This allows one to construct an I2C object using ids that are specific
to the stmhal port, eg machine.I2C('X'). Right now the implementation
of I2C uses software I2C but the idea is to just change the C-level I2C
protocol functions to hardware implementations later on.
stdio.h was included in all HAL files only to provide
definition of NULL symbol
"stdio.h" includes "types.h" which contains some conflicting definitions
with "drivers/cc3000/inc/socket.h"
HAL Driver before v1.4.2 had a bug which caused clearing all pending
flags in MSR, TSR, RF0R and RF1R instead of only the requested one.
This is why micropython got away without explicitly clearing flags
in IRQ handler.
Current version of HAL drivers optimize IRQ handler by using precalculated
DMA register address and stream bitshift instead of calculating it on every interrupt.
Since we skip call to `HAL_DMA_Init` on reused DMA, fields StreamBaseAddress and StreamIndex
of DMA handle are not initialized and thus leads to SegFault in `DMA_IRQHandler`.
HAL_DMA_Init is a big routine and we do not need to call it on each use of DMA
(ex.: series of I2C operations) and DMA_CalcBaseAndBitshift is really small and
releasing it increases code size by only 8 bytes.
If a port defines MICROPY_READER_POSIX or MICROPY_READER_FATFS then
lexer.c now provides an implementation of mp_lexer_new_from_file using
the mp_reader_new_file function.
Implementations of persistent-code reader are provided for POSIX systems
and systems using FatFS. Macros to use these are MICROPY_READER_POSIX and
MICROPY_READER_FATFS respectively. If an alternative implementation is
needed then a port can define the function mp_reader_new_file.
Its addition was due to an early exploration on how to add CPython-like
stream interface. It's clear that it's not needed and just takes up
bytes in all ports.
If an I2C send/recv fails then the peripheral is now checked to see if
it's in a "stuck" state waiting for the stop bit, and if so then it is
reset so that the next I2C transaction can proceed.
This patch also de-inits the I2C peripheral in the init() method, before
init'ing it again.
New keyword option in constructor and init() method is "dma=<bool>".
DMA is now disabled by default for I2C transfers because it currently does
not handle I2C bus errors very well (eg if slave device doesn't ACK or
NACK correctly during a transfer).
The DMA state is always HAL_DMA_STATE_RESET because of the memset clearing
all the data, so prior to this patch HAL_DMA_DeInit was never called. Now
it is always called to make sure the DMA is properly reset.
Now, to use frozen bytecode all a port needs to do is define
FROZEN_MPY_DIR to the directory containing the .py files to freeze, and
define MICROPY_MODULE_FROZEN_MPY and MICROPY_QSTR_EXTRA_POOL.
In order to have more fine-grained control over how builtin functions are
constructed, the MP_DECLARE_CONST_FUN_OBJ macros are made more specific,
with suffix of _0, _1, _2, _3, _VAR, _VAR_BETEEN or _KW. These names now
match the MP_DEFINE_CONST_FUN_OBJ macros.
