Add BeagleBone AI Support

[Adafruit_Blinka-hackapet.git] / 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 7597ca662e4c5a35fa0a3fe9fa7065d9d4f2e84d..0e061e62380d888880ab2a79624c4ec903bfce08 100644 (file)
--- a/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
+++ b/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
@@ -6,13 +6,12 @@ import hid
 
 # Here if you need it
 MCP2221_HID_DELAY = float(os.environ.get("BLINKA_MCP2221_HID_DELAY", 0))
 
 # Here if you need it
 MCP2221_HID_DELAY = float(os.environ.get("BLINKA_MCP2221_HID_DELAY", 0))

-# Use to set delay between reset and device reopen
+# Use to set delay between reset and device reopen. if negative, don't reset at all

 MCP2221_RESET_DELAY = float(os.environ.get("BLINKA_MCP2221_RESET_DELAY", 0.5))
 
 # from the C driver
 # http://ww1.microchip.com/downloads/en/DeviceDoc/mcp2221_0_1.tar.gz
 # others (???) determined during driver developement
 MCP2221_RESET_DELAY = float(os.environ.get("BLINKA_MCP2221_RESET_DELAY", 0.5))
 
 # from the C driver
 # http://ww1.microchip.com/downloads/en/DeviceDoc/mcp2221_0_1.tar.gz
 # others (???) determined during driver developement

-# pylint: disable=bad-whitespace

 RESP_ERR_NOERR = 0x00
 RESP_ADDR_NACK = 0x25
 RESP_READ_ERR = 0x7F
 RESP_ERR_NOERR = 0x00
 RESP_ADDR_NACK = 0x25
 RESP_READ_ERR = 0x7F


@@ -35,7 +34,6 @@ RESP_I2C_WRITINGNOSTOP = 0x45  # ???
 MCP2221_RETRY_MAX = 50
 MCP2221_MAX_I2C_DATA_LEN = 60
 MASK_ADDR_NACK = 0x40
 MCP2221_RETRY_MAX = 50
 MCP2221_MAX_I2C_DATA_LEN = 60
 MASK_ADDR_NACK = 0x40

-# pylint: enable=bad-whitespace

 
 
 class MCP2221:
 
 
 class MCP2221:


@@ -53,7 +51,8 @@ class MCP2221:
     def __init__(self):
         self._hid = hid.device()
         self._hid.open(MCP2221.VID, MCP2221.PID)
     def __init__(self):
         self._hid = hid.device()
         self._hid.open(MCP2221.VID, MCP2221.PID)

-        self._reset()
+        if MCP2221_RESET_DELAY >= 0:
+            self._reset()

         self._gp_config = [0x07] * 4  # "don't care" initial value
         for pin in range(4):
             self.gp_set_mode(pin, self.GP_GPIO)  # set to GPIO mode
         self._gp_config = [0x07] * 4  # "don't care" initial value
         for pin in range(4):
             self.gp_set_mode(pin, self.GP_GPIO)  # set to GPIO mode


@@ -268,7 +267,7 @@ class MCP2221:
 
         # and now the read part
         while (end - start) > 0:
 
         # and now the read part
         while (end - start) > 0:

-            for retry in range(MCP2221_RETRY_MAX):
+            for _ in range(MCP2221_RETRY_MAX):

                 # the actual read
                 resp = self._hid_xfer(b"\x40")
                 # check for success
                 # the actual read
                 resp = self._hid_xfer(b"\x40")
                 # check for success


@@ -286,6 +285,8 @@ class MCP2221:
                     continue
                 if resp[2] in (RESP_READ_COMPL, RESP_READ_PARTIAL):
                     break
                     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)
 
             # move data into buffer
             chunk = min(end - start, 60)


@@ -295,7 +296,7 @@ class MCP2221:
 
     # pylint: enable=too-many-arguments
 
 
     # pylint: enable=too-many-arguments
 

-    def i2c_configure(self, baudrate=100000):
+    def _i2c_configure(self, baudrate=100000):

         """Configure I2C"""
         self._hid_xfer(
             bytes(
         """Configure I2C"""
         self._hid_xfer(
             bytes(