers of the DMA controller. The
config() method allows any or all of these values to be set simultaneously
and adds a trigger keyword argument to allow the setup to immediately be
triggered. The read and write attributes (or keywords in config()) accept
either actual addresses or any object that supports the buffer interface.
The active() method provides read/write control of the channel's activity,
allowing the user to start and stop the channel and test if it is running.
Standard MicroPython interrupt handlers are supported through the irq()
method and the channel can be released either by deleting it and allowing
it to be garbage-collected or with the explicit close() method.
Direct, unfettered access to the DMA controllers registers is provided
through a proxy memoryview() object returned by the DMA.registers attribute
that maps directly onto the memory-mapped registers. This is necessary for
more fine-grained control and is helpful for allowing chaining of DMA
channels.
As a simple example, using DMA to do a fast memory copy just needs:
src = bytearray(32*1024)
dest = bytearray(32*1024)
dma = rp2.DMA()
dma.config(read=src, write=dest, count=len(src) // 4,
ctrl=dma.pack_ctrl(), trigger=True)
# Wait for completion
while dma.active():
pass
This API aims to strike a balance between simplicity and comprehensiveness.
Signed-off-by: Nicko van Someren <nicko@nicko.org>
Signed-off-by: Damien George <damien@micropython.org>
Angus Gratton