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i2c_device: remove write(stop=), write_then_readinto(stop=) #55

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Jul 26, 2020
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40 changes: 14 additions & 26 deletions adafruit_bus_device/i2c_device.py
Original file line number Diff line number Diff line change
Expand Up @@ -62,7 +62,6 @@ class I2CDevice:
def __init__(self, i2c, device_address, probe=True):

self.i2c = i2c
self._has_write_read = hasattr(self.i2c, "writeto_then_readfrom")
self.device_address = device_address

if probe:
Expand All @@ -85,10 +84,10 @@ def readinto(self, buf, *, start=0, end=None):
end = len(buf)
self.i2c.readfrom_into(self.device_address, buf, start=start, end=end)

def write(self, buf, *, start=0, end=None, stop=True):
def write(self, buf, *, start=0, end=None):
"""
Write the bytes from ``buffer`` to the device. Transmits a stop bit if
``stop`` is set.
Write the bytes from ``buffer`` to the device, then transmit a stop
bit.

If ``start`` or ``end`` is provided, then the buffer will be sliced
as if ``buffer[start:end]``. This will not cause an allocation like
Expand All @@ -97,11 +96,10 @@ def write(self, buf, *, start=0, end=None, stop=True):
:param bytearray buffer: buffer containing the bytes to write
:param int start: Index to start writing from
:param int end: Index to read up to but not include; if None, use ``len(buf)``
:param bool stop: If true, output an I2C stop condition after the buffer is written
"""
if end is None:
end = len(buf)
self.i2c.writeto(self.device_address, buf, start=start, end=end, stop=stop)
self.i2c.writeto(self.device_address, buf, start=start, end=end)

# pylint: disable-msg=too-many-arguments
def write_then_readinto(
Expand All @@ -113,7 +111,6 @@ def write_then_readinto(
out_end=None,
in_start=0,
in_end=None,
stop=False
):
"""
Write the bytes from ``out_buffer`` to the device, then immediately
Expand All @@ -136,30 +133,21 @@ def write_then_readinto(
:param int out_end: Index to read up to but not include; if None, use ``len(out_buffer)``
:param int in_start: Index to start writing at
:param int in_end: Index to write up to but not include; if None, use ``len(in_buffer)``
:param bool stop: Deprecated
"""
if out_end is None:
out_end = len(out_buffer)
if in_end is None:
in_end = len(in_buffer)
if stop:
raise ValueError("Stop must be False. Use writeto instead.")
if self._has_write_read:
# In linux, at least, this is a special kernel function call
self.i2c.writeto_then_readfrom(
self.device_address,
out_buffer,
in_buffer,
out_start=out_start,
out_end=out_end,
in_start=in_start,
in_end=in_end,
)

else:
# If we don't have a special implementation, we can fake it with two calls
self.write(out_buffer, start=out_start, end=out_end, stop=False)
self.readinto(in_buffer, start=in_start, end=in_end)

self.i2c.writeto_then_readfrom(
self.device_address,
out_buffer,
in_buffer,
out_start=out_start,
out_end=out_end,
in_start=in_start,
in_end=in_end,
)

# pylint: enable-msg=too-many-arguments

Expand Down