Commit Graph

61 Commits

Author SHA1 Message Date
robert-hh 65fa7fd8bb mimxrt/machine_timer: Use soft-timer implementation for machine.Timer.
This releases the hardware timers for other tasks, which need a higher
resolution and faster response.  And it is less port-specific code.
2022-10-27 14:09:29 +11:00
Jim Mussared 43bcfb148b mimxrt/Makefile: Split up SRC_C variables.
This improves clarity a bit, but also ensures that only the required files
are added to SRC_QSTR.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-12 00:08:49 +11:00
Jim Mussared d6d8722558 extmod: Make extmod.mk self-contained.
This makes it so that all a port needs to do is set the relevant variables
and "include extmod.mk" and doesn't need to worry about adding anything to
OBJ, CFLAGS, SRC_QSTR, etc.

Make all extmod variables (src, flags, etc) private to extmod.mk.

Also move common/shared, extmod-related fragments (e.g. wiznet, cyw43,
bluetooth) into extmod.mk.

Now that SRC_MOD, CFLAGS_MOD, CXXFLAGS_MOD are unused by both extmod.mk
(and user-C-modules in a previous commit), remove all uses of them from
port makefiles.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-11 23:31:49 +11:00
Jim Mussared 87011f6353 extmod/extmod.mk: Make extmod.mk handle GIT_SUBMODULES.
This applies to nimble, btstack, axtls, mbedtls, lwip.

Rather than having the ports individually manage GIT_SUBMODULES for these
components, make extmod.mk append them when the relevant feature is
enabled.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-11 23:29:09 +11:00
Jim Mussared 67d05ed02b ports: Make generated pin.c handling more consistent across ports.
Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-11 23:18:46 +11:00
Jim Mussared 17f2783e4a all: Use += rather than = everywhere for CFLAGS/LDFLAGS/LIBS.
This avoids a surprise where an = can cancel out an earlier +=.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-10-11 23:17:41 +11:00
robert-hh 8e54225140 mimxrt: Format the firmware image to match the new teensy loader.
The new teensy loader keeps the file system under certain conditions:
- The file size is properly set in the file header.
- The header version is 4.3

These changes are implemented here, requiring a backport of
fsl_flexspi_nor_boot.c.  There is still a problem with the command line
version of the teensy loader, which fails on the first attempt.  At the
second attempt it works.  The GUI version of the teensy loader is fine.
2022-09-13 18:35:48 +10:00
Jim Mussared be83c08f46 ports: Always append to GIT_SUBMODULES.
Avoids overwriting submodules required by base makefiles.

Signed-off-by: Jim Mussared <jim.mussared@gmail.com>
2022-08-03 00:05:26 +10:00
Angus Gratton fdfe4eca74 ports: Always include debug information in the ELF.
For bare metal ARM & xtensa targets, passing -g will make the ELF file
larger but doesn't change the binary size.  However, this means tools like
gdb, addr2line, etc can extract source-level information from the ELF.

Also standardise -ggdb to -g, these produce the exact same ELF file on
arm-none-eabi-gcc and will use DWARF format for all these ports.
2022-07-29 11:24:00 +10:00
robert-hh 80339f1a33 ports: Adapt mimxrt, nrf and rp2 ports to work with latest TinyUSB.
rp2: change tud_task() to tud_task_ext().

mimxrt: use lib/tinyusb/src/portable/chipidea/ci_hs/dcd_ci_hs.c instead of
lib/tinyusb/src/portable/nxp/transdimension/dcd_transdimension.c.

nrf: add a definition for the changed tud_task().  tud_task() is changed
to tud_task_ext(), and the #define for backward compatibility is in
src/device/usbd.h.

The items I know which are fixed with this version:
- Fix for the SAMD USB lock-up.
- Support the MIMXRT11XX series of MCUs.
- Fix a wrong pin definition for MIMXRT1050_EVKB.

Tested with the MIMXRT boards, rp2 Pico, SAMD boards, nrf board.
2022-07-19 11:27:21 +10:00
Damien George b89422ceaa extmod: Always use custom mbedtls error message code.
All ports that use mbedtls use the custom error messages in
mp_mbedtls_errors.c.  This commit simplifies the build so that ports don't
need to explicitly add this file, it's now used by default when mbedtls is
enabled.

