X-Git-Url: https://git.ayoreis.com/hackapet/Adafruit_Blinka_Displayio.git/blobdiff_plain/e3c50c29dff1fef1f2499917d7d985d77be1f42d..962da8e9e2a79ea00dcca34222bde8dea3883065:/displayio/i2cdisplay.py

diff --git a/displayio/i2cdisplay.py b/displayio/i2cdisplay.py
index fd498a7..b2d38dc 100644
--- a/displayio/i2cdisplay.py
+++ b/displayio/i2cdisplay.py
@@ -1,4 +1,7 @@
 # SPDX-FileCopyrightText: 2020 Melissa LeBlanc-Williams for Adafruit Industries
+# SPDX-FileCopyrightText: 2020 Erik Tollerud
+# SPDX-FileCopyrightText: 2021 Jim Morris
+# SPDX-FileCopyrightText: 2021 James Carr
 #
 # SPDX-License-Identifier: MIT
 
@@ -13,21 +16,24 @@ displayio for Blinka
 * Adafruit Blinka:
   https://github.com/adafruit/Adafruit_Blinka/releases
 
-* Author(s): Melissa LeBlanc-Williams
+* Author(s): Melissa LeBlanc-Williams, Erik Tollerud, James Carr
 
 """
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_Blinka_displayio.git"
 
+import time
+import busio
+import digitalio
+
 
 class I2CDisplay:
     """Manage updating a display over I2C in the background while Python code runs.
     It doesn’t handle display initialization.
     """
 
-    def __init__(self, i2c_bus, *, device_address, reset=None):
-        # pylint: disable=unnecessary-pass
+    def __init__(self, i2c_bus: busio.I2C, *, device_address: int, reset=None):
         """Create a I2CDisplay object associated with the given I2C bus and reset pin.
 
         The I2C bus and pins are then in use by the display until displayio.release_displays() is
@@ -36,17 +42,68 @@ class I2CDisplay:
         :py:func`displayio.release_displays` first, otherwise it will error after the first
         code.py run.
         """
-        pass
 
-    def reset(self):
-        """Performs a hardware reset via the reset pin. Raises an exception if called
-        when no reset pin is available.
+        if reset is not None:
+            self._reset = digitalio.DigitalInOut(reset)
+            self._reset.switch_to_output(value=True)
+        else:
+            self._reset = None
+        self._i2c = i2c_bus
+        self._dev_addr = device_address
+
+    def _release(self):
+        self.reset()
+        self._i2c.deinit()
+        if self._reset is not None:
+            self._reset.deinit()
+
+    def reset(self) -> None:
+        """
+        Performs a hardware reset via the reset pin if one is present.
+        """
+
+        if self._reset is None:
+            return
+
+        self._reset.value = False
+        time.sleep(0.0001)
+        self._reset.value = True
+
+    def begin_transaction(self) -> None:
         """
-        raise NotImplementedError("I2CDisplay reset has not been implemented yet")
+        Lock the bus before sending data.
+        """
+        while not self._i2c.try_lock():
+            pass
 
-    def send(self, command, data):
-        """Sends the given command value followed by the full set of data. Display state,
-        such as vertical scroll, set via send may or may not be reset once the code is
+    def send(self, command: bool, data, *, toggle_every_byte=False) -> None:
+        # pylint: disable=unused-argument
+        """
+        Sends the given command value followed by the full set of data. Display state,
+        such as vertical scroll, set via ``send`` may or may not be reset once the code is
         done.
         """
-        raise NotImplementedError("I2CDisplay send has not been implemented yet")
+        # NOTE: we have to have a toggle_every_byte parameter, which we ignore,
+        # because Display._write() sets it regardless of bus type.
+
+        if command:
+            n = len(data)
+            if n > 0:
+                command_bytes = bytearray(n * 2)
+                for i in range(n):
+                    command_bytes[2 * i] = 0x80
+                    command_bytes[2 * i + 1] = data[i]
+
+                self._i2c.writeto(self._dev_addr, buffer=command_bytes, stop=True)
+
+        else:
+            data_bytes = bytearray(len(data) + 1)
+            data_bytes[0] = 0x40
+            data_bytes[1:] = data
+            self._i2c.writeto(self._dev_addr, buffer=data_bytes, stop=True)
+
+    def end_transaction(self) -> None:
+        """
+        Release the bus after sending data.
+        """
+        self._i2c.unlock()