X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/blobdiff_plain/498d20f05e125c355acf4bfccc9e35bb7461f9d5..99ce0ad895659a2e1ba26003d4b5f78e6471f8e4:/src/adafruit_blinka/microcontroller/am65xx/i2c.py

diff --git a/src/adafruit_blinka/microcontroller/am65xx/i2c.py b/src/adafruit_blinka/microcontroller/am65xx/i2c.py
new file mode 100644
index 0000000..f4dbd25
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+++ b/src/adafruit_blinka/microcontroller/am65xx/i2c.py
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+# SPDX-FileCopyrightText: 2021 Melissa LeBlanc-Williams for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+"""Generic Linux I2C class using PureIO's smbus class"""
+from Adafruit_PureIO import smbus
+
+
+class I2C:
+    """I2C class"""
+
+    MASTER = 0
+    SLAVE = 1
+    _baudrate = None
+    _mode = None
+    _i2c_bus = None
+
+    # pylint: disable=unused-argument
+    def __init__(self, bus_num, mode=MASTER, baudrate=None):
+        if mode != self.MASTER:
+            raise NotImplementedError("Only I2C Master supported!")
+        _mode = self.MASTER
+
+        # if baudrate != None:
+        #    print("I2C frequency is not settable in python, ignoring!")
+
+        try:
+            self._i2c_bus = smbus.SMBus(bus_num)
+        except FileNotFoundError:
+            raise RuntimeError(
+                "I2C Bus #%d not found, check if enabled in config!" % bus_num
+            ) from RuntimeError
+
+    # pylint: enable=unused-argument
+
+    def scan(self):
+        """Try to read a byte from each address, if you get an OSError
+        it means the device isnt there"""
+        found = []
+        for addr in range(0, 0x80):
+            try:
+                self._i2c_bus.read_byte(addr)
+            except OSError:
+                continue
+            found.append(addr)
+        return found
+
+    # pylint: disable=unused-argument
+    def writeto(self, address, buffer, *, start=0, end=None, stop=True):
+        """Write data from the buffer to an address"""
+        if end is None:
+            end = len(buffer)
+        self._i2c_bus.write_bytes(address, buffer[start:end])
+
+    def readfrom_into(self, address, buffer, *, start=0, end=None, stop=True):
+        """Read data from an address and into the buffer"""
+        if end is None:
+            end = len(buffer)
+
+        readin = self._i2c_bus.read_bytes(address, end - start)
+        for i in range(end - start):
+            buffer[i + start] = readin[i]
+
+    # pylint: enable=unused-argument
+
+    def writeto_then_readfrom(
+        self,
+        address,
+        buffer_out,
+        buffer_in,
+        *,
+        out_start=0,
+        out_end=None,
+        in_start=0,
+        in_end=None,
+        stop=False
+    ):
+        """Write data from buffer_out to an address and then
+        read data from an address and into buffer_in
+        """
+        if out_end is None:
+            out_end = len(buffer_out)
+        if in_end is None:
+            in_end = len(buffer_in)
+        if stop:
+            # To generate a stop in linux, do in two transactions
+            self.writeto(address, buffer_out, start=out_start, end=out_end, stop=True)
+            self.readfrom_into(address, buffer_in, start=in_start, end=in_end)
+        else:
+            # To generate without a stop, do in one block transaction
+            readin = self._i2c_bus.read_i2c_block_data(
+                address, buffer_out[out_start:out_end], in_end - in_start
+            )
+            for i in range(in_end - in_start):
+                buffer_in[i + in_start] = readin[i]