Signed-off-by: Damien George <damien@micropython.org>
2022-07-18 22:55:22 +10:00
David Lechner 81dbea1ce3 shared/readline: Use MP_REGISTER_ROOT_POINTER().
This uses MP_REGISTER_ROOT_POINTER() to register the readline_history root
pointer array used by shared/readline.c and removes the registration from
all mpconfigport.h files.

This also required adding a new MICROPY_READLINE_HISTORY_SIZE config option
since not all ports used the same sized array.

Signed-off-by: David Lechner <david@pybricks.com>
2022-07-18 13:48:49 +10:00
Philipp Ebensberger 434974ec77 mimxrt/Makefile: Fix some minor formatting inconsistencies. 2022-06-24 17:58:27 +10:00
Philipp Ebensberger c957c76f4d mimxrt/Makefile: Rework floating point config.
Reworks source file and compile flags selection for floating point support.
2022-06-24 17:58:27 +10:00
Philipp Ebensberger bec0524dbf mimxrt/Makefile: Rework board flash type handling.
Reworks handling and configuration of different board flash types in the
Makefile, linker scripts and board makefile fragments.
2022-06-24 17:58:27 +10:00
Philipp Ebensberger 84339aa8ec mimxrt/Makefile: Modify handling of SDCARD option.
Removes separate `if` case in Makefile for setting SDCARD option define.
2022-06-24 17:58:27 +10:00
Philipp Ebensberger b1aec393b1 mimxrt/Makefile: Modify handling of SDRAM option.
Replaces preprocessor macro for SDRAM option from #ifdef to #if in order to
allow always setting the define `MICROPY_HW_SDRAM_AVAIL` just with the
appropriate value 0/1.  This eliminates one `if` in the Makefile.
2022-06-24 17:58:27 +10:00
Philipp Ebensberger fbc50196ad mimxrt/Makefile: Refactor Makefile and divide it into sections.
Reworks grouping of Makefile variables and reorders variable values in
alphabetic order.
2022-06-24 17:58:25 +10:00
David Lechner c118b5d0e4 extmod/extmod.mk: Separate out extmod file list from py.mk to extmod.mk.
This separates extmod source files from `py.mk`.  Previously, `py.mk`
assumed that every consumer of the py/ directory also wanted to include
extmod/.  However, this is not the case.  For example, building mpy-cross
uses py/ but doesn't need extmod/.

This commit moves all extmod-specific items from `py.mk` to `extmod.mk` and
explicitly includes `extmod.mk` in ports that use it.

Signed-off-by: David Lechner <david@pybricks.com>
2022-06-21 00:14:34 +10:00
Damien George f5769698e5 extmod/modlwip: Clean up inclusion of modlwip in build process.
The following changes are made:

- Guard entire file with MICROPY_PY_LWIP, so it can be included in the
  build while still being disabled (for consistency with other extmod
  modules).

- Add modlwip.c to list of all extmod source in py/py.mk and
  extmod/extmod.cmake so all ports can easily use it.

- Move generic modlwip GIT_SUBMODULES build configuration code from
  ports/rp2/CMakeLists.txt to extmod/extmod.cmake, so it can be reused by
  other ports.

- Remove now unnecessary inclusion of modlwip.c in EXTMOD_SRC_C in esp8266
  port, and in SRC_QSTR in mimxrt port.

Signed-off-by: Damien George <damien@micropython.org>
2022-06-20 23:37:38 +10:00
robert-hh a0432ed9cb mimxrt: Update port to work with new nxp_driver v2.10.
The nxp_driver v2.10 allows for/requires some changes to the code:

- Remove some part of pwm_backlog.*, which is provided by the lib now.
- Change eth.c: the newer versions have additional parameters of the
  library versions.
- Change sdcard.c: use TransferBlocking instead of TransferNonblocking.
- Add some support for the MIMXRT1176 device.
- Set the clocks for UART, I2C, Timer.
- Integrate the I2S module and fix a rebase error.
- Use blocking transfer only for SPI.  It's faster and interferes less with
  other modules.
- Use the clock_config.c files of library v2.8.5.  The mimxrt files keeps
  the clock_config.c files from Verson 2.8.5.  With clock_config.c from
  v2.10, the boards do not work.  Refactoring of the clock set-up is on the
  to-do list.
- Enable expiry timers for UART, I2C and SPI, avoiding a stall in library
  code.
- The clock_config.* files are moved from the board-specific directories to
  the boards directory and given a MCU related name.
2022-06-03 10:48:49 +10:00
robert-hh ca41eda281 mimxrt/mphalport: Fix USB CDC RX handling to not block when unprocessed.
Changes in this commit:
- Fix USB CDC RX handling to not block when unprocessed.  The fix follows
  5873390226.
- Fix dupterm rx.
- Remove some obsolete lines.
2022-04-11 12:30:59 +10:00
MikeTeachman 1f6cb8f047 mixmrt/machine_i2s: Add I2S protocol support.
This commit adds support for machine.I2S on the mimxrt port.  The I2S API
is consistent with the existing stm32, esp32, and rp2 implementations.

