This new DMA API corrects possible cache coherency issues on chips with
D-Cache, when working with buffers at arbitrary memory locations (i.e.
supplied by Python code).
The API is used by SPI to fix an issue with corrupt data when reading from
SPI using DMA in certain cases. A regression test is included (it depends
on external hardware connection).
Explanation:
1) It's necessary to invalidate D-Cache after a DMA RX operation completes
in case the CPU reads (or speculatively reads) from the DMA RX region
during the operation. This seems to have been the root cause of issue
#13471 (only when src==dest for this case).
2) More generally, it is also necessary to temporarily mark the first and
last cache lines of a DMA RX operation as "uncached", in case the DMA
buffer shares this cache line with unrelated data. The CPU could
otherwise write the other data at any time during the DMA operation (for
example from an interrupt handler), creating a dirty cache line that's
inconsistent with the DMA result.
Fixes issue #13471.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
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 is now consistent with other ports.
Also renamed `pin_{board/cpu}_pins_locals_dict` to
`machine_pin_{board/cpu}_pins_locals_dict`.
This work was funded through GitHub Sponsors.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
The contents of machine_mem.h, machine_i2c.h and machine_spi.h have been
moved into extmod/modmachine.h.
Signed-off-by: Damien George <damien@micropython.org>
The machine_i2c_type, machine_spi_type and machine_timer_type symbols are
already declared in extmod/modmachine.h and should not be declared anywhere
else.
Also move declarations of machine_pin_type and machine_rtc_type to the
common header in extmod.
Signed-off-by: Damien George <damien@micropython.org>
This is a "normal" SPI peripheral with no external pins, to avoid having to
grow spi_obj[] for just this one board map it as SPI ID 3 (board has SPI
IDs 1,2 already).
Signed-off-by: Angus Gratton <angus@redyak.com.au>
This commit adds initial support for STM32H5xx MCUs. The following
features have been confirmed to be working on an STM32H573:
- UART over REPL and USB CDC
- USB CDC and MSC
- internal flash filesystem
- machine.Pin
- machine.SPI transfers with DMA
- machine.ADC
- machine.RTC
- pyb.LED
- pyb.Switch
- pyb.rng
- mboot
Signed-off-by: Damien George <damien@micropython.org>
Seems unused outside of spi.c, spi_obj[] array is the expected way to
iterate these.
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
Replace "master" with "controller" and "slave" with "peripheral" in
comments, errors, and debug messages.
Add CONTROLLER and PERIPHERAL constants to pyb.SPI and pyb.I2C classes;
retain MASTER and SLAVE constants for backward compatiblity.
Allows reserving CAN, I2C, SPI, Timer and UART peripherals. If reserved
the peripheral cannot be accessed from Python.
Signed-off-by: Damien George <damien@micropython.org>
The aim here is to have spi.c contain the low-level SPI driver which is
independent (not fully but close) of MicroPython objects and methods, and
the higher-level bindings are separated out to pyb_spi.c and machine_spi.c.
Requesting a baudrate of X should never configure the peripheral to have a
baudrate greater than X because connected hardware may not be able to
handle higher speeds. This patch makes sure to round the prescaler up so
that the actual baudrate is rounded down.
With this and previous patches the stm32 port can now be compiled using
object representation D (nan boxing). Note that native code and frozen mpy
files with float constants are currently not supported with this object
representation.
The DMA peripheral is limited to transferring 65535 elements at a time so
in order to send more than that the SPI driver must split the transfers up.
The user must be aware of this limit if they are relying on precise timing
of the entire SPI transfer, because there might be a small delay between
the split transfers.
Fixes issue #3851, and thanks to @kwagyeman for the original fix.
Rather than pin objects themselves. The actual object is now pin_X_obj and
defines are provided so that pin_X is &pin_X_obj. This makes it so that
code that uses pin objects doesn't need to know if they are literals or
objects (that need pointers taken) or something else. They are just
entities that can be passed to the map_hal_pin_xxx functions. This mirrors
how the core handles constant objects (eg mp_const_none which is
&mp_const_none_obj) and allows for the possibility of different
implementations of the pin layer.
For example, prior to this patch there was the following:
extern const pin_obj_t pin_A0;
#define pyb_pin_X1 pin_A0
...
mp_hal_pin_high(&pin_A0);
and now there is:
extern const pin_obj_t pin_A0_obj;
#define pin_A0 (&pin_A0_obj)
#define pyb_pin_X1 pin_A0
...
mp_hal_pin_high(pin_A0);
This patch should have minimal effect on board configuration files. The
only change that may be needed is if a board has .c files that configure
pins.
genhdr/pins.h is an internal header file that defines all of the pin
objects and it's cleaner to have pin.h include it (where the struct's for
these objects are defined) rather than an explicit include by every user.
Newer versions of the HAL use names which are cleaner and more
self-consistent amongst the HAL itself. This patch switches to use those
names in most places so it is easier to update the HAL in the future.
There is an underlying hardware SPI driver (built on top of the STM HAL)
and then on top of this sits the legacy pyb.SPI class as well as the
machine.SPI class. This patch improves the separation between these
layers, in particular decoupling machine.SPI from pyb.SPI.
The SPI sub-system is independent from the uPy state (eg the heap) and so
can safely persist across a soft reset. And this is actually necessary for
drivers that rely on SPI and that also need to persist across soft reset
(eg external SPI flash memory).
The routine waits for the DMA to finish, which is signalled from a DMA IRQ
handler. Using WFI makes the CPU sleep while waiting for the IRQ to arrive
which decreases power consumption. To make it work correctly the check for
the change in state must be atomic and so IRQs must be disabled during the
check. The key feature of the Cortex MCU that makes this possible is that
WFI will exit when an IRQ arrives even if IRQs are disabled.
Header files that are considered internal to the py core and should not
normally be included directly are:
py/nlr.h - internal nlr configuration and declarations
py/bc0.h - contains bytecode macro definitions
py/runtime0.h - contains basic runtime enums
Instead, the top-level header files to include are one of:
py/obj.h - includes runtime0.h and defines everything to use the
mp_obj_t type
py/runtime.h - includes mpstate.h and hence nlr.h, obj.h, runtime0.h,
and defines everything to use the general runtime support functions
Additional, specific headers (eg py/objlist.h) can be included if needed.
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.
Angus Gratton