X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/0bc5711e69ff03db0a46adc2ffa1ee2819b0b1ef..03548b64a8d7b407b4ae6464c5ffc551be8fc0be:/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py

diff --git a/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py b/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
index 0275e66..7b62c3f 100644
--- a/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
+++ b/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
@@ -1,3 +1,6 @@
+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
 """Chip Definition for MCP2221"""
 
 import os
@@ -189,7 +192,7 @@ class MCP2221:
             # bus release will need "a few hundred microseconds"
             time.sleep(0.001)
 
-    # pylint: disable=too-many-arguments
+    # pylint: disable=too-many-arguments,too-many-branches
     def _i2c_write(self, cmd, address, buffer, start=0, end=None):
         if self._i2c_state() != 0x00:
             self._i2c_cancel()
@@ -198,7 +201,7 @@ class MCP2221:
         length = end - start
         retries = 0
 
-        while (end - start) > 0:
+        while (end - start) > 0 or not buffer:
             chunk = min(end - start, MCP2221_MAX_I2C_DATA_LEN)
             # write out current chunk
             resp = self._hid_xfer(
@@ -223,6 +226,8 @@ class MCP2221:
             # yay chunk sent!
             while self._i2c_state() == RESP_I2C_PARTIALDATA:
                 time.sleep(0.001)
+            if not buffer:
+                break
             start += chunk
             retries = 0
 
@@ -285,6 +290,8 @@ class MCP2221:
                     continue
                 if resp[2] in (RESP_READ_COMPL, RESP_READ_PARTIAL):
                     break
+            else:
+                raise RuntimeError("I2C read error: max retries reached.")
 
             # move data into buffer
             chunk = min(end - start, 60)
@@ -294,7 +301,7 @@ class MCP2221:
 
     # pylint: enable=too-many-arguments
 
-    def i2c_configure(self, baudrate=100000):
+    def _i2c_configure(self, baudrate=100000):
         """Configure I2C"""
         self._hid_xfer(
             bytes(
@@ -325,7 +332,7 @@ class MCP2221:
         out_start=0,
         out_end=None,
         in_start=0,
-        in_end=None
+        in_end=None,
     ):
         """Write data from buffer_out to an address and then
         read data from an address and into buffer_in