I2S features:
- controller transmit and controller receive
- 16-bit and 32-bit sample sizes
- mono and stereo formats
- sampling frequencies from 8kHz to 48kHz
- 3 modes of operation:
  - blocking
  - non-blocking with callback
  - uasyncio
- configurable internal buffer
- optional MCK

Tested with the following development boards:
- MIMXRT1010_EVK, MIMXRT1015_EVK, MIMXRT1020_EVK, MIMXRT1050_EVK
- Teensy 4.0, Teensy 4.1
- Olimex RT1010
- Seeed ARCH MIX

Tested with the following I2S hardware peripherals:
- UDA1334
- GY-SPH0645LM4H
- WM8960 codec on board the MIMXRT boards and separate breakout board
- INMP441
- PCM5102
- SGTL5000 on the Teensy audio shield

Signed-off-by: Mike Teachman <mike.teachman@gmail.com>
2022-03-30 14:12:40 +11:00
Damien George 9a3e1a1808 mimxrt/moduos: Convert module to use extmod version.
Signed-off-by: Damien George <damien@micropython.org>
2022-03-09 10:03:23 +11:00
robert-hh 5ea85b7a85 mimxrt/boards: Add board files for MIMXRT1015 and MIMXRT1015_EVK.
OCOTP_Init() has been removed from mphalport.c.  The library files are
missing for the MIMXRT1015, and for just reading the OCOTP the Init is not
required.
2022-03-08 23:08:44 +11:00
robert-hh c1841c2d45 mimxrt: Simplify Makefile in selection of flash type.
Simplify it a little bit by combining two sections regarding the
flash type. Thanks to @alphaFred for suggesting it.
2022-01-27 17:05:45 +11:00
robert-hh 84b76e4fbf mimxrt: Allow for board-specific flash driver files.
If in a board's mkconfigboard.mk the following symbol is set:

MICROPY_HW_BOARD_FLASH_FILES = 1

then the files:

($BOARD)_flexspi_flash_config.h  and
qspi_nor_flash_config.c  and/or
qspi_hyper_flash_config.c

are expected in the board directory. Otherwise the common files from
the hal directory are used.
2022-01-27 16:53:30 +11:00
robert-hh 5ca56aaf16 mimxrt: Tidy up the board flash related files.
- Move the qspi_xxxx_flash_config.c files to hal.
  It turned out that they are less board than flash type specific.
- Change to a common flexspi_flash_config.h header file.
2021-12-14 20:31:20 +01:00
robert-hh c5dbbf71c0 mimxrt: Use -Og instead of -O0 for DEBUG builds.
Thanks for the hint, Damien. The DEBUG build got very large recently.
The major difference is, that inline function are now inlined and
not included as a function. That's good and maybe bad. The good thing is,
that the code speed si now close to the final code. It could be worse
in single step debugging. I'll see.

Setting this option caused a new warning and a formatting error
to pop up at different places. Fixed as well.
2021-12-14 08:07:52 +01:00
robert-hh 1e9eaa7af5 mimxrt: Add a driver for the DP83848 PHY device.
Just another choice for the PHY interface.

Added: Keyword option phy_clock=LAN.IN or LAN.OUT
to define the source of the 50MHZ clock for the PHY
interface. The RMII clock is not enabled if it
is generated by a PYH board. Constants:

LAN.IN  The clock is provided by the PHY board.
LAN.OUT The clock is provided by the MCU board.

