The delay_half parameter must be specified by the port to set up the
timing of the software SPI. This allows the port to adjust the timing
value to better suit its timing characteristics, as well as provide a
more accurate printing of the baudrate.
It's simpler to just default to always using software SPI if no specific
peripheral id/name is given. To use hardware SPI users must specify a
hardware peripheral id as the first parameter to the SPI constructor.
There is no need to take src_len and dest_len arguments. The case of
reading-only with a single output byte (originally src_len=1, dest_len>1)
is now handled by using the output buffer as the input buffer, and using
memset to fill the output byte into this buffer. This simplifies the
implementations of the spi_transfer protocol function.
The main thing is to change the DMA code in a way that the structure
DMA_Stream_TypeDef (which is similar to DMA_Channel_TypeDef on stm32l4)
is no longer used outside of dma.c, as this structure only exists for the
F4 series. Therefore I introduced a new structure (dma_descr_t) which
handles all DMA specific stuff for configuration. Further the periphery
(spi, i2c, sdcard, dac) does not need to know the internals of the dma.
The first argument to the type.make_new method is naturally a uPy type,
and all uses of this argument cast it directly to a pointer to a type
structure. So it makes sense to just have it a pointer to a type from
the very beginning (and a const pointer at that). This patch makes
such a change, and removes all unnecessary casting to/from mp_obj_t.
Previously, SPI was configured by a board defining MICROPY_HW_ENABLE_SPIx
to 0 or 1. Now, the board should define MICROPY_HW_SPIx_SCK, MISO, MOSI
and NSS. This makes it the same as how I2C is configured.
py/mphal.h contains declarations for generic mp_hal_XXX functions, such
as stdio and delay/ticks, which ports should provide definitions for. A
port will also provide mphalport.h with further HAL declarations.
There is an issue sending 1 byte on the SPI bus using DMA, but it only
occurs when the transmit is done for the first time after initialising
the SPI and DMA peripherals. All other cases (sending 2 or more bytes,
doing send_recv, doing recv first) work okay. We sidestep this issue by
using polling (not DMA) for all 1 byte transfers. This is fine because
a 1 byte transfer can't be interrupted and doesn't need the benefits of
DMA (and using polling for this case is more efficient).
Resolves#1456.
Extracted GPIO clock enable logic into mp_hal_gpio_clock_enable
and called from anyplace which might need to use GPIO functions
on ports other than A-D.
Thanks to Dave Hylands for the patch.
This removes hard-coded DMA init params from dma_init(), instead defining
these parameters in a DMA_InitTypeDef struct that gets passed as an
argument to dma_init()
This makes dma_init more generic so it can be used for I2S and SD Card,
which require different initialization parameters.
Previous to this patch the printing mechanism was a bit of a tangled
mess. This patch attempts to consolidate printing into one interface.
All (non-debug) printing now uses the mp_print* family of functions,
mainly mp_printf. All these functions take an mp_print_t structure as
their first argument, and this structure defines the printing backend
through the "print_strn" function of said structure.
Printing from the uPy core can reach the platform-defined print code via
two paths: either through mp_sys_stdout_obj (defined pert port) in
conjunction with mp_stream_write; or through the mp_plat_print structure
which uses the MP_PLAT_PRINT_STRN macro to define how string are printed
on the platform. The former is only used when MICROPY_PY_IO is defined.
With this new scheme printing is generally more efficient (less layers
to go through, less arguments to pass), and, given an mp_print_t*
structure, one can call mp_print_str for efficiency instead of
mp_printf("%s", ...). Code size is also reduced by around 200 bytes on
Thumb2 archs.
With this patch str/bytes construction is streamlined. Always use a
vstr to build a str/bytes object. If the size is known beforehand then
use vstr_init_len to allocate only required memory. Otherwise use
vstr_init and the vstr will grow as needed. Then use
mp_obj_new_str_from_vstr to create a str/bytes object using the vstr
memory.
Saves code ROM: 68 bytes on stmhal, 108 bytes on bare-arm, and 336 bytes
on unix x64.
Pulled in and modified work done by mux/iabdalkader on cc3k driver, from
iabdalkader-cc3k-update branch. That branch was terribly messy and had
too many conflicts to merge neatly.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.
Decided to write own script to pull documentation from comments in C code.
Style for writing auto generated documentation is: start line with ///
and then use standard markdown to write the comment. Keywords
recognised by the scraper begin with backslash. See code for examples.
Running: python gendoc.py modpyb.c accel.c adc.c dac.c extint.c i2c.c
led.c pin.c rng.c servo.c spi.c uart.c usrsw.c, will generate a HTML
structure in gendoc-out/.
gendoc.py is crude but functional. Needed something quick, and this was
it.
The three classes I2C, SPI and USART now have a fairly uniform (Python)
API. All are constructed, initialised and deinitialised in the same
way. They can have most of their parameters set, using keyword arguments.
All have send and recv (although slightly different with I2C requiring an
address in master mode). recv can do inplace receiving (ie store the
data in a previously-created bytearray).
It's just polling mode at the moment, but interrupt and DMA would be
nice to add.
Damien George
Dave Hylands
Tobias Badertscher
blmorris
Emmanuel Blot
Paul Sokolovsky