docs/library/machine.I2C: Deconditionalise all methods.

The cc3200 port is now similar enough to the standard machine.I2C API so
that all conditionals can be removed.

docs/library/machine.I2C.rst

@@ -9,49 +9,30 @@ 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
 
-        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,
+    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
-        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
 
 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).
-
-.. only:: not port_wipy
-
-    .. class:: I2C(id=-1, \*, scl, sda, freq=400000)
+.. class:: I2C(id=-1, \*, scl, sda, freq=400000)
 
    Construct and return a new I2C object using the following parameters:
 
@@ -70,19 +51,7 @@ Constructors
 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.
-
-.. only:: port_esp8266
-
-    .. method:: I2C.init(scl, sda, \*, freq=400000)
+.. method:: I2C.init(scl, sda, \*, freq=400000)
 
   Initialise the I2C bus with the given arguments:
 
@@ -102,8 +71,6 @@ General Methods
    those that respond.  A device responds if it pulls the SDA line low after
    its address (including a write bit) is sent on the bus.
 
-   Note: on WiPy the I2C object must be in master mode for this method to be valid.
-
 Primitive I2C operations
 ------------------------
 
@@ -204,12 +171,3 @@ methods are convenience functions to communicate with such devices.
 
    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.