The default is LAN.OUT or the value set in mpconfigboard.h, which
is currently set to IN only for the SEEED ARCH MIX board. Usage etc:

lan = LAN(phy_type=LAN.PHY_DP83848, phy_clock=LAN.IN)
2021-12-14 08:07:52 +01:00
robert-hh 81f706aee4 mimxrt: Support PWM using the FLEXPWM and QTMR modules.
Frequency range 15Hz/18Hz to > 1 MHz, with decreasing resolution of the
duty cycle.  The basic API is supported as documentated, except that
keyword parameters are accepted for both the instatiaton and the
PWM.init() call.

Extensions: support PWM for channel pairs.  Channel pairs are declared by
supplying 2-element tuples for the pins.  The two channels of a pair must
be the A/B channel of a FLEXPWM module.  These form than a complementary
pair.

Additional supported keyword arguments:

- center=value Defines the center position of a pulse within the pulse
  cycle.  The align keyword is actually shortcut for center.

- sync=True|False: If set to True, the channels will be synchronized to a
  submodule 0 channel, which has already to be enabled.

- align=PWM.MIDDLE | PMW.BEGIN | PWM.END. It defines, whether synchronized
  channels are Center-Aligned or Edge-aligned.  The channels must be either
  complementary a channel pair or a group of synchronized channels.  It may
  as well be applied to a single channel, but withiout any benefit.

- invert= 0..3. Controls ouput inversion of the pins.  Bit 0 controls the
  first pin, bit 1 the second.

- deadtime=time_ns time of complementary channels for delaying the rising
  slope.

- xor=0|1|2 xor causes the output of channel A and B to be xored.  If
  applied to a X channel, it shows the value oif A ^ B.  If applied to an A
  or B channel, both channel show the xored signal for xor=1.  For xor=2,
  the xored signal is split between channels A and B.  See also the
  Reference Manual, chapter about double pulses.  The behavior of xor=2 can
  also be achieved using the center method for locating a pulse within a
  clock period.

The output is enabled for board pins only.

CPU pins may still be used for FLEXPWM, e.g. as sync source, but the signal
will not be routed to the output.  That applies only to FLEXPWM pins.  The
use of QTMR pins which are not board pins will be rejected.

As part of this commit, the _WFE() statement is removed from
ticks_delay_us64() to prevent PWM glitching during calls to sleep().
2021-11-24 13:48:27 +11:00
robert-hh e7572776c3 mimxrt: Add dht_readinto() to the mimxrt module, and freeze dht.py.
The change affects dht.py from the drivers directory as well to include the
logic for the mimxrt port.
2021-10-25 23:49:28 +11:00
robert-hh c2e4759cfa mimxrt/modmachine: Implement machine.WDT() and machine.reset_cause().
The API follows that of rp2, stm32, esp32, and the docs.

    wdt=machine.WDT(0, timeout)

        Timeout is given in ms. The valid range is 500 to 128000 (128
        seconds) with 500 ms granularity. Values outside of that range will
        be silently aligned.

    wdt.feed()

        Resets the watchdog timer (feeding).

    wdt.timeout_ms(value)

        Sets a new timeout and feeds the watchdog.

        This is a new, preliminary method which is not yet documented.

    reset_cause = machine.reset_cause()

        Values returned:

        1  Power On reset
        3  Watchdog reset
        5  Software reset: state after calling machine.reset()

More elaborate API functions are supported by the MCU, like an interrupt
called a certain time after feeding.  But for port cosistency that is not
implemented.
2021-10-25 15:43:56 +11:00
robert-hh 1866ed7e2e mimxrt/eth: Add LAN support and integrate the network module.
This commit implements 10/100 Mbit Ethernet support in the mimxrt port.

The following boards are configured without ETH network:
- MIMXRT1010_EVK
- Teensy 4.0

The following boards are configured with ETH network:
- MIMXRT1020_EVK
- MIMXRT1050_EVK
- MIMXRT1060_EVK
- MIMXRT1064_EVK
- Teensy 4.1

Ethernet support tested with TEENSY 4.1, MIMRTX1020_EVK and MIMXRT1050_EVK.
Build tested with Teensy 4.0 and MIMXRT1010_EVK to be still working.
Compiles and builds properly for MIMXRT1060_EVK and MIMXRT1064_EVK, but not
tested lacking suitable boards.

Tested functions are:
- ping works bothway
- simple UDP transfer works bothway
- ntptime works
- the ftp server works
- secure socker works
- telnet and webrepl works

The MAC address is 0x02 plus 5 bytes from the manifacturing info field,
which can be considered as unique per device.

