make chip_select pin optional in SPI four wire

on Odroid C4 the chip_select is controller by the spi_meson_spicc driver, in case the SPI_CS0 is used as chip_select pin in the FourWire class Resource Busy exceptions are thrown.

diff --git a/displayio/_fourwire.py b/displayio/_fourwire.py
index 61be810d45303555fa45291437e38c1e64967b8d..65b7654d4f3b32238d735d2ccdd3ebb25c57c9fa 100644 (file)
--- a/displayio/_fourwire.py
+++ b/displayio/_fourwire.py
@@ -44,7 +44,7 @@ class FourWire:
         spi_bus: busio.SPI,
         *,
         command: microcontroller.Pin,
         spi_bus: busio.SPI,
         *,
         command: microcontroller.Pin,

-        chip_select: microcontroller.Pin,
+        chip_select: Optional[microcontroller.Pin] = None,

         reset: Optional[microcontroller.Pin] = None,
         baudrate: int = 24000000,
         polarity: int = 0,
         reset: Optional[microcontroller.Pin] = None,
         baudrate: int = 24000000,
         polarity: int = 0,


@@ -61,15 +61,20 @@ class FourWire:
         """
         self._dc = digitalio.DigitalInOut(command)
         self._dc.switch_to_output(value=False)
         """
         self._dc = digitalio.DigitalInOut(command)
         self._dc.switch_to_output(value=False)

-        self._chip_select = digitalio.DigitalInOut(chip_select)
-        self._chip_select.switch_to_output(value=True)
+
+        if chip_select is not None:
+            self._chip_select = digitalio.DigitalInOut(chip_select)
+            self._chip_select.switch_to_output(value=True)
+        else:
+            self._chip_select = None
+

         self._frequency = baudrate
         self._polarity = polarity
         self._phase = phase
 
         if reset is not None:
             self._reset = digitalio.DigitalInOut(reset)
         self._frequency = baudrate
         self._polarity = polarity
         self._phase = phase
 
         if reset is not None:
             self._reset = digitalio.DigitalInOut(reset)

-            self._reset.switch_to_output(value=True)
+            self._reset.switch_to_output(value=False)

         else:
             self._reset = None
         self._spi = spi_bus
         else:
             self._reset = None
         self._spi = spi_bus


@@ -78,7 +83,10 @@ class FourWire:
         self.reset()
         self._spi.deinit()
         self._dc.deinit()
         self.reset()
         self._spi.deinit()
         self._dc.deinit()

-        self._chip_select.deinit()
+
+        if self._chip_select is not None:
+            self._chip_select.deinit()
+

         if self._reset is not None:
             self._reset.deinit()
 
         if self._reset is not None:
             self._reset.deinit()
 


@@ -123,7 +131,11 @@ class FourWire:
         data: ReadableBuffer,
     ):
         self._dc.value = data_type == DISPLAY_DATA
         data: ReadableBuffer,
     ):
         self._dc.value = data_type == DISPLAY_DATA

-        if chip_select == CHIP_SELECT_TOGGLE_EVERY_BYTE:
+
+        if (
+            self._chip_select is not None
+            and chip_select == CHIP_SELECT_TOGGLE_EVERY_BYTE
+        ):

             for byte in data:
                 self._spi.write(bytes([byte]))
                 self._chip_select.value = True
             for byte in data:
                 self._spi.write(bytes([byte]))
                 self._chip_select.value = True


@@ -146,10 +158,18 @@ class FourWire:
         self._spi.configure(
             baudrate=self._frequency, polarity=self._polarity, phase=self._phase
         )
         self._spi.configure(
             baudrate=self._frequency, polarity=self._polarity, phase=self._phase
         )

+<<<<<<< HEAD

         self._chip_select.value = False
         return True
         self._chip_select.value = False
         return True

+=======
+
+        if self._chip_select is not None:
+            self._chip_select.value = False
+>>>>>>> 87a1bde (make chip_select pin optional in SPI four wire)

 
     def _end_transaction(self) -> None:
         """End the SPI transaction by unlocking and setting Chip Select"""
 
     def _end_transaction(self) -> None:
         """End the SPI transaction by unlocking and setting Chip Select"""

-        self._chip_select.value = True
+        if self._chip_select is not None:
+            self._chip_select.value = True
+

         self._spi.unlock()
         self._spi.unlock()