Selected drivers: make mode a bound variable

IMAGE_DISPLAY.md

@@ -186,7 +186,8 @@ Bound variables:
 * `source` The path of the source image file.
 * `rows` Image dimensions in pixels.
 * `cols`
-* `mode` Mode used to create a FrameBuffer
+* `mode` Mode used to create a FrameBuffer: values correspond to
+[FrameBuffer constants](https://docs.micropython.org/en/latest/library/framebuf.html#constants).
 * `data` Image data bytes, with layout as per binary file.
 
 ## 3.3 Using a Python image file

drivers/gc9a01/gc9a01.py

@@ -77,12 +77,12 @@ class GC9A01(framebuf.FrameBuffer):
         self.width = width
         self._spi_init = init_spi
         self._gscale = False  # Interpret buffer as index into color LUT
-        mode = framebuf.GS4_HMSB
-        self.palette = BoolPalette(mode)
+        self.mode = framebuf.GS4_HMSB
+        self.palette = BoolPalette(self.mode)
         gc.collect()
         buf = bytearray(height * width // 2)  # Frame buffer
         self.mvb = memoryview(buf)
-        super().__init__(buf, width, height, mode)
+        super().__init__(buf, width, height, self.mode)
         self._linebuf = bytearray(width * 2)  # Line buffer (16-bit colors)
 
         # Hardware reset

drivers/gc9a01/gc9a01_8_bit.py

@@ -63,12 +63,12 @@ class GC9A01(framebuf.FrameBuffer):
         self.height = height  # Logical dimensions for GUIs
         self.width = width
         self._spi_init = init_spi
-        mode = framebuf.GS8  # Use 8bit greyscale for 8 bit color.
-        self.palette = BoolPalette(mode)
+        self.mode = framebuf.GS8  # Use 8bit greyscale for 8 bit color.
+        self.palette = BoolPalette(self.mode)
         gc.collect()
         buf = bytearray(height * width)  # Frame buffer
         self.mvb = memoryview(buf)
-        super().__init__(buf, width, height, mode)
+        super().__init__(buf, width, height, self.mode)
         self._linebuf = bytearray(width * 2)  # Line buffer (16-bit colors)
 
         # Hardware reset

drivers/ili93xx/ili9341.py

@@ -62,12 +62,12 @@ class ILI9341(framebuf.FrameBuffer):
         self.width = width
         self._spi_init = init_spi
         self._gscale = False  # Interpret buffer as index into color LUT
-        mode = framebuf.GS4_HMSB
-        self.palette = BoolPalette(mode)
+        self.mode = framebuf.GS4_HMSB
+        self.palette = BoolPalette(self.mode)
         gc.collect()
         buf = bytearray(self.height * self.width // 2)
         self.mvb = memoryview(buf)
-        super().__init__(buf, self.width, self.height, mode)
+        super().__init__(buf, self.width, self.height, self.mode)
         self._linebuf = bytearray(self.width * 2)
         # Hardware reset
         self._rst(0)

drivers/ili94xx/ili9486.py

@@ -92,12 +92,12 @@ class ILI9486(framebuf.FrameBuffer):
         self._short = min(height, width)
         self._spi_init = init_spi
         self._gscale = False  # Interpret buffer as index into color LUT
-        mode = framebuf.GS4_HMSB
-        self.palette = BoolPalette(mode)
+        self.mode = framebuf.GS4_HMSB
+        self.palette = BoolPalette(self.mode)
         gc.collect()
         buf = bytearray(height * width // 2)
         self.mvb = memoryview(buf)
-        super().__init__(buf, width, height, mode)  # Logical aspect ratio
+        super().__init__(buf, width, height, self.mode)  # Logical aspect ratio
         self._linebuf = bytearray(self._short * 2)
 
         # Hardware reset

drivers/st7789/st7789_4bit.py

@@ -96,12 +96,12 @@ class ST7789(framebuf.FrameBuffer):
         self._spi_init = init_spi  # Possible user callback
         self._lock = asyncio.Lock()
         self._gscale = False  # Interpret buffer as index into color LUT
-        mode = framebuf.GS4_HMSB  # Use 4bit greyscale.
-        self.palette = BoolPalette(mode)
+        self.mode = framebuf.GS4_HMSB  # Use 4bit greyscale.
+        self.palette = BoolPalette(self.mode)
         gc.collect()
         buf = bytearray(height * -(-width // 2))  # Ceiling division for odd widths
         self.mvb = memoryview(buf)
-        super().__init__(buf, width, height, mode)
+        super().__init__(buf, width, height, self.mode)
         self._linebuf = bytearray(self.width * 2)  # 16 bit color out
         self._init(disp_mode, orientation)
         self.show()