Some boards do not wire the RESET and INT pin of the PHY transceiver.  For
operation, these are not required.  If they are defined, they will be used.
2021-10-25 15:14:26 +11:00
Philipp Ebensberger 7e62c9707a mimxrt/sdram: Add SDRAM support.
Adds support for SDRAM via `SEMC` peripheral. SDRAM support can be
enabled in the mpconfigboard.mk file by setting `MICROPY_HW_SDRAM_AVAIL`
to `1` and poviding the size of the RAM via `MICROPY_HW_FLASH_SIZE`.

When SDRAM support is enabled the whole SDRAM is currently used used
for MicroPython heap.

Signed-off-by: Philipp Ebensberger
2021-10-22 08:23:24 +02:00
Philipp Ebensberger 0d7366c912 mimxrt: Rework flash configuration.
- Moves definition of BOARD_FLASH_SIZE and other header files related to
	flash configuration into the Makefile.
- Adds board specific clock_config.h.
- Adds board.h, pin_mux.h, and peripherals.h as they are
	required by NXP MCU SDK in order to use our own clock_config.h.
- Renames board specific FlexSPI configuration files.
- Updates flash frequency of MIMXRT1020_EVK
- Creates separated flash_config files for QSPI NOR and
	QSPI Hyper flash.
- Unifies VFS start address to be @ 1M for 1010 and 1020 boards.
- Unifies 1050EVK boards
- Adds support to both NOR and HyperFlash on boards with
	both capabilities.
- Adds automatic FlexRAM initialization to start-up code based on
	linker script and NXP HAL.
- Applies code formatting to all files in mimxrt port.

With this change the flash configuration is restructured and
organized. This simplifies the configuration process and
provides a better overview of each board's settings. With the integration
of clock_config.h, board.h, pin_mux.h, and peripherals.h we gain better
control of the settings and clock configurations. Furthermore the
implementation of an explicit FlexRAM setup improves the system
performance and allows for performance tuning.

Signed-off-by: Philipp Ebensberger
2021-09-14 13:52:52 +02:00
robert-hh 61b7c098b9 mimxrt/machine_bitstream: Add bitstream function to machine module.
Following the code example for ESP32 of Jim Mussard.

As a side effect:
- mp_hal_ticks_cpu() was implemented,
- mp_hal_get_cpu_freq() and mp_hal_ticks_cpu_init() were added and used.
- mp_hal_pin_high() and mp_hal_pin_low() were changed for symmetry
2021-09-10 13:32:53 +10:00
Philipp Ebensberger 87f97e490c mimxrt/sdcard: Implement SDCard driver.
- Configures `PLL2->PFD0` with **198MHz** as base clock of
	`USDHCx` peripheral.
- Adds guards for SDCard related files via `MICROPY_PY_MACHINE_SDCARD`
- Adds creation of pin defines for SDCard to make-pins.py
- Adds new configuration option for SDCard peripheral pinout
        to mpconfigport.h
- Adds interrupt handling support instead of polling
- Adds support for `ADMA2` powered data transfer
- Configures SDCard to run in HS (high-speed mode) with **50MHz** only!

SDCard support is optional and requires `USDHC` peripheral.
Thus this driver is not available on `MIMXRT1010_EVK`.
SDCard support is enabled by setting `MICROPY_PY_MACHINE_SDCARD = 1`
in mpconfigboard.mk.

Signed-off-by: Philipp Ebensberger
2021-09-07 20:45:33 +02:00
robert-hh 1074c784b0 mimxrt: Add support for Hyperflash chips.
Hyperflash is used by the MIMXRT1050_EVKB, MIMXRT1060_EVK and
MIMXRT1064_EVK boards.

This commit includes:
- add support for Hyperflash
- modify MIMXRT1060_EVK and MIMXRT1064_EVK to change from QSPI to
  hyperflash.
- minor incidental changes to other boards so they still build

Note: Erasing a sector on the hyperflash is slow. It takes about a second,
which seems too long, but matches the data sheet.
2021-07-31 16:25:40 +10:00
robert-hh 98c5703027 mimxrt/machine_i2c: Add hardware-based machine.I2C to machine module.
It uses non-blocking transfer of data.  Advantage over SoftI2C:
- Higher data rate up to ~3 MHZ.
- Full protocol support.
2021-07-15 00:36:31 +10:00
Damien George 136369d72f all: Update to point to files in new shared/ directory.
Signed-off-by: Damien George <damien@micropython.org>
2021-07-12 17:08:10 +10:00
robert-hh efa97beb99 tools/autobuild: Add mimxrt port to build scripts for nightly builds.
The firmware for Teensy 4.0, Teensy 4.1 and MIMXRT1020_EVK are created.
Users of other MIMXRT10xx_EVK boards should be able to build the firmware
themselves, they might need specific DEBUG settings.

