Merge tag 'v1.9.1'2.0.0-alpha.0

Fixes for stmhal USB mass storage, lwIP bindings and VFS regressions

This release provides an important fix for the USB mass storage device in
the stmhal port by implementing the SCSI SYNCHRONIZE_CACHE command, which
is now require by some Operating Systems.  There are also fixes for the
lwIP bindings to improve non-blocking sockets and error codes.  The VFS has
some regressions fixed including the ability to statvfs the root.

All changes are listed below.

py core:
- modbuiltins: add core-provided version of input() function
- objstr: catch case of negative "maxsplit" arg to str.rsplit()
- persistentcode: allow to compile with complex numbers disabled
- objstr: allow to compile with obj-repr D, and unicode disabled
- modsys: allow to compile with obj-repr D and PY_ATTRTUPLE disabled
- provide mp_decode_uint_skip() to help reduce stack usage
- makeqstrdefs.py: make script run correctly with Python 2.6
- objstringio: if created from immutable object, follow copy on write policy

extmod:
- modlwip: connect: for non-blocking mode, return EINPROGRESS
- modlwip: fix error codes for duplicate calls to connect()
- modlwip: accept: fix error code for non-blocking mode
- vfs: allow to statvfs the root directory
- vfs: allow "buffering" and "encoding" args to VFS's open()
- modframebuf: fix signed/unsigned comparison pendantic warning

lib:
- libm: use isfinite instead of finitef, for C99 compatibility
- utils/interrupt_char: remove support for KBD_EXCEPTION disabled

tests:
- basics/string_rsplit: add tests for negative "maxsplit" argument
- float: convert "sys.exit()" to "raise SystemExit"
- float/builtin_float_minmax: PEP8 fixes
- basics: convert "sys.exit()" to "raise SystemExit"
- convert remaining "sys.exit()" to "raise SystemExit"

unix port:
- convert to use core-provided version of built-in import()
- Makefile: replace references to make with $(MAKE)

windows port:
- convert to use core-provided version of built-in import()

qemu-arm port:
- Makefile: adjust object-file lists to get correct dependencies
- enable micropython.mem_*() functions to allow more tests

stmhal port:
- boards: enable DAC for NUCLEO_F767ZI board
- add support for NUCLEO_F446RE board
- pass USB handler as parameter to allow more than one USB handler
- usb: use local USB handler variable in Start-of-Frame handler
- usb: make state for USB device private to top-level USB driver
- usbdev: for MSC implement SCSI SYNCHRONIZE_CACHE command
- convert from using stmhal's input() to core provided version

cc3200 port:
- convert from using stmhal's input() to core provided version

teensy port:
- convert from using stmhal's input() to core provided version

esp8266 port:
- Makefile: replace references to make with $(MAKE)
- Makefile: add clean-modules target
- convert from using stmhal's input() to core provided version

zephyr port:
- modusocket: getaddrinfo: Fix mp_obj_len() usage
- define MICROPY_PY_SYS_PLATFORM (to "zephyr")
- machine_pin: use native Zephyr types for Zephyr API calls

docs:
- machine.Pin: remove out_value() method
- machine.Pin: add on() and off() methods
- esp8266: consistently replace Pin.high/low methods with .on/off
- esp8266/quickref: polish Pin.on()/off() examples
- network: move confusingly-named cc3200 Server class to its reference
- uos: deconditionalize, remove minor port-specific details
- uos: move cc3200 port legacy VFS mounting functions to its ref doc
- machine: sort machine classes in logical order, not alphabetically
- network: first step to describe standard network class interface

examples:
- embedding: use core-provided KeyboardInterrupt object

1 files changed, 35 insertions, 78 deletions

diff --git a/docs/library/machine.I2C.rst b/docs/library/machine.I2C.rst
index cdeb246eb..a1b417890 100644
--- a/docs/library/machine.I2C.rst
+++ b/docs/library/machine.I2C.rst
@@ -1,4 +1,5 @@
 .. currentmodule:: machine
+.. _machine.I2C:
 
 class I2C -- a two-wire serial protocol
 =======================================
@@ -9,86 +10,55 @@ level it consists of 2 wires: SCL and SDA, the clock and data lines respectively
 I2C objects are created attached to a specific bus.  They can be initialised
 when created, or initialised later on.
 
-.. only:: port_wipy
+Printing the I2C object gives you information about its configuration.
 
-    Example::
+Example usage::
 
-        from machine import I2C
+    from machine import I2C
 
-        i2c = I2C(0)                         # create on bus 0
-        i2c = I2C(0, I2C.MASTER)             # create and init as a master
-        i2c.init(I2C.MASTER, baudrate=20000) # init as a master
-        i2c.deinit()                         # turn off the peripheral
+    i2c = I2C(freq=400000)          # create I2C peripheral at frequency of 400kHz
+                                    # depending on the port, extra parameters may be required
+                                    # to select the peripheral and/or pins to use
 
-Printing the i2c object gives you information about its configuration.
+    i2c.scan()                      # scan for slaves, returning a list of 7-bit addresses
 
-.. only:: port_wipy
+    i2c.writeto(42, b'123')         # write 3 bytes to slave with 7-bit address 42
+    i2c.readfrom(42, 4)             # read 4 bytes from slave with 7-bit address 42
 
-    A master must specify the recipient's address::
-
-        i2c.init(I2C.MASTER)
-        i2c.writeto(0x42, '123')        # send 3 bytes to slave with address 0x42
-        i2c.writeto(addr=0x42, b'456')  # keyword for address
-
-    Master also has other methods::
-
-        i2c.scan()                          # scan for slaves on the bus, returning
-                                            #   a list of valid addresses
-        i2c.readfrom_mem(0x42, 2, 3)        # read 3 bytes from memory of slave 0x42,
-                                            #   starting at address 2 in the slave
-        i2c.writeto_mem(0x42, 2, 'abc')     # write 'abc' (3 bytes) to memory of slave 0x42
-                                            # starting at address 2 in the slave, timeout after 1 second
+    i2c.readfrom_mem(42, 8, 3)      # read 3 bytes from memory of slave 42,
+                                    #   starting at memory-address 8 in the slave
+    i2c.writeto_mem(42, 2, b'\x10') # write 1 byte to memory of slave 42
+                                    #   starting at address 2 in the slave
 
 Constructors
 ------------
 
-.. only:: port_wipy
-
-    .. class:: I2C(bus, ...)
-
-       Construct an I2C object on the given bus.  `bus` can only be 0.
-       If the bus is not given, the default one will be selected (0).
+.. class:: I2C(id=-1, \*, scl, sda, freq=400000)
 
-.. only:: not port_wipy
+   Construct and return a new I2C object using the following parameters:
 
-    .. class:: I2C(id=-1, \*, scl, sda, freq=400000)
-
-       Construct and return a new I2C object using the following parameters:
-
-          - `id` identifies the particular I2C peripheral.  The default
-            value of -1 selects a software implementation of I2C which can
-            work (in most cases) with arbitrary pins for SCL and SDA.
-            If `id` is -1 then `scl` and `sda` must be specified.  Other
-            allowed values for `id` depend on the particular port/board,
-            and specifying `scl` and `sda` may or may not be required or
-            allowed in this case.
-          - `scl` should be a pin object specifying the pin to use for SCL.
-          - `sda` should be a pin object specifying the pin to use for SDA.
-          - `freq` should be an integer which sets the maximum frequency
-            for SCL.
+      - `id` identifies the particular I2C peripheral.  The default
+        value of -1 selects a software implementation of I2C which can
+        work (in most cases) with arbitrary pins for SCL and SDA.
+        If `id` is -1 then `scl` and `sda` must be specified.  Other
+        allowed values for `id` depend on the particular port/board,
+        and specifying `scl` and `sda` may or may not be required or
+        allowed in this case.
+      - `scl` should be a pin object specifying the pin to use for SCL.
+      - `sda` should be a pin object specifying the pin to use for SDA.
+      - `freq` should be an integer which sets the maximum frequency
+        for SCL.
 
 General Methods
 ---------------
 
-.. only:: port_wipy
-
-    .. method:: I2C.init(mode, \*, baudrate=100000, pins=(SDA, SCL))
-
-      Initialise the I2C bus with the given parameters:
-
-         - ``mode`` must be ``I2C.MASTER``
-         - ``baudrate`` is the SCL clock rate
-         - ``pins`` is an optional tuple with the pins to assign to the I2C bus.
+.. method:: I2C.init(scl, sda, \*, freq=400000)
 
-.. only:: port_esp8266
+  Initialise the I2C bus with the given arguments:
 
-    .. method:: I2C.init(scl, sda, \*, freq=400000)
-
-      Initialise the I2C bus with the given arguments:
-
-         - `scl` is a pin object for the SCL line
-         - `sda` is a pin object for the SDA line
-         - `freq` is the SCL clock rate
+     - `scl` is a pin object for the SCL line
+     - `sda` is a pin object for the SDA line
+     - `freq` is the SCL clock rate
 
 .. method:: I2C.deinit()
 
@@ -100,9 +70,7 @@ General Methods
 
    Scan all I2C addresses between 0x08 and 0x77 inclusive and return a list of
    those that respond.  A device responds if it pulls the SDA line low after
-   its address (including a read bit) is sent on the bus.
-
-   Note: on WiPy the I2C object must be in master mode for this method to be valid.
+   its address (including a write bit) is sent on the bus.
 
 Primitive I2C operations
 ------------------------
@@ -192,8 +160,7 @@ methods are convenience functions to communicate with such devices.
    The argument `addrsize` specifies the address size in bits (on ESP8266
    this argument is not recognised and the address size is always 8 bits).
 
-   On WiPy the return value is the number of bytes read.  Otherwise the
-   return value is `None`.
+   The method returns `None`.
 
 .. method:: I2C.writeto_mem(addr, memaddr, buf, \*, addrsize=8)
 
@@ -202,14 +169,4 @@ methods are convenience functions to communicate with such devices.
    The argument `addrsize` specifies the address size in bits (on ESP8266
    this argument is not recognised and the address size is always 8 bits).
 
-   On WiPy the return value is the number of bytes written.  Otherwise the
-   return value is `None`.
-
-Constants
----------
-
-.. data:: I2C.MASTER
-
-   for initialising the bus to master mode
-
-   Availability: WiPy.
+   The method returns `None`.