The Makefile had to be changed in order to build the .bin file as well.
2021-07-01 12:29:16 +10:00
robert-hh f45412793e mimxrt/machine_spi: Add the SPI class to the machine module.
This class supports SPI bus controller mode, with blocking transfers.

SPI device numbers start at 0, to comply with the pinout of the Teensy
boards.  With the configured clock frequency the fastest baud rate is
33MHz.  For messages longer 16 bytes DMA is used.  The class uses the
existing framework with extmod/machine_spi.c.

Extended driver options:

- drive=n with n being between 1 and 6 or PIN.POWER_1 to PIN.POWER_6.
  Since the pins used by the SPI are fixed, no Pin settings can be made.
  Thus the drive option is added allowing to control ringing and crosstalk
  on the connection.

- gap_ns=nnnnn is the time between sent data items in a frame given in ns.
  Default is 2 clock cycles.
2021-06-26 22:14:47 +10:00
robert-hh 8edc3aacdd mimxrt/modutime: Extend the time module.
Methods added:
- time.time()
- time.time_ns()
- time.gmtime()
- time.localtime()
- time.mktime()

The rp2 port was uses as the template for the change.
2021-06-16 01:50:09 +10:00
robert-hh 7417c6ac91 mimxrt/machine_pin: Implement pin.irq() functionality. 2021-06-16 01:42:10 +10:00
robert-hh 689476c576 mimxrt/machine_uart: Add the UART class to the machine module.
The implementation uses the LPUARTx devices.  Up to 8 UARTs can be used,
given that the pins are accessible.  E.g. 8 on Teensy 4.1, 5 on
MIMXRT1020_EVK.

For Tennsy 4.0 and 4.1 the UART numbers are as printed on the pinout 1..N.
The MIMXRT10xx-EVK boards have only one UART named, which gets the number
1.  All other UART are assigned to different Pins:

MIMXRT1010-EVK:
    D0/D1   UART 1
    D6/D7   UART 2
    A0/D4   UART 3

MIMXRT1020-EVK:
    D0/D1   UART 1
    D6/D9   UART 2
    D10/D12 UART 3
    D14/D15 UART 4
    A0/A1   UART 5

MIMXRT1050-EVK, MIMXRT1060-EVK, MIMXRT1064-EVK:
    D0/D1   UART 1
    D7/D6   UART 2
    D8/D9   UART 3
    A1/A0   UART 4
2021-06-16 01:21:15 +10:00
Philipp Ebensberger b8c65b174f mimxrt/machine_adc: Add the ADC class to the machine module.
This adds the machine.ADC class with the read_u16() method.  make-pins.py
and supporting files are updated to generate ADC information.
2021-06-04 00:51:58 +10:00
robert-hh bbdc98f72e mimxrt: Enable many Python and some extmod features.
Besides Python features this includes the extmod modules which make use of
the Pin module, especially machine.softSPI, machine.SoftI2C and onewire.
2021-06-04 00:38:18 +10:00
robert-hh a40e1473dc mimxrt: Add floating point support.
Since not all boards support double fp, all board specific .mk files are
affected too.
2021-06-04 00:37:22 +10:00
robert-hh 2f365d234e mimxrt/machine_rtc: Add the RTC class to the machine module.
Initial version, using the LP RTC clock.  It provides setting the date and
time with rtc.init() or rtc.datetime(), and reading the date and time with
rtc.datetime() or rtc.now().  The method weekday() reports the weekday of
the current date.  It starts with 0 for Monday.

The tuple order for datetime() and now() matches the CPython sequence:
(year, month, day, hour, minute, second, microsecond, TZ).  TZ is ignored
and reported as None.  Microsecond is provided at a best effort.

If a battery is not supplied, the default boot date/time is 1970/1/1 0:0:0.
With a battery, the clock continues to run even when the board is not
powered.  The clock is quite precise.  If not, using rtc.calibration() may
help.
2021-06-03 15:24:04